ML19007A241

TSD-14-006, Rev. 5, Conestoga-Rovers and Associates Report: Evaluation of Hydrogeological Parameters in Support of Zion Restoration Project.

ML19007A241
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Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	10/13/2014
From:	Decker R Zion Restoration Project
To:	Vaaler M Division of Decommissioning, Uranium Recovery and Waste Programs
M VAALER DUWP
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TSD-14-006, Rev. 5
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Text

-ZionSolutions, LLC. Technical Support Document ZION SOLUTIONSuc 'innIRI s=t"mn o.peny Originator:

Reviewer:

Approval:

TSD 14-006 Conestoga-Rovers and Associates Report: Evaluation of Hydrogeological Parameters in Support of Zion Restoration Project Revision 5 Conestoga-Rovers AssQciates Date: 10/13/2014 Name Date: /1lef Robert F. Decker Date: to!} J y www.CRAworld.com Evaluation of Hydrological Parameters in Support of Dose Modeling for the Zion

Restoration Project Zion Restoration Project Zion, Illinois Revision 5 Prepared for: ZionSolutions Conestoga-Rovers & Associates 8615 W. Bryn Mawr Avenue Chicago, Illinois 60631 Septmeber 2014

• 054638

• Report No. 3 Table of Contents Page Section 1.0 Introduction ...............................................................................................

1 Section 2.0 Development of Conceptual Site Model Components for Existing Conditions 1 2.1. An Evaluation of the Transport of Groundwater to Lake Michigan

................

1 2.2. Estimation of the Effects of Dilution on Contaminants Entering Lake Michigan via Groundwater

....................................................................................................

2 2.2.1. Complete Mixing Approach

.............................................................................

2 2.2.2. Shoreline Mixing Approach

..............................................................................

3 2.3. An Evaluation of the Effectiveness of the Silty Clay Aquitard at the Base of the Shallow Aquifer

................................................................................................

4 Section 3.0 Development of CSM Components for Decommissioning Activities

.............

4 3.1. Basement Fill Alternatives

...............................................................................

4 3.1.1. Riprap Scenario

................................................................................................

5 3.1.2. 3-inch Clean Concrete Scenario

.......................................................................

5 3.1.3. Sand Scenario

...................................................................................................

5 3.1.4. Riprap and Flowable Fill Scenario

....................................................................

5 3.1.5. Surface Cover

...................................................................................................

6 3.2. Final Disposition of the Sheet Pile Wall

...........................................................

6 3.3. An Evaluation of the Risk of Compromising the Silty Clay Aquitard at the Base of the Shallow Aquifer During Decommissioning Activities

................................. 6 Section 4.0 Development of Post

-Decommissioning CSM Components

.........................

6 4.1. An Evaluation of Groundwater Flow Through and Around Subsurface Structures Left in Place

......................................................................................................

7 4.1.1. Deterioration of the Sheet Pile Wall Over Time

..............................................

7 4.2. An Assessment of the Feasibility of a Future Site Occupant Installing a Water Well at the Site

................................................................................................. 8 4.2.1. Potential Capture Zone and Drawdown ..........................................................

9 4.3. Rise in Lake Michigan Surface Water Elevation

.............................................

11 4.4. De Minimus Scenarios

...................................................................................

12 4.4.1. Basement Overflow Scenario

........................................................................

12 4.4.1.1. Assumpt ion 1 - No Evaporation

..............................................................

14 4.4.1.2. Assumption 2 - Pan Evaporation

.............................................................

14 4.4.1.3. Assumption 3 - Lake Evaporation

............................................................

15 4.4.1.4. Assumption 4 - Evapotranspiration

........................................................

16 4.4.2. Hydrogeologic Feasibility of a Pond for Fish Consumption

...........................

16 Table of Contents Page Section 5.0 Dose Modeling Parameters

......................................................................

17 5.1. Thickness of Contaminated Zone

...................................................................

17 5.1.1. Scenario 1

-Shallow Aquifer

..........................................................................

17 5.1.2. Scenario 2 - Vadose Zone and Shallow Aquifer

............................................

18 5.2. Contaminated/Saturated Zone Field Capacity

...............................................

19 5.3. Density of Contaminated/Saturated Zone .....................................................

20 5.4. Contaminated/Saturated Zone Total Porosity

...............................................

21 5.5. Contaminated/Saturated Zone Effective Porosity

.........................................

21 5.5.1. Effective Porosity with Respect to Flow through a Porous Medium .............

22 5.6. Contaminated/Saturated Zone Hydraulic Conductivity

................................

23 5.7. Saturated Zone Hydraulic Gradient

...............................................................

24 5.8. Groundwater Velocity

....................................................................................

25 5.9. Precipitation

...................................................................................................

25 5.10. Runoff Coefficient

..........................................................................................

26 5.11. Well Pump Intake Depth

................................................................................

27 5.12. Contaminated Fraction Below Water Table

..................................................

27 5.12.1. Scenario 1 - Contaminated Zone from Water Table to Top of Aquitard

...... 27 5.12.2. Scenario 2 - Contaminated Zone from Ground Surface to Top of Aquitard . 27 Section 6.0 References

...............................................................................................

28

List of Figures Figure 4.1 Site Location

Figure 4.2 Site Plan List of Tables (within text)

Page Table 4.1 Loss of Thickness in the Sheet Pile Wall Due to Corrosion (mm)

................................. 7 Table 4.2 Loss of Thickness in the Sheet Pile Wall Due to Pitting (mm)

....................................... 8 Table 4.3 Hypothetical Water Well Parameters

.........................................................................

10 Table 4.4 Hypothetical Water Well Capture Zone and Drawdown

............................................

11 Table 4.5 Substructure Dimensions

............................................................................................

13 Table 4.6 Time to Over Top the Foundation Assuming No Evaporation

....................................

14 Table 4.7 Time to Over Top the Foundation Assuming Pan Evaporation

...................................

15 Table 4.8 Time to Over Top the Foundation Assuming Lake Evaporation

................................. 15 Table 4.9 Time to Over Top the Foundation Assuming Evapotranspiration Rates

....................

16 Table 5.1 Thickness of the Saturated Portion of the Shallow Aquifer

........................................

18 Table 5.2 Thickness of the Vadose Zone and Shallow Aquifer

...................................................

18 Table 5.3 Literature Values of Field Capacity

.............................................................................

19 Table 5.4 Field Capacity

..............................................................................................................

19 Table 5.5 Dry Soil Bulk Densi ty ...................................................................................................

20 Table 5.6 Soil Porosity

................................................................................................................

21 Table 5.7 Effective Porosity (Specific Yield) Based on Field Capacity

.........................................

22 Table 5.8 Hydraulic Conductivity Determined by Laboratory Analysis of Soil Samples

.............

23 Table 5.9 Hydraulic Conductivity Determined by Single Well Response Test

............................

24 Table 5.10 Hydraulic Gradient

......................................................................................................

24 Table 5.11 Estimates of Groundwater Velocity

............................................................................

25 Table 5.12 10-Year Average Precipitation

....................................................................................

26 Table 5.13 RESRAD Runoff Coefficients

........................................................................................

26 Table 5.14 Contaminated Fraction Below the Water Table

.........................................................

28 List of Appendices

Appendix A August 2012 Subsurface Investigation to Determine Site Specific Partition Coefficient (Kd) Values Letter Report (dated September 17, 2012)

Appendix B December 12, 2012 Geotechnical Subsurface Investigation Letter Report (dated March 1, 2013, revised January 14, 2014) Appendix C September 30, 2013 Single Well Response Test Letter Report (dated November 13, 2013) Appendix D September 30, 2013 Geotechnical Subsurface Investigation Letter Report (dated November 15, 2013)

Section 1.0Introduction Conestoga-Rovers & Associates (CRA) was retained by ZionSolutions, LLC (ZionSolutions) for hydrogeology consulting services related to the Zion Restoration Project at the former Zion Nuclear Power Station in Zion, Lake County, Illinois (Site).

This report provides an evaluation of several components of the Conceptual Site Model (CSM) and preliminary estimates of hydrogeological parameters. The parameters are considered accurate but may change as new information becomes available. These parameters are used in radionuclide release, transport , and dose modeling activities performed by ZionSolutions.

Section 2.0Development of Conceptual Site Model Components for Existing Conditions This section provides an evaluation of specific components of the CSM applicable to current Site conditions, decommissioning activities, and post

-decommissioning use of the Site.

2.1.An Evaluation of the Transport of Groundwater to Lake Michigan Groundwater at the Site generally flows from areas west of the Zion Station Protected Area (PA) eastward towards Lake Michigan (Lake) within the unconfined upper sand unit which underlies the Site to a depth of approximately 33 feet below ground surface (bgs) (the Shallow Aquifer). There are variations in flow directions and rates due to the presence of subsurface structures (e.g., Reactor, Containment, Auxiliary, Turbine , and Crib House buildings).

The seepage velocity (also called the specific discharge) is the average velocity of groundwater flowing through a porous medium. The average seepage velocity of 137 feet per year (ft/y) is representative of groundwater due to the natural gradient. The seepage velocity of 0 to 104 ft/y is representative of the natural velocity attenuated by the subsurface structures (e.g., building basements and the sheet pile wall) and describes conditions ranging from stagnant (0 ft/y) west of the Crib House to 58 ft/y for groundwater flowing around the edge of the sheet pile wall (see Section 5.8). The estimated travel time of groundwater from the PA to Lake Michigan is on the order of less than 1 year to over 2 years.

The volume of groundwater flowing through the Shallow Aquifer from the PA into Lake Michigan (groundwater flux) can be approximated by the following calculation:

The saturated thickness = 21.5 ft The length of the area of interest = 830 ft (north to south)

Cross section area is (21.5 ft)x(830 ft) = 1.78E+04 ft 2 Porosity = 0.353 Saturated pore portion of the cross sectional area = (1.78E+04 ft 2)x(0.35 3) = 6.30E+03 ft 2 Groundwater flux into the Lake using the low end groundwater velocity (assuming structures and basements remain in place) = (6.

30E+03 ft 2)x(104 ft/y) = 6.58E+05 ft 3/y x 7.48 gal/ft 3 = 4.92E+06 gal/y Groundwater flux into the Lake using the high end groundwater velocity (assuming structures and basements are removed) = (6.

30E+03 ft 2) x (1 37 ft/y) = (8.60E+05 ft 3/y) x (7.48 gal/ft

3) = 6.43E+06 gal/y 2.2.Estimation of the Effects of Dilution on Contaminants Entering Lake Michigan via Groundwater The total volume of water in Lake Michigan is estimated to be 1,180 cubic miles or about 1.3E+15 gallons (1). The stream flow entering the Lake is approximately 7.92 cubic miles per year (8.72E+12 gallons per year), and the discharge to Lake Huron is approximately 11.8 cubic miles per year (1.30E+13 gallons per year)

(2). The average residence time (the time between entry and discharge/evaporation) for water in the Lake is 99 years (1), which is equivalent to an exchange of 3.6E+10 gallons per day. Also, the Lake waters undergo an annual inversion which mixes the water as part of the natural lake processes (3). Although estimating the dilution requires release

-specific information, the general scale of dilution can be illustrated using dilution factors calculated by the mixing of hypothetical Site contaminants in groundwater flux with the surface water volume of Lake Michigan. Two dilution estimation methods are evaluated below. The complete mixing approach is suitable for estimating long term mixing and dilution over a period of many years. The shoreline mixing approach is suitable for estimating the potential impact at the shoreline adjacent to the Site.

2.2.1.Complete Mixing Approach A release of dissolved contaminants to the Lake would be diluted by mixing with the existing volume of Lake water due to the annual inversion of the Lake and currents. This dilution factor can be estimated for the volume of groundwater flux from the Site as explained above and its mixing each year with Lake Michigan surface water. A conservative dilution factor can be estimated by mixing the Site groundwater flux with the total influx of water to Lake Michigan. Using the lower range of groundwater velocity, this yields a dilution factor of:

=1.31+13 4.92+06=2.67+06 The higher range of groundwater velocity yields a dilution factor of:

=1.31+13 6.43+06=2.04+06 This estimates the dilution of a (hypothetical) continuous source of groundwater contamination entering Lake Michigan from the Site.

2.2.2.Shoreline Mixing Approach The dilution factor was also calculated for the near

-shore area of the Lake adjacent to the Site, where recreational swimmers and ecological receptors may be affected. The length along the shore of the area of concern is assumed to be 830 ft, based upon the approximate length of the PA along the shore line. The distance into Lake Michigan of the area of concern was assumed to be 100 yards (300 ft), based upon the distance a recreational swimmer is likely swim into the Lake. The depth of water at 100 yard s is 23 ft, based upon the depth of water at B

-81, a preconstruction borehole location. The cross

-sectional area is 300 ft x 23 ft / 2 = 3,450 ft 2 (assuming the lakebed slope is linear).

23 ft 3.45E+03 ft 2 300 ft Surface currents in Lake Michigan are driven by winds and are ephemeral in direction and velocity. Subsurface currents consistent with longshore drift have been described in an Illinois State Water Survey (ISWS) study at Wilmette, Illinois (approximately 30 miles south of Zion)

(4). The following median current velocities were described:

1.137 cm/s at a station 2.1 meters (m) deep and 107 m from shore 1.518 cm/s at a station 5.2 m deep and 213 m from shore (4 p. 17) Based on the average current velocity of the near shore station (1.137 cm/s or 1.18E+06 ft/y) times the cross-sectional area (3.45E+03 ft

2) yields a total volume of water of 4.06E+09 ft 3/y (or 3.04E+10 gal/y).

The volume of groundwater discharging into the Lake from the Site was estimated to be 6.43+06 gal/y, assuming the basements and sheet pile wall are removed and 4.92E+06 gal/y assuming the basements and sheet pile wall remain in place (see Section 2.1). The dilution factor for each of these scenarios was calculated to be:

3.04+10 6.43+06 =.+ (subsurface structures removed) 3.04+10 4.92+06 =.+ (subsurface structures remaining)

These dilution factors are very conservative and unlikely to represent the true dilution of groundwater into the Lake, since these values do not account for water exiting the near

-shore area further into the Lake. 2.3.An Evaluation of the Effectiveness of the Silty Clay Aquitard at the Base of the Shallow Aquifer The silty clay unit (found under the Shallow Aquifer) (also referred to herein as the Silty Clay Aquitard) is approximately 30 ft thick and overlies the lower sand unit. The silty clay unit is laterally extensive at the Site and the underlying lower sand unit has exhibited a significant confining pressure (artesian pressure at boring B

-43) and a strong upward vertical gradient (5). To the extent that groundwater flow can occur through the silty clay unit, the groundwater in the lower sand unit would move upward into the upper sand unit (Shallow Aquifer). The building foundations for the Containment Buildings, Auxiliary Building, Turbine Building, and Crib House are set in or near the upper portion of the silty clay unit. However, the silty clay unit extends approximately 15 ft below the deepest structural feature at the Site.

The silty clay unit's low permeability and upward vertical gradient limits the potential for the migration of contaminants or radionuclides to the underlying lower sand unit or the regional bedrock aquifers.

Section 3.0Development of CSM Components for Decommissioning Activities Several components of the CSM require evaluation or refinement prior to their incorporation into risk assessment and dose modeling for the Site. An evaluation of these components may guide the selection of decommissioning technologies for their use in the CSM.

3.1.Basement Fill Alternatives The CSM anticipates that the basements will generally remain in place and be filled with 'clean' concrete (no detectable residual radioactivity from Site operations) originating from the demolition of aboveground buildings and structures or other fill material. The scenarios described below are hypothetical.

3.1.1.Riprap Scenario During the demolition of aboveground concrete structures, large pieces of riprap will be produced (e.g., using an excavator with a pneumatic hammer attachment) and staged at the Site. The basements would then be backfilled with large clean concrete pieces (protruding rebar must be removed), and sand would be used to fill the voids during backfilling.

This fill material would act as a framework gravel, with incomplete infilling of void spaces by sand. The resulting porosity is expected to be high, ranging from 25

-40% for riprap

-sand mixtures and 40 to 45% for uniform riprap. Groundwater can readily flow through this material. The area of fresh concrete surfaces would be minimized, which would reduce the pH impact due to calcium leaching.

3.1.2.3-inch Clean Concrete Scenario Under this scenario, during the demolition of aboveground concrete structures, large pieces of riprap will be produced and staged at the Site. A mobile concrete crusher would be used to reduce the clean concrete to 3"x3" pieces. The basements would then be backfilled with 3"x3" crushed concrete. Pea gravel may be used to top off partially demolished basement rooms and other enclosed spaces.

This fill material would act as an open framework gravel. The resulting porosity is expected to be high, ranging from 25

-40% for 3"x3" concrete

-sand mixtures and 40 to 50% for uniform 3"x3" concrete. Groundwater can readily flow through this material. The area of fresh concrete surfaces would be maximized, which would generally increase the pH impact due to calcium leaching.

3.1.3.Sand Scenario Under this scenario, sand backfill is used as an alternative fill material and may be selected based on the sorption characteristics of the radionuclides of concern. The resulting porosity is expected to be typical of sand, ranging from 25-40%. Groundwater can readily flow through this material. The use of sand backfill would minimize the pH impacts from fresh concrete surfaces. The sand backfill would also minimize the potential for settling over time. However, sand cannot be compacted if it is placed in a room below grade that is not open at the top due to load bearing or similar considerations for the remaining structure.

3.1.4.Riprap and Flowable Fill Scenario Under this scenario, during demolition of above ground concrete structures, large pieces of riprap are produced and staged at the Site. The basements would then be backfilled with large clean concrete pieces (protruding rebar must be removed), and flowable fill (grout fill) would be used to fill the voids during backfilling.

The flowable fill may be composed of a blend of cement, fly ash, sand and gravel, slag, and/or water. The flowable fill will solidify upon standing. Water in contact with the flowable fill is expected to exhibit an elevated pH due to the chemical makeup of the concrete and fly ash. However, the building foundations and low permeability of the flowable fill will limit the amount of groundwater that can be exposed to the fill.

3.1.5.Surface Cover The surface cover for the filled building basements is currently proposed to consist of approximately 3 feet of sand/soil.

3.2.Final Disposition of the Sheet Pile Wall The current decommissioning scenario allows the sheet pile wall to remain intact at the end of the project. It is assumed that the sheet pile wall will not be cut off below grade or damaged during the decommissioning, but will continue in its current use for shoreline erosion control.

3.3.An Evaluation of the Risk of Compromising the Silty Clay Aquitard at the Base of the Shallow Aquifer During Decommissioning Activities The current decommissioning plan for the Site will allow the deeper building foundations to remain in place. Excavation activities for foundation removal will be limited to slab-on-grade and shallow building foundations.

As previously stated in Section 2.3, the silty clay unit is approximately 30 ft thick and extends at least 15 ft below the deepest building foundations at the Site. Since there will not be any excavation to a depth that the silty clay unit could be affected, the unit is expected to remain intact during and after the decommissioning process. The silty clay unit will continue to act as a laterally extensive aquitard which limits the potential for the vertical movement of groundwater at the Site.

Section 4.0Development of Post

-Decommissioning CSM Components Several components of the post

-decommissioning CSM require evaluation or refinement prior to their incorporation into risk assessment and dose modeling for the Site. An evaluation of these components may guide the selection of decommissioning technologies or their use in the CSM.

4.1.An Evaluation of Groundwater Flow Through and Around Subsurface Structures Left in Place If the basements and sheet wall are perforated but left in place, the impediment on groundwater flow will be reduced but not completely eliminated. There will be some restrictions and retardation of the overall flow of groundwater from areas to the west toward Lake Michigan. However, the primary flow of groundwater will continue to be toward the Lake. Some vertical migration of groundwater will occur within the Shallow Aquifer as groundwater flows through and around these subsurface structures.

If the buildings and sheet pile wall are left intact (not perforated for flow), then a localized stagnation of groundwater around these barriers will occur since groundwater is prevented from flowing through these structures toward the Lake.

4.1.1.Deterioration of the Sheet Pile Wall Over Time During construction of the Site in 1968, a cofferdam (also called a sheet pile wall) was built along the Lake side of the Crib House to allow the first sections of circulating water pipe and their easements to be installed dry. The cofferdam was constructed of sheet piling installed parallel to the Lake with sections (called walers) extending about 415 feet north and south of the Crib House. There is no indication that protective coatings or cathodic protection were used. The sheet piling was left in place at the completion of the construction for shore erosion protection. "Should the sheet piling deteriorate there can be no deleterious effect on the Crib House or any other safety

-related structures. The Crib House and safety

-related structures are self-contained and do not depend on the sheeting for protection" (6 pp. 2.4-14). The sheet pile wall was constructed of U.S. Steel MZ27 sheet piling (new standard designation PZ27)

(7). MZ27 sheet piling is 0.375

-inches [9.5 millimeters (mm

)] thick.

Corrosion rates for sheet pile walls have been estimated based on available literature.

Table 4.1 presents the estimated loss of thickness due to corrosion, and Table

4.2 presents

the loss of thickness due to pitting.

Table 4.1 Loss of Thickness in the Sheet Pile Wall Due to Corrosion (mm)

Installation Years from Installation 5 25 50 75 100 Undisturbed natural soils (sand, silt, clay, schist, etc.)

(8) 0.00 0.30 0.60 0.90 1.20 Common fresh water (river, ship canal, etc.) in the zone of high attack (water line) (8) 0.15 0.55 0.90 1.15 1.40 Table 4.1 Loss of Thickness in the Sheet Pile Wall Due to Corrosion (mm)

Installation Years from Installation 5 25 50 75 100 Duluth-Superior Harbor accelerated fresh water corrosion (maximum of 0

-3 meters) (9) 0.50 2.50 5.00 7.50 10.00 Duluth-Superior Harbor accelerated fresh water corrosion (greater than 3 meters)

(9) 0.20 1.00 2.00 3.00 4.00 Pitting, or localized corrosion, will occur at a more rapid rate (2 to 3 times that of the average corrosion rate) (10). Table 4.2 Loss of Thickness in the Sheet Pile Wall Due to Pitting (mm)

Installation Years from Installation 5 25 50 75 100 Undisturbed natural soils (sand, silt, clay, schist, etc.)f 0 0.9 1.8 2.7 3.6 Common fresh water (river, ship canal, etc.) in the zone of high attack (water line) f 0.45 1.65 2.7 3.45 4.2 Duluth-Superior Harbor accelerated fresh water corrosion (maximum of 0

-3 meters) 1.5 7.5 15 22.5 30 Duluth-Superior Harbor accelerated fresh water corrosion (greater than 3 meters) 0.6 3 6 9 12 Notes: 1. Loss due to pitting is based on 3 times the corrosion rate

. f ArcelorMittal 2008 (8 p. 3/6 to 3/7)

Clark et al. 2009 (9)

The sheet pile wall is approximately 45 years old (2013

-1968=45). Based on its age and the expected corrosion rates, perforations may be present in the upper 10 ft of the saturated zone if accelerated corrosion rates apply. If normal corrosion rates apply, the upper 10 ft is expected to remain intact for >100 years. The remaining depth, although structurally weakened by corrosion, is generally expected to remain intact for 30 to >100 years. The sheet pile wall will act as a significant barrier to groundwater flow while intact and is expected to slowly pit and corrode over a period of decades or centuries, with failure in the upper 10 feet significantly preceding the remainder of the wall. Once the pitting penetrates the wall, its effectiveness as a hydraulic barrier will decline.

4.2.An Assessment of the Feasibility of a Future Site Occupant Installing a Water Well at the Site Three potential scenarios exist for the installation and use of a residential water well installed into the Shallow Aquifer at the Site:

1) A well installed within the basement of a former building filled with clean concrete pieces

2) A well installed between the former buildings and the Lake

3) A well installed closer to the Lake Under the current decommissioning scenario, the basements would be filled with clean concrete pieces.

As a practical matter, the drilling of a well through clean concrete pieces is much more difficult and expensive than drilling a well in any other nearby location.

In the case where the basements are filled with a grouted mixture, drilling a well is even more difficult. The yield of such a well would be limited to the rate at which water could enter the building through perforations and may not be sufficient to provide for residential use. Additionally, the water in the former basements would exhibit undesirable taste and odor characteristics due to the elevated pH that is anticipated due to the presence of clean concrete pieces.

A hypothetical well installed between the major buildings and the sheet pile wall could easily be installed within the Shallow Aquifer. This well would be in an area of low groundwater flow or even stagnation. Its yield would be somewhat restricted by the approximately 15 to 20 ft of saturated thickness of this aquifer. However, such a well is anticipated to produce sufficient water for a single residential use scenario.

A hypothetical well installed downgradient of the buildings (near the Lake) could be installed and used easily. It would likely yield much more water as the recharge to the well would include Lake water. The quality of water of such a well (located near the Lake) may not make it appropriate for drinking water purposes without treatment due to potential biological contamination.

4.2.1.Potential Capture Zone and Drawdown The potential capture zone and drawdown were calculated based upon the scenario of a hypothetical water well being installed within the PA, between the buildings and the sheet pile wall. The calculations were performed assuming two conditions: the sheet pile wall remains in place (gradient = 0.0039) and, the sheet pile wall is removed (gradient = 0.0051).

The steady state Todd equation (11) was used for the capture zone calculation. It can be described for an unconfined aquifer as follows:

Where, Twidth is the capture width at an infinite upgradient distance (ft)

Ymax is one half of the total capture width (ft)

Q is the pumping rate (ft 3/day) h 1 is the measured groundwater elevation above the base of the aquifer upgradient of the pumping well (ft) h 2 is the measured groundwater elevation above the base of the aquifer downgradient of the pumping well (ft)

L is the distance over the two water level measuring locations K is the hydraulic conductivity for the aquifer (ft/day)

The steady

-state Theim equation for an unconfined aquifer (12) was used to determine the drawdown. It can be described as follows:

Where, K is the hydraulic conductivity for the aquifer (ft/day)

Q is the pumping rate (ft 3/day) b 1 is the saturated thickness at distance r 1 from the pumping well (ft) b 2 is the saturated thickness at distance r 2 from the pumping well (ft)

The following parameters were utilized to calculate the capture zone and drawdown:

Table 4.3 Hypothetical Water Well Parameters Parameter Symbol Units Value Source Aquifer thickness b ft 21.53 Section 5.1.1 Hydraulic conductivity K cm/s 5 x 10-3 Section 5.6 Hydraulic gradient i ft/ft 0.0039, 0.0051 Section 5.7 Pumping Rate Q m 3/yr 250 RESRAD Default Based upon the parameters listed in Table 4.3 (above), the expected capture zone and drawdown for a well located within the Shallow Aquifer with varying pumping rates are presented in Table 4.4 below. These calculations were performed based upon a gradient of 0.0039 ft/ft to simulate the sheet pile wall in place and a gradient of 0.0051 to simulate the sheet pile wall being removed or degraded over time.

The estimated width of the capture zone s at the center of pumping are calculated to be 6.77 ft (based upon a gradient with the sheet pile wall in place) and 5.18 ft (based upon a gradient with sheet pile wall being removed or degraded over time). The drawdown as based upon both of these gradients is nominal under this pumping rate. These are the capture zones which can be generally expected in a well located within the Shallow Aquifer when pumped at the average rate of 250 m 3/yr [0.13 gallons per minute (gpm)

], under their respective conditions.

The average pumping rate within the Shallow Aquifer was determined to be 10.9 gpm. This rate is based upon ISGS water well logs for wells located within 2 miles of the Site with pumping rates provided. The maximum pumping rate with the sheet pile wall in place or removed is expected to be approximately 20 gpm. However, the capture zone and drawdown are expected to be greater with the sheet pile wall in place. This is due to the restricted gradient in place by the sheet pile wall. These calculations do not take into account the close proximity to Lake Michigan and the likely recharge provided by the Lake. Therefore, the actual maximum pumping rate with the sheet pile wall removed is likely to be greater than the estimated rate. The capture zone and drawdown under these scenarios will be further developed with modeling in order to account for complexities outside the reach of these calculations.

Table 4.4 Hypothetical Water Well Capture Zone and Drawdown Pumping Rate i=0.0039 (sheet pile wall in place) i=0.0051 (sheet pile wall removed)

(gpm) (m 3/yr) Capture Zone (ft) Drawdown (ft) Capture Zone (ft) Drawdown (ft) 0.13 250 10.2 0.04 8.04 0.03 0.5 995 40.4 0.20 30.9 0.19 1 1,991 80.9 0.46 61.9 0.44 5 9,955 404 3.08 309 2.96 10 19,910 809 7.20 618 6.92 15 29,865 1,213 12.4 928 11.9 20 39,820 1,618 19.3 1,237 18.4 25 49,774 * * *

• Notes: *Water well cannot support this pumping rate.

4.3.Rise in Lake Michigan Surface Water Elevation Since the Shallow Aquifer and the Lake are directly connected, it is possible for a zone of stagnation to occur if the Lake water level rises above the groundwater level. The pressure from the Lake water entering the groundwater would prevent the groundwater from reaching the Lake.

If the water level in Lake Michigan were to rise, it could cause a reversal of flow westward. The Lake has historical, measured fluctuations of over 6 ft. Even under these extreme conditions, a groundwater flow reversal would be localized and found only near the Lake, as the regional flow would still flow eastward towards Lake Michigan. A zone of stagnation would occur where the two groundwater flow fronts meet. In order for this to occur , the Lake water level would have to be higher than the groundwater level.

Monthly average water levels in Lake Michigan/Huron have been recorded beginning in 1918. Between 1918 and 2013, the average water level in Lake Michigan was 578.8 ft above mean sea level (amsl). The lowest monthly average Lake level was 576.02 ft amsl in January 2013. The highest monthly average Lake level was 582.35 ft amsl in October 1986 (13) (14) (15). 4.4.De Minimus Scenarios There are several scenarios that are unlikely and have been determined to have minimal consequence.

These scenarios are discussed in the following sections.

4.4.1.Basement Overflow Scenario The basement overflow scenario assumes that the basement walls and floors are left intact during the decommissioning (or alternatively that any building penetrations have been sealed over time). The basements would then fill up over time due to the infiltration of precipitation and eventually overflow.1 Basement overflow rates were calculated based upon basement depths, precipitation rate, and evaporation rate. These calculations determine how long it will take for the substructures to fill with water assuming substructures are left in place with the superstructure roof removed. This scenario also assumes that no cracks are present in the basement walls. The average annual precipitation rate, as detailed in Section 5.8 below, of 32.61 inches/y was utilized. These calculations were performed for each structure with a significant substructure. Basement depths and dimensions for each substructure are presented in the table below. For the purpose of these calculations, 3 ft were subtracted from the building depths to account for the proposed removal of the upper 3 ft of the substructure.

1 An additional consideration for the scenario where the walls are left intact is the buoyancy of the structure, which must be taken into consideration prior to the removal of the above ground structures and other building loads. The buoyancy of subsurface structures is not evaluated in this report.

Table 4.5 Substructure Dimensions Finish Grade (ft amsl) Top of Basement Floor (ft amsl) Adjusted depth of basementf (ft) Adjusted depth of basementf (in) Area (ft 2) Volume (ft 3) Unit 1 Containment 591 568 20 240 2.00E+04 4.01E+05 Unit 2 Containment 591 568 20 240 2.00E+04 4.01E+05 Fuel Handling Building 591 576 12 144 9.18E+03 1.10 E+05 Auxiliary Building 591 542 46 552 2.90E+04 1.34E+06 Turbine Building 591 560 28 336 1.21E+05 3.38E+06 Lake Crib House 591 539 49 588 3.14E+04 1.54E+06 Wastewater Treatment Facility 591 578 10 120 9.45E+03 9.45E+04 Notes: f Three feet were subtracted from the building depths to account for the upper 3 feet of basement that will be removed This scenario was run under four different assumptions: 1) Assuming no evaporation, 2) Assuming a pan evaporation rate, 3) Assuming a lake evaporation rate, and 4) Assuming evapotranspiration.

This scenario only accounts for rainwater falling directly into the substructure and does not account for runoff into the substructure. Further, this scenario was also run assuming each of the following: the basements are open holes with no backfill, the basements are backfilled with sand, and the basements are backfilled with riprap. It was assumed that the sand backfill will have a porosity of 0.35, based upon the September 2013 investigation. The riprap is assumed to have a porosity of 0.45 (16). The sand and riprap backfill were accounted for by multiplying the number of years to fill the open hole by their respective porosities. The backfill to be used on Site will likely be a combination of sand and riprap. These calculations provide a likely range of the years it will take for the unperforated basements to fill with water.

The following basic calculation steps were utilized to determine the fill rates:

Step 1: Annual Precipitation Rate - Evaporation Rate = Annual Water Accumulation Step 2: (Basement Depth)/(Annual Water Accumulation) = Years to Fill Basement Step 3: (Years to Fill Basement) x (Porosity) = Years to Fill Basement Considering Backfill Material

4.4.1.1.Assumption 1 - No Evaporation The first scenario assumes that the substructures fill based upon the average precipitation rate and does not take into account any loss of water. This scenario is highly unlikely, since evaporation of water will occur. Based upon these parameters, the expected fill time of each substructure is presented below.

Table 4.6 Time to Over Top the Foundation Assuming No Evaporation Structure Average Precipitation Rate (inches/y)

Time to Over

-Top the Foundation (Years) No Fill Sand Fillf Riprap Fill Unit 1 Containment 32.61 7.36 2.58 3.31 Unit 2 Containment 32.61 7.36 2.58 3.31 Fuel Handling Building 32.61 4.42 1.55 1.99 Auxiliary Building 32.61 16.93 5.92 7.62 Turbine Building 32.61 10.30 3.61 4.64 Lake Crib House 32.61 18.03 6.31 8.11 Wastewater Treatment Facility 32.61 3.68 1.29 1.66 Notes: f This calculation assumes the basements are filled with sand. The porosity of sand is assumed to be 0.35, based upon the September 2013 investigation. This calculation assumes the basements are filled with riprap. The porosity of riprap is assumed to be 0.45, based upon guidelines from the U.S. Department of the Interior (16). 4.4.1.2.Assumption 2 - Pan Evaporation Pan evaporation rates are determined from direct loss of water from a pan over time. The pan evaporation rate utilized in this analysis was determined from an Illinois pan evaporation isoline map presented in an ISWS lake evaporation study (17). The ISWS study (17) utilized pan evaporation data from 17 stations in and near Illinois collected between May through October over a 16 year period to derive a state

-wide map. This method is limited in that it only accounts for the months of May through October. Evaporation during the winter months is likely to be less.

This scenario assumes that the substructures fill with water based upon the average precipitation rate and accounts for the loss of water due to evaporation. An evaporation rate of 28 inches/y was assumed based upon "Pan Evaporation" studies performed in Illinois (17). Based upon these parameters, the expected fill time of each substructure is presented below. Actual fill times may be less, since this does not account for evaporation between November and April.

Table 4.7 Time to Over Top the Foundation Assuming Pan Evaporation Structure Pan Evaporation rate (inches/y)

Water Gain (inches/y)

Time to Over

-Top the Foundation (Years) No Fill Sand Fillf Riprap Fill Unit 1 Containment 28 4.61 52.06 18.22 23.43 Unit 2 Containment 28 4.61 52.06 18.22 23.43 Fuel Handling Building 28 4.61 31.24 10.93 14.06 Auxiliary Building 28 4.61 119.74 41.91 53.88 Turbine Building 28 4.61 72.89 25.51 32.80 Lake Crib House 28 4.61 127.55 44.64 57.40 Wastewater Treatment Facility 28 4.61 26.03 9.11 11.71 Notes: f This calculation assumes the basements are filled with sand. The porosity of sand is assumed to be 0.35, based upon the September 2013 investigation. This calculation assumes the basements are filled with riprap. The porosity of riprap is assumed to be 0.45, based upon guidelines from the U.S. Department of the Interior (16). 4.4.1.3.Assumption 3 - Lake Evaporation The third scenario assumes that the substructures fill with water based upon the average precipitation rate and also accounts for the loss of water due to evaporation. An evaporation rate of 31 in/y was assumed based upon studies performed in Illinois (17). This evaporation rate is an annual average over a 52 year period between 1911 and 1962. Lake evaporation rates were computed in the ISWS study by utilizing air temperature, dew point temperature, wind movement , and solar radiation. Based upon the Lake evaporation rate near the Zion area, the expected fill time of each substructure is presented below.

Table 4.8 Time to Over Top the Foundation Assuming Lake Evaporation Structure Lake Evaporation rate (inches/y)

Water Gain (inches/y)

Time to Over

-Top the Foundation (Years) No Fill Sand Fillf Riprap Fill Unit 1 Containment 31 1.61 149.07 52.17 67.08 Unit 2 Containment 31 1.61 149.07 52.17 67.08 Fuel Handling Building 31 1.61 89.44 31.30 40.25 Auxiliary Building 31 1.61 342.86 120.00 154.29 Turbine Building 31 1.61 208.70 73.04 93.91 Lake Crib House 31 1.61 365.22 127.83 164.35 Wastewater Treatment Facility 31 1.61 74.53 26.09 33.54 Notes: f This calculation assumes the basements are filled with sand. The porosity of sand is assumed to be 0.35, based upon the September 2013 investigation. This calculation assumes the basements are filled with riprap. The porosity of riprap is assumed to be 0.45, based upon guidelines from the U.S. Department of the Interior (16).

4.4.1.4.Assumption 4 - Evapotranspiration Evapotranspiration is the evaporation of water from plants, soil, and other surfaces to the atmosphere. This scenario most accurately depicts the filled basement state. The mean annual potential evapotranspiration near the Zion area is expected to be 28 inches/y, based upon a potential evapotranspiration isoline map of Illinois, as presented in an ISWS study (17). Based upon the evapotranspiration rate near the Zion area, the expected fill time of each substructure is presented below. Table 4.9 Time to Over Top the Foundation Assuming Evapotranspiration Rates Structure Evapotranspiration Rate (inches/y)

Water Gain (inches/y)

Time to Over

-Top the Foundation (Years) No Fill Sand Fillf Riprap Fill Unit 1 Containment 28 4.61 52.06 18.22 23.43 Unit 2 Containment 28 4.61 52.06 18.22 23.43 Fuel Handling Building 28 4.61 31.24 10.93 14.06 Auxiliary Building 28 4.61 119.74 41.91 53.88 Turbine Building 28 4.61 72.89 25.51 32.80 Lake Crib House 28 4.61 127.55 44.64 57.40 Wastewater Treatment Facility 28 4.61 26.03 9.11 11.71 Notes: f This calculation assumes the basements are filled with sand. The porosity of sand is assumed to be 0.35, based upon the September 2013 investigation. This calculation assumes the basements are filled with riprap. The porosity of riprap is assumed to be 0.45, based upon guidelines from the U.S. Department of the Interior (16). 4.4.2.Hydrogeologic Feasibility of a Pond for Fish Consumption To receive water containing radionuclides released from the basement fill CSM, a pond would have to be constructed downgradient from the major building basements. Two simple types of surface water impoundments or ponds could hypothetically be constructed at the Site in the area between the former buildings and the Lake. The first type of pond construction would rely on groundwater to seep into the pond and to provide a base level (freeboard) of surface water. The second type of pond would be constructed such that the pond is lined or has some barrier to hold and contain surface water recharge and precipitation infiltration.

Neither of these pond types is likely to be constructed by a single resident due to engineering and cost issues. In addition, if a resident wished to use surface water, Lake Michigan is nearby.

The first type of pond would have to be excavated to a depth of over 10 to 15 ft in order to intercept the groundwater table. This type of construction would require engineered side walls, shoring, and other methods to keep the pond from collapsing (as it is constructed into sands).

The second type of pond, which relies upon surface recharge, would require a liner or bottom of some sort. Without a liner or bottom in the pond, any of the surface water captured in the pond would easily recharge through the Shallow Aquifer and seep to the groundwater table. As such, an engineered liner would have to be constructed.

Given the engineering design and costs to construct either of these pond types, this exposure pathway is highly unlikely.

Section 5.0Dose Modeling Parameters This section provides input parameters to be used for dose pathway calculations. These include selected physical and hydraulic property parameters that may be input to the DUST

-MS model where the floor of a major building such as a Containment Building includes surface contamination. This contaminated material is instantaneously released into a band of water and the radionuclides are transported in this band through the building into and through the down gradient natural system to receptor locations. The DU ST-MS model uses selected parameter values to calculate the water concentration outputs which are then input into the RESRAD or RESRAD OFFSITE code for calculation of the pathway dose. Site specific parameters are based on field studies conducted in 2012 and 2013, which are described in the reports provided in Appendix A through D.

5.1.Thickness of Contaminated Zone For the RESRAD Family of Codes , "Thickness of the Contaminated Zone" is defined as "the distance between the shallowest and the deepest depth of contamination" (18 pp. 4-25). Thickness of the contaminated zone is an important physical parameter in the RESRAD and RESRAD

-OFFSITE codes. This parameter is evaluated for two scenarios: contaminated zone that extends from the water table to the bottom of the saturated zone and a contaminated zone that extends from ground surface to the bottom of the saturated zone.

5.1.1.Scenario 1

-Shallow Aquifer This potential scenario assumes that contamination extends from the water table to the top of the Silty Clay Aquitard at the base of the Shallow Aquifer. This thickness can be estimated using the boring logs for the wells situated immediately downgradient from the central plant area, as provided in Table 5.1 below:

Table 5.1 Thickness of the Saturated Portion of the Shallow Aquifer Boring Location March 13, 2013 Water Level (ft amsl) Aquitard Surface (ft amsl)f Thickness (ft) Thickness (meters) MW-ZN-01S 578.95 562.18 16.8 5.1 MW-ZN-02S 579.43 555.21 24.2 7.4 MW-ZN-03S 579.72 556.54 23.2 7.1 MW-ZN-04S 579.47 557.51 22.0 6.7 Average 21.5 6.6 Notes: fThe Shallow Aquifer includes stratigraphic units containing gravel, sand, and silt with sand

. 5.1.2.Scenario 2 - Vadose Zone and Shallow Aquifer This potential scenario assumes that contamination extends from the ground surface to the top of the Silty Clay Aquitard at the base of the Shallow Aquifer. This thickness can be estimated using the boring logs for the wells situated immediately downgradient from the central plant area, as provided in Table 5.2 below: Table 5.2 Thickness of the Vadose Zone and Shallow Aquifer Boring Ground Surface (ft amsl) Aquitard Surface (ft amsl) f Thickness (ft) Thickness (meters) MW-ZN-01S 591.43 562.18 29.3 8.9 MW-ZN-02S 591.21 555.21 36.0 11.0 MW-ZN-03S 591.54 556.54 35.0 10.7 MW-ZN-04S 591.01 557.51 33.5 10.2 Average 33.4 10.2 Notes: f The Shallow Aquifer includes stratigraphic units containing gravel, sand, and silt with sand

.

Note: The subsurface material near the Site buildings is composed of native fill material; as such, the material may be variable across the area. The MW

-ZN-03S boring log indicates that a 1 foot thick silty clay till layer is present at 11 feet bgs, followed by a silt and sand layer and a silt with sand layer to a depth of 35 feet bgs. Due to the nature of the source of the soil in the area and the comparable aquifer thicknesses at nearby boring locations, the thickness of the shallow aquifer at MW

-ZN-03 is estimated to be 35 fee t.

5.2.Contaminated/

Saturated Zone Field Capacity Field capacity is defined as the ratio of the volume of water retained in the soil sample (after all downward gravity drainage has ceased) to the total volume of the sample (19). Laboratory measurements of field capacity typically measure the volumetric water content of a soil sample under a negative pressure of 1/10 or 1/3 bar (20) (21). A volumetric water content greater than the field capacity is not available for plant use because it drains away quickly. The wilting point is the maximum pressure that a plant can exert to overcome the tension of the water adhering to the soil. The wilting point corresponds to a negative pressure of 15 bars. The water content of a soil between the field capacity (1/10 to 1/3 bar) and the wilting point (15 bar) is called the available water content. Literature values of field capacity for different soil textures are provided in the table below:

Table 5.3 Literature Values of Field Capacity Soil Texture Field Capacity at 1/3 bar in percent by volumef Soil Texture Field Capacity at 1/3 bar in percent by volumef Sand 1.8 - 16.4 Sandy Clay Loam 18.6 - 32.4 Loamy sand 6.0 - 19.0 Clay Loam 25.0 - 38.6 Sandy loam 12.6 - 28.8 Silty Clay Loam 30.4 - 42.8 Loam 19.5-34.5 Sandy Clay 24.5 - 43.3 Silt Loam 25.8 - 40.2 Silty Clay 33.2 - 44.2 Silt - - Clay 32.6 - 46.6 Notes: f Source: Nachabe 1998 (21). The listed range is +/

- one standard deviation about the mean

Laboratory measurements of field capacity and water retention were determined using a compression/decompression chamber method. This method places a saturated soil sample onto a porous ceramic plate which is then placed in a closed chamber. A known amount of pressure is then established in the chamber, which forces water out of the soil sample and into the porous plate and out of the chamber. The water holding capacity of the soil is determined by the amount of water held in the soil sample versus the dry weight of the sample. The amount of pressure applied during each test ranged from 0.1 bar to 15 bar. Soil water retention curves were developed using the water content at different pressure points. The soil water retention curves are included in Appendix D. The laboratory estimates of field capacity at 1/10 bar and 1/3 bar are shown in the table below:

Table 5.4 Field Capacity Soil Boring Identifier Sample Identifier Field Capacity (%)

0.1 bar 1/3 bar GT2-MW-01S GT2-MW-01S-5 10.4 4.7 GT2-MW-01S GT2-MW-01S-20 3.6 1.2 GT2-MW-01S GT2-MW-01S-28 6.5 2.5 GT2-MW-02S GT2-MW-02S-5 10.3 4.1 Table 5.4 Field Capacity Soil Boring Identifier Sample Identifier Field Capacity (%)

0.1 bar 1/3 bar GT2-MW-02S GT2-MW-02S-26 8.9 3.8 GT2-MW-06S GT2-MW-06S-5 3.9 1.8 GT2-MW-06S GT2-MW-06S-20 2.9 1.0 Arithmetic mean 6.64 2.73 Typical field capacity values for sand range from 1.8% to 16.4% by volume at 1/3 bar (21). The arithmetic mean of the laboratory values for field capacity at 1/3 bar is 2.7 3% by volume, which is within the range of the literature values.

The Data Collection Handbook to Support Modeling Impacts of Radioactive Material in Soil (Yu et al., 1993) defines field capacity as the ratio of the volume of water retained in the soil sample (after all downward gravity drainage has ceased) to the total volume of the sample (19). To meet this narrative definition, Romano & Santini (2002) recommend using the volumetric water content at 0.1 bar as the estimate of field capacity for coarse

-grained soils (e.g., sands)

(20). The average field capacity of the soil samples at 0.1 bar is 6.64% by volume.

This is consistent with field capacity values identified by the International Atomic Energy Agency (IAEA) for sand ranging from 6% for coarse sand to 10% for fine sand (22 p. 4). 5.3.Density of Contaminated/

Saturated Zone The proposed model scenario is based on the transport of contaminants in groundwater released from the major building basements in the down

-gradient direction toward Lake Michigan. Under this scenario, the contaminants would be transported through both the disturbed sand unit to the west of the sheet pile wall and the native sand unit to the east of the sheet pile wall.

Since the transport will encompass both disturbed and undisturbed sands, the average value of laboratory measurements (of saturated zone samples) is used to estimate the bulk density of native sands and fill mixture in the saturated zone

2. These values are provided in Table 5.5 below: Table 5.5 Dry Soil Bulk Density Soil Boring Identifier Sample Identifier Bulk Density (pcf) BulkDensity (gm/cm 3) GT2-MW-01S GT2-MW-01S-5 112.6 1.80 GT2-MW-01S GT2-MW-01S-20 118.0 1.89 2 Soil samples collected in the earlier investigation on December 12, 2012 were also submitted for laboratory analysis of dry bulk density. However, a review of the laboratory report resulted in the rejection of the analytical results for dry bulk density due to inconsistency with grain size distribution. The results were comparable to a dense-graded aggregate such as MDOT 21AA rather than the fine to medium sand at the Site. As a result, the dry soil bulk density values from the December 12, 2012 investigation have been excluded from the evaluation.

Table 5.5 Dry Soil Bulk Density Soil Boring Identifier Sample Identifier Bulk Density (pcf) BulkDensity (gm/cm 3) GT2-MW-01S GT2-MW-01S-28 115.3 1.85 GT2-MW-02S GT2-MW-02S-5 118.4 1.90 GT2-MW-02S GT2-MW-02S-26 112.5 1.80 GT2-MW-06S GT2-MW-06S-5 102.2 1.64 Arithmetic mean 113.2 1.81 5.4.Contaminated/

Saturated Zone Total Porosity The proposed model scenario is based on the transport of contaminants in groundwater released from the major building basements in the down

-gradient direction toward Lake Michigan. Under this scenario, the contaminants would be transported through both the disturbed sand unit to the west of the sheet pile wall and the native sand unit to the east of the sheet pile wall. Since the transport will encompass both disturbed and undisturbed sands, the average value of laboratory measurements (from saturated zone samples) is used to estimate the total porosity, as provided in Table 5.6 below: Table 5.6 Soil Porosity Boring Identifier Sample Identifier Porosity (% by volume)

GT2-MW-01S GT2-MW-01S-5 33.2 GT2-MW-01S GT2-MW-01S-20 29.7 GT2-MW-01S GT2-MW-01S-28 31.6 GT2-MW-02S GT2-MW-02S-5 33.4 GT2-MW-02S GT2-MW-02S-26 36.9 GT2-MW-06S GT2-MW-06S-5 39.3 GT2-MW-06S GT2-MW-06S-20 42.7 Arithmetic mean 35.3 5.5.Contaminated/

Saturated Zone Effective Porosity The term "effective porosity" can refer to the retention of water against gravity drainage (also called specific retention) or the portion of porosity that is interconnected and allows the flow of groundwater.

The Data Collection Handbook to Support Modeling Impacts of Radioactive Material in Soil (19) defines effective porosity as the total porosity minus the field capacity. This is consistent with the specific retention-based definition of effective porosity as described by Bear (1972):

"In the case of a phreatic aquifer, water is actually drained out of the pore space, and air is substituted as the water table drops. However, not all water contained in the pore space is removed by gravity drainage (say, toward a depression in the ground water table caused by a pumping well). A certain amount of water is held in place against gravity in the interstices between grains under molecular forces and surface tension. Hence, the storativity of a phreatic aquifer is less than the porosity by a factor called specific retention (the ratio of water retained against gravity to the bulk volume of a soil sample). Reflecting this phenomenon, the storativity of a phreatic aquifer is often referred to as specific yield. The term effective porosity is also often used in this context. However, one should be careful not to confuse this usage of the term with that effective porosity referring to flow through a porous medium" (23 p. 8).

Since the effective porosity is used to calculate transport time in groundwater (24 pp. E-19), smaller values are considered more conservative (i.e., they reduce transport time). Total porosity and field capacities determined during the September 30, 2013 investigation were utilized to calculate the effective porosity (specific yield), as described in Table 5.7 below: Table 5.7 Effective Porosity (Specific Yield) Based on Field Capacity Boring Identifier Sample Identifier Porosity Field Capacity at 0.1 bar (%)

Effective Porosity (%)

GT2-MW-01S GT2-MW-01S-5 33.2 10.4 22.8 GT2-MW-01S GT2-MW-01S-20 29.7 3.6 26.1 GT2-MW-01S GT2-MW-01S-28 31.6 6.5 25.1 GT2-MW-02S GT2-MW-02S-5 33.4 10.3 23.1 GT2-MW-02S GT2-MW-02S-26 36.9 8.9 28.0 GT2-MW-06S GT2-MW-06S-5 39.3 3.9 35.4 GT2-MW-06S GT2-MW-06S-20 42.7 2.9 39.8 Arithmetic mean 35.3 6.6 28.6 The average effective porosity value of 28.6% is appropriate to use for RESRAD models.

5.5.1.Effective Porosity with Respect to Flow through a Porous Medium The second definition of the term "effective porosity" refers to the portion of porosity that is interconnected and allows the flow of groundwater. The average velocity of groundwater can be expressed as (23 pp. 121

-122): V = Q/nA = q

/n where: V is the average groundwater velocity (m/s)

Q is the volumetric flow rate (m 3/s) q is the specific discharge (m/s) n is the volumetric porosity A is the cross sectional area (m

2)

However, part of the fluid in the pore space is immobile due to adhesion between the solid surface and the molecules of the fluid or when the porous medium includes a large number of dead

-end pores. In this case, the effective porosity with respect to flow through a porous medium is defined as:

e where: V is the average groundwater velocity (m/s) q is the specific discharge (m/s) e is the effective porosity (m 3/ m 3) e e (25 p. 36). Since the average groundwater velocity is inversely proportional to the effective porosity, smaller values of effective porosity are conservative. Based on the average total porosity of 35% described above, a conservative estimate of the effective porosity with respect to flow through a porous medium is 35 x 0.80 = 28

%.

The effective porosity value of 28% is appropriate to use for the Disposal Unit Source Term (DUST) models. 5.6.Contaminated/

Saturated Zone Hydraulic Conductivity Soil samples were collected in December 2012 and September 2013 for hydraulic conductivity analysis using a flexible wall permeameter. The hydraulic conductivity results are shown in Table 5.8 below.

Table 5.8 Hydraulic Conductivity Determined by Laboratory Analysis of Soil Samples Boring Location Sample Identifier Hydraulic Conductivity Saturated Zone Hydraulic Conductivity (cm/s) (m/y) (cm/s) (m/y) GT MW 01s S-121212-LP-01 (S-01) 5.10E-03 1.61E+03 - - - - GT MW 01s S-121212-LP-02 (S-02) 5.60E-03 1.77E+03 5.60E-03 1.77E+03 GT MW 01s S-121212-LP-03 (S-03) 9.10E-03 2.87E+03 9.10E-03 2.87E+03 GT MW 02s S-121212-LP-04 (S-04) 3.30E-03 1.04E+03 - - - - GT MW 02s S-121212-LP-05 (S-05) 2.40E-03 7.57E+02 2.40E-03 7.57E+02 GT2-MW-01S GT2-MW-01S-5 5.36E-03 1.69E+03 - - - - GT2-MW-01S GT2-MW-01S-20 3.94E-03 1.24E+03 3.94E-03 1.24E+03 GT2-MW-01S GT2-MW-01S-28 3.13E-02 9.88E+03 3.13E-02 9.88E+03 GT2-MW-02S GT2-MW-02S-5 1.26E-03 3.98E+02 - - - - GT2-MW-02S GT2-MW-02S-26 1.96E-03 6.19E+02 1.96E-03 6.19E+02 GT2-MW-06S GT2-MW-06S-5 1.04E-02 3.28E+03 - - - - Geometric Mean 4.85 E-03 1.53E+03 5.56 E-03 1.75E+03 Single well response tests were performed on monitoring wells in September 2013. The single well response tests were performed by introducing an aluminum slug into each well and recording the water level in the well as it equilibrated with the water table. The results of the slug tests are provided in Table 5.9 below.

Table 5.9 Hydraulic Conductivity Determined by Single Well Response Test Well ID Test Type Analytical Method Saturated Zone Hydraulic Conductivity (cm/s) (m/y) MW-01S Falling Head Hvorslev 3.51E-02 1.11E+04 MW-01S Rising Head Hvorslev 2.46E-02 7.77E+03 MW-02S Falling Head Hvorslev 4.36E-03 1.37E+03 MW-02S Rising Head Hvorslev 4.70E-03 1.48E+03 MW-03S Falling Head Hvorslev 2.51E-03 7.91E+02 MW-03S Rising Head Hvorslev 2.49E-03 7.86E+02 MW-04S Falling Head Hvorslev 7.49E-03 2.36E+03 MW-04S Rising Head Hvorslev 7.16E-03 2.26E+03 MW-06S Rising Head Hvorslev 5.18E-03 1.63E+03 MW-07S Falling Head Hvorslev 5.40E-02 1.70E+04 MW-07S Rising Head Hvorslev 2.18E-02 6.88E+03 Geometric mean 9.11E-03 2.88E+03 The geometric mean of the single well response tests is 2.88E+03 m/y. This result is generally consistent with laboratory permeater tests on soil samples collected in December 2012 and September 2013.

These data are also in the range of hydraulic conductivity for a sand material based on literature values.

The single well response tests are considered to better represent in situ aquifer conditions than laboratory permeater tests.

5.7.Saturated Zone Hydraulic Gradient Hydraulic gradients were estimated for areas in the central plant area (east of the Turbine Building), the southern plant area (which is generally unaffected by the sheet pile wall) and the western area (upgradient of the PA). The resulting hydraulic gradients are described in Table 5.10 below: Table 5.10 Hydraulic Gradient Date Western Area Gradient (near MW-ZN-06s) Southern Area Gradient (near MW-ZN-05s) Central Area Gradient (near MW-ZN-01s) July 2006 0.0015 0.0054 0.0000 - 0.0040 October 2007 0.0016 0.0050 0.0000 - 0.0042 September 2008 0.0020 0.0059 0.0000 - 0.0038 September 2009 0.0012 0.0027 0.0000 - 0.0038 September 2010 0.0019 0.0059 0.0000 - 0.0040 September 2011 0.0021 0.0056 0.0000 - 0.0022 Table 5.10 Hydraulic Gradient Date Western Area Gradient (near MW-ZN-06s) Southern Area Gradient (near MW-ZN-05s) Central Area Gradient (near MW-ZN-01s) September 2012 0.0022 0.0044 0.0000 - 0.0053 March 2013 0.0022 0.0056 0.0000 - 0.0042 Average 0.0018 0.0051 0.0000 - 0.0039 Note: The central area is that region that includes the Protected Area of the Site.

The RESRAD model may be used for scenarios where the sheet pile wall is in place (using a conservative gradient of 0.0039 ft/ft

). Alternately, if the scenario assumes that the sheet pile wall has been removed or degraded over time, the natural gradient downgradient of the PA is expected to be 0.0051 ft/ft. 5.8.Groundwater Velocity The groundwater velocity can be calculated by the equation:

v= where: K is the hydraulic conductivity i is the hydraulic gradient T is the total soil porosity Groundwater velocities for different scenarios are provided in Table 5.11 below.

Table 5.11 Estimates of Groundwater Velocity Scenario Hydraulic Gradient Groundwater Velocity (m/y) Assuming structures and basements remain in place 0.0039 31.8 Assuming structures and basements are removed 0.0051 41.6 Notes: 1. Using a hydraulic conductivity of 2.88E+03 m/y and a total porosity of 35.3%

5.9.Precipitation The average precipitation for the Site was estimated using weather information from the Waukegan Harbor station (WHRI2), located approximately 5 miles south of the Site, for the period from 2003 through 2012. Table 5.12 presents a summary of the precipitation data:

Table 5.12 10-Year Average Precipitation Year Precipitation (inches) (26) Precipitation (meters) 2012 26.87 0.682 2011 38.28 0.972 2010 30.21 0.767 2009 42.50 1.080 2008 37.69 0.957 2007 32.72 0.831 2006 32.92 0.836 2005 20.63 0.524 2004 33.98 0.863 2003 30.34 0.771 Average 32.61 0.828 Standard Deviation 6.19 0.157 Notes: 1. Waukegan Harbor Station (WHRI2) 5.10.Runoff Coefficient A runoff coefficient value of 0.2 is identified as the RESRAD default value. Site

-specific runoff coefficients can be developed based on soil type and land use based on the information provided in Table 5.13: Table 5.13 RESRAD Runoff Coefficients Environment Coefficient Value Agriculturalf Flat land with average slopes of 0.3 to 0.9 m/mi c 1 0.3 Hilly land with average slopes of 46 to 76 m/mi c 1 0.1 Rolling land with average slopes of 4.6 to 6.1 m/mi c 1 0.2 Intermediate combinations of clay and loam c 2 0.2 Open sandy loam c 2 0.4 Tight, impervious clay c 2 0.1 Cultivated lands c 3 0.1 Woodlands c 3 0.2 Urban Flat, residential area

- about 30% impervious C r 0.4 Moderately steep, residential area

- about 50% impervious C r 0.65 Moderately steep, built

-up area - about 70% impervious C r 0.8 Notes: fThe runoff coefficient for an agricultural environment is given by C r = 1 - c 1 - c 2 - c 3 (18 pp. E-7).

A Site-specific runoff coefficient for the post

-decommissioning land use of 0.2 has been estimated based on an agricultural environment with flat land, open sandy loam, and cultivated lands (1 - 0.3 - 0.4 -

0.1 = 0.2). A runoff coefficient of 0.2 is appropriate for the Site because it is consistent with the proposed post

-decommissioning land use of the Site and is also the broadly applicable default value.

Additionally, the RESRAD runoff coefficient appears to be based on the "Rational Method" for calculating peak flows from small watersheds. Tables of runoff coefficients for the Rational Method should be compatible with RESRAD and may be used to develop different model scenarios (27) (12 pp. 61-62). 5.11.Well Pump Intake Depth The model scenario includes a hypothetical well installed in the shallow sand aquifer with a pump intake at the base of the aquifer. Based on the "Thickness of Contaminated Zone" parameter (Section 5.1), the pump intake depth is 33.44 ft (10.19 meters) for this scenario.

5.12.Contaminated Fraction Below Water Table The contaminated fraction below the water table is based on the CSM. The following two scenarios are evaluated:

Scenario 1 - contaminated zone from water table to top of aquitard Scenario 2 - contaminated zone from ground surface to top of aquitard

Under the current CSM, Scenario 1 is the preferred alternative.

5.12.1.Scenario 1 - Contaminated Zone from Water Table to Top of Aquitard This scenario assumes that contamination extends from the water table to the top of the Silty Clay Aquitard at the base of the Shallow Aquifer. The contaminated fraction below the water table under this scenario is 100%.

5.12.2.Scenario 2 - Contaminated Zone from Ground Surface to Top of Aquitard This scenario assumes that contamination extends from the ground surface to the top of the Silty Clay Aquitard at the base of the Shallow Aquifer. The contaminated fraction below the water table can be estimated using the boring logs for the wells situated immediately downgradient from the central plant area. This is summarized in Table 5.14:

Table 5.14 Contaminated Fraction Below the Water Table Boring Ground Surface (ft amsl) Groundwater Surface on March 13, 2013 (ft amsl) Aquitard Surface (ft amsl) Fraction Below the Water Table MW-ZN-01S 591.43 578.95 562.18 57% MW-ZN-02S 591.21 579.43 555.21 67% MW-ZN-03S 591.54 579.72 556.54 66% MW-ZN-04S 591.01 579.47 557.51 66% Average 64% Section 6.0References

1. Great Lakes Information Network. Lake Michigan Facts and Figures. October 15, 2013.

2. Klein, David H.

Fluxes, Residence Times, and Sources of Some Elements to Lake Michigan. Water, Air, and Soil Pollution. Dordrecht, Holland : D. Reidel Publishing Company, 1975. Vol. 4.

3. Government of Canada and U.S. Environmental Protection Agency. The Great Lakes: An Environmental Atlas and Resource Book, Third Edition. 1995.

4. Bhowmik, Nani G., et al., et al. Velocity Distribution at Two Sites Within the Southern Basin of Lake Michigan. Champaign : Illinois State Water Survey, 1991. Report of Investigation 115.

5. Dames and Moore. Report: Foundation Investigation, Proposed Nuclear Power Plant, Zion, Illinois (Rough Draft). October 9, 1967.

6. Commonwealth Edision Company. Zion Station Updated Final Safety Analysis Report (UFSAR). May 1996.

7. Sargent & Lundy Engineers.

Drawing B-7: Crib House - Sheet Pile Wall Plan & Elevation, Zion Station Unit 1&2, Commonwealth Edison Co., Chicago, Illinois. 1969.

8. ArcelorMittal.

Piling Handbook, 8th edition. 2008.

9. Clark, Gene, et al., et al.

Duluth-Superior Harbor Freshwater Corrosion Update. s.l.

Minnesota Sea Grant, University of Minnesota, November 2009.

10. Revie, R Winston.

Uhlig's Corrosion Handbook, Second Edition. New York, NY : Wiley Interscience, 2000.

11. Grubb, Stuart. Analytical Model for Estimation of Steadystate Capture Zones of Pumping Wells in Confined and Unconfined Aquifers. Groundwater. January 1993. Vol. 31, 1.

12. Fetter, C.W.

Applied Hydrogeology, 3rd Edition. New York : Macmillan, 1994.

13. U.S. Army Corps of Engineers. Great Lakes Water Level Table for Lake Michigan/Huron, 1918-1950. 2004.

14. -. Great Lakes Water Level Table for Lake Michigan/Huron, 1951-1980. 2004.

15. -. Great Lakes Water Level Table for Lake Michigan/Huron, 1981-2013. 2013.

16. Frizell, Kathleen H., Ruff, James F. and Mishra, Subhendu.

Simplified Design Guidelines for Riprap Subjected to Overtopping Flow. s.l. : U.S. Department of the Interior, Hydraulic Investigations and Laboratory Services Group , 1999.

17. Roberts, Wyndham J. and Stall, John B.

Lake Evaporation in Illinois. Urbana, Illinois

Illinois State Water Survey, 1967. Report of Investigation 57.

18. Yu, C., et al., et al. User's Manual for RESRAD, Version 6. s.l. : U.S. Department of Energy, July 2001.

19. Yu, C., et al., et al.

Data Collection Handbook to Support Modeling Impacts of Radioactive Material in Soil. Argonne, Illinois : Argonne National Laboratory, April 1993.

20. Romano, N. and Santini, A. Field. Methods of Soil Analysis, Part 4, Physical Methods. Madison : Soil Science Society of America, 2002.

21. Nachabe, M. H. Refining the Definition of Field Capacity in the Literature. Journal of Irrigation and Drainage Engineering. s.l. : American Society of Civil Engineers, August 1998. Vol. 124, 4.

22. International Atomic Energy Agency. Field Estimation of Soil Water Content A Practical Guide to Methods, Instrumentation and Sensor Technology. Vienna : s.n., February 2008.

23. Bear, Jacob.

Dynamics of Fluids in Porous Media. New York

Dover Publications, Inc., 1972.

24. Yu, C., et al., et al.

User's Manual for RESRAD-OFFSITE, Version 2. s.l. : U.S. Department of Energy, July 2007.

25. de Marsily, Ghislain.

Quantitative Hydrogeology: Groundwater Hydrology for Engineers. s.l. : Academic Press, Inc., 1986.

26. Weather Underground. Weather History for Waukegan, IL. April 12, 2013.

27. Kuichling, Emil and Hering, Rudolph. The Relation Between the Rainfall and the Discharge of Sewers in Populous Districts. With Discussion by Rudolph Hering. s.l. : American Society of Civil Engineers, 1889.

28. USDA Natural Resources Conservation Service. Soil Quality Indicators. June 2008.

29. Zion Station.

Un-Fueled Safety Analysis Report. July 1995.

30. Eid, Ratep (Boby) Abu. Decommissioning Survey and Site Characterization Issues and Lessons Learned. Presentation at the Workshop on Radiological Characterization for Decommissioning, Studsvik, Sweden. s.l. : U.S. Nuclear Regulatory Commission, April 2012.

31. U.S. Nuclear Regulatory Commission.

Standard Format and Content of License Termination Plans for Nuclear Power Reactors, Regulatory Guide 1,179, rev.1. June 2011.

32. -. NRC's Review Process and Expectations for Dose Assessment. Slides presented at NRC Public Meeting with NASA to discuss options for demonstrating compliance with NRC Requirements for Plum Brook Sediments. September 3, 2008. ML08259042. 33. -. Characterization, Survey, and Determination of Radiological Criteria. Consolidated Decommissioning Guidance. September 2006. Vol. 2. NUREG-1757 rev. 1. 34. -. Results of Evaluations for Realistic Exposure Scenarios. Results of the License Termination Rule Analysis, Attachment 6. May 2, 2003. SECY-03-0069. 35. -. Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM). August 2000. NUREG-1575 rev. 1.

36. -. Use of Rubblized Concrete Dismantlement to Address 10 CFR 20, Subpart E, Radiological Criteria for License Termination. February 14, 2000. SECY-00-0041.

37. Battelle Pacific Northwest Laboratories. Technical Basis for Translating Contamination Levels to Effective Dose Equivalent. Residual Radioactive Contamination from Decommissioning. s.l. : U.S. Nuclear Regulatory Commission, 1992. Vol. 1. NUREG/CR-5512, PNL-7994,.

38. Whitman, Christine T and Meserve, Richard A.

Memorandum of Understanding Between the Environmental Protection Agency and the Nuclear Regulatory Commission: Consultation and Finality on Decommissioning and Decontamination of Contaminated Sites. s.l. : U.S.

Environmental Protection Agency and U.S. Nuclear Regulatory Commission, October 9, 2002. OSWER 9295.8-06a.

39. U.S. Environmental Protection Agency. Example Exposure Scenarios. Washington, DC : s.n., April 2004.

40. -. Calculating Upper Confidence Limits for Exposure Point Concentrations at Hazardous Waste Sites. December 2002. OSWER 9285.6-10. 41. -. Risk Assessment Guidance for Superfund: Volume III - Part A, Process for Conducting Probabilistic Risk Assessment. December 2001. EPA 540-R-02-002.

42. U.S. Government Printing Office. Radiological Criteria for Unrestricted Release. U.S. Code of Federal Regulations. July 25, 2013. Title 10, Part 20.1402. 43. -. National Primary Drinking Water Regulations. U.S. Code of Federal Regulations. July 1, 2010. Title 40, Part 141. 44. -. National Secondary Drinking Water Regulations. U.S. Code of Federal Regulations. July 1, 2010. Title 40, Part 143.

45. Commonwealth Edison Company. Zion Station Historical Site Assessment. 1999.

46. Conestoga-Rovers & Associates, Inc.

Hydrogeologic Investigation Report, Fleetwide Assessment, Zion Station, Zion, Illinois, Revision 1. September 2006. 045136(22).

47. County Board, Lake County, Illinois. Regional Framework Plan. February 13, 2007.

48. Illinois Pollution Control Board.

Illinois Administrative Code Title 35 Part 742 Tiered Approach to Corrective Action Objectives. 2013.

49. Natural Resources Conservation Service.

Urban Hydrology for Small Watersheds, TR-55. s.l. : U.S. Department of Agriculture, June 1986.

50. Klocke, Norman L. and Hergert, Gary W.

G90-964 How Soil Holds Water. Historical Materials from University of Nebraska

-Lincoln Extension. s.l. : University of Nebraska-Lincoln, 1990.

51. Werner, Hal. Measuring Soil Moisture for Irrigation Water Management. Brookings : South Dakota State University, April 2002.

52. Karkanis, P. G.

Determining Field Capacity and Wilting Point Using Soil Saturation by Capillary Rise. Canadian Agricultural Envineering. 1983. Vol. 25, 1.

Appendix A August 2012 Subsurface Investigation to Determine Site Specific Partition Coefficient (Kd) Values Letter Report (dated September 17, 2012)

September 17, 2012 Reference No. 054638 Mr. Robert Decker ZionSolutions, LLC 101 Shiloh Blvd Zion, IL 60099

Dear Mr. Decker:

Re: Subsurface Investigation to Determine Site-Specific Partition Coefficient (K d) Values Zion Nuclear Power Station Decommissioning Project Conestoga-Rovers & Associates (CRA) was retain ed by ZionSolutions, LLC (ZionSolutions) for hydrogeology consulting services related to the decommissioning of the Zion Nuclear Power Station in Zion, Lake County, Illinois (Site). On August 20-21, 2012, CRA participated in a subsurface investigation to collect samples for laboratory analysis of Site-specific partition coefficients (K d) for cobalt (60Co), cesium (137Cs), strontium (90 Sr), iron (55Fe), and nickel (63 Ni).

The subsurface investigation included the advancement of three soil borings in the vicinity of existing monitoring wells on the eastern portion of the Site. The location of each soil boring is described in the following table:

Identifier Narrative Location Northing Easting Kd-SB-MW-1s Approximately 28 feet east of MW-1s 641831.57 343806.08 Kd-SB-MW-2s Approximately 10 feet north of MW-2s 641785.68 343788.49 Kd-SB-MW-3s Approximately 12 feet northwest of MW-3s 641725.42 343770.03 Drilling services were provided by Direct Push Analytical Corp. of St. Charles, Illinois using a Geoprobe 7822DT track mounted rig. Samples we re collected continuous ly using a 2.25-inch outer diameter by 48-inch probe rod equipped with polyethylene terephthalate (PETG) liners.

The borings were logged by a CRA geologist. Th e boring logs are provided in Attachment 1.

Soil samples were selected for laboratory analysis based on the professional judgment of the field geologist to be representative of the following stratigraphic units at the Site:

Fill Sand - Sand which originated as natural beach sand excavated during the construction of the facility in the early 1970s and then returned to the excavation as fill

material; Native Sand - Beach sand which was not disturbed by construction activities at the facility; and, September 17, 2012 2 Reference No. 054638 Silts and Clays - Low permeability deposits of natural lake bottom and glacial till material which underlie the upper sand units.

The following soil samples were selected for laboratory analysis:

Boring Depth Interval (feet bgs) Sample Number Stratigraphic Unit Kd-SB-MW-01s 12-16 L112102CJGSSB001B fill sand (saturated) Kd-SB-MW-01s 24-28 L112102CJGSSB001C native sand (saturated) Kd-SB-MW-01s 32-36 L112102CJGSSB001D silt Kd-SB-MW-03s 24-28 L212204CJGSSB002C silt and clay The samples were screened for radiological contamination in accordance with ZionSolutions' standard operating procedures prior to shipment to the Brookhaven National Laboratory via overnight courier.

If you have any questions or comment, please feel free to contact me by email (dsoutter@craworld.com) or telephone (773-380-9933).

Yours truly, CONESTOGA-ROVERS & ASSOCIATES Douglas G. Soutter DS/ko/1 Encl.

cc: Phil Harvey, CRA ATTACHMENT 1

Appendix B December 12, 2012 Geotechnical Subsurface Investigation Letter Report (dated March 1, 2013, revised January 14, 2014)

January 14, 2014 Reference No. 054638 Mr. Robert Decker ZionSolutions, LLC 101 Shiloh Blvd Zion, IL 60099

Dear Mr. Decker:

Re: December 12, 2012 Geotechnical Subsurface Investigation Zion Nuclear Power Station Decommissioning Project Revision 1 Conestoga-Rovers & Associates (CRA) was retained by ZionSolutions, LLC (ZionSolutions) for hydrogeology consulting services related to the decommissioning of the Zion Nuclear Power Station in Zion, Lake County, Illinois (Site). On December 12, 2012, CRA participated in a subsurface investigation to collect samples for laboratory analysis of the following geotechnical parameters: porosity, bulk density, particle density, hydraulic conductivity, and grain size.

The subsurface investigation included the advancement of two soil borings in the vicinity of existing monitoring wells on the eastern portion of the Site. The location of each soil boring is described in the following table:

Boring Narrative Location GT-MW-0 1s Approximately 3 feet north of Kd

-SB-MW-1s GT-MW-0 2s Approximately 3 feet north of Kd

-SB-MW-2s Drilling services were provided by Direct Push Analytical Corp. of St. Charles, Illinois using a Geoprobe track mounted rig. Samples were collected continuously using a 2.25-inch outer diameter by 48

-inch probe rod equipped with polyethylene terephthalate (PETG) liners. The borings were logged by a CRA geologist. The boring logs are provided in Attachment 1.

Five (5) soil samples were selected for geotechnical analysis based on stratigraphic observations made during the August 2012 Site-specific partition coefficient subsurface investigation. The pre-determined soil sample depths were intended to target the following stratigraphic units at the Site: Fill Sand - Sand which originated as natural beach sand excavated during the construction of the facility in the early 1970s and then returned to the excavation as fill material.

Native Sand - Beach sand which was not disturbed by construction activities at the facility.

The following soil samples were selected for laboratory analysis:

Boring Depth Interval (feet bgs 1) Sample Identifier Targeted Stratigraphic Unit GT-MW-01s 2-5 S-121212-LP-01 (S-01) fill sand (vadose zone

) GT-MW-01s 16-20 S-121212-LP-02 (S-02) fill sand (saturated zone) GT-MW-01s 24-28 S-121212-LP-03 (S-03) native sand (saturated zone)

GT-MW-02s 2-5 S-121212-LP-04 (S-04) fill sand (vadose zone)

GT-MW-02s 12-16 S-121212-LP-05 (S-05) fill sand (saturated zone)

The samples were screened for radiological contamination in accordance with ZionSolutions' standard operating procedures prior to shipment to CRA's laboratory in Plymouth, Michigan via overnight courier.

Results T he results of the geotechnical analyses of each sample collected are summarized in the tables below. The laboratory report is provided as Attachment 2. The dry soil bulk density results were rejected due to laboratory errors.

Boring Sample Identifier Hydraulic Conductivity (cm/s 2) Porosity (%) Particle Density (unitless)

GT-MW-01s S-121212-LP-01 (S-01) 5.1x10-3 9.25 2.64 GT-MW-01s S-121212-LP-02 (S-02) 5.6x10-3 16.69 2.67 GT-MW-01s S-1 21212-LP-03 (S-03) 9.1x10-3 20.40 2.71 GT-MW-02s S-121212-LP-04 (S-04) 3.3x10-3 23.97 2.74 GT-MW-02s S-121212-LP-05 (S-05) 2.4x10-3 25.66 2.66 Arithmetic mean

- - 19.19 2.68 Geometric mean 4.60x10 - - - 1 bgs - below ground surface.

2 cm/s - centimeters per second.

Boring Sample Identifier Grain Size Distribution % Gravel % Sand % Silt or Clay GT-MW-01s S-121212-LP-01 (S-01) 4.1 84.1 11.8 GT-MW-01s S-121212-LP-02 (S-02) 3.1 90.3 6.6 GT-MW-01s S-121212-LP-03 (S-03) 7.9 89.2 2.9 GT-MW-02s S-121212-LP-04 (S-04) 5.5 73.0 21.5 GT-MW-02s S-121212-LP-05 (S-05) 12.8 77.4 9.8

If you have any questions or comment, please feel free to contact me by email (dsoutter@craworld.com) or telephone (773-380-9933).

Yours truly, CONESTOGA-ROVERS & ASSOCIATES Douglas G. Soutter DS/ko/4 Encl.

cc: Phil Harvey, CRA ATTACHM ENT 1 BORING LOGS

ATTACHM ENT 2 GEOTECHNICAL LABORATORY REPORT

Liquid Plastic Plasticity Maximum %<#200 Class-Water Satur-Void Borehole Size Content Density ation 0 Limit Limit Index Sieve ification Ratio Summary of Laboratory Results CONESTOGA-ROVERS ASSOCIATES CONESTOGA-R.OVERS Average 2.64 T(oe) a CONESTOGA-ROVERS ASTM 1/10/2013 Dry Dry a PT /P20oC Average 2.67 a

CONESTOGA-ROVERS 1/10/2013

=

=

= = PT iP200 C

Average 2.71 T(aG) a CONESTOGA-ROVE.RS ASTM R.

1/10/2013

= = NIA NIA

= = Ip20 D c

Average 2.74 T(De) a CONESTOGA-ROVERS 1/10/2013

a= P T/p20 D c =

Average 2.66 T(aG) a

& ASSOCIATES 54638

______________

__

________________

_

-",5,-' ______________

_ SAMPLED BY: Description of Soil: (SP-SM) SAND, trace silt and gravel Unit Weight Determination:

PERMEABILITY TEST ON GRANULAR SOILS 0 2434 LAB No.: 14-Jan-13 D. Kribs R. Bentley Diameter D (em): 7.62 Moisture content during compaction in the cell: 7% Area A (cm 2): 45.60 Dry Density (Ibfft\ 112.4 Sample height H (em): 15 Ratio of standard Proctor:

1232.2 Particle Size Summarv Percent Finer By Sieve Size Weight 3" a v 3/4" 100 e #4 95.9 S #10 91.4 a #40 81.1 d #200 11.8 Permeability Test Results Test No. Head 'h' Q t(sec) Permeability em em' k (em/sec) 1 106 200 86 0.051 7.067 7.2E-03 2 101 200 107 0.041 6.733 6.1E-03 3 96 200 130 0.034 6.400 5.3E-03 4 91 200 166 .. 0.026 6.067 4.4E-03 5 86 200 194 0.023 5.733 3.9E-03 6 81 200 206 0.021 5.400 3.9E-03 5.1E-03 CONESTOGA-ROVERS ASSOCIATES Zion Former Generating Facility Energy Solutions 54638

-'1,,2,,/1=2/'-'1,,2

_______ _

SAMPLED BY: Description of Soil: (SP-SM) SAND, trace silt and gravel Unit Weight Determination:

PERMEABILITY TEST ON GRANULAR SOILS ASTM D 2434 14-Jan-13 D. Kribs R. Bentley Diameter D (em): 7.62 Moisture content during compaction in the cell: 15% Area A (cm 2):

Dry Density (Ib/te):

Sample height H (em): Ratio of standard Proctor:

Particle Size Summary Percent Finer By Sieve Size a 3/4" a

d Permeability Test Results Test No. Head 'h' Q Permeability em em' k (em/sec)

---

.. CON EST. .OGA-ROVERS & ASSOCIATES Energy Solutions 54638

-'1,,2/-'12"'1-"12=--

______ _

SAMPLED BY: Description of Soil: (SP) SAND, trace silt and gravel Unit Weight Determination:

PERMEABILITY TEST ON GRANULAR LAB No.:

D. Kribs R. Bentley Diameter D (em): 6.35 Moisture content during compaction in the cell: 18% 2): 31.67 Dry Density (lb/ft\

Sample height H (em): Ratio of standard Proctor: Particle Size Summary Percent Finer By Sieve Size 3/4" e d Permeability Test Results Test No. Head 'h' Q t{sec) Permeability k (em/sec) 72 1.1 CONESTOGA-ROVERS

& ASSOCIATES Zion Former Generating Facility 54638

-'1"'2/-'12"'1-"12=---

_______ _ 04 SAMPLED BY: Description of Soil: (SM) Silty SAND, trace gravel Unit Weight Determination:

PERMEABILITY TEST ON GRANULAR ASTM D 2434 LAB No.' 14-Jan-13 D. Kribs R. Bentley Diameter D (em): 7.62 Moisture content during compaction in the cell: 3% Area A (cm 2): 45.60 Dry Density (!b/ft3):

112.9 Sample height H (em): 15 Ratio of standard Proctor:

1237.3 Particle Size Summary Percent Finer By Sieve Size Weight 3" a 3/4" 100 e #4 94.5 S #10 89.7 a #40 78.6 d #200 21.5 Permeability Test Results Test No. Head 'hi Q t(sec) Permeability em em' k(cm/sec) 1 112 200 155 0.028 7.467 3.8E-03 2 107 200 174 0.025 7.133 3.5E-03 3 102 200 193 0.023 6.800 3.3E-03 4 97 200 218 0.020 6.467 3.1E-03 5 92 200 244 0.018 6.133 2.9E-03 6 87 200 265 0.017 5.800 2.9E-03 3.3E-03

& ASSOCIATES PROJECT:

LOCATION:

CLIENT:

PROJECT NO.:

SAMPLE DATE:

_______ _ SAMPLE LOCATION:

SAMPLE No.:

_______ _ SAMPLE DEPTH:

-..:'1,,6_'

-,-______ _ SAMPLED BY: -=L"is"a-'-P-"u"ne"h'---

______ _ Description of Soil: (SP-SM) SAND with gravel, trace silt Unit Weight Determination:

PERMEABILITY TEST ON GRANULAR SOILS ASTM 0 2434 TEST DATE: TESTED BY: LAB No.: CHECKED BY: 14-Jan-13 D. Kribs R. Bentley Diameter 0 (em): 7.62 Moisture content during compaction in the cell: 10% Area A (cm 2): 45.60 Dry Density (lb/ft3):

123.4 Sample height H (em): 15 Ratio of standard Proctor:

1352.4 Particle Size Summary Percent Finer By Sieve Size G 3" a 3/4" 96 I #4 87.2 S #10 80.8 a #40 69.2 d #200 9.8 Permeability Test Results Test No. Head 'h' Q t(sec) Q1At h/L Permeability em em' k(cmfsec) 106 200 210 0.021 7.067 3.0E,()L __ 2 101 200 264 0.017 6.733

__ 3 96 200 284 0.015 6.400 2,£E:2L _4 91 200 317 0.014 6.067 _5 86 200 344 0.013 5.733 6 81 200 369 0.012 5.400 2.2E-03 AVERAGE 2.4E-03

6 4 3 2 1.5 1 3/4 1/2 3/8 3 4 6 81°14162030 405°6010°140200 100 95 I'e. 90 85 80 75 70 65 :c 60 \ s 55 "' \ oc W 50 z G: 45 z W 40 W a. 35 30 25 20 15 10 5 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE DISTRIBUTION CONESTOGA-ROVERS

6 4 3 2 1.5 3/4 1/2 38 3 4 6 81014162030405060100140200 100 T 95 90 .. 85 80 75 70 >-65 \ :r: 60 $: 55 oc UJ 50 z >-45 z UJ ii 40 UJ a. 35 30 25 20 15 10 5 0 100 10 1 0.1 0.01 0.001

6.6 GRAIN

SIZE DISTRIBUTION CONESTOGA-ROVERS

&

6 4 3 2 1.5 1 A 1/2 3/8 3 4 6 81014162030405060100140200 100 [\1 95 90 '1--

85 80 75 70 f-65 Q 60 UJ 55 OJ a:: UJ 50 z f-45 z UJ 40 UJ a. 35 30 25 20 15 10 \ 5 0 100 10 1 0.1 0.01 0.001 GRAIN SIZE DISTRIBUTION CONESTOGA-ROVERS

& 121'-

6 4 3 2 1.5 !'1-1/2 3/8 3 4 6 8 10 14 16 20 30 40 50 60 100 140 200 100 95 r--.. 90 85 80 75 70 >-65 60 \ s >-55 \ m W 50 z u:: >-45 z W \ 40 W a. 35 , 30 25 20 15 10 5 0 100 10 1 0.1 0.01 0.001 GRAIN DISTRIBUTION CONESTOGA-ROVERS

& -

6 4 3 2 1.5 1 3/4 1/23/8 3 4 6 8 10 14 16 20 30 40 50 60 100 140 200 100 1\ 95 90 85 80 ". 75 70 f-65 \ 60 S >-55 W 50 z f-45 z W 40 W a. \ 35 30 25 20 15 10 5 0 100 10 1 0.1 0.01 0.001 J

• 0100 060 030 010

• GRAIN SIZE DISTRIBUTION CONESTOGA-ROVERS 054638

£) & ASSOCIATES eRA Project No. 054638 Sample Date SamplelD Dry Unit Weight (pcf) 12/12/2012 5-01 149.5 12/12/2012 5-02 138.8 12/12/2012 5-03 134.6 12/12/2012 5-04 130 12/12/2012 5-05 123.4 Zion Former Generating Facility Zion,IL Soil Porosity Specific Water Unit Void Ratio Gravity Weight (pcf) 2.64 62.4 0.102 2.67 62.4 0.200 2.71 62.4 0.256 2.74 62.4 0.315 2.66 62.4 0.345 Porosity (%) 9.248737374 16.69067512 20.40401173 23.96593674 25.65548487 Appendix C September 30, 2013 Single Well Response Test Letter Report (dated November 13, 2013)

8615 W. Bryn Mawr Avenue, Chicago, Illinois 60631-3501 Telephone: (773) 380-9933 Fax: (773) 380-6421 www.CRAworld.com November 13, 2013 Reference No.

054638-21 DRAFT Mr. Robert Decker ZionSolutions, LLC 101 Shiloh Blvd Zion, IL 60099

Dear Mr. Decker:

Re: September 30, 2013 Single Well Response Tests Zion Nuclear Power Station Decommissioning Project Conestoga-Rovers & Associates (CRA) was retained by ZionSolutions, LLC (ZionSolutions) for hydrogeology consulting services related to the decommissioning of the Zion Nuclear Power Station in Zion, Lake County, Illinois (Site). On September 30, 2013, CRA performed single well response tests (commonly referred to as slug tests) on four onsite monitoring wells located to the east of the Protected Area (PA) (MW

-ZN-01S, MW-ZN-02S, MW-ZN-03S, MW-ZN-04S) and two monitoring wells located to the west of the PA (MW-ZN-06S, MW-ZN-07S) to determine the hydraulic conductivity of the shallow sand aquifer. Figure 1 presents the monitoring well locations where single well response tests were conducted. The tests were performed using a slug to rapidly change the water level within the monitoring well. The water level within the well during the test was monitored using a pressure transducer and data logger.

CRA evaluated the data collected by the pressure transducer and data logger to determine the hydraulic conductivity using AQTESOLV software. Groundwater level response data and results from the aquifer test analy ses are presented in Attachment A. The Hvorslev method was utilized for analysis.

This method is appropriate for unconfined conditions in sand. The calculated hydraulic conductivities for each test and the geometric mean of these values are presented below: Well ID Test Method Hydraulic Conductivity (ft/sec)[1] Hydraulic Conductivity (cm/sec)[2] Hydraulic Conductivity (m/y)[3] MW-01S Test 1- Falling Hvorslev 1.15E-03 3.51E-02 1.11E+04 MW-01S Test 1- Rising Hvorslev 8.08E-04 2.46E-02 7.77E+03 MW-02S Test 2- Falling Hvorslev 1.43E-04 4.36E-03 1.37E+03 MW-02S Test 2- Rising Hvorslev 1.54E-04 4.70E-03 1.48E+03 MW-03S Test 1- Falling Hvorslev 8.22E-05 2.51E-03 7.91E+02 1 ft/sec - feet per second.

2 cm/sec - centimeters per second.

3 m/y - meters per year.

Table Continued Well ID Test Method Hydraulic Conductivity (ft/sec)[1] Hydraulic Conductivity (cm/sec)[2] Hydraulic Conductivity (m/y)[3] MW-03S Test 1- Rising Hvorslev 8.17E-05 2.49E-03 7.86E+02 MW-04S Test 1- Falling Hvorslev 2.46E-04 7.49E-03 2.36E+03 MW-04S Test 1- Rising Hvorslev 2.35E-04 7.16E-03 2.26E+03 MW-06S Test 2 Rising Hvorslev 1.70E-04 5.18E-03 1.63E+03 MW-07S Test 2- Rising Hvorslev 7.16E-04 2.18E-02 6.88E+03 MW-07S Test 3- Falling Hvorslev 1.77E-03 5.40E-02 1.70E+04 Geometric mean 2.99E-04 9.11E-03 2.88E+03 The geometric mean of the single well response tests is 2.88 E+03 m/y. This result is generally consistent with laboratory permeater tests on soil samples collected in December 2012 and September 2013. The December 2012 hydraulic conductivity laboratory data resulted in a geometric mean of 1.45E+03 m/y and the September 2013 laboratory data resulted in a geometric mean of 1.73E+03 m/y. These data are also in the range of hydraulic conductivity for a sand material based on literature values

. The single well response tests are considered to better represent in situ aquifer conditions than laboratory permeater tests.

If you have any questions or comment, please feel free to contact me by email (dsoutter@craworld.com) or telephone (773-380-9933).

Yours truly, CONESTOGA-ROVERS & ASSOCIATES Douglas G. Soutter

DS/ko/13 Encl. cc: Phil Harvey, CRA 1 ft/sec - feet per second.

2 cm/sec - centimeters per second.

3 m/y - meters per year.

ATTACHM ENT 1 AQTESOLV ANALYSIS

Appendix D September 30, 2013 Geotechnical Subsurface Investigation Letter Report (dated November 15, 2013)

8615 W. Bryn Mawr Avenue, Chicago, Illinois 60631-3501 Telephone: (773) 380-9933 Fax: (773) 380-6421 www.CRAworld.com November 15, 2013 Reference No.

054638-21 DRAFT Mr. Robert Decker ZionSolutions, LLC 101 Shiloh Blvd Zion, IL 60099

Dear Mr. Decker:

Re: September 30, 2013 Geotechnical Subsurface Investigation Zion Nuclear Power Station Decommissioning Project Conestoga-Rovers & Associates (CRA) was retained by ZionSolutions, LLC (ZionSolutions) for hydrogeology consulting services related to the decommissioning of the Zion Nuclear Power Station in Zion, Lake County, Illinois (Site). On September 30, 2013, CRA completed a subsurface geotechnical investigation at the Site. The purpose of the investigation was to collect soil samples for laboratory analysis in an effort to determine Site

-specific values for the following geotechnical parameters:

bulk density, hydraulic conductivity, porosity, and field capacity.

The subsurface investigation included the advancement of three soil borings in the vicinity of existing monitoring wells on the eastern and western portions of the Site.

Figure 1 presents the locations of the three soil borings.

The soil boring identifier and the approximate location of each soil boring is described in the following table:

Table 1 - Boring identifiers and approximate locations Soil Boring Identifier Easting Northing Narrative Location GT2-MW-01s 343 ,798 641 , 834 Approximately 5 feet north of MW

-01s GT2-MW-02s 343,789 641,7 82 Approximately 5 feet north of MW

-02s GT2-MW-06s 343,287 641,724 Approximately 7 feet north of MW

-06s Drilling services were provided by Testing Services Corporation (TSC) of Carol Stream, Illinois using a drill rig equipped with 4.25

-inch inside diameter hollow stem augers

. Samples were collected at select intervals using Shelby tubes when possible. Samples that could not be contained within the Shelby tubes were collected as bagged samples and remolded by the laboratory. Soil samples were also collected for field capacity analysis. The borings were logged by a CRA geologist. The boring logs are provided in Attachment 1.

A total of seven soil samples from the three soil boring locations were selected for geotechnical analysis to confirm the results of prior analyses at the east side of the Site and to acquire geotechnical data from the west side of the Site. The pre-determined soil sample depths were intended to target the following stratigraphic units at the Site:

Fill Sand - Sand which originated as natural beach sand excavated during the construction of the facility in the early 1970s and then was returned to the excavation as fill material.

Native Sand - Beach sand which was not disturbed by construction activities at the facility. The following soil samples were selected for laboratory analysis:

Table 2 - Selection of samples for analysis Soil Boring Identifier Target Depth Interval (feet bgs) 1 Sample Identifier Target Stratigraphic Unit GT2-MW-01s 2-5 GT2-MW-01S-5 fill sand (vadose zone

) 16-20 GT2-MW-01S-20 fill sand (saturated zone) 24-28 GT2-MW-01S-28 native sand (saturated zone)

GT2-MW-02s 2-5 GT2-MW-02S-5 fill sand (vadose zone) 12-26 GT2-MW-02S-26 fill sand (saturated zone)

GT2-MW-06s 2-5 GT2-MW-06S-5 native sand (vadose zone) 16-20 GT2-MW-06S-20 native sand (saturated zone)

The samples were screened for radiological contamination in accordance with ZionSolutions' standard operating procedures prior to hand delivery to TSC's laboratory in Carol Stream. Soil samples were shipped to Agvise Laboratory (Agvise) in Northwood, North Dakota via overnight courier.

Results The laboratory reports are provided as Attachment 2. Hydraulic conductivity, porosity , and bulk density values were determined by TSC. Field capacity valu es were determined by Agvise.

The following presents an overview of the results compared to literature values.

Hydraulic Conductivity

The hydraulic conductivity for sand is expected to be between 3E-04 to 3E-03 centimeters per second (cm/s) or 1E+02 and 1E+05 meters per year (m/y) based upon the Argonne National Laboratory (ANL) Data Collection Handbook (Yu, et al., 1993). The geometric mean of the laboratory results is 1.73E+03 m/y, which falls within the expected range. The laboratory results are summarized in Table 3 below.

1 bgs - below ground surface

Soil Porosity The Illinois Tiered Approach to Corrective Action Objectives (TACO) default value for the total porosity of sand is 32% by volume. Fetter (Fetter, 1994) lists a range of 25 to 50% for well sorted sand or gravel. The arithmetic mean of the laboratory porosity values is 35.3%, which falls within the range of literature values.

Bulk Density

The Illinois TACO default value for the dry bulk density of sand is 1.8 kg/L or 112.4 pounds per cubic foot (pcf). The arithmetic mean of the laboratory bulk density values is 1.82 g/cm 3 (113.6 pcf), which is similar to the literature value. Table 3 - Hydraulic conductivity, bulk density, and porosity Soil Boring Identifier Sample Identifier Hydraulic Conductivity (cm/s) Hydraulic Conductivity (m/y) Porosity Bulk Density (pcf) (%) GT2-MW-01S GT2-MW-01S-5 5.36E-03 1.69E+03 33.2 112.6 GT2-MW-01S GT2-MW-01S-20 3.94E-03 1.24E+03 29.7 118 GT2-MW-01S GT2-MW-01S-28 3.13E-02 9.88E+03 31.6 115.3 GT2-MW-02S GT2-MW-02S-5 1.26E-03 3.98E+02 33.4 118.4 GT2-MW-02S GT2-MW-02S-26 1.96E-03 6.19E+02 36.9 112.5 GT2-MW-06S GT2-MW-06S-5 1.04E-02 3.28E+03 39.3 102.2 GT2-MW-06S GT2-MW-06S-20 8.77E-03 2.77E+03 42.7 116.2 Arithmetic mean

- - - - 35.3 113.6 Geometric mean 5.48E-03 1.73E+03 - - - - Soil Water Retention Curves and Field Capacity Field capacity is defined as the ratio of the volume of water retained in the soil sample, after all

downward gravity drainage has ceased, to the total volume of the sample. For most soils, the field capacity corresponds to a negative pressure of 0.1 bar (sand), 0.2 bar (silty clay loam), or 0.3 bar (loam)

(Klocke & Hergert, 1990). Laboratory measurements of field capacity typically use a negative pressure of 1/3 bar (Nachabe, 1998). A volumetric water content greater than the field capacity is not available for plant use because it drains away quickly. The wilting point is the maximum pressure that a plant can exert to overcome the tension of the water adhering to the soil. The wilting point corresponds to a negative pressure of 15 bars.

Typical field capacity values range from 2.8% to 3.9%

1 for sand and loamy sand, respectively (USDA Natural Resources Conservation Service, 2008). The arithmetic mean of the laboratory values for field capacity is 2.7% by volume. Soil water retention curves were developed using the water content under negative pressures of 0

-15 bar. The soil water retention curves are included in Attachment 3.

Table 4 - Field Capacity Soil Boring Identifier Sample Identifier Field Capacity (%)

0.1 bar 1/3 bar GT2-MW-01S GT2-MW-01S-5 10.4 4.7 GT2-MW-01S GT2-MW-01S-20 3.6 1.2 GT2-MW-01S GT2-MW-01S-28 6.5 2.5 GT2-MW-02S GT2-MW-02S-5 10.3 4.1 GT2-MW-02S GT2-MW-02S-26 8.9 3.8 GT2-MW-06S GT2-MW-06S-5 3.9 1.8 GT2-MW-06S GT2-MW-06S-20 2.9 1.0 Arithmetic mean 6.64 2.73 References Fetter, C. (1994). Applied Hydrogeology, 3rd Edition. New York: Macmillan.

Klocke, N. L., & Hergert, G. W. (1990). G90

-964 How Soil Holds Water. Historical Materials from University of Nebraska

-Lincoln Extension. University of Nebraska

-Lincoln. Nachabe, M. H. (1998, August). Refining the Definition of Field Capacity in the Literature. Journal of Irrigation and Drainage Engineering, 124(4). American Society of Civil Engineers.

USDA Natural Resources Conservation Service. (2008, June). Soil Quality Indicators.

Yu, C., Loureiro, C., Cheng, J. J., Jones, L. G., Wang, Y. Y., Chia, Y. P., & Faillace, E. (1993, April). Data Collection Handbook to Support Modeling Impacts of Radioactive Material in Soil. Argonne, Illinois: Argonne National Laboratory.

1 1 to 1.4 inches of water per foot of soil assuming a soil porosity of 30% (1/(12x3)=2.8% or 1.4/(12x3)=3.9%).

If you have any questions or comment, please feel free to contact me by email (dsoutter@craworld.com) or telephone (773-380-9933). Yours truly, CONESTOGA-ROVERS & ASSOCIATES Douglas G. Soutter

DS/ko/12 Encl.

cc: Phil Harvey, CRA

ATTACHM ENT 1 BORING LOGS

ATTACH MENT 2 GEOTECHNICAL LABORATORY REPORTS TSC CLIENT:Conestoga R overs & Associates8615 W. Bryn Mawr Ave.Chicago, IL 60631PROJECT:L-80,843Exploratory Soil Borings Zion Solutions

Zion, IllinoisSOIL TESTING

SUMMARY

BoringLocationSampleNumberDepth(Feet)SoilType MC%Density(Bulk)pcfSpecificGravity(Est)Porosity(N)HydraulicConductivitycm/secGT 2MW-01S15SM4.8112.62.733.25.36 x 10

-3GT 2MW-01S220SP10.9118.02.729.73.94 10

-3GT 2MW-01S328SP - SM13.7115.32.731.63.13 x 10

-2GT 2MW-02S15SP - SM5.5118.42.733.41.26 x 10

-3GT 2MW-02S226SP - SM5.8112.52.736.91.96 x 10

-3GT 2MW-06S15SM4.3102.22.739.31.04 x 10

-2GT 2MW-06S220SP - SM20.6116.22.742.78.77 x 10

-3MCMoisture Content Est Estimated Specific Gravity NPorosity AGVISE

ATTACHMENT 3 SOIL WATER RETENTION CURVES

0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-01s-5 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-01s-20 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-01s-28 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-02s-5 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-02s-26 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-06s-5 0 0 5 10 15 20 25 300.1 1 10100100010000100000Moisture (%)

Pressure (cm H2O)

GT2-MW-06s-20 0