2022-12-21_PERMIT FILE - M2022001

• Permit No: M2022001
• IBM Index Class Name: Permit File
• Doc Date: 12/21/2022
• Doc Name Note: Response No 7
• Doc Name: Adequacy Review Response
• From: Red Tierra Equities, LLC/Civil Resources, LLC
• To: DRMS
• Email Name: PSH
• Email Name: JLE
• Media Type: D
• Archive: No

Table 6
Base Model and Modeled Site Groundwater Level Full Buildout Both Sites
Full Buildout and
Mitigation Difference From
Location Baseline All SW Baseline Conditions
Patnd a House 47363 4736.0 -0 33
Cline House 47368 4737.3 050
Harding House 4736.6 47378 1.25
Wiedeman House 13434 47382 4739.6 140
Madman House 13218 4738.5 4738.1 -0.40
Sharp House 47384 47380 -0.44
HS Land and Cattle 47326 4732.1 -0.50
Karbowski Brave House 4725.5 47229 -2 55
Schmidt Well 4714.4 4708.9 -5 54
United Well 4712.0 4706.3 -5.69
Owens Well 4714.2 47102 400
Wright House 47174 4711 1 -6 30
Schmidt House 47184 47153 -3.10
Smit House 47188 4716.5 -2 30
Kissler House 47295 47294 -010
Woolverton House 4730.8 47307 -010
Shimon House 4733.0 47331 0.10
Kern House 47338 4733.9 010
Rainbolt House 4735.9 47360 008
Gilcrest Valley HS 4737.0 47366 -0 37
6.3.2 Mitigation Scenario 2—Discharge to Infiltration Pond
Scenario 2 is similar to Scenario 1 in that it uses the Drain and Well Packages to remove water from the model.
Scenario 2 then utilizes the Recharge Package to add the approximate amount of water removed back to the model in
the cells north of Cell 7 to simulate an infiltration pond in that location. Discharging to an infiltration pond located onsite
is the recommended scenario because it will allow all infrastructure to be constructed inside of the DRMS Affected Area
boundary and has the added benefit of mitigating the drop of groundwater head elevations to the north of the site as a
result of slurry wall obstruction.
6.3.2.1 Phase 1
In addition to the underdrain or dewatering wells discussed in Section 6.3.1.1,the infiltration pond will be constructed
prior to the Cell 4 slurry wall and the underdrain or dewatering wells. Water is removed from the system by the
dewatering wells or underdrain and piped to a manhole located towards the southern end of the site west of the Western
Mutual Ditch. Water is then piped north through the middle of the site to the infiltration pond. The infiltration pond is
expected to be five(5)acres in size, approximately twenty-five(25)feet in depth north of Cell 7, and completed in native
aggregate. The recharge rate for the pond area was set to 0.705 feet per day which resulted in 281,044 cubic feet per
day of recharge or 3.25 cubic feet per second,which corresponds to the amount of water removed by the Well Package.
Figure 11 depicts the site layout for this phase and the head contours. Table 7 shows the groundwater head elevation
for the wells to the north of the site:
Groundwater Model Report—Section 20 Gravel Mine Site -12- August 2022