2023-01-10_PERMIT FILE - M2023001 ‎(12)‎

• Permit No: M2023001
• IBM Index Class Name: Permit File
• Doc Date: 1/10/2023
• Doc Name Note: Exhibit G - Water Information
• Doc Name: Application
• From: J-2 Contracting Company
• To: DRMS
• Email Name: PSH
• Email Name: JLE
• Media Type: D
• Archive: No

Fair Meadows Pit Groundwater Evaluation
November 19, 2022 Page 2 of 28
A detailed discussion of the Hydrogeologic analysis, model parameter selection and assumptions,
and discussion of the model results and their sensitivity and uncertainty are included in Appendix
A - Groundwater Evaluation and Modeling.
Results
We used the USGS MODFLOW2000 (Harbaugh et al, 2000) modeling program to evaluate the
existing and future groundwater conditions at the Fair Meadows pit. Using reasonable boundary
conditions and aquifer properties, the model predicts that water levels will rise up to +2.5 feet on
the up-gradient (northwest) corner of the pit (Figure A9). Mounding up to 1 ft high can be
expected within approximately 1000 feet north and west of the mine property. The downstream
shadowing effect is constrained within an approximately 1,000 foot wide zone between the pit and
the Poudre River, and shadowing does not exceed approximately -1.5 ft. There are no registered
production (non-monitoring) wells that are within the area of+/- 1 foot change. Well permit no.
28964 registered to Robert Davis is located in the northwest corner of the Mine property.
However, according to the mine engineer (J&T), the Davis property is now owned by the mine
and they intend to abandon the well.
To evaluate potential high water caused by the slurry wall, we identified 16 registered wells that
have reported water level depths(when drilled) less than 10 feet deep. Of these, only well permit
2020-F, belonging to the Summit Group of Southern Wisconsin, is within the zone of expected
water level rise of between+0.5 and +1 ft. There are six registered wells that are currently being
monitored by Broken Arrow Investments (BAI)that are within the area of expected mounding of
0.5 to 1.0 ft. None of these wells have measured water levels shallower than 11 ft so no impact
is expected. Well 374-WCB (Davis Farms) is the only other up-gradient well with an expected
rise in the water table between +0.5 and +1.0 ft. The Davis well is reportedly 86 ft deep, with a
measured water level of 31 ft when drilled. It reportedly can pump approximately 1200 gpm, one
of the highest within the model area. The expected rise in water level will likely benefit production
by increasing the aquifer saturated aquifer thickness and available drawdown.
Considering that the seasonal water table fluctuates approximately 2-4 feet, and there are no
registered wells located within the predicted water level change of+/- 1 ft, we believe the overall
impact of the mine slurry wall will be insignificant.
If you have any questions, please give me a call.
Sincerely,
McGrane Water Engineers,Inc.
I_
Dennis McGrane, P.E.,C.P.G
McGrane Water Engineering,LLC
1669 Apple Valley Rd. •Lyons,CO 80540•Phone:[phone]
E-Mail:[e-mail] Web: ttp://www.mcgranewaterengineering.com