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<br /> 6/12 <br />6.4.7 Exhibit G- Water Information <br /> <br />24. PJD date clarification: Section 2.7.2 states a preliminary jurisdictional determination <br />(PJD) request was submitted to the USACE on May 21, 202 [sic]. Please clarify the year <br />the request was submitted. <br /> <br />Response: The preliminary PJD request was submitted to USACE on May 21, 2020. <br /> <br />25. Water impacts: Rule 6.4.7 requires if the operation “is not expected to directly affect <br />surface or groundwater systems, a statement and sufficient demonstration of that <br />expectation shall be submitted”. The modeling results presented in Appendix 4.6 indicate <br />groundwater may be exposed in Mine Plan Blocks 0-10 and 20-30 (see first Condition for <br />Approval in the enclosed Division of Water Resources letter). Section 2.7.5 (Exhibit G) <br />discusses SWSP/16CW3102 which covers cover depletions from both the Holcim Bear <br />Creek Quarry and the Holcim Wetlands; but it does not specifically address any <br />depletions from the Red Creek Quarry. In addition, surface water may be impacted as <br />discussed in Comment No. 19 above. Please address the following: <br /> <br />a. If the current SWSP is to cover depletions at the proposed RCQ, it must be <br />explicitly stated in the SWSP and approved by the Colorado Division of Water <br />Resources prior to exposing groundwater. Please provide a commitment in writing <br />to obtaining such an approval prior to exposing groundwater in the RCQ. <br /> <br />Response: The following written commitment is in Section 2.7.5: An approval <br />from DWR will be obtained prior to exposing groundwater. <br /> <br />b. Ensure the response to Comment No. 19 includes an expected infiltration rate and <br />how much water could be expected to infiltrate within the 72-hour time frame <br />(see second Condition for Approval in the enclosed Division of Water Resources <br />letter), relative to a given frequency storm event (e.g., could the runoff volume <br />captured within the reclaimed pit from a 25-year [or other frequency], 24-hour <br />storm event infiltrate within 72 hours?). <br /> <br />Response: See response to comment 19 and refer to the Engineering Calculation Set. <br /> <br />26. Well Locations: Paragraph 2.7.3 references Appendix 4.3 for the well permits and <br />indicates the five monitoring wells were “spatially distributed”. A review of the UTM <br />coordinates for Well Permits 326171 and 326172 show they are less than 2 meters <br />apart. A map of the monitoring well locations was not found during the review of the <br />other application Exhibits and appendices. Please: <br /> <br />a. Confirm the coordinates for Well Permits 326171 and 326172 are correct on <br />the monitoring well permits, or correct the coordinates in the permit <br />documents, and <br />Response: The referenced wells were completed in two different lithologies (Fort <br />Hayes limestone and Codell sandstone) and are in close proximity to each other in <br />order to monitor the hydrologic conditions in both formations. This clarification is <br />provided in Section 2.7.3. <br />b. Provide a reference map showing the locations of the monitoring wells. <br /> <br />Response: Figure 2.7.3-1 Groundwater Well Location Map is provided in Section <br />2.7.3. <br />