2022-02-23_PERMIT FILE - M2021059 (13)

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To- Nlr. Peter Hays Date: February 21, 2022 Page 4 Comment 9 On Page 12, Section 7.0, the Applicant states the backfilling and sloping sides of mining cells with excess topsoil will occur during reclamation. Please explain the earthmoving processes the Applicant intends to implement to backfill and compact the mined slopes and shorelines with topsoil during reclamation. Response 9 LRM will either tram or truck-haul topsoil to its location for placement. They will grade material out with a track mounted dozer to the water's edge. Utilizing the same track-hoe utilized for mining, an experienced operator will push/place material at the proper grade below the water's surface. LRM will also take advantage of the fluctuating groundwater table to push material beneath the water surface at the lowest groundwater elevation of the season. Once mining of a cell is complete, LRM will perform a bathymetric and verify compliance with the rule. Comment 10 On Page 12, Section 7.1, the Applicant states the Dunn Pit will be returned to a post-mining land use of wildlife habitat with groundwater sources ponds as each of the three phases are completed. Please commit to providing the Division with a copy of the final groundwater augmentation plan approved by the Division of Water Resources (DWR), when available. Response 10 LRM will provide the Division a copy of the final Augmentation Plan, once approved. LRM commits to use its Walters and Bokelman Pits site as the point of replacement (Decree 2009CWO105),which is already approved for augmenting the Dunn Pit site. LRM submitted a Gravel Pit Well Permit application and Substitute Water Supply Plan(SWSP) on September 1, 2021 to the DWR (invoice order #10256). The SWSP request covers January 2023 through December 2023 and describes estimated consumptive use from pit evaporation, dust suppression, aggregate entrainment, and reclamation vegetation establishment. The augmentation plan will include these components along with the water commissioner's shrink to move water down the Big Thompson. Comment 11 The Applicant has not obtained the final augmentation plan for the groundwater exposure of the three groundwater ponds at the conclusion of the Dunn Pit reclamation. Therefore, the Division will require the Applicant to provide a reclamation bond to include the backfilling of the exposed groundwater until the final augmentation plan is obtained from the DWR. The Division calculated the reclamation bond based on this requirement. 20220209_1045_DBMS_Adequacy_Revieiv_Response_MASTE R.docx TELEST®