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Joanna Williams <br /> March 12,2018 <br /> Page 2 <br /> limitations of the available augmentation credits. The required fee of$257 for the combined site <br /> has been submitted. <br /> PROJECT DESCRIPTION <br /> Morton—Holton Lakes Mine <br /> The Morton-Holton Lakes Mine comprises roughly 180 acres located in portions of the SE'/4 of <br /> Section 1 and the NE'/4 of Section 12 of Township 1 North, Range 67 West, 6th P.M., Weld <br /> County, Colorado (the Morton Property) and 203 acres located in portions of the SW'/4 of <br /> Section 6 and the NWt/4 of Section 7 of Township 1 North, Range 66 West, 6th P.M. (the Holton <br /> Property) In March 2017 an amendment to Permit No. M-2008-082 ("AMO 1") issued by the <br /> Division of Reclamation Mining and Safety to RMCC that establishes a single, combined and <br /> contiguous mine area under that permit. RMCC's current mining plan for the properties is <br /> shown in the attached Figure 1. <br /> Water is used to wash mined product and for dust suppression. Water is also lost through <br /> evaporation of exposed ground water. In the current SWSP, Stage 6B was planned to be <br /> dewatered through 2018. However,with the current extended period of free river anticipated and <br /> because RMCC's current lease with the City of Aurora has more than sufficient credits to replace <br /> the additional evaporation depletions, Stage 6B is planned to be incrementally filled with free <br /> river water in March 2018. RMCC estimates 1.0 acre of groundwater is currently exposed in <br /> Stage 613. The planned incremental fill of Stage 6B (starting this month) to a depth of 12 ft will <br /> result in an exposed ground water surface area of 5 acres. If free river conditions do not continue <br /> long enough to fill to a depth of 12 ft, RMCC will maintain the water level that is achieved under <br /> free river conditions in Stage 6B at the time the call comes on by installing culverts in the divider <br /> berm between Stages 6B and 6A and by dewatering from Stage 6B to Stage 6A as described <br /> above. RMCC's water supply lease from the City of Aurora is sufficient to replace the <br /> additional evaporative depletions for the increase in water surface area in Stage 6B. <br /> RMCC's currently approved plan allows for the on-going mining through the end of 2018 at <br /> Stage 3 and Stage 4. Mining at Stages 6A and 6B has been completed. It is now expected that <br /> Stage 6A will expose up to 3.0 acres of ground water beginning in March 2018 through the end <br /> of the mining plan. The ground water surface area in Stage 613, as explained, is expected to <br /> increase from 1 acre to 5.0 acres in March 2018. <br /> Mining at Stage 3 began in June 2017 and is anticipated to be completed in the next couple of <br /> months. Stage 3 currently exposes approximately 1.0 acre of ground water and is expected to be <br /> partially backfilled in the Spring of 2018 such that exposed ground water surface area will be <br /> reduced from 1 acre to `/2 acre in May 2018. Ultimately, Stage 3 will be backfilled with <br /> overburden from other stages, which will fully eliminate all exposed groundwater and preclude <br /> the need for any future fill depletions. The slurry wall at Stage 4 has been constructed and Stage <br />