Laserfiche WebLink
Abdullah Javed <br /> December 3, 2019 <br /> Page 2 of 6 <br /> operations at this site will no longer be mining sand and gravel and will instead only <br /> mine granite, future requests for SWSPs must be applied for pursuant to S37-92-308, <br /> C.R.S. <br /> In accordance with the letter dated April 30, 2010 from the Colorado Division of <br /> Reclamation, Mining, and Safety ("DRMS"), mining operators must comply with the <br /> requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations <br /> for the protection of water resources. The April 30, 2010 letter from DRMS requires <br /> that you provide information to DRMS to demonstrate you can replace long term <br /> injurious stream depletions that result from mining related exposure of ground water. <br /> In accordance with approach nos. 1 and 3, you have indicated that a bond has been <br /> obtained for $1,145.736 through DRMS to assure that depletions from groundwater <br /> evaporation do not occur in the unforeseen event, or events, which would lead to the <br /> abandonment of the Pit. In addition, Front Range Aggregates owns and has dedicated <br /> five shares of Twin Lakes Reservoir and Canal Company to cover these potential long <br /> term depletions. Front Range Aggregates must continue to commit those shares to this <br /> plan until such time as the State Engineer authorizes the release of this commitment. <br /> DEPLETIONS <br /> The depletions that result from the mining operation over the period of this SWSP include <br /> evaporation from exposed ground water, dust suppression, dewatering, and water lost <br /> with the mined product. Evaporation losses will result from the exposure of ground water <br /> in the settling ponds, an aggregate washing pond, dewatering trenches and two small <br /> sumps. The maximum exposed water surface area during this SWSP period will be 5.0 <br /> acres. <br /> Gross annual evaporation at the mining operation is estimated to be 46.0 inches per year <br /> and the monthly distribution is as depicted on the attached Table 1. Net evaporation is <br /> defined as gross evaporation less the consumptive use of water by vegetation that <br /> naturally occurred at the site prior to construction of the pit. The historical consumptive <br /> use was assumed to be equal to the effective precipitation, which was estimated as 70% of <br /> the 12.51 inches of average annual precipitation based on data from the Canon City <br /> weather station over the period 1893 through 2016. The net evaporation for the exposed <br /> water surface is 37.32 inches per year with a monthly distribution as shown on the <br /> attached Table 1. The total annual stream depletion resulting from the exposure of <br /> groundwater is estimated to be 15.53 acre-feet, which includes months of potential ice <br /> cover (December, January, and February). <br /> Ice covered periods may include the months of December, January, and February based on <br /> the Canon City weather station average temperatures of 22.5°F for December, 26.23°F for <br /> January, and 24.13°F for February. However, for the purpose of this SWSP, the Applicant <br /> shall replace the net evaporation depletions from the exposed ground water surface area <br /> that may occur during the potential ice covered period (the months of December, January, <br /> and February) for any time that the exposed ground water in the pit is not completely <br /> covered by ice. Computation of the net evaporation during any time that the pond is not <br /> completely covered by ice shall be determined as the pro-rata amount of the monthly <br /> gross evaporation rate distribution amount identified in the State Engineer's General <br />