2018-07-13_HYDROLOGY - M1977344 - Laserfiche WebLink

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Ms. Lindsay M. Griffith, P.E. July 13, 2018 Page 3 of 6 annual rate of withdrawal. Ground water in the CodeR Sandstone has not been shown to meet this standard; therefore, it is presumed to be tributary to the Arkansas River. The SWSP approved on July 28, 2014 did not discuss the timing of ground water depletions or the assertion that if ground water is exposed/intercepted, it does not discharge to the Arkansas River (i.e., it is nontributary). The SWSP request dated October 1, 2015 indicates the water intercepted and utilized at the quarry is from surface water sources and not ground water. The October 1, 2015 SWSP request also assumes that depletions at the quarry have an instantaneous depletion on the Arkansas River. These claims are in conflict with the statements from the December 31, 2013 Letter Report and the December 31, 2013 Technical Memorandum. In order to quantitatively evaluate and decide if water in the East Pond, North Pond, and Glory Hole includes a mix of surface and ground water, the July 22, 2016 SWSP required that each of these ponds must be equipped with a staff gauge by September 1, 2016 and daily readings of the each staff gauge must be provided with the monthly accounting. Additionally, the applicant was required to install and maintain a rain gauge located near the ponds and report daily rainfall that occurs at the mining site with the monthly accounting. The degree to which pond stage varies and can be correlated to precipitation should help provide a definitive basis for whether or not depletions are occurring to surface water inflows or through ground water exposure. This determination will also decide whether those depletions should be lagged to the Arkansas River or not. A summary of the data collected to date was provided by letters dated June 22, 2017 and April 25, 2018. This office will continue to work with the Applicant during the approval period of this SWSP to determine the appropriate methodology to lag depletions from the Holcim Quarry. The Duck Pond (WDID 1205118, permit no. 44376-F) is the subject of the decree granted in case no. 92CW35, and is not included as part of this SWSP. The decree in case no. 92CW35 allows for up to 8.3 acres of exposed groundwater and the associated evaporation depletions from the 8.3 -acre pond are identified as 31.13 acre-feet per year. The decree in case no. 92CW35 also allows up to 55 acre-feet per year to be pumped from the Duck Pond as an alternate point of diversion under the Porter Ditch priority for dust suppression purposes. The depletions due to evaporation and dust suppression uses associated with the Duck Pond shall be administered according to the decree in case no. 92CW35 and are not included as part of this SWSP. Prior SWSPs have requested that potential surplus water from case no. 92CW35 that was not consumed by the operation of the Duck Pond be used to replace depletions from other ponds identified in this SWSP. This SWSP does not include this request; therefore, the water identified in case no. 92CW35 is not part of this SWSP and will not be used for replacement under this SWSP. REPLACEMENTS The evaporation losses for the pond areas, plus the operational losses, are estimated to total 74.64 acre-feet per year (net evaporation from 4.7 acres of water surface is estimated to be 16.64 acre-feet/year and water pumped for dust control is estimated to be 58 acre-feet/year). Replacement water will be furnished by the Pueblo Board of Water Works