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Tri-County Gravel Pit, M77-205 Page 5 of 13 <br /> February 27, 2025 <br /> 2. The Tri-County Pit is currently operating under a CDPHE discharge permit that <br /> allows the pit to discharge dewatering water directly to the North Fork. Using <br /> the pit dewatering volume to irrigate the field instead can reduce the <br /> frequency and volume of dewatering discharge to the river and help mitigate <br /> associated water quality impacts to the North Fork from the dewatering <br /> discharge. <br /> Depletions <br /> The projected depletions for the period of this SWSP consist of net evaporation from <br /> exposed groundwater surface area, water removed in the mined product, water from <br /> washed product, dust suppression and dewatering. The anticipated net operational <br /> depletions during this SWSP are 6.76 acre-feet per year. <br /> Evaporation <br /> During this SWSP period, the Applicant anticipates 19.2 acres of exposed groundwater <br /> consisting of 17.6 acres from the Reclaimed Pond and 1.6 acres from dewatering <br /> trenches. The augmentation plan decreed in case no. 99CW216 allows for a maximum <br /> surface area of the exposed groundwater of 33.4 acres and 90.13 acre-feet per year <br /> of evaporative depletions. Since the 19.2 acres of exposed groundwater is less than <br /> the 33.4 acres covered under the augmentation plan, no additional replacement is <br /> needed under this SWSP to cover evaporative depletions. <br /> Dust Suppression <br /> The anticipated operational depletions due to dust suppression is 8,000 gallons per <br /> day from April through November, or 5.99 acre-feet per year as shown in Tables 3 and <br /> 4 (attached). <br />