Laserfiche WebLink
Colona Pit SWSP Page 4 of 13 <br /> September 10, 2025 <br /> Intermittent Fill <br /> Water consumption by the mining operation will include water removed from the tributary <br /> stream system by intermittent fill of the gravel pit as mined product is removed. An <br /> estimated 7,639 tons/year or approximately 92,000 tons/year of aggregate will be removed <br /> monthly from the Colona Pit. <br /> Initial or intermittent fill, Vff, is calculated as follows: <br /> Vfif = (Vmm- Vbf) • (1 - porosity) - V,P <br /> where Vmm is the volume of mined material below the water table, <br /> Vbf is the volume of material backfilled (0), <br /> porosity is 0.25, <br /> V,pis the volume of water lost with mined product, <br /> and the specific weight of mined material used in the calculations is 133.33 <br /> lbs/ft3 (1 .8 tons/yd3). <br /> The intermittent fill is estimated at 1.7 acre-feet/month or 21.0 acre-feet/year, as shown <br /> on attached Table 2. <br /> Water Lost with Mined Product <br /> Mined product below the groundwater table will continue to be removed via "wet mining" <br /> techniques and will not be washed; therefore, four percent (4%) of mined material by weight <br /> is charged as water lost with mined product. Based on an estimated 7,639 tons/month or <br /> approximately 92,000 tons/year of aggregate removed, the <br /> The water lost with the mined product is estimated at 0.22 acre-feet/month or 2.70 <br /> acre-feet/year, as shown on attached Table 2. <br />