Laserfiche WebLink
7 <br /> dry." Also, "The average precipitation at Pueblo is approximately 12 inches/year. The average <br /> potential evapotranspiration in the area is reported to be 12.2 to 15.8 inches/year (Sanford and <br /> Selnick, 2013). Pan evaporation rates in the Pueblo area are much higher, typically 50 to 60 inches <br /> between May and September (Colorado Climate Center, 2016). Given precipitation, climate <br /> conditions, topography and soil types in the area, there is little potential for deep percolation and <br /> shallow groundwater except for in alluvium along creeks and rivers. This is substantiated by the <br /> absence of groundwater in the GCC quarry, history of dry wells at the site, St. Charles River being <br /> under losing conditions in the area, and lack of any nearby shallow wells used for domestic or <br /> livestock supply. A check of Colorado Division of Water Resource records did not reveal any Fort <br /> Hayes wells cross gradient or downgradient of the site within 5 miles." Furthermore, "The setting <br /> of the GCC site is such that there is a minimal likelihood of shallow groundwater occurrence or for <br /> impact to groundwater from normal or currently planned operations. The potential pathways for <br /> development and movement of groundwater are primarily along the Fort Hayes/Codell contact <br /> and/or the within the Codell Sandstone. If saturation were to occur in these units it would tend to <br /> move along the direction of dip to the northeast" (note correction of typo in CCG report indicating <br /> northwest). Therefore, if saturation were to develop it would migrate in this down dip direction <br /> along the sandstone/shale contact, not topographically downgradient along Arroyo B. <br /> Due to the climate, water management and low permeability of the subject formations, GCC <br /> considers development of significant saturation from the sedimentation pond within any <br /> reasonable timeframe extremely unlikely. GCC believes it has documented the possibility of <br /> groundwater infiltration downgradient of the sedimentation basin through ten (10) years of MW- <br /> 001A monitoring data and other sound hydrogeological reasoning. GCC believes the measures in <br /> place and proposed are protective of the existing and reasonably potential future uses of <br /> groundwater. <br /> 10. Within TR-06, the Close Consulting Group's March 17, 2016 technical evaluation states <br /> water is allowed to accumulate in the in-pit sedimentation basin a maximum of three days <br /> before being discharged by pump to Arroyo B, in accordance with GCC's Colorado Discharge <br /> Permit, Please provide a copy of the approved discharge permit for this activity. With the <br /> recent approval of TR-05, please demonstrate the Colorado Department of Public Health and <br /> Environment, Water Quality Control Division is aware the quarry's storm water, collected in <br /> the in-pit sedimentation basin and discharged to Arroyo B, will now come in contact with <br /> backfilled kiln feed material from the main kiln baghouse. <br /> Please see figure 4 for a copy of CDPHE stormwater discharge Permit No. COGS01540 and its <br /> Stormwater Management Plan. Stockpiles of Raw Materials, Overburden, Topsoil and several other <br /> materials are already listed in Section 3.1 (Potential Sources of Pollution) of the Stormwater <br /> Management Plan. Kiln feed material is considered to fit the definition of Raw Materials. <br /> 11. Please commit to providing the Division with well construction details and completion <br /> diagrams once the well has been constructed. <br />