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14. In conforntunce with Rule 6,J.7(I 1, please state alTinnatively whether the pmixtsed <br />sherry wall installation is expected to directly atTect surface or groundwater systems within <br />the affected land and surrounding area. FULLY ADDRiSSE?D <br />E S. En conformance with Rule 6.d.7(2)(b), please provide a characterization of the alluvial <br />ayuifer in the alTcxaed land and sum~unding area which includes the !'ollowing: <br />• f {ydraulic gradient, and direction of groundwater movement <br />• Description of the St. Vrain Creek for the reach adjacent to the slurry wall <br />installation (gaining ur losing stream, channel stability. bank stability, presence ul' <br />riparian vegetation) <br />• Description of the normal surfaccigroundw•ater interaction and function throughout <br />a 12-month cycle in the atlected land and surrounding arw (including SL Vrain River) <br />Fl1LLY ADDRESSED <br />IG. En contbmt:utee with Rule 6.4.7(2 )I h), plrf_sc provide a representalive cross sectional <br />diagram file each of the three (3) mined lakes which adcyuately depicts the features of the <br />alluvial ayuifer within the affected land and surrounding ana. The cross sectional diagram <br />should he drawn ro scale and provide the following inforntution: <br />• Existing reelaintrd excavation(s) and hdce high water mark(s) <br />• Groundwater (prizomctric) surface <br />• Propitsed slurry wall installation <br />• St. Vrain Stream Channel (from top of tiurth Battk to top of South flank) <br />• 100-}'ear Flatdplain boundaries (existing & proposed) & elevations <br />• St. Vrain Crock - Floodwav boundaries <br />• Any existing registered wells within b(HI Ices of the slwry wall installation <br />• Ordinary high water mark of the St. Vrain River <br />• Invert of the St. Vrain River <br />• Significant wetlands, and~`or woody riparian vegetation <br />F1:1.1-}' ADDRESSiD <br />17. In contitnnance with Rule 3.1.6(1), please quantify the vertical and horizontal extent of <br />impact to the groundwater surface and normal groundwater recharge or tloty pattern(s) <br />upon completion of the slurry wall installation. Et is the Division's experience with other <br />slurry wall installations that there is typir;illy a "mounding" and "shadowing" effect. <br />I~hcsr impacts arc typically yu;uuified through L.KUUndwater modeling and Held verified <br />through a groundwater moniUtring program. r\Iso, please descnhe and show on a map the <br />location of any water leature (well, spring, wetland, riparian vegctationl or pcmt:nent <br />man-made stnrcture (leach Held, sewer line, highway bridge support, sepuc tank, rte) that <br />is within the scope (radius) of intlucnce of either nunutding or shadowing, and assess the <br />impact to such feature or stnrcture. Finally, please describe the mitigation measures that <br />will be employed to minimize the impact on the various water features ur man-made <br />structures. FULL}' ADDRESSED <br />IS. Please provide a map which depicts the lateral extent of the "floodway" and 10(t-year <br />tloodplain tier the St. Vrain River, elevation of the 100-year t)ood surface, location of the <br />existing reclaimed lakes, and proposal slurry wall installation. FULL}' ADDRESSED <br />x <br />