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68( 781 <br /> I/,1-‘1 P,'I M1 E ENGINEERING 81 SURVEYING ifs I s AMES!$EROF THE WAGNER GROUP <br /> 1625 Navaho Drive.Box 19746*Raleigh, North Carolina 27619*(919)8720300 En Olnaa a•AICNH.cua•Plann. . r.",, <br /> June 26, 1981 <br /> Mr. Richard P. Badham <br /> American Stone Company <br /> P.O. Box 720 <br /> Greensboro, North Carolina 27402 <br /> Dear Mr. Badham: <br /> On June 10, 1981, I visited your company's quarry on Highway 54 <br /> west of Carrboro in Orange County. The purpose of my visit was to in- <br /> spect the geological and ground-water conditions at the site and to <br /> estimate the impact of quarry, expansion on the water table. <br /> The present quarry pit covers an area of slightly less than 5 <br /> acres and is located on the northwest side of SR 1104. The former pit <br /> is located on the southwest side of SR 1104 and is now owned by the <br /> Orange County Water and Sewer Authority. Currently it is filling with <br /> water and is used as an emergency, water supply reservoir. <br /> In the quarry pit, the exposed rocks show the general bedding <br /> planes to dip towards the north at approximately 80 to 85 0. The strike <br /> is about NNE, and the rock appears to be a felsic tuff. <br /> As I understand, during the years of quarry operations at this <br /> site there has never been a water-related complaint from the nearby <br /> residents. The quarry's well at about 450 feet from the present pit <br /> and 180 feet in depth has supplied adequate quantities of water to the <br /> offices and shops for several years with no problems. In a 200-foot <br /> well at the former office site and approximately 500 feet from the <br /> former pit, the static water level was measured at 36.0 feet below <br /> ground surface on the day of my visit. <br /> It appears to me that the ground-water conditions at this site <br /> are similar to approximately a half-dozen other quarry sites with <br /> which I an familiar. Basically the water table falls to the base of <br /> a fractured zone at the quarry wall. At that level the water discharges <br /> into the pit, and the level of maximum drawdown is established. The <br /> water table slopes upward logarithmically from that level forming a <br /> cone of depression around the pit, The limits of such a cone of de- <br /> pression generally extend to between 300 feet and 500 feet from the <br /> quarry walls. The extent of the cone is influenced by many factors, <br /> the most prominent of which are thickness of soil cover, the size, <br /> extent and degree of interconnection of the fracture zones, and the <br /> amount of precipitation in the area. ,•'r <br /> I have found no evidence that the ground-water conditions at your <br /> company's quarry are essentially different from others in the Piedmont <br /> Province of our State. In my opinion the extent of the come of depres- r <br /> sion will shift as the size of the pit changes, but it probably will l <br /> not extend beyond 500 feet from the pit walls. <br /> 172 Meeting Slreet•Charieston,South Carolina 29401•(803)577-9981 <br /> REAVINO,PENNSYLVANIA CPOTTSVILLE,PENNSYLVANIA METUCHEN,NEW JERSEY:RALEIGH,NORTH CAROLINA <br /> KILL DEVIL HILLS,NORTH CAROLINA OGREENVILLE.NORTH CAROLINA❑CHARLESTON SOUTH CAROLINA;HVNTSVILLE AL?SAMA <br />