Regional Effect of Pumping Ground Water from Deep Fracture Systems in the Conyers Area, Rockdale County, Georgia

Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.A 72-hour aquifer test was conducted to investigate the yield and interconnectivity of deep fracture systems in the City of Conyers, Rockdale County, Georgia. Wells tapping the deep fracture systems in the underlying igneous and metamorphic crystalline rock have yields ranging from 100 to 350 gallons per minute and can be pumped on a continuous basis. During the test, drawdown in excess of 30 feet was observed at distances as much as 6,200 feet from a pumped well and in observation wells located in two separate topographic basins. The regional effect of pumping is substantial and indicates that wells tapping deep subhorizontal fracture systems can reverse the natural (unstressed) hydraulic gradient and produce large influence areas around the pumped well. Wells tapping into the same (or similar) zones may interfere with each other, even across large distances, causing decreased well yield. Understanding the hydrologic characteristics of subhorizontal systems is critical in managing the water resource in these types of geologic settings.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors