Georgia Water Science Center
This report is available online in pdf format (2.8 MB): USGS WRIR 98-4202 ()
Kristen Bukowski McSwain
U.S. Geological Survey Water-Resources Investigations Report 98-4202, 49 pages (Published 1999)
In 1995, the U.S. Navy requested that the U.S. Geological Survey conduct an investigation to describe the hydrogeology of the Upper Floridan aquifer in the vicinity of the Marine Corps Logistics Base, southeast and adjacent to Albany, Georgia. The study area encompasses about 90 square miles in the Dougherty Plain District of the Coastal Plain physiographic province, in Dougherty and Worth Counties—the Marine Corps Logistics Base encompasses about 3,600 acres in the central part of the study area.
The Upper Floridan aquifer is the shallowest, most widely used source of drinking water for domestic use in the Albany area. The hydrogeologic framework of this aquifer was delineated by description of the geologic and hydrogeologic units that compose the aquifer; evaluation of the lithologic and hydrologic heterogeneity of the aquifer; comparison of the geologic and hydrogeologic setting beneath the base with those of the surrounding area; and determination of ground-water-flow directions, and vertical hydraulic conductivities and gradients in the aquifer.
The Upper Floridan aquifer is composed of the SuwanneeLimestone and Ocala Limestone and is divided into an upper and lower water-bearing zone. The aquifer is confined below by the Lisbon Formation and is semi-confined above by a low-permeability clay layer in the undifferentiated overburden. The thickness of the aquifer ranges from about 165 feet in the northeastern part of the study area, to about 325 feet in the southeastern part of the study area. Based on slug tests conducted by a U.S. Navy contractor, the upper water-bearing zone has low horizontal hydraulic conductivity (0.0224 to 2.07 feet per day) and a low vertical hydraulic conductivity (0.0000227 to 0.510 feet per day); the lower water-bearing zone has a horizontal hydraulic conductivity that ranges from 0.0134 to 2.95 feet per day.
Water-level hydrographs of continuously monitored wells on the Marine Corps Logistics Base show excellent correlation between ground-water level and stage of the Flint River. Ground-water-flow direction in the southwestern part of the base generally is southeast to northwest; whereas, in the northeastern part of the base, flow directions generally are east to west, as well as from west to east, thus creating a ground-water low. Groundwater flow in the larger study area generally is east to west towards the Flint River, with a major ground-water-flow path existing from the Pelham Escarpment to the Flint River and a seasonal cone of depression the size of which is dependent upon the magnitude of irrigation pumping during the summer months.
Calculated vertical hydraulic gradients (based upon data from 11 well-cluster sites on the Marine Corps Logistics Base) range from 0.0016 to 0.1770 foot per foot, and generally are highest in the central and eastern parts of the base. The vertical gradient is downward at all wellcluster sites.
Abstract
Introduction
Purpose and scope
Description of study area and Marine Corps Logistics Base
Well-numbering system
Methods of investigation
Previous investigations
Acknowledgments
Geology
Lisbon Formation
Ocala Limestone
Suwannee Limestone
Undifferentiated overburden
Hydrogeology of the Upper Floridan aquifer
Hydraulic characteristics of the undifferentiated overburden
Hydraulic characteristics of the Upper Floridan aquifer
Ground-water levels
Vertical hydraulic gradients
Ground-water flow in the Upper Floridan aquifer
Upper water-bearing zone
PSC areas 1, 2, 3, and 26
PSC areas 6, 10, 12, 13, and 22
Lower water-bearing zone
Summary
Selected references
Appendixes
Appendix A—Records of wells in the study area
Appendix B—Records of wells drilled by ABB Environmental Services, Inc., on the Marine Corps Logistics Base, Albany, Georgia
Appendix C—Lithologic logs of selected wells drilled in the Upper Floridan aquifer in the vicinity of the Marine Corps Logistics Base near Albany, Georgia
This report is available online in pdf format (2.8 MB): USGS WRIR 98-4202 ()
To view the PDF document, you need the Adobe Acrobat® Reader installed on your computer. (A free copy of the Acrobat® Reader may be downloaded from Adobe Systems Incorporated.)
Recent USGS publications on Georgia or Georgia Water-Resources Information
For more information, please contact webmaster-ga@usgs.gov.