Compilation of Rules and Regulations of the State of Georgia › Department 391 - RULES OF GEORGIA DEPARTMENT OF NATURAL RESOURCES › Chapter 391-3 - ENVIRONMENTAL PROTECTION › Subject 391-3-16 - RULES FOR ENVIRONMENTAL PLANNING CRITERIA › Rule 391-3-16-.02 - Criteria For Protection of Groundwater Recharge Areas

Current
				through Rules and Regulations filed through June 27, 2024
(1) Background. Variable levels of recharge
				area protection can be based upon the State's hydrogeology (e.g., areas such as
				the Dougherty Plain where a major aquifer crops out would receive a relatively
				high degree of protection whereas other areas, such as the shale hills of
				northwest Georgia, would receive a lower degree of Protection). Recharge area
				protection within the significant recharge areas would be further refined,
				based upon the local susceptibility or vulnerability to human induced pollution
				(e.g., high, medium, or low). The significant recharge areas have already been
				identified and mapped (about 22-23% of the State). Pollution susceptibility
				mapping is ongoing. Existing statutes are adequate for protection of the
				remaining recharge areas (about 77-78% of the State).
(2) Definitions:
(a) "Aquifer" means any stratum or zone of
				rock beneath the surface of the earth capable of containing or producing water
				from a well. (Note: this is the same definition as in the Groundwater Use
				Act.)
(b) "DRASTIC" means the
				standardized system for evaluating groundwater pollution potential using the
				hydrogeologic settings described in U.S. Environmental Protection Agency
				document EPA-600/287-035 (Note: the DRASTIC methodology is the most widely used
				technique for evaluating pollution susceptibility).
(c) "Pollution Susceptibility" means the
				relative vulnerability of an aquifer to being polluted from spills, discharges,
				leaks, impoundments, applications of chemicals, injections and other human
				activities in the recharge area.
(d) "Pollution Susceptibility Maps" means
				maps of relative vulnerability to pollution prepared by the Department of
				Natural Resources, using the DRASTIC methodology. Pollution susceptibility maps
				categorize the land areas of the State into areas having high, medium and low
				groundwater pollution potential.
(e) "Recharge Area" means any portion of the
				earth's surface, where water infiltrates into the ground to replenish an
				aquifer.
(f) "Significant Recharge
				Areas" means those areas mapped by the Department of Natural Resources in
				Hydrologic Atlas 18 (1989 edition). Mapping of recharge areas is based on
				outcrop area, lithology, soil type thickness, slope, density of lithologic
				contacts, geologic structure, the presence of karst, and potentiometric
				surface. Significant recharge areas are as follows in the various geologic
				provinces of Georgia:
1. In the Valley and
				Ridge and in the Cumberland Plateau, significant recharge areas outcrop areas
				of carbonate rock where low slope (less than 8% slope) conditions prevail. Such
				areas commonly are characterized by karst topography (caves and
				sinkholes).
2. In the Piedmont and
				in the Blue Ridge, rocks have little primary porosity, with most groundwater
				being stored in the overlying soils. The significant recharge areas are those
				with thicker soils. Field mapping indicates that thick soils in the Piedmont
				and Blue Ridge are characterized by a density of two or more geologic contacts
				per four squares miles (source:1976 1:500,000 Geologic Map of Georgia) and
				slopes lower than 8%.
3. In the
				Coastal Plain, the significant recharge areas are the surface outcroppings of
				the large and extensively used drinking water aquifers (e.g., the Floridian,
				the Clayton, etc.) and soils having high permeability according to the 1976
				1:750,000 Soils Association Map of Georgia.