Use of environmental tritium to characterize ground water flow systems in regolith and crystalline fractured-rock hydrogeologic settings

Conference · Mon Mar 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5949724

Stewart, L M ^[1]; Rose, S E ^[2]

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1. Geological Survey, Atlanta, GA (United States)
2. Georgia State Univ., Atlanta, GA (United States). Geology Dept.

Environmental tritium concentrations measured in 84 ground-water, surface-water, and precipitation samples collected throughout the Piedmont and Blue Ridge physiographic provinces of northern Georgia were used in conjunction with available geological and hydrochemical data to develop general concepts of ground-water flow within a regolith and crystalline fractured-rock system. Tritium concentrations ranged from 0 tritium units (TU) in water sampled from unpumped wells completed in fractured bedrock to 34 TU in water sampled from pumped wells screened at various intervals within the overlying regolith. Tritium concentrations measured in spring discharge, streamflow, and precipitation also were within this range. The distribution of tritium indicates that tritiated water is retained within the regolith and that pumping is an important mechanism for mixing water of different ages within the flow system. Simulations using an analytical mixing model were performed to estimate the degree of mixing and the residence time of ground water within the flow system. Results of the simulations compared favorably with other geological and hydrochemical data. Simulated residence times for tritiated water indicated that ground-water residence times may be greater than 37 years within the bedrock fractures, but as little as 15 years in pumped bedrock wells and streams. Estimates of ground-water ages were based on environmental tritium concentrations produced by thermonuclear bomb testing conducted during the years of 1961-1962.

• OSTI ID: 5949724
• Report Number(s): CONF-9304188-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:4; Conference: 42. annual Geological Society of America (GSA) Southeastern Section meeting, Tallahassee, FL (United States), 1-2 Apr 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AQUIFERS
HYDROLOGY
GEORGIA
GROUND WATER
FLOW MODELS
AGE ESTIMATION
GEOLOGIC FRACTURES
RADIOECOLOGICAL CONCENTRATION
RAIN
STREAMS
TRITIUM
ATMOSPHERIC PRECIPITATIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DEVELOPED COUNTRIES
ECOLOGICAL CONCENTRATION
GEOLOGIC STRUCTURES
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL MODELS
NORTH AMERICA
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
RADIOISOTOPES
SURFACE WATERS
USA
WATER
YEARS LIVING RADIOISOTOPES
580000* - Geosciences