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Environmental tracers as indicators of karst conduits in groundwater in South Dakota, USA

Hydrogeology Journal

By:
, , and
DOI: 10.1007/s10040-007-0232-7

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Abstract

Environmental tracers sampled from the carbonate Madison aquifer on the eastern flank of the Black Hills, South Dakota, USA indicated the approximate locations of four major karst conduits. Contamination issues are a major concern because these conduits are characterized by direct connections to sinking streams, high groundwater velocities, and proximity to public water supplies. Objectives of the study were to estimate approximate conduit locations and assess possible anthropogenic influences associated with conduits. Anomalies of young groundwater based on chlorofluorocarbons (CFCs), tritium, and electrical conductivity (EC) indicated fast moving, focused flow and thus the likely presence of conduits. ??18O was useful for determining sources of recharge for each conduit, and nitrate was a useful tracer for assessing flow paths for anthropogenic influences. Two of the four conduits terminate at or near a large spring complex. CFC apparent ages ranged from 15 years near conduits to >50 years in other areas. Nitrate-N concentrations >0.4 mg/L in groundwater were associated with each of the four conduits compared with concentrations ranging from <0.1 to 0.4 mg/L in other areas. These higher nitrate-N concentrations probably do not result from sinking streams but rather from other areas of infiltration. ?? Springer-Verlag 2007.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Environmental tracers as indicators of karst conduits in groundwater in South Dakota, USA
Series title:
Hydrogeology Journal
DOI:
10.1007/s10040-007-0232-7
Volume
16
Issue:
2
Year Published:
2008
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Hydrogeology Journal
First page:
263
Last page:
280