Karst groundwater vulnerability determined by modeled age and residence time tracers

MaryLynn Musgrove; Bryant C. Jurgens; Stephen P. Opsahl

doi:10.1029/2023gl102853

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Karst groundwater vulnerability determined by modeled age and residence time tracers

MaryLynn Musgrove·Bryant C. Jurgens·Stephen P. Opsahl

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Abstract

Karst aquifers are a vital groundwater resource globally, but features such as rapid recharge and conduit flow make them highly vulnerable to land-surface contamination. We apply environmental age tracers to the south-central Texas Edwards aquifer, a karst resource in a rapidly urbanizing and drought-prone region, to assess vulnerability to land-surface contamination and risks unique to karst aquifers. We show that vulnerability of Edwards aquifer groundwater follows similar spatial and depth patterns common to porous-media type aquifers, despite complicated karst hydrogeologic features. Shallow and unconfined parts are more vulnerable to land-surface contamination than the deeper and confined parts, although even the oldest groundwater is mixed with some recent recharge. When modeled age-tracer results are coupled with other independent geochemical tracers of water-rock interaction specific to karst settings, they can yield insight into residence time and associated vulnerability.

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Geophysical Research Letters Article

Source-reported bounding extent: 28.95832731254596° to 30.54366239128437° latitude; -100.81367338316534° to -96.77473383220936° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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MaryLynn Musgrove, Bryant C. Jurgens, Stephen P. Opsahl. 2023-09-14. Karst groundwater vulnerability determined by modeled age and residence time tracers. https://doi.org/10.1029/2023gl102853

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