The fast transport of degradable pollutants into groundwater through a process called focused recharge is a widespread and previously underestimated risk, a study suggests. Relatively little is known about how water quality on a large spatial scale is affected by the fast flow of short-lived pollutants into the groundwater through localized features such as enlarged cracks and fissures--a process known as focused recharge. Andreas Hartmann and colleagues used a continental-scale model to quantify the risk of groundwater contamination by degradable pollutants in the carbonate rock regions of Europe, Northern Africa, and the Middle East. The authors compared the travel times of water from the land surface to the subsurface with the degradation times of various pollutants, including the veterinary pharmaceutical salinomycin, the pesticide glyphosate, and the bacterial pathogen Escherichia coli. Up to 50% of contaminants reached the groundwater before degrading through focused recharge, compared with less than 1% via diffuse recharge, or widespread infiltration, alone. Additional simulations estimated that the glyphosate level in groundwater is up to 19 times the maximum permissible concentration in Europe, assuming that focused recharge occurs. According to the authors, the rapid transit of pollutants into the groundwater poses a challenge for water and land use management.
Article #2020-24492: "Risk of groundwater contamination widely underestimated because of fast flow into aquifers" by Andreas Hartmann et al.
MEDIA CONTACT: Andreas Hartmann, University of Freiburg, Freiburg, GERMANY; email: andreas.hartmann@hydmod.uni-freiburg.de
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Journal
Proceedings of the National Academy of Sciences