Deep well study finds contamination in at least 12,000-year-old water
Groundwater that has lingered in Earth’s depths for more than 12,000 years is surprisingly vulnerable to modern pollution from human activities. Once in place, that pollution could stick around for thousands of years, researchers report online April 25 in Nature Geoscience. Scientists previously assumed such deep waters were largely immune to contamination from the surface.
“We can’t just drill deep and expect to run away from contaminants on the land surface,” says Scott Jasechko, a study coauthor and water resources scientist at the University of Calgary in Canada.
Groundwater quenches the thirst of billions of people worldwide and accounts for roughly 40 percent of the water used in agriculture. Water percolating from the surface into underground aquifers can carry pollutants such as pesticides and salt along for the ride.
Jasechko and colleagues weren’t looking