‘Fossil’ groundwater is not immune to modern-day pollution

Deep well study finds contamination in at least 12,000-year-old water

Scott Jasechko

DEEP WATER  Deep groundwater wells, such as this hand-pumped well in Uganda being operated by water resources scientist Scott Jasechko, can contain mixes of old and young water and traces of pollution.

Merhawi GebreEgziabher

Groundwater that has lingered in Earth’s depths for more than 12,000 years is surprisingly vulnerable to modern pollution from human activities.