Dr. Alexander Van Geen
Earth Institute Contact: Dr. Alexander Van Geen
Elevated arsenic levels in groundwater pumped from tubewells across South and Southeast Asia is a major health concern affecting hundred of millions of people. One key feature of the problem is the extreme spatial (and rarely temporal) variability of arsenic levels observed in shallow aquifers in the region. This complicates prediction, but, on the other hand, creates an opportunity for mitigation as most villagers are within drilling distance to aquifers that are low in arsenic. Rather than focusing on costly and complicated water treatment, Columbia scientists have been exploring novel ways to predict (while drilling) whether a particular depth interval is likely to yield groundwater low in arsenic. This is a lab-based project, which involves detailed geochemical and mineralogical analysis of borehole sediment profiles. These samples include wash borings (drill cuttings) obtained in January 2007 from several locations in Bangladesh where the level of arsenic in groundwater is already well known.