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Removal of Arsenic Using a Cationic Polymer Gel Impregnated with Iron Hydroxide
Published on: June 28, 2019
Overpumping leads to California groundwater arsenic threat
Ryan Smith1, Rosemary Knight2, Scott Fendorf3
1Department of Geophysics, Stanford University, 397 Panama Mall, Stanford, California, 94305, USA. rgsmith@stanford.edu.
Abstract:
Water resources are being challenged to meet domestic, agricultural, and industrial needs. To complement finite surface water supplies that are being stressed by changes in precipitation and increased demand, groundwater is increasingly being used. Sustaining groundwater use requires considering both water quantity and quality. A unique challenge for groundwater use, as compared with surface water, is the presence of naturally occurring contaminants within aquifer sediments, which can enter the water supply. Here we find that recent groundwater pumping, observed through land subsidence, results in an increase in aquifer arsenic concentrations in the San Joaquin Valley of California. By comparison, historic groundwater pumping shows no link to current groundwater arsenic concentrations. Our results support the premise that arsenic can reside within pore water of clay strata within aquifers and is released due to overpumping. We provide a quantitative model for using subsidence as an indicator of arsenic concentrations correlated with groundwater pumping.
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