Structural basin

Geology

Organic chemistry

Aquifer

Groundwater

Surface water

Biology

Water supply

Geomorphology

Arsenic contamination of groundwater

San Joaquin

Soil science

Subsidence

Chemistry

Geotechnical engineering

Ecology

Arsenic

Water resource management

Water quality

Hydrology (agriculture)

Environmental science

Groundwater-related subsidence

Environmental engineering

Nature Communications

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.

Overpumping leads to California groundwater arsenic threat