IRB approval was obtained from Duke University and Ho Chi Minh
Science University and the Department of Natural Resource and Environment
of Dong Thap Province. The study site spans approximately
70 km north to south in the Dong Thap province of Vietnam. Wells
were selected based on government approval, as well as consent from
individual well owners. In total, 68 groundwater wells were tested as
well as 5 surface water samples from the Mekong River.