Arsenic contamination of groundwater in the Red River Delta in Vietnam, VietAs Phase II

Project summary

The use of groundwater for drinking water has been promoted by DANIDA and other aid organisations in both Vietnam and Bangladesh. Unfortunately it was discovered that the groundwater in these countries may contain far too much arsenic, leading to mass poisoning at an unprecedented scale. 11 million people are at risk in Vietnam and more than 100 million people worldwide. The poor rural population without access to advanced water treatment is most exposed to arsenic poisoning. There is a great need for devising strategies that may mitigate the groundwater arsenic problem. Unfortunately we still lack the fundamental understanding of arsenic mobilization processes, which is required to devise such strategies. In addition the affected countries need more expertise to properly handle the situation. The objectives of Phase II of VietAs aim at improving this situation by: (a) strengthening the Vietnamese research capacity in the field of groundwater, and; (b) improving the knowledge of the geochemical and hydrogeological processes that control the release and transport of arsenic in groundwater. Objective a) will be addressed by conducting cooperative research, educating staff, Ph.D and M.Sc. students and giving Short Courses. Objective b) will be addressed by studying the mechanisms leading to arsenic mobilization, the flushing of arsenic from aquifers and the hydrogeological controlling factors. Gained insight will be incorporated in models which we will employ to work out scenarios for the implementation of low arsenic groundwater abstraction strategies. The prospects of achieving our goals in Phase II are good because we have used Phase 1 to: a) build up an internationally recognised, multidisciplinary group of researchers covering geochemistry, hydrogeology, geology, and numerical modelling; b) establish a well instrumented field site for research on arsenic in groundwater, and; (c) have established efficient cooperation with highly qualified and motivated Vietnamese research teams. Phase II will give us the opportunity in a joint effort to make a major step forward towards solving the groundwater arsenic problem.

Outputs

Project Completion Report:

The overall objective of the VietAs project has been to strengthen the research capacity in water resources planning and management in Vietnam. Project partners have been: Hanoi University of Mining and Geology, Hanoi University of Science, the Geological Survey of Denmark and Greenland and the Department of Water & Environmental, Technical University of Denmark. The project was implemented during two phases from 2004 to 2012.
The research focus has been on groundwater geochemistry in the Red River delta aquifers, more specific on naturally occurring arsenic and salty groundwater in these aquifer systems. The training component included education of 25 master and four PhD students and support to the permanent staff members. Modern research equipment has been purchase to the Vietnamese institutions and their personnel have been trained in its use. The research themes on groundwater arsenic and salty has been on obtaining a fundamental insight regarding the controlling hydrogeologicai and geochemical processes ieading to elevated contents of these compounds in groundwater. This objective has been reached through field studies, laboratory work and numerical modelling. A generic model has been developed, which expiains observed distribution of arsenic in the delta based on the reactivity of organic material and iron-oxides controlled by sediments age. The studies on the salty groundwater have also resulted in the development of a regional model.