Field Visit to An Phú: Unveiling Arsenic Contamination Levels

The CMDA covers 200,000 sq. km from the coastline of Vietnam to Cambodia’s northern border with Lao PDR. It sustains 35 million people dependent on its groundwater for drinking, irrigation, and other purposes. But the aquifer faces critical challenges, including groundwater declines, land subsidence, and increasing arsenic pollution and other contaminants.

Arsenic contamination in groundwater poses significant health risks and undermines the sustainability of agricultural in the Mekong Delta. Research by Papacostas et al. 2008 highlighted geomorphological factors as critical determinants of arsenic distribution in groundwater in the Mekong Delta, particularly in Cambodia. Research by Nguyen et al. in 2021 documented the severe health risks associated with arsenic-contaminated groundwater in Long An and Tien Giang Provinces in Viet Nam, emphasizing the urgent need for action. 

Dr. Khai from HCMC University of Technology (HCMUT) is establishing a groundwater monitoring research site in An Giang to understand these issues further. Collaborating with a team of Vietnamese and international PhD students, monitoring wells have been installed to study the geochemistry, microbiology, and lithology of near-river aquifers that exhibit elevated levels of arsenic contamination. The IUCN team visited the site and met the research team to discuss the challenges of arsenic contamination. This collaboration aims to provide insights and support country partners in improving groundwater management practices to mitigate contamination risks and ensure sustainable use for vulnerable populations.

Dr. Khai's team members are vacuuming to preserve the sample © IUCN Viet Nam

The study involves drilling at 11 randomly selected sites perpendicular to the river to collect sediment samples. These samples are vital for assessing arsenic and cadmium levels in both soil and groundwater. The project’s broader goal is to understand how these contaminants affect local agriculture and, ultimately, the health of communities that rely on groundwater sources.

The drilling process was designed to capture variations in contamination across different depths, shedding light on how arsenic migrates through sediments and interacts with underground water systems. The samples will help pinpoint factors influencing the buildup of heavy metals, providing crucial data to inform mitigation strategies.

However, the research face difficulties, particularly in securing residents' permission to drill in certain areas. This resulted in a few adjustments to the original sampling plan, underscoring the importance of fostering trust and cooperation with local communities in environmental aspects. 

 

Mud samples were taken from a drilling site © Ha Quang Khai

 

The CMDA Project and Collaborative Initiatives

This visit is part of a broader collaboration under the CMDA project on managing shared waters between Cambodia and Viet Nam. The project aims to promote sustainable groundwater management in the Mekong Delta by understanding cross-border water dynamics, pollution sources and strategies for mitigating contamination risks.

The partnership with HCMUT is a potential step in expanding the scope of research on arsenic contamination. The study results will generate actionable insights for groundwater protection, aligning with CMDA’s mission to secure safe drinking for communities in the Mekong region for the well-being of the locals.

IUCN team members and Dr. Khai took photo at the survey site © IUCN Viet Nam