Unauthorized excavation activities contributing to environmental contamination downstream

The Mekong Basin, a vital water resource for several Southeast Asian countries, is currently facing a significant environmental challenge: transboundary pollution from upstream sources, particularly from Myanmar's mining activities.

Recent findings by the Department of Pollution Control have revealed high levels of arsenic in the major rivers of the upper North, including the Kok, Sai, and Ruak, which flow into Thailand's Chiang Mai and Chiang Rai provinces. This contamination is believed to be a result of lawless mining activities near the Thai border.

Environment Minister Chalermchai Sri-on has emphasized the importance of early action, citing the need to provide reassurance and relief to the public. He has also highlighted the need for active involvement from China, within the Mekong-Lancang Cooperation, to address the root causes of the transboundary pollution.

Assoc Prof Aksara Putthividhya, a lecturer with the Department of Water Resource Engineering at Chulalongkorn University, stated that Thailand has previously experienced heavy metal contamination. Domestic incidents of heavy metal contamination can be addressed through national mechanisms, but transboundary pollution presents a more complex challenge.

To combat this issue, the Office of National Water Resources has been suggested as Thailand's central hub for coordinating and facilitating efforts related to the pollution issue. A pilot project is underway to remove contaminated sediments, with the potential for expansion to other rivers if results prove successful.

Arsenic, a common contaminant, can be filtered using activated carbon, while arsenic V may require check dams to trap contaminated particles. However, the lack of detailed information hampers effective intervention, and other toxic chemicals present in mine runoff may demand entirely different approaches.

The organization actively coordinating "water diplomacy" to address environmental impacts of unregulated mining in Myanmar's rebel areas and improve water quality along the Thailand border is ASEAN (Association of Southeast Asian Nations). The Mekong River Commission Secretariat, another key player, supports data sharing, regional cooperation, and joint management of transboundary water resources to safeguard the health of the Mekong Basin.

The situation has been classified as "moderately serious" by the Mekong River Commission Secretariat, which has reiterated its commitment to supporting member countries and dialogue partners. However, the Klity Creek case, involving high lead levels despite extensive cleanup efforts, serves as a cautionary tale in rehabilitation projects.

In response, the Ministry of Natural Resources and Environment has pledged to deploy silk-screen filtration technology in the Kok River by the end of the year. This initiative, along with the ongoing efforts of various organisations, offers hope for a cleaner, healthier Mekong Basin in the future.

Unauthorized excavation activities contributing to environmental contamination downstream