Filtering Pollutants in Kok River with Silk-Screen Nets
Announcement of Silk-Screen Net Sediment Filtration Plan for Kok River
A new initiative to combat heavy-metal contamination in the Kok River, originating from upstream rare-earth mining activities in Myanmar, has been proposed by the Department of Water Resources. The plan, which involves installing specially designed silk-screen nets along the riverbanks, is set to commence at four initial sites—three in Mae Ai district of Chiang Mai and one in Mueang district of Chiang Rai.
The project, estimated to cost approximately 173 million baht, is aimed at reducing the downstream movement of toxic sediments and potentially capturing up to 70% of contaminated sediment, according to initial tests. It's important to note that the budget does not yet include the cost of sediment rehabilitation downstream.
The sub-committee on surface water quality, chaired by Deputy Prime Minister Prasert Jantararuangtong, has agreed in principle with the department's proposal. Public hearings were held in August 2025, with detailed designs expected to be finalised by next month. Implementation could begin as early as December 2025.
If successful, the project could be expanded to other affected sections of the Kok River to further mitigate sediment contamination. The plan is inspired by a model of sediment collection used in previous lead contamination remediation in Klity Creek, Kanchanaburi province.
The silk-screen net approach replaces an earlier plan to construct check dams in forested zones, which was projected to cost over six billion baht. This nature-based solution is designed as a practical secondary measure especially if upstream negotiations on pollution control fail. The filtration nets act as a physical barrier to reduce downstream movement of toxic sediments effectively, aiming to improve water quality and protect riverine communities.
It's worth mentioning that the project does not yet specify the number of sites where work will commence beyond the initial four sites mentioned earlier. Neither does it include any mention of public hearings or detailed designs being finalized. However, the department's chief, Teerachun Boonyasit, made this announcement.
The project will be closely monitored, and its success could pave the way for similar initiatives in other rivers affected by heavy-metal contamination. Stay tuned for updates on this significant development in water resource management.
[1] Source: Department of Water Resources, August 2025 press release.
In light of the Department of Water Resources' announcement, there could be potential possibilities for integrating science related to environmental-science and health-and-wellness, considering the project aims to improve water quality and protect riverine communities. Furthermore, advancements in environmental-science, such as therapies-and-treatments for contaminated water, could become increasingly important as the project continues to evolve and expand, particularly in addressing climate-change-related issues like heavy-metal contamination in other rivers.
