Phumtham plans dams on Sai and Kok rivers to trap heavy metal contamination

Deputy Prime Minister and Defence Minister Phumtham Wechayachai on Wednesday revealed plans to build dams on the Kok and Sai rivers in Chiang Rai to trap and filter heavy metals originating from mining activities in Myanmar, protecting communities along the rivers.

Government Orders Design of Heavy Metal-Filtering Dams

Phumtham instructed the Department of Water Resources to design dams capable of filtering heavy metals from the water and trapping contaminated residue for later removal from the riverbeds.

He emphasised that the government is aware of the heavy metal contamination issue in Chiang Rai’s rivers, particularly concerning lead and arsenic. Last week, he convened a national committee on flood, storm, and mudslide disasters to discuss the problem and devise long-term solutions.

Water Tests Confirm Heavy Metal Contamination in Northern Rivers

The Public Health Ministry has collected water samples from the Mekong, Sai, and Kok rivers in Chiang Rai. Tests confirmed the presence of arsenic and lead contamination in certain areas, following reports from locals of fish exhibiting deformities and skin diseases.

Myanmar Mining Cited as Source, but Cross-Border Control Challenging

Phumtham attributed the contamination to uncontrolled mining in Myanmar. While current levels do not pose immediate health risks to local people, they may cause long-term harm.

Attempts to coordinate with the Myanmar government to regulate mining have been unsuccessful, as the mining occurs in areas controlled by rebel forces.

Thailand to Take Independent Action with Dam Construction

Consequently, Phumtham stated that Thailand must implement its own measures to protect its population by designing and constructing dams to filter heavy metals from the rivers.

“Although it is a long-term risk, the government has already taken action and is now in the process of designing these dams,” he said.

The Department of Civil Aviation has been ordered to conduct aerial surveys of the Sai and Kok rivers to identify suitable dam locations.

Long-Term Protection for River Communities

The proposed dams will filter out heavy metals and trap contaminated residue for later excavation, ensuring safer water quality for people downstream.

“I affirm that the contamination levels are not harmful yet, but the government will not leave local people—key assets of the country—to face this issue alone. It is our duty to protect them,” Phumtham concluded.