CHIANG RAI – The Peoples Network has sent a letter to Prime Minister and Interior Minister Anutin Charnvirakul, proposing 10 urgent steps to tackle pollution in the Kok, Sai, Ruak, and Mekong rivers, calling for a shutdown of illegal upstream mines and a plan to test farmland soils

The letter urges swift action on cross-border pollution linked to unlawful mining in the upper Mekong basin, especially rare earth and gold operations near the headwaters of the Kok and Sai rivers.

According to Ms. Rakdao Pritchard, coordinator of the People’s Network, communities in Chiang Rai and Chiang Mai, as well as downstream areas, are facing heavy metal contamination in river systems. The reported sources are mines in Shan State and tributaries feeding the upper Mekong, including the Kok, Sai, and Ruak.

The network says the government must work to close mines in Myanmar, since stopping the source will reduce river pollution. It also calls for long-term river basin restoration. With the government four months into office, the network sets out ten urgent actions:

Secure new raw water sources to replace the Kok, Sai, Ruak, and Mekong for regional tap water. Priority districts include Mueang Chiang Rai, Wiang Chai, Mae Sai, Chiang Saen, and Chiang Khong. Lab tests of tap water show arsenic and barium are present, though still within limits. People face ongoing exposure risks from bioaccumulation. The Provincial Waterworks Authority is also absorbing higher treatment costs and using more chemicals. New sources offer a more sustainable fix.
Provide alternative water sources for village waterworks in Mae Na Wang and Tha Ton, Mae Ai district, Chiang Mai. Locals cannot use the Kok for village supply. Upgrade village systems along the Kok, Sai, Ruak, and Mekong, at least 30 villages in Mae Ai district in Chiang Mai, and Mueang Chiang Rai, Wiang Chai, Wiang Chiang Rung, Mae Chan, Doi Luang, Mae Sai, Chiang Saen, Chiang Khong, and Wiang Kaen in Chiang Rai. The goal is to add treatment capacity to remove heavy metals, especially where groundwater lies close to contaminated river channels.
Test soils for heavy metals on 12,000 rai of floodplain along the Kok in Tha Ton, Mae Ai, Chiang Mai. This area received direct mine-derived sediments from Myanmar during the major floods of 2024. The zone is a key farming area. The government should also plan to test wet-season rice from more than 100,000 rai in the Kok and Sai–Ruak irrigation schemes before harvest in late October to November.

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Ms. Rakdao said pre-harvest rice testing protects both the rice industry and consumers. If heavy metals are found, the state must remove contaminated crops and compensate farmers for costs and lost income. If no contamination is found, the state should issue certificates to help farmers sell their rice and give buyers confidence.

Establish heavy metal testing centres in Chiang Rai and Chiang Mai. These centres would monitor water, riverbed sediment, farm soils, crops, fish, aquatic life, and human biomarkers in the Kok, Sai, Ruak, and Mekong basins. Access to testing is now limited, costly, and slow because most samples must go to Bangkok. The Ministry of Public Health’s Medical Sciences Centre 1/1 in Chiang Rai lacks sufficient capacity, leaving people without up-to-date data.
Suspend imports of all minerals from Myanmar until importers can demonstrate that shipments do not come from mines polluting the Kok, Sai, Ruak, and Mekong.
Cancel sediment-trap weirs or curtain projects. There is no proof that they reduce heavy metal contamination in rivers. They would also damage farmland and harm ecosystems. The Department of Water Resources does not have a mandate to handle pollution control.
Form a joint task force of government, academics, and civil society to:

Find pathways to shut down mines in Myanmar.
Build surveillance for heavy metals in drinking and domestic water, soils, farm products, aquatic species, and human health.
Provide relief to people affected by mining in Myanmar.
Set restoration plans for the Kok, Sai, Ruak, and Mekong.

Open formal talks with Myanmar and China. Ask both countries to take responsibility for mining-related pollution affecting communities in Thailand.
Improve crisis communication so all groups can access timely information, both online and offline. Materials should reach ethnic communities in the languages they use.
Review and delay power purchase agreements for the Pak Beng hydropower project on the Mekong in Lao PDR. Conduct studies on risks from mining-derived toxins in the upper Mekong. If the river becomes a reservoir, heavy metals will settle in the impoundment, with severe ecological and public health impacts.

The network stresses urgency, both to stop the source of contamination and to protect water, food safety, and livelihoods across Chiang Rai and Chiang Mai.