Thailand: Cross Border River Contamination Impacts Agriculture in Northern Regions

Since March 2025, heavy metals have been detected in rivers entering Chiang Rai Province, raising concern for irrigation across an estimated 133,000 rai (21,317 hectares) of farmland and drinking water for about 14,000 households. However, monitoring shows a mixed picture: elevated arsenic in river sediment and water, but all recent food and tap-water samples within safety standards. Thailand has confirmed treated water is safe, committed funding to relocate its raw water source, and expanded international cooperation with Japan, UNIDO, Australia, and China.