Arsenic Contamination Disrupts Water Supply in Mae Sai

According to a report by Khaosod Online Thailand on November 10, 2026, residents in 14 villages across the Mae Sai and Wiang Phang Kham sub-districts of Chiang Rai province are facing a severe water crisis. The Pollution Control Department (PCD) has confirmed that arsenic levels in the Sai River have reached 28 times the standard safety limit. Additionally, the river water has exhibited extreme turbidity, measured at 14,000 NTU, which significantly exceeds the 6,000 NTU capacity of local water treatment systems. As a result, the Provincial Waterworks Authority has been forced to suspend tap water production and distribution, as the raw water source is currently unusable. PCD Director-General Dr. Surin Worakitthamrong stated that authorities are now prioritizing the identification of alternative water sources. Emergency measures are underway, including the deployment of water trucks and mobile drinking water production units to assist the affected population. For residents and travelers in the area, this situation poses a significant challenge to daily hygiene and water consumption. It remains to be confirmed how long the contamination will persist and when the water treatment facilities will be able to resume normal operations. Local authorities are continuing to monitor the water quality and provide updates on the availability of safe water supplies.