CHIANG RAI – After alarming reports surfaced about arsenic levels in the Kok River, the Provincial Waterworks Authority (PWA) has committed an investment of 15 million baht to implement a comprehensive strategy addressing contamination in the vital raw water sources drawn from the Sai, Ruak, and Kok Rivers. This initiative is crucial for ensuring the health and safety of the local population who depend on these water sources for their daily needs.
The agency has emphasized that tap water in Chiang Rai remains safe not only for household use but also for drinking purposes. To enhance transparency and public confidence, the PWA has mandated more frequent water quality inspections. This proactive approach aims to keep the community informed about water safety and mitigate any public anxiety regarding potential contamination.
Jakrapong Kamchan, Governor of the PWA, provided insights into the situation by explaining that the issue began with troubling news concerning gold mining activities at the source of the Kok River, located in Shan State, Myanmar. These mining operations have led to the disruption of natural sediment levels in the river, and subsequent test results revealed alarming concentrations of heavy metals that exceeded established safety standards.
This scenario has understandably raised significant concerns about the safety of water for the communities that rely heavily on tap water for their daily consumption and domestic activities. It is essential for local authorities to address these fears comprehensively.
In response to the contamination crisis, the PWA has collaborated with various stakeholders including Chiang Rai’s governor, the local natural resources office, the Pollution Control Department, elected officials, and community leaders. Together, they have engaged in a meticulous process of collecting water samples from critical locations such as the Kok River and the Maeyao-Doiha Friendship Bridge to assess the water quality accurately.
The results of the tests indicated that all key physical properties of the water met the established tap water standards, and no hazardous contamination was detected. This finding reassures the residents of Chiang Rai that their tap water remains safe for drinking and everyday use, contributing to public health and well-being.
The PWA is now committed to conducting water quality checks every two weeks, a significant increase from the previous annual inspections. Samples are meticulously taken from various points, including raw water sources, production systems, storage tanks, and even directly from households. Regular updates on these results are meticulously shared with the public to maintain transparency and trust.
In the most recent checks conducted in July 2025, both the Chiang Rai and Mae Sai branches confirmed the absence of arsenic in the water supply. The results for other potentially harmful heavy metals are anticipated to be released in about two weeks, which will provide further assurance to the community.
Moreover, the PWA has launched an extensive plan to effectively manage and mitigate heavy metal contamination in raw water sources. Upgrades are currently underway at the three water treatment plants to enhance their capability to handle chemicals efficiently and improve the overall quality of the water supplied to residents.
The treatment facilities at Wang Kham in Chiang Rai, Mae Sai, and Koh Chang utilize water sourced from the Sai, Kok, and Ruak Rivers. Significant investments totaling over 15 million baht are being directed toward the installation of six new chemical dosing systems. Future plans include the integration of advanced treatment systems specifically designed to remove heavy metals effectively from the water.
On the international cooperation front, in April, director Phongsak Diewwilai of the PWA’s Region 9 engaged in discussions with Mr. Myint Zaw Lin, the Consul General of Myanmar in Chiang Mai. Their meeting focused on developing collaborative strategies to address and resolve chemical contamination issues linked to gold mining activities in Mong Sat and Mong Yawn, Myanmar, demonstrating a commitment to cross-border environmental management.
Mr. Myint Zaw Lin expressed Myanmar’s readiness to collaborate with Thailand in efforts to halt and rectify the contamination problem. He committed to reaching out to officials in Mong Sat, Mong Yawn, and other relevant agencies to ensure that the initiatives are carried out effectively and without delay.
In June, the PWA leadership convened with residents in the Mae Sai district to openly discuss their concerns regarding water quality following the contamination reports. To build public confidence in the quality of tap water, officials demonstrated their commitment by consuming the tap water in front of locals and sharing detailed information about safety standards and testing procedures.
Governor Jakrapong Kamchan reiterated that the PWA is diligently monitoring water quality and adjusting its treatment protocols as necessary. Their priority remains to ensure that the water in the Mekong, Ruak, Sai, and Kok Rivers is consistently safe and free from harmful contaminants.
In the near future, PWA teams will be deployed to Chiang Rai to thoroughly review water production processes and testing methodologies. Regular updates will be provided to the residents to reinforce their confidence in the safety and quality of their tap water supply, which is essential for community health.
