Bangkok Government Moves on Pollution Control Zones After Fish Deaths

Fish began dying on November 10 in Bang Khanak Canal in Chachoengsao province, and the Thai government now plans to propose designating affected areas of the Prachin Buri River Basin as pollution control zones. Deputy Spokesperson of the Prime Minister's Office Lalida Persvivatana said on November 8 that the government had not ignored pollution concerns and planned to pursue the designation.

The proposal is undergoing data collection before submission to the National Environment Board. No official declaration has been made. That filing is the milestone that determines what happens next.

What triggered the response?

Dead fish floating in the Bang Pakong River alarmed residents and people who fish in the area. They fear the deaths connect to water contamination in the Prachin Buri River Basin, which feeds the Bang Pakong.

No official investigation has established the cause. No agency has confirmed a link between the two incidents.

Bang Khanak Canal sits in Bang Khanak subdistrict, Bang Nam Priao district. The location is the confluence of the Bang Pakong and Prachin Buri rivers, and the starting point of the Saen Saep Canal, which runs toward Bangkok.

A temple along the waterway posted a notice advising people not to collect the dead fish until test results confirm whether they are safe. Some of the fish had reportedly been dead for several days.

Sasiphong Siritharo, a 27-year-old monk at the temple, told Channel 7 that people from outside the area had come to collect the dead fish. He did not know whether they intended to eat or sell them. He added that potential buyers might not know where the fish came from.

At the time of reporting, officials had not launched an investigation into the cause of the fish deaths.

What do the water tests show?

The contamination concerns in Prachin Buri date back to major flooding at the end of September. Residents noticed an oily film on floodwater surfaces. The material allegedly came from an industrial waste landfill in the province.

Water test results showed contamination with petroleum hydrocarbons, excessive oil and grease, and several metals.

Residents reported developing itchy rashes and scabs after contact with the water. Rice crops in flooded fields reportedly died, despite normally surviving underwater for several months.

The allegations against the industrial waste landfill remain unconfirmed by any published official finding. The government has not named the facility.

What does the pollution control zone designation change?

The designation, if approved by the National Environment Board, would open the affected locations to further investigation and remedial measures. Thailand's environmental authorities use such zones to concentrate monitoring and enforcement powers on a defined watershed.

For the material stream at issue, the case turns on a single waste stream: industrial waste from a landfill that residents say entered floodwater and moved through two connected river basins. The confirmation or rejection of that pathway rests with investigators who have not yet begun work on the fish deaths.

Three questions remain open:

• Will the National Environment Board approve the pollution control zone designation, and on what geographic boundary?
• Will officials open a formal investigation into the November 10 fish deaths in Bang Khanak Canal?
• Will testing confirm a hydraulic link between the Prachin Buri Basin contamination and the Bang Pakong fish kill?

The next milestone is procedural: completion of the data collection phase and submission of the zone proposal to the National Environment Board. Until that board rules, the affected areas carry no special pollution control status, and the fish deaths carry no official cause.