Officials investigate brown seawater at Patong Beach

Officials have collected water samples for laboratory analysis after brown seawater was reported along about 1.5 kilometres of Patong Beach in Phuket.

The inspection on July 21 followed a visit to the area by Natural Resources and Environment Minister Suchart Chomklin and Deputy Interior Minister Worasit Liengprasit on July 20. Officials from the Environmental and Pollution Control Office Region 15, the Phuket Provincial Office of Natural Resources and Environment and Patong Municipality inspected Patong Beach, Khlong Pak Bang and Kalim Beach.

Inspectors said they found no evidence that a nearby hotel construction site had discharged wastewater into Khlong Pak Bang. They said rain had instead washed concrete residue from the site into the canal. The contractor had cleaned the area, while officials ordered a sediment trap to be installed and told Patong Municipality to monitor compliance with environmental measures required under the project’s Environmental Impact Assessment.

The water in Khlong Pak Bang was described as brownish-green during the afternoon high tide. The Ministry of Natural Resources and Environment said the seawater near the canal mouth was dark brown and affected by what it described as an algal bloom. It said the high tide had pushed seawater back into the canal, making the water appear almost black.

Officials also checked drainage outlets at Kalim Beach after complaints about wastewater entering the sea. They reported that the water flowing from the outlets was clear, with no obvious signs of pollution.

Authorities said the latest discolouration may have been caused by another phytoplankton bloom, but laboratory analysis is expected to determine the exact cause and whether pollution contributed. The Environmental and Pollution Control Office Region 15 said it would continue monitoring the situation.