The oil slick previously reported in waters around Koh Larn have now been found floating in the sea and washing ashore at Jomtien Beach, Chon Buri, on Monday, 10 August. Pattaya City has warned residents and tourists not to swim at Jomtien Beach while the substance is assessed. The slick was reported both along the shoreline and in the seawater, with significant amounts seen near Jomtien and Koh Larn. Cleanup and testing begin Pattaya City officials sent workers to collect samples of the black, oil, determine how far the pollution has spread and begin removing it from the affected area. The discovery at Jomtien follows the earlier report of slicks around Koh Larn, suggesting the pollution has moved across waters used by tourist boats, swimmers and visitors travelling between the island and mainland Pattaya. Authorities have not yet confirmed what the substance is or where it came from. The city said the assessment was still under way and urged people to exercise caution. Two possible sources under investigation Pattaya Deputy Mayor Manoch Nongyai said investigators were considering two possible explanations: an illegal discharge from a vessel, or material drifting into the area from around Laem Chabang. Officials from the Marine Department and environmental agencies have joined Pattaya City in the inquiry. Swimming warning remains in place Pattaya City has not said when Jomtien Beach will reopen for swimming. Until testing and cleanup work clarify the scale and nature of the pollution, the warning applies to residents and tourists alike. Pictures courtesy of Khaosod Related story Pattaya-probes-oil-like-slick-on-koh-larn-beaches Join the discussion? 11 August 2026
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