Wastewater overflow, not oil, caused slick in Pattaya Bay

High-angle view shows Pattaya Bay that was threatened by black slick caused by wastewater overflow near Bali Hai Pier in South Pattaya.

PATTAYA, Thailand – Deputy Mayor Manot Nongyai clarified that the large black slick observed floating near Bali Hai Pier is not oil but overflowed wastewater from the South Pattaya Canal Pumping Station.

Social media was abuzz on June 15 following a video clip showing a boat navigating what appeared to be an oil slick in Pattaya Bay. High-angle photos further confirmed the presence of a black contaminant in the water, sparking immediate concern and triggering an investigation.

Deputy Mayor Manot Nongyai (right) inspects the South Pattaya canal pumping station following the wastewater overflow incident, ensuring swift response and environmental assessment.

Deputy Mayor Manot inspected the South Pattaya Canal Pumping Station and Bali Hai Pier on June 16, stating that a malfunction in the wastewater pipeline system occurred around 5 p.m. on June 15, causing the sudden shutdown of the main wastewater pumping station, PS1. This station, responsible for collecting wastewater from South Pattaya, directs it to the Nongyai wastewater treatment pond.

Due to the shutdown, wastewater overflowed into the sea, resulting in the visible black slick captured in videos and photographs. Repair efforts spanned approximately four hours, during which the wastewater treatment system was restored to normal operation. Subsequent water quality tests conducted the following morning confirmed that conditions have returned to normal.