The Philippine Coast Guard has launched an investigation into the presence of yellowish liquid waste in the waters of Manila Bay just off Pasay City.
The waste was first sighted on Sunday, April 25. It was soon traced back to Sarangani, a privately-owned vessel currently moored at the Manila Yacht Club near the US Embassy building.
The waste had spread out more than 500 metres from the yacht. This then prompted the coast guard and the Department of Environment and Natural Resources (DENR) to prohibit other vessels from approaching to within 2.5 kilometres of the shoreline to lower the risk of the waste reaching further out to sea.
The coast guard said the yacht had only one person on board at the time of the spill. This individual has been identified as the yacht's oiler, who said he was entrusted by the owner to look after the vessel while moored.
The waste was discharged by Sarangani's cooling system shortly after the generator was switched on, a coast guard spokesman told local media.
Investigators believe algae buildup in the cooling system had caused the discolouration in the discharged wastewater.
DENR pollution response personnel have collected samples at the site for laboratory analysis.
The DENR said the yacht has been placed under custody as part of the investigation, the results of which will determine whether the owner will be charged with maritime pollution violations with a corresponding fine of PHP10,000 (US$206) to PHP20,000 (US$412).