Shell has shut down one of its oil processing units at the Shell Energy and Chemical Parks at Pulau Bukom in Singapore, to facilitate investigation into a suspected leak in the system, Singapore's Maritime and Port Authority (MPA) and National Environment Agency (NEA) said.
The oil processing unit is used to produce refined oil products such as diesel. Water drawn from the sea is used as part of the process to cool the refined oil products in the unit.
Shell estimated that a few tonnes of the refined oil products were leaked, together with the cooling water discharge.
In response, the company has laid containment and absorbent booms and sprayed dispersants in the channel where the cooling water is being discharged.
The in-built oil skimmer system in the channel has also been activated. Containment and absorbent booms have been laid at the mouth of the channel, to prevent residual oil leaked from spreading into the sea. No oil patches are currently observed in the vicinity of Pulau Bukom, according to MPA.
MPA and Shell have deployed boats to clean up light oil sheens observed off Pulau Bukom using both dispersants and absorbent booms.
Agencies are closely monitoring the situation and have deployed satellites and drones for surveillance.
As a precaution, oil absorbent booms will be laid at Sisters' Islands Marine Park and at the beaches on Sentosa. Navigational traffic in the area is not affected. There is no impact to bunkering operations in the Port of Singapore.