June 19, 2024
SINGAPORE – Efforts to clean up the oil spill are still under way, after the authorities expanded containment efforts to more areas on June 17.
Caused by an incident where the Netherlands-flagged dredging boat Vox Maxima hit the Singapore-flagged bunker vessel Marine Honour on June 14, the spill has stained coastlines at East Coast Park, Labrador Nature Reserve, Keppel Bay, the Southern Islands and Sentosa.
Preventive measures have been set up off Changi East, as well as biodiversity-sensitive areas at the Chek Jawa Wetlands in Pulau Ubin, Coney Island Park and Pasir Ris Park.
The Straits Times takes a closer look at the cleanup efforts.
Q: What happened in the immediate aftermath of the spill?
Following the incident between the vessels, the Maritime and Port Authority of Singapore (MPA) “immediately deployed” its nearest patrol craft – assigned to patrol Singapore’s waters 24/7 – to the incident site, and sprayed dispersants on the spill after assessing the situation.
Dispersants are chemicals that break up oil into smaller droplets, which can be mixed with water.
Captain Chong Jia Chyuan, port master with MPA, said all its response crafts were activated to spray dispersants on the spill during the optimal “window of opportunity” for the oil to react with the dispersant. He did not specify how long the “window of opportunity” lasted.
He added that the authority also activated its oil spill response contractor to collect the oil at sea and set up booms around the two affected vessels. These booms refer to containment booms, which are floating devices that create a barrier to trap oil. Once oil is contained, oil skimmer machines help collect the oil from the water surface.
“Our first priority was to ensure the safety of the vessels and to immediately stop the oil from further leaking into the sea,” Capt Chong said. He said the crew immediately isolated the damaged tank on the Marine Honour by transferring the remaining oil from the damaged cargo tank to the vessel’s other tanks.
No more oil escaped into the sea on the evening of June 14, he noted.
The captain and crew are still on board the Vox Maxima to assist with MPA’s investigation.
The Vox Maxima has since been towed further away from the incident site to allow port operations to resume.
Q: What were the next steps in the cleanup efforts?
Following the initial containment strategy in the immediate vicinity of the two vessels, Capt Chong said more booms for coastal protection purposes were laid near the coastlines while equipment was used to collect oil trapped there, starting from June 15, the day after the incident.
Due to rapid tidal movements, MPA chose to collect oil in certain areas first before activating booms to contain them in areas with natural constrictions or catchment areas.
Capt Chong said he does not have a timeline on when MPA’s investigation into the incident will be completed, as it is subject to the complexity of the incident and cooperation from relevant parties, including the captain and crew on Vox Maxima.
In response to further improvements to MPA’s recovery efforts for future oil spill incidents, he declined to comment as the incident is still under investigation, so the authority will have to first understand the cause of the spill.
Q: What equipment is needed to contain the spread of the spill?
Containment booms are used to create a barrier to trap oil.
Skimmers are then used to lift the oil off the water surface – around the containment booms – into storage tanks.
Separately, absorbent booms are used in biodiversity-sensitive areas as they can contain and absorb oil.
The Current Buster system, towed by two vessels, goes to affected areas to collect contaminated seawater and sieves oil out through a pump for skimmers to collect. It can collect up to 50 cubic m of oil at a time.
Drones that can travel up to about 60m above sea level, with a battery life of 25 minutes each, are used to direct Current Buster systems to affected areas, as they can capture clearer aerial views of the water surface. This is because there is a lot of reflection on the water surface when observed from a vessel.
MPA will deploy booms totalling 3.1km in length, three skimmers, three Current Buster systems, three drones and 18 oil spill response craft over the next few days.
Capt Chong could not provide the exact amount spent on cleanup efforts so far, as many agencies are involved in the operation and more time is needed to work out the figures for the manpower, logistics and craft involved.
Q: Why did the oil spill continue to spread, despite MPA’s quick response to the incident?
The authority said tidal movements were one of the reasons for the spread, as parts of the spill were carried onto the shore with the receding movement of the tides and out to sea.
Transport Minister Chee Hong Tat said in a Facebook post on June 18 that booms may not completely prevent the spill from spreading, as some of it could be carried by tidal currents and waves, which may go above or below the booms.
A major oil spill incident in 1997, involving the collision of two oil tankers, led to a spill of 29,000 tonnes of heavy fuel oil, about 72 times the amount of oil leaked in the current incident.
However, the leak of the damaged cargo tank in 2024 led to a spill of low-sulphur fuel oil, which is less viscous or less resistant to movement compared with heavy fuel oil, which may explain the widespread movement of the oil spill this time.
Additionally, cleanup operations are more effective in the day when drones can be used to spot the spills, although MPA is still carrying out night operations.
When asked if MPA’s equipment quantity met international standards, Capt Chong said the authority does risk assessments to understand scenarios requiring the use of various equipment.
He noted that MPA has a salvage company – to provide solutions for damaged vessels – that provides standby resources to attend to different kinds of spills.
Capt Chong added that MPA will do regular review exercises to determine if its equipment is sufficient.