29 March 2014

How do the professionals deal with oil spills?

Yesterday, I found out from Andy Lee of Oil Spill Response who gave a most informative "Oil Spill Awareness" talk as part of the Sentosa Community Resilience Programme.
Thanks to Grace Lee, Rebecca Tan and Gwee Xin Lin for inviting me to be a part of this.

Andy shared about Oil Spill Response, a "non-profit company which provides resources to respond to oil spills efficiently and effectively on a global basis" to members which are mainly oil companies. Their services can only be activated by the oil spiller. The Singapore team takes care of regional oil spills, and supports international situations if manpower needed.
Andy explained clearly and helped non-specialists like me understand the important considerations in cleaning up an oil spill. The most important step is to determine the type of oil that has been spilled. There are basically 4 groups of oil types. All oil floats on water. Pour point and viscosity measures reveal how solid the oil is. When oil becomes solid, it is hard to recover. Volatility measures the tendency for the oil to evaporate. If this tendency to evaporate is high, there is "less response" to cleaning up the oil spill. The recent Singapore oil spills were of the Group 3 variety. Once oil sinks to the sea bottom, it "tends to biodegrade naturally, so there is no response". There is a response only when oil spills impact the shoreline. Sentosa participants highlighted that there are corals and other marine life at the sea bottom that might be affected when oil sinks to the bottom.
What happens to the oil after it is spilled? It spreads, following currents. The oil emulsifies, taking up water and expanding greatly in volume with time. Oil starts to break down when exposed to sunlight, oxidises, and microbes naturally decompose the oil in the water. Larger marine life may also accidentally eat the oil when they eat oil-covered food or prey. If all this natural decomposition takes place, why remove the oil?  Because oil is hazardous and natural decomposition takes much too long.  In Oil Spill Response, "we want the oil to become small droplets to expedite and speed up natural decomposition" says Andy.
What are the Responses to an oil spill?
Salvage involves efforts, after the collision, to contain and recover remnants in the vessel and to stop the leak. Surveillance is done to find out what kind of oil is spilled on the water and thus what kind of response to take. Andy also showed a photo of a cap developed by Oil Spill Response after the Deep Horizon Oil Spill in the Gulf of Mexico in April 2010 which lasted for months because the oil industry did not have a readily available cap to stop crude oil from gushing out of a broken well.
Andy explained that dispersants are chemicals that expedite breaking oil into finer droplets to speed up natural decomposition of oil. He highlighted that dispersants cannot be used freely. Different countries have different rules about the use of dispersants. Oil Spill Response will only apply dispersants under favourable conditions that ensure proper mixing. For example, proper water depth (at least 10m). In calm conditions, Oil Spill Response will try not to apply dispersant. High waves, choppy water is ideal for proper mixing. Andy also said that dispersant can only be applied within 24 hours or 48 hours at maximum. After that, the oil becomes too emulsified and viscosity becomes too high for the dispersants to break up the oil. As to which is the best dispersant, Andy says they are all similar. To a question on whether they use degreasers?, Andy said no. But he couldn't explain the difference between degreasers and dispersants. Andy explains that the chemicals found in dispersants are also found in household cleaning agents. He also highlights that toxicity is a function of concentration and time. He didn't really respond when I asked about a study that found that an oil-dispersant mixture is many times more toxic than just the oil alone or dispersant alone.
Where it is allowed, oil may be burnt at the site. Collected floating oil is contained within a fire retardament boom and then set on fire. There is a need to consider the oil type, the thickness of the layer of oil, and weather conditions such as wind that may spread fire. Burning results in air pollution, and leaves behind residual pollution. Andy says in Singapore in situ burning not allowed (probably as outlined in the Environmental Pollution Control Act 1999). The photo on the right is of an "Octopus Skimmer" which can remove 250 tonnes of oil per hour. But this is restricted by the availability of temporary waste storage.
During an oil spill, there is also an effort to protect the shoreline and prevent oil from landing on the shore. It is best to have the equipment ready to protect the shoreline, before the oil spill hits the shore. Actions at the offshore spill site and on shore can take place concurrently. Oil Spill Response also has capabilities for "Oiled Wildlife" response, and have contacts with trained vets and handlers. I visited an Oil Spill Response exhibition in Jun 2012. While impressive, the set up is clearly more suitable for situations where a lot of seabirds are affected. For Singapore, we are unlikely to face this situation.
Andy stressed the importance of being prepared for oil spills. Oil Spill Response provides training at all levels, from people who put out the booms, manage skimmers, to management to plan and release budget. For oil spill contingency planning, it is important to outline all the roles and responsbilities of stakeholders, so everyone knows what they are supposed to do. Oil Spill Response can also conduct a third party audit to ensure they have proper training and proper planning. Exercises and drills should be conducted to test out the system, identify the time and resources needed, and unforseen gaps.
Andy then shared a case study for Singapore.
It appears Oil Spill Response was only involved in one of the 30 Jan 2014 spills. The 400m tonnes spill of  Group 3 type oil.
Action by Oil Spill Response was to skim spilled oil off the water and recover these onto another vessel, to be discharged by an NEA approved vendor The green area was where they were located for the containment phase. The red areas were where the oil hit the shorelines. Here's more about what volunteers saw about the oil spill impact on Kusu Island and St John's Island.
He shared these photos of the effort on this oil spill.
Andy also shared about an oil spill in Thailand from an SBM. Point of interest, in Singapore, I know of at least one SBM:  The 5km long SBM pipeline that runs from Pulau Bukom to an area just off Pulau Sebarok which allows Very Large Crude Carriers (VLCC)s to transfer crude to the refineries on Bukom. Here's more from the Shell briefing on plans to replace the SBM pipeline.
The response in Thailand included application of dispersant and clean up of the shore.
12 tonnes of dispersant were sprayed by a Hercules plane. Dispersants were not sprayed near the shore as proper water depth (at least 10m) was needed to ensure proper mixing.
Oil Spill Response had models to predict accurately the impact zone. Surveys were done to determine shoreline profiles and prioritise the areas to clean up. Oil stuck on rocks and cliffs were removed with high pressure hot washing, the resulting floating oil were collected with booms and then skimmed off.
On sandy shores, oil soaked sand is shoveled out into bags and removed. As tides move on the shore, the oil may eventually get buried. One response is to dig up sand, allow the surf to churn up the oil-sand mixture, and then skim off the oil. Andy recommends NOT using a bulldozer to remove oil soaked sand as this may drastically change the profile of the beach and have unintended effects.
Andy reminds that we must make sure we don't trek oil out of the impact zone and thus damage an even larger area. For example, in rest areas for workers and volunteers, or places where the collected oil is contained before final disposal.
Before his talk, Andy showed us a video of the work done by Oil Spill Response. I tended to focus on the images of dispersant application which I still find disturbing. I asked if Oil Spill Response had developed alternatives to dispersants, Andy reiterated that dispersants are the easiest and cheapest way to expedite breaking oil into finer droplets to speed up natural decomposition of oil.

The services of Oil Spill Response can only be activated by the oil spiller, after which Oil Spill Response will move out within 24 hours. Meanwhile, MPA has their own equipment and stockpile to deploy at the accident site. MPA will usually prod the oil spiller to quickly activate someone to do the oil spill cleanup.

This talk is part of Sentosa's Island Resilience Week, conducted every year. Attending this talk were staff from the Sentosa Island Operations which includes facility maintenance, landscaping, transport, security, described as a "Mini Town Council" by one of the friendly team members.

After the talk, there was sharing of the enormous amount of work the Sentosa Island Operations team did to take care of our shores during the oil spills during the Lunar New Year. This included daily surveillance of the shores on land and by boat on the water so oil could be removed before it hit the shores. Among the many actions that needed to be taken, included alerting Resorts World Sentosa and Underwater World Singapore about the possibility of water contamination for their captive animals.

Prior to the talk, Sentosa came up with a great list of questions. Which Lee Tsen Yang and Karenne Tun of NParks National Biodiversity Centre kindly helped to answer.

Q: How does oil spill like these happens/What kind of incidents are there
Possible factors that can result in maritime collisions in Singapore

1. Sheer volume of shipping traffic: from Singapore’s maritime sector recorded good growth in 2013: MPA. (7 Jan 2014). Channel News Asia.
  • Annual vessel arrival tonnage = 2.33 billion gross tonnes in 2013, representing an increase of 3.2% from 2012.
  • Cargo throughput = 32.6 billion standard-sized containers in 2013, up 2.9% from 2012.
  • Still the world’s top bunkering port in 2013.

2. Limited sea space:
  • At any one time, there are about 1,000 vessels in the Singapore port, while a vessel leaves or arrives Singapore every 2-3 mins. From Other facts you may not know on the MPA website.
  • Approximately 600 sq km of sea space. From the IUCM booklet, 2013

Incidents so far

from various news sources, including Singapore Infopedia
  • 1997 : Orapin Global tanker collided with Evoikos tanker south of the Singapore Port Limit at the Singapore Strait: 28,463 tons of heavy fuel oil
  • 2000 : Natuna Sea tanker ran aground off Batu Berhanti (Indonesia – 8km south of Sentosa): 7,000 tones of crude oil.
  • 2002 : MV Hermion freighter collided with Neptank VII bunker-tanker at the Eastern Anchorage: 450 tons of marine fuel oil.
  • 2010 : Bunga Kelana 3 oil tanker collided with MV Waily bulk carrier 13km off Changi: 2,500 tons of Bintulu light crude oil
  • 2012 : Kota Tenaga container vessel collided with SEEB VLCC 2.7km south of P Sebarok: 5 tons of marine fuel oil. Sunny Horizon bulk carrier collided with DL Salvia LPG carrier at Temasek Fairway: 60 tons of bunkers
  • 2013 : Oriental Pioneer bulk carrier collided with Atlantic Hero bulk carrier 6.6km south west of Tanah Merah Ferry Terminal, 2 Jul : 100 tons of fuel oil.
[Comment by Ria: here's a chart of the recent oil spills in Singapore from "Major oil spills in Singapore history" Today Online 2 Jul 13 also on wildsingapore news]

Q: What are those that has happened recently that (potential) affected Sentosa and Southern Islands?
The Evoikos (1997), Natuna Sea (2002), and the Bunga Kelana incidents (2010) have or may potentially have affected Sentosa and the Southern Islands given the scale and location of these incidents. Having said that, the bulk of collisions tend to occur at the southern waters of Singapore – that’s where all the refineries, container ports, fairways, Traffic Separation Scheme etc. are – coupled with the fact that we have limited sea space and huge vessel traffic, any incident occurring here would potentially affect Sentosa and the Southern Islands.

Q: What kind of stakeholders are involved?
The Maritime and Port Authority coordinates the seaward response operations (containment and cleanup), together with the National Environment Agency who coordinates landward clean-up, work in partnership with agencies managing coastal assets, vessel insurers (the “Protection and Indemnity Clubs”), the International Tanker Owners Pollution Federation Limited, and professional oil spill response vendors in their Oil Spill Response Plans. The NParks were included in these plans in 2010.

Q: How do companies prevent, mitigate, and resolve the oil spill issues?
Ship-owners: According to Hetherington, C., Flin, R., Mearns, K. (2006) Safety in shipping: the human element. Journal of Safety Research 37(2006) 401-411, between 43% to 80% of incidents are caused by human factors, and amongst the most common causes are: error of judgement, improper lookout, and failure to comply with regulations. Although there are international Conventions that cover aspects such as training, proper manning of the vessel to minimise crew fatigue etc., ship owners can do more to ensure that their vessels comply with, or exceed the standards stipulated in these Conventions.

Port Authorities: Given that vessels passing through the Singapore Strait are monitored using the Vessel Traffic Information System, officers manning the System must remain vigilant in tracking vessels and identifying potential collision situations.

Coastal asset owners (e.g. lagoon operators, refineries operators, fish farms etc): To have localised measures in place to prevent or minimise oil spill from their facilities or to counter the impacts of spills arising from external sources. Examples of such are; absorption booms that can be deployed to seal off the lagoon, informing tenants early so that they can carry out measures to minimise monetary losses etc.

Q: How are the oil spill waste cleaned/treated?
In general, MPA coordinates the seaward response operations. MPA’s immediate plan of action, based on what we know, is to attempt to contain the oil at its source (prevention of spreading) with the use of booms, skimmers etc, and then clean up remnant oil patches at sea. All coastal asset agencies will then have to put up localised measures as a last line of defence in the protection of their assets. The recovered oil, whether it is recovered on sea or land, must then be disposed/dealt with in accordance to NEA’s regulations.

Q: What are the impacts or consequences of these oil spill, e.g. marine life around the affected area?
Marine life can be impacted by oil directly when the oil contacts their surface, or indirectly, from the oil-associated chemicals that may affect them at the cellular or molecular levels.

The severity of oil related impacts will depend two main factors - exposure (ie, the amount and type of oil that comes into contact with the marine life) and duration (ie, the duration of exposure, either spot or pulsed).

These, in turn, are influenced by a wide variety of factors, including:
  • Time of spill and the prevailing hydrodynamics
  • Tidal height
  • Strength and direction of wind, if any
  • Rain/storms
  • Use of dispersants

Q: What actions have been taken to ensure the well being of these marine life ?
The primary objective should be to prevent contact between the oil and the marine life. This can be achieved containing the oil at sea so it does not make landfall and contact the marine life.

If oil does come into contact marine life, it is important to conduct rapid site assessments to determine the specific circumstances before proposing any follow up action.

Q: Who has involved in the monitoring of marine life ?
Currently, NParks is the lead technical agency involved in conducting initial rapid assessments. NParks depends on all concerned stakeholders and the general public to be our eyes and to report any oil-related observation so that NParks can followup in a timely manner with all response agencies. On top of that, there are several nature groups, as well as academics, in Singapore that regularly monitor our coastal and marine habitats.

Q: How should cleaning be done by the agencies or Sentosa to minimize impact on marine life?
There are numerous variables that would shape the way clean up can be done with minimal impact, such as substrate type, impacted habitat etc. Luckily, there are numerous manuals and guidelines to guide any response actions. In general though, clean up operations should be left to professionals with the proper training and access to personal protective equipment to reduce the risks associated with oil- based contaminants.

Q: What should Sentosa and/or public be aware of, and what areas can we help in?
Given the toxic nature of hydrocarbons, it is advisable for the general public to refrain from handling the oil. Members of the public can act as spotters, informing SDC/NParks (depending on location) of oil slicks that land on shore. This information will then be relayed to MPA so that they can adjust their response measures, as well as NEA, so that they can cordon off the area, evaluate if it’s the right time to do the clean up, take photos of the slick for claims purposes etc.

While SDC’s assets are covered in MPA’s oil spill response plans, it would be good to develop booming plans (if you/MPA don’t already have them) so that MPA can better coordinate the seaward response.

Awareness is key, and being proactive with reporting any oil spill observations is extremely helpful to the oil spill response agencies.
The public and SDC can play an important role in supporting response agencies, for example, they could potentially assist in carrying out (safe) animal rescue operations as well as assist in post cleanup monitoring efforts.

Once again, I thank Grace Lee, Rebecca Tan and Gwee Xin Lin for inviting me to be a part of this great initiative by Sentosa on dealing with oil spills. And also Lee Tsen Yang and Karenne Tun of NParks National Biodiversity Centre for answers to the very good questions Sentosa raised about oil spills.

I am indeed glad to know that there are many people concerned about our shores, and I look forward to working together with them to develop a more comprehensive and coordinated response to oil spills by everyone, including ordinary people and volunteers.


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