March 24 marks the 29th anniversary of the Exxon Valdez accident. On this date in 1989, one of the most catastrophic – if not the most catastrophic – oil spills of the 20th century took place. The tanker Exxon Valdez was departing the Port of Valdez, Alaska with a full load of North Slope crude oil, of approximately 1.26 million barrels, destined for Long Beach when it grounded on Bligh Reef in Prince William Sound. About 258,000 barrels of cargo were spilled as eight cargo tanks ruptured, causing one of the most shocking environmental disasters in the history of US.
How did the accident happen?
The US tankship Exxon Valdez had departed the Port of Valdez in Alaska, 1,263,000 barrels of crude oil, when it grounded on Bligh Reef in Prince William Sound, near Valdez, Alaska. At the time of the grounding, the vessel was under the navigational control of the third mate. No injuries, but 258,000 barrels of cargo were spilled resulting in catastrophic damage to the environment.
Specifically, according to a report by the National Transportation Safety Board (NTSB), the third mate and the master of Exxon Valdez were on the bridge, moments before the accident. The two men were discussing about the route of the ship, when the master told the third mate that he would leave the bridge for a little while. He also instructed him to inform him (the master) when the ship was about to return to the traffic lanes, leaving the third mate in charge of this.
A little later the third mate ordered a hard right, to return to the traffic lanes and informed the master, through a phone call. When the call ended the third mate noticed that the course of the vessel had not changed. Namely, he said that despite the fact that the ship was swinging right, the radar did not show that. After a few moments he called again the master telling him “I think we are in serious trouble”.
At the end of the call, the ship hit the bottom and it sustained a series of sharp jolts for about 10 seconds. The third mate then tried to steer left, but because of the hard right swinging, the vessel could not turn left. When the ship stopped, the third mate reported that he smelled gas and crude oil vapor.
About 258,000 barrels of cargo were spilled in the sea. The damage to the vessel was estimated at $25 million, the cost of the lost cargo at $3.4 million, and the cost of the clean-up of the oil spill at $1.85 billion.
Environmental Pollution
When the accident happened, Exxon Valdez was carrying approximately 55 million US gallons (210,000 m3) of oil, of which about 10.1 to 11 million US gallons (240,000 to 260,000 bbl; 38,000 to 42,000 m3) ended up in the Prince William Sound. This spill had an enormous effect on animals, the coastline and indigenous population:
- The amount of oil spilled could fill 125 Olympic-sized swimming pools.
- Immediate effects included the deaths of 250,000 seabirds, 2,800 sea otters, 12 river otters, 300 harbor seals, 247 bald eagles, 22 orcas, and an unknown number of salmon and herring.
- 1,300 miles of coastline were hit by the oil spill.
- The oil spill affected 11,000 square miles of ocean.
- The spill caused over $300 million of economic harm to more than 32 thousand people whose livelihoods depended on commercial fishing.
- Tourism decreased by 8% in south central Alaska and by 35% in southwest Alaska in the year after the spill.
- Twelve years after the spill, oil could still be found on half of the 91 randomly selected beaches surveyed.
The clean-up operations started shortly after the accident using booms and skimmers. However, not all of the equipment was available at the time, and the thickness of the oil damaged some of it. As a result, and despite the help that many volunteers offered, only 10% of total oil was actually completely cleaned. Namely, studies have shown that more than 26 thousand gallons (98 m3) of oil remain in the contaminated shoreline, declining at a rate of less than 4% per year. Until today, oil remains on the beaches and has the same chemical compounds as those it had 11 days after the incident.
Click on this link to view Simulator demonstration of Exxon Valdex mishap.
Source:https://safety4sea.com/learn-from-the-past-exxon-valdez-incident/