Tuesday, January 7, 2014

Exxon Valdez Oil Spill

Exxon Valdez Oil Spill
Prince William Sound, Alaska, 1989 

Summary data:
Date: March 24, 1989
Place: Prince William Sound, Alaska
Type of accident: Crude oil spillage
Outcome: The Exxon Valdez supertanker ran aground on Bligh Reef, the “grounding” of the ship ruptured, and led to the oil spill by releasing nearly 260 000 barrels of crude oil into Alaska's Prince William Sound.

Oil spill overview and location
Exxon Valdez carried 53,094,510 gallons (1,264,155 barrels) of oil. The amount spilled was nearly 20%, which corresponds to nearly 260 000 barrels.

What happened?

On March 24, 1989, the tanker Exxon Valdez, sailing from Valdez, Alaska to Los Angeles, California, ran aground on Bligh Reef in Prince William Sound, Alaska. The vessel was traveling outside normal shipping lanes in an attempt to avoid ice. Within six hours of the grounding, the Exxon Valdez spilled approximately 10.9 million gallons of its 53 million gallon cargo of Prudhoe Bay crude oil. Eight of the eleven tanks on board were damaged. The oil would eventually impact over 1,100 miles of non-continuous coastline in Alaska, making the Exxon Valdez one of the largest oil spill in U.S. waters.

The oil slick (blue areas) eventually extended 470 miles southwest from
Bligh Reef. The spill area eventually totaled 11,000 square miles. 

(Source: Exxon Valdez Oil Spill Trustee Council)

Why? How?

Several investigations have been conducted. Even today, the reasons of such accident are still not completely defined, but some of them have been already identified.

One of them relies on the fact that Exxon Shipping Company could have failed to supervise the master and provide a rested and sufficient crew for Exxon Valdez.
Moreover, one member of the crew may have failed to properly handle the vessel, possibly due to fatigue or excessive workload.
Exxon Shipping Company failed to properly maintain the Raytheon Collision Avoidance System (RAYCAS) radar, which, if functional, would have indicated to the third mate an impending collision with the Bligh Reef by detecting the "radar reflector", placed on the next rock inland from Bligh Reef for the purpose of keeping boats on course via radar.

Effects upon environment

Fortunately, this accident did no human victims. However, marine and wild lives were the hardest hit by the oil spill. Lives of millions of fishes almost came to a standstill. Some were killed by eating oil-contaminated food, while others were starved to death because of the spoiling of plankton and larva on which they were dependent. Moreover, the thick layer of oil on the surface disrupted the whole marine life beneath it.

Exxon, which was the owner of the vessel, originally was ordered by a federal court to pay $5 billion in punitive damages in 1994. A federal appeal in 2006 reduced it to $2.5 billion. In 2008 the United States Supreme Court further reduced the damages to just over $500 million. More than $2 billion has been spent on cleanup and recovery.

Coasts cleaning in Prince William Sound


This accident prompted the United States and other countries to impose more stringent standards to ships that are operating in their waters.
Concern over the Exxon Valdez oil spill led directly to several legislative and regulatory changes designed to prevent oil spills and facilitate clean-up attempts. The 1990 Oil Pollution Act and 1990 Oil Pollution and Liability Act established a U.S. federal cleanup fund paid for by a 5 cent per barrel oil tax, mandated double hull containment systems for all new vessels in excess of 5000 tons by 2005, established minimum liability limits for shippers, and raised the caps on the maximum liability for oil spills. In Alaska, the state government passed a law requiring the Alyeska Pipeline Company to stockpile enough equipment to combat a 300,000-barrel spill. Oil dispersant storage areas are now located for quick deployment anywhere in the state. As for port procedures, both a tug and an emergency response vessel now escort each tanker leaving the Port of Valdez. Tankers now face a speed limit in the main channel of 10 knots, and ship captains now are tested for alcohol an hour before sailing. Tankers can no longer leave the channel for any reason except emergency, and the Coast Guard’s radar surveillance has been enhanced. The spill also created new interest in scientific research that has resulted in several new methods for cleaning up oil spills.

The video below summarizes the big lines of this accident, and the lessons to be learned after 25 years :

 Exxon Valdez Oil Spill: In the Wake of Disaster

 (Source : The New York Times)

·      Exxon Valdez Oil Spill - Alaska Ressources Library & Information Services :       http://www.arlis.org/docs/vol2/a/EVOS_FAQs.pdf
·      Exxon Valdez Oil Spill Trustee Council
·      The New York Time – Time Topics – Exxon Valdez oil spill

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