The Exxon Valdez was a 301-metre, 214,861 deadweight-tonne supertanker operated by Exxon Shipping Company. On 23 March 1989 it loaded approximately 200,000 cubic metres (1.26 million barrels) of Alaska North Slope crude oil at the Valdez Marine Terminal in Prince William Sound, Alaska.

The tanker departed Valdez at 21:12 on 23 March 1989 bound for Long Beach, California. Captain Joseph Hazelwood had been drinking before the departure. Coast Guard Vessel Traffic Service authorized a course change from the outbound shipping lane into the inbound lane to avoid icebergs from the Columbia Glacier.

At 23:53 Captain Hazelwood handed control to Third Mate Gregory Cousins — who was not certified for the relevant waters — and left the bridge. Cousins ordered a course correction to return to the outbound lane but the order was insufficient.

24 March 1989

The Exxon Valdez ran aground on Bligh Reef at 00:04 Alaska Standard Time on 24 March 1989. The reef tore open eight of the eleven cargo tanks. Approximately 41,600 cubic metres (260,000 barrels, 11 million US gallons) of Alaska North Slope crude oil flowed into Prince William Sound across the following four hours.

Captain Hazelwood’s blood alcohol concentration tested at approximately 0.06 percent more than nine hours after the grounding; back-calculation indicated approximately 0.20 percent at the time of grounding — above the maritime limit of 0.04.

The spill response

The contractually responsible spill response consortium (Alyeska Pipeline Service Company) was under-equipped. Containment booms did not arrive at the wreck for approximately 12 hours. A storm on 26-27 March 1989 spread the oil across approximately 2,100 km of Alaska coastline before mechanical recovery could begin.

Recovery operations across 1989-1992 mechanically removed approximately 14 percent of the spilled oil. Beach cleaning crews using hot water pressure washing across 1989-1990 — costing approximately $2 billion — harmed intertidal organisms that the high-pressure water displaced; cooler scientific reviews in the 1990s concluded the cleaning had been counterproductive.

Ecological toll

The 1989-1990 spill killed an estimated:

— 250,000 seabirds — 2,800 sea otters — 300 harbour seals — 250 bald eagles — 22 killer whales (the resident AT1 transient pod lost 9 of its 22 members; the pod has not reproduced since 1989 and has been designated functionally extinct) — billions of salmon and herring eggs

The 2010 reassessment by the Exxon Valdez Oil Spill Trustee Council documented persistent crude oil deposits in approximately 80 sites across Prince William Sound, decaying at approximately 4 percent per year.

Captain Hazelwood was acquitted of felony charges in 1990 and convicted only of misdemeanour negligent discharge of oil; the conviction was overturned on appeal then reinstated.

The 1994 Anchorage federal jury awarded Alaska commercial fishers $5 billion in punitive damages against Exxon. The US Supreme Court reduced the award to approximately $500 million in 2008. Per fisher recovery was approximately $15,000.

The Oil Pollution Act of 1990 required US-waters tankers to convert to double-hulled construction by 2015. The single-hulled Exxon Valdez was rebuilt and continued in operation under several names — Sea River Mediterranean, Dong Fang Ocean — until being scrapped in India in 2012.