Exxon Valdez oil spill | A Matter of Scale

Exxon Valdez aground at Prince William Sound

March 24, 1989, the Exxon Valdez ran aground rupturing 8 of its 11 cargo holds. No lives were lost however, the ship released 257,000 barrels of oil in its accident at Prince William Sound, though four perished later during the cleanup. The Valdez lost the equivalent of 10.7 million gallons. The accident released the equivalent of 17 Olympic sized swimming pools full of oil. They are still feeling the effects 23 years later. (634,941 gallons fills an Olympic sized pool…)

The Exxon Valdez oil spill was not the largest in history. In 1978, the Amoco Cadiz was wrecked off the coast of France and spilled six times as much oil (1.5 million barrels). However, that spill dissipated quickly since the wreck occurred, unlike the Exxon Valdez incident, in the open seas. Gas retailers were quick to take advantage of the spill, raising prices at the pump by as much as 14 cents.

Nearly $400 million of the Exxon settlement was used by the government to purchase 650,000 acres that included 1,400 miles of shoreline along Prince William Sound as well as 287 salmon spawning streams in order to protect against development.

In the aftermath of the incident Congress passed the Oil Pollution Act of 1990, strengthening regulations on oil tankers and oil tank operators. Oil companies engaged in the Alaska trade were ordered to switch to double-hulled tankers by the year 2015. In Prince William Sound, tugs escorted tankers all the way to the open sea while fully-qualified pilots remained at the helm until all vessel were beyond Bligh Reef.

Deep Water Horizon Fire (AP Photo/US Coast Guard)

At 09:45 p.m. CDT April 20, 2010, during the final phases of drilling the exploratory well at Macondo, a geyser of seawater erupted from the marine riser onto the rig, shooting 240 ft (73 m) into the air. This was soon followed by the eruption of a slushy combination of mud, methane gas, and water. The gas component of the slushy material quickly transitioned into a fully gaseous state and then ignited into a series of explosions and then a firestorm. Workers immediately attempted to activate theblowout preventer, but it failed.

Since the Deepwater Horizon explosion, 11 lives were lost and the uncapped oil well has released an estimated 100,000 barrels of oil per day. Since the beginning of this event, there has been an estimate release of 6.3 million barrels of oil.

100,000 bpd x 63 days = 6,300,000 million barrels x 42 gallons per barrel = 264,600,000 million gallons.

The Deep Water Horizon accident has released enough oil/hydrocarbons to fill 417 Olympic sized swimming pools.

Conservatively we have another 40 days before the relief wells are completed. If they were done on August 1, we will have added another 40 days or 4 million barrels (168 million gallons) of oil to the current ecological disaster… Worst Case Scenario: If they were not done until August 30, it would add another 70 days or 7 million barrels of oil (294 million gallons). So our best and worst case totals, assuming nothing else more catastrophic occurs:

Best Case Total: 63+40 = 103 million barrels or 415 Million gallons of oil, the equivalent of 400 Exxon Valdez spills.

Worst Case Total: 63+70 = 133 million barrels or 559 million gallons of oil, the equivalent of 517 Exxon Valdez spills.

With such catastrophic numbers, the effect on the environment, both on the land and the sea will be incredible and likely to be felt for decades to come.