Urhobo Historical Society


Urhobo Historical Society thanks Oil Spill Intelligence Report, Arlington, MA, U.S.A. for this report and for permiting it to be distributed.


Oil Spill Intelligence Report

This summary was designed to provide background information for students and members of the general public on spill-related topics. You may copy and distribute this information freely provided that the source is attributed as Oil Spill Intelligence Report, Arlington, MA, U.S.A.

For more information about the Oil Spill Intelligence Report newsletter, contact the Client Services department by phone at 781/641-5125, by fax at 781/648-8707, or by e-mail at dcrowley@cutter.com.

This fact sheet was written with students and the general public in mind. You may distribute this information freely provided that the source is attributed as Oil Spill Intelligence Report, Arlington, MA, U.S.A.

Yearly spillage

Every year 100 million US gallons of oil spill. This is equal to 100 school gymnasiums:
     Typical school gymnasium = 45' X 45' X 66' 
                              = 133,650 cubic feet
                 1 cubic foot = 7.481 gallons
       Gym holds 999,387 gallons (almost 1 million gallons).
The biggest spill ever occurred during the 1991 Persian Gulf war when about 240 million gallons spilled from oil terminals and tankers off the coast of Saudi Arabia. The second biggest spill occurred over a ten-month period (June 1979 - February 1980) when 140 million gallons spilled at the Ixtoc I well blowout in the Gulf of Mexico near Ciudad del Carmen, Mexico. But even all the oil spilled during the Persian Gulf spill is only about 1/3 of what the US uses in one day!

 The Exxon Valdez spill in Alaska was approximately 11 million gallons. That spill was only about the 35th largest in the world, though it was the largest in the US. It came from a huge supertanker that was about the size of 15 gyms in length X 4 gyms wide X 2 gyms deep (which held 66 million gallons). 

Why does all that oil spill?

We use a lot of oil and it needs to be transported. The US uses 710 million gallons per day. In fact, every 22 minutes, the US uses up what spilled in the Exxon Valdez spill. The world uses 2.73 billion gallons (2,730 gyms full) per day.

 Every day 31.5 billion gallons of oil are at sea being transported. But not all spills come from tankers. Some comes from storage tanks, pipelines, oil wells, tankers and vessels cleaning out tanks.

What is all that oil used for?

How does it spill?

What happens to oil when it spills?

Oil generally floats because it is lighter than water.

A good experiment to do here is to add vegetable oil, which acts like crude oil, to food-colored water in a large, clear plastic soda bottle with a cap. Shake it and watch how the oil always settles on top.

30-40% evaporates in the first 24-48 hours; these are the most poisonous (toxic) portions, as well as the portions that are the most soluble, and flammable.

Oil tends to float and spread out into a very thin film on the water surface...usually only about 0.1 mm thick...then spreads even thinner to a sheen, which is one tenth or one one-hundredth of this. Sheens are often seen as rainbow-like or silvery in puddles in parking lots.

It is very rare for oil to sink. It needs to adhere to heavier particles such as sand, algae, or silt to sink. An exception is a kind of oil used for burning in electric utility plants. This oil can actually sink in water since it is heavier than water. 

What are the environmental impacts?

These impacts are very often grossly exaggerated in the public media. Environmentalist groups have been notorious in spreading misinformation about environmental effects. Nevertheless, oil can have a significant impact on marine larvae, birds and mammals in particular, and to a lesser extent on fish.

Some components of oil are toxic if exposure occurs within the first two days of a spill (1 part per million [ppm], i.e. one gallon in one million gallons, can be toxic to invertebrate larvae; 1000 ppm for fish). Oil on feathers hinders the water-repellancy of the bird. Oil on fur takes away its insulating capacities. 

What happens after a spill occurs?

Response teams often protect sensitive areas with booms (floating barriers) and help oiled wildlife by cleaning birds and fur-bearing mammals with detergent. The most common cleanup techniques are outlined below:

Who else might be affected by an oil spill?

Fishing industry, resorts and recreation areas, water supplies for drinking and industry. 

What about prevention?

Since cleanup after an oil spill is so ineffective and so difficult, and does not always fully rehabilitate affected areas, prevention is most important. Effective prevention plans might include:

What can students do?

Don't spill used motor oil. Return used oil to a service station for proper disposal at a facility that will clean and recycle the oil. Reduce usage of fuels, electricity, and plastics.