How Oil Spills Occur:
Petroleum is used as a vehicle fuel, heating source for homes and industry, for electricity generation, and as a feedstock for the chemical industry. Because of the huge demand for oil, enormous quantities are moved from production areas to where the oil is used. Oil is pumped from the ground, refined, transported and stored. There are many steps in this process during which oil can spill from well heads, drill rigs, tankers, pipelines and storage tanks. Oil may leak from ocean-going ships during accidental and deliberate spills. Oil spills can happen on land or water when oil is incorrectly handled, there are railway or truck accidents, tankers or barges collide, the insides of tankers are washed, and when natural oil deposits seep.
Not all spills are man-made. Crude oil is made by the earth from decayed plants and animals which lived millions of years ago. Oil has been in the environment for a long time. Some oil lies below the ocean floor and can seep into the ocean through cracks. As much as 1.5 million barrels of oil may enter the ocean from natural seeps each year. When these leaks occur, as when spills occur, natural organisms and chemical processes act to break down the oil over time. This process is called natural bio remediation.
What Happens When Oil Spills:
When oil spills and mixes with water it can contaminate drinking water, kill fish and poison wildlife. Just one quart of oil may pollute up to 200,000 gallons of water! Oil is harmful to shellfish, finfish, marine mammals and waterfowl living near the spill. Oil spills are ugly and are expensive to clean up. In addition, damage to fisheries places a hardship on those who make their living by fishing.
When oil enters the ocean it quickly begins to change and disperse. Though oil is toxic, it becomes less so with time. Winds and waves help spread and disperse the oil. Some oil will evaporate. Some will form into tar balls and sink to the bottom where they may remain for a long time, slowly releasing hydrocarbons into the water. Bacteria in the water attack and digest the oil. If people act quickly after the spill, they can scoop up some of the oil and stop it from causing worse damage to the environment.
Effects on the Food Chain:
Each tier of the marine food chain can be affected by an oil spill. Oil floating on the water may contaminate plankton (very small, swimming or floating plants and animals). When small fish eat the plankton, they also eat the oil. Larger fish, bears and humans who eat these fish will ingest oil too. Marine animals and birds can eat oil or it can get on their fur and feathers. When oil gets on a bird's feathers, the feathers lose their insulation capability and the bird can't adjust its body temperature and dies. Oil may obstruct the germination and growth of marine plants.
How Do We Clean Up Oil Spills:
It is important to act fast to clean up an oil spill and prevent the oil from spreading to a bigger area. Spills can happen in the open seas, close to shores, or in lakes, streams and rivers. Spills on land can contaminate groundwater or streams. How the spill is cleaned up depends on where it happened. In smaller bodies of water oil does not spread as much and cleanup is easier.
Oil floating on the surface can be held away from the shore by booms and cleared with skimmers. Booms are barriers that extend about three feet below the water surface. They are anchored near the shoreline. Booms intercept and contain the oil. Skimmers, such as vacuum machines or oil absorbent plastic ropes, are placed inside the boom to scoop up the oil. Booms and fences are often of little use in the open seas. They cannot contain a spill when there are big waves or strong currents. Once the oil is whipped into a froth called a mousse, skimming is difficult. Sometimes chemicals are used to speed the disposal of the oil into small globules that are more easily eaten by microorganisms.
Upon reaching the shoreline, oil clean up occurs in several ways:
A) Manual pickup - hand tools are used to collect and bag oily materials. This method improves the appearance of the beaches.
B) Tar mat breakup / removal – tar mats, which are thick asphalt-like coverings of oil, are slow to degrade, can be broken with hand tools and then scattered or collected.
C) Tilling/raking - Oil that is under the surface is exposed by using a rake to turn over the topsoil. Raking or tilling helps in natural degradation or bioremediation (discussed below).
D) Spot washing - hand-held high pressure washing tools are used to remove small accumulations of oil. The runoff water is collected and processed.
These techniques may not remove oil trapped under rocks or in beach sediments. A technique called Bioremediation has worked to remove underlying oil. Bioremediation involves covering the oiled area with "fertilizers" that contain microorganisms, like bacteria. These microorganisms speed the natural degradation processes already at work. It is thought that the more microorganisms at work, the faster the oil will be removed. Bioremediation is less disruptive to the environment than other techniques. It simply improves on nature's own way of destroying oil.
Several large oil spills have brought attention to the damage that can result from such occurrences.
1991 -The Persian Gulf War: Although the war in the Middle East was brief, it left behind a damaged environment. Huge quantities of oil (2.5 to 4 million barrels) were dumped into the Persian Gulf. It was the largest oil spill in history. The oil may have destroyed or severely disrupted the area's marine ecosystem. The oil covered some 600 square miles of sea surface and blackened 300 miles of coastline. The waters of the Gulf contain coral reefs, mangrove swamps, and beds of sea grass and algae, as well as birds, sea turtles, fish and marine mammals. All these plants and animals were affected by the oil. Mangrove swamps and other kinds of wetlands are very sensitive to oil because their root systems are above water and can become coated or clogged with oil.
Because this oil spill happened during a time of war, clean-up actions were delayed. Efforts were made to protect a few delicate areas. If action could have been taken earlier, less oil would have gotten into the water. Booms and skimmers were set up and used to protect some areas. People from all over the world went to the area to help with the cleanup.
March of 1989 -The Exxon Valdez: The worst spill in U.S. history occurred when the supertanker, Exxon Valdez, ran aground in Prince William Sound, Alaska. About 11 million gallons (260,000 barrels) of oil spilled from the tanker. It spread out to 900 miles of shoreline. This shoreline and neighboring islands are home to deer, bears, seals, otters, whales, birds and fish, and other plants and animals.
This was the first large spill in an enclosed, cold body of water. These conditions made clean-up very difficult. The oil slick spread quickly. Chemical dispersants could not be used because the seas were too calm for them to be effective. Then high winds drove the oil into a mousse. In the months following the spill, workers collected more than 36,000 oiled birds and more than 1,000 sea otters. The number killed was several times the number found. Some people say that it will be 20 to 70 years before the seabird population fully recovers. Cleanup costs of this spill exceeded $2 billion. The cleanup involved deployment of more than 10,000 people, several hundred boats, aircraft, and special equipment.
January 2, 1988-The Monongahela River Spill: Approximately one million gallons of oil accidentally spilled into the Monongahela River in Western Pennsylvania when an above-ground oil storage tank failed. In a matter of seconds, a 30 foot wave of heavy oil surged over containment barriers and spilled into the river, threatening the water supplies of more than a million people living downriver. Swift action was necessary to safeguard these water supplies. Thousands of feet of booms were used to contain the oil as workers pumped it into barges and tanker trucks. Even with this massive cleanup effort, eight water suppliers in three states were forced to shut their intake for a few days.
Now we have the BP oil spill occurring in the Gulf of Mexico. The leak is the result of catastrophic failure of the drilling rig which now lies at the bottom of the ocean some 5000 feet below the surface. 29 lives were lost during this tragic event. It is widely believed that this spill will result in the largest man made ecological disaster U.S. History. Currently believed to be leaking at a rate of 200,000 gallons/5000 barrels per day and is expected to take at least 90 days to get this leak under control. It appears as though many avoidable mistakes were made to reduce drilling costs; but it will likely be many months before the whole truth is disclosed.
Oil Spill Laws:
Governments have laws regulating oil spills. In the United States, spills of oil and other chemicals must be reported to the National Response Center so action can be taken to contain the spill and clean it up to reduce pollution and assess environmental impacts. Many states and local governments have similar laws.
We may not know for years, if ever, the full extent of the environmental damages caused by oils spills. Finding ways to prevent the spills from occurring and better ways of mitigating the damages when they do occur should be of the highest priority. The USEPA regulates Underground Storage Tanks (USTs) and requires replacement of old tanks, corrosion protection for new tanks and pipes, and leak detection systems for tanks. After the Monongahela spill, some governments, including Pennsylvania, passed laws requiring Above-ground Storage Tanks (ASTs) to be inspected and built to modern technical standards to reduce future leaks.
The U.S. Congress enacted the Oil Pollution Act of 1990 which makes the Marine Spill Response Corporation (MSRC) the official response group for oil spills from oil tankers. The bill also requires that all oil tankers have double hulls by 2010. The law also provides money for quick response teams in the 10 U.S. Coast Guard districts.
We will see how the situation unfolds in the Gulf of Mexico and how well or poorly the government manages this crisis and whether or not the corporations that are profiting in the billions of dollars are accordingly held responsible for the decisions that led to this avoidable disaster.