A review of the containment and cleanup methods employed during the Chevron and Shell incidents in the Gulf of Mexico is presented. The paper also reviews the research and development program being undertaken by the Environmental Protection Agency to develop improved technology for oil spill containment and response. This includes information on the development of sorbent systems and oil containment booms capable of operations at relative velocities in excess of two knots.
There are over 10,000 discharges of oil to the fresh or marine water environment annually from accidents consisting of millions of gallons, from large tanker accidents, such as that which occurred in San Francisco Harbor in December 1970, or the Santa Barbara drilling incident, which continued from January through June 1969, or the Gulf of Mexico drill rig incidents in 1970 and 1971, or from small accidental spills in harbors or rivers as is the case in the New York Harbor where at least one reportable oil spill occurs each day. Unknown sources such as deliberate discharge from tanker ballast operations could add additional millions of gallons per year to the marine environment.
The effects of oil spilled into the environment have been well documented, varying from minimal damage to extensive deleterious effects in the ecosystem. In addition, resources such as beaches, harbors and marinas are seriously curtailed or temporarily removed from further use pending effective cleanup operations.
Oil spills which detrimentally affect the value of natural or man-made resources, must be removed from the affected environment. Although many methods for "REMOVAL" may be considered, this paper concerns itself only with those techniques for harvesting or cleaning up spilled oil from a marine or fresh water environment.
By referring to "harvesting" of spilled oil, have further limited the discussion to the use of mechanical removal systems with or without additives. It does not consider the use of chemical dispersants or biological additives which spread the oil or disperse it into the water column,
Before proceeding with the discussion on methods of harvesting oil spills, I wish to emphasize that there is universal agreement that "prevention" of oil spills is much preferred to cleaning them up. Besides the obvious esthetic reasons, the economics associated with cleaning up spilled oil is always written in red ink. For example, the crude oil only has a value of about 8 cents per gallon before it is spilled. When it is on the water it loses its valuable light ends and becomes contaminated with salts and water. It is now even less valuable and somewhat of a burden for any further processing, even if it were recovered. Add to this the large cost of recovering or harvesting the oil, estimated at $l.OO/gallon for large spills, plus special handling required at a refinery for this small fraction of the refinery's throughput, and it becomes axiomatic that there are no profits to the spiller which can be accrued to an oil spill cleanup operation. Costs for some large spills are as follows.
