Tankers and the Environment
Oil pollution from ships was first recognized as a problem during World War I, but it was not until 1954 that the United Kingdom arranged a conference which resulted in the adoption of the first international treaty to prevent oil pollution of the seas from ships. The Convention itself was concerned only with operational oil pollution from merchant ships - there was no attempt to introduce measures concerning accidental pollution, nor to deal with pollution by other substances. But the fact that the Convention was adopted at all was something of an achievement, since only eight of 32 countries attending said they regarded oil pollution as a problem and some did not want a convention at all.
The Convention's main weapon was the establishment of a series of zones where the discharge of oily wastes was prohibited, a device that had been used by individual countries ever since the 1920s. The Convention also required the provision in ports of facilities for the reception of waste oils from non-tankers (there were no such requirements for tankers, which produced far greater quantities of waste oil). The 1954 Convention was therefore limited in its achievements - but from this point on, marine pollution from ships was always to be on the international agenda and Article XXI stated that responsibilities for the Convention would be taken over by the International Maritime Organization (IMO) as soon as it came into being.
IMO had been created by means of a treaty adopted in 1948 at a conference organized by the United Nations, primarily to develop international measures to improve shipping safety. It was assumed that the treaty would receive the acceptances required for entry into force within a few years but some Governments were suspicious of the whole idea of regulating shipping by international means and the new agency did not meet for the first time until 1959.
The most important measures adopted by IMO are contained in international treaties usually known as conventions. These are developed and adopted by representatives of the Organization's 153 Member Governments. IMO also adopts recommendations, codes of practice and guidelines and has developed a successful technical co-operation programme which is designed to help Member Governments put these measures into practice.
By the 1960s there was evidence that oil pollution from ships was becoming more of a threat: the amount of oil being moved by sea was increasing, as were the numbers and sizes of tankers. There was also mounting evidence that the 1954 OILPOL Convention was not as effective as some had hoped.
In 1962 IMO called a conference to amend the Convention. The amendments entered into force in May 1967 - but by then international attitudes to oil pollution had been changed for ever by one dramatic event: the sinking of the tanker Torrey Canyon on 17 March of the same year and the spilling of 120,000 tons of crude oil into the sea off the south-west coast of England. Torrey Canyon suddenly catapulted the oil pollution problem into a glare of international attention, all of it negative. The disaster was monumental. Approximately 30 million gallons of oil were spilled in the English Channel. The disaster illuminated the environmental devastation that resulted, as well as the unsuccessful methods used by authorities to deal with the catastrophe.
The grounding of the Torrey Canyon was the biggest marine pollution disaster in history at the time and it was to have profound consequences. Something, it was agreed, would have to be done - and it would have to be done at an international level. That meant it would have to be done through IMO. In 1973 IMO adopted the International Convention for the Prevention of Pollution from Ships, 1973, which covers pollution by chemicals, packed goods, sewage and garbage as well as oil. This was modified by a protocol in 1978 and is now usually known as MARPOL 73/78. MARPOL 73/78 greatly limits the amount of oil which may be discharged into the sea during routine operations and bans it completely in some areas.
The 1989 grounding of the tanker EXXON VALDEZ in Prince William Sound, which resulted in the largest oil spill in U.S. waters, led to the passage of the Oil Pollution Act of 1990. Section 4115 of the Oil Pollution Act of 1990 (OPA 90 or the Act) (Pub. L. 101-380) added section 3703a to Title 46 U.S. Code. Section 3703a(a) requires a double hull to be fitted on a vessel if it is constructed or adapted to carry, or carries, oil in bulk as cargo or cargo residue. Double hull means watertight protective spaces that do not carry any oil and which separate the sides, bottom, forward end, and aft end of tanks that hold any oil within the cargo tank length from the outer skin of the vessel. A vessel that is constructed or undergoes a major conversion under a contract placed on June 30, 1990, or later must have a double hull fitted at the time of construction or major conversion (with certain exceptions in the Act). An existing vessel that is constructed or that undergoes a major conversion under an earlier contract must be fitted with a double hull in accordance with a timetable in 46 U.S.C. 3703a(c)(3), which commences January 1, 1995.
Current law already requires double hulls on all new tankers, and establishes a phase-out schedule for existing single-hulled vessels. However, the phase out will not be complete until 2010, and some of these vessels may continue to operate on the seas until 2015.
A substantial amount of oil imported into the United States is transported aboard foreign flag vessels. Since the Act applies to all vessels in U.S. waters, including foreign vessels, the Coast Guard recognized that U.S. double hull regulations would have a significant global impact. Therefore, the Coast Guard has also worked at the international level to establish double hull standards. The International Maritime Organization (IMO) is a specialized United Nation agency which oversees international maritime affairs. IMO has been responsible for developing various international conventions, such as the International Convention for the Safety of Life at Sea, 1974, (SOLAS 74), and the International Convention for the Prevention of Pollution by Ships, 1973, as amended by the Protocol of 1978 (MARPOL 73/78).
A report was provided to Congress by the Coast Guard in December 1992, titled, ``Alternatives to Double Hull Tank Vessel Design.'' The report, required by Section 4115(e) of OPA 90, evaluated alternative tank vessel designs to the double hull, to determine which, if any, could provide protection to the environment equal to or exceeding the double hull. The report's conclusions were: (1) At this time, the Coast Guard has not identified equivalent designs to the double hull tanker for the prevention of oil outflow due to groundings; (2) shortcomings exist in the current tanker evaluation methodology; (3) environmental performance standards and a specific methodology for the evaluation of alternative designs in terms other than oil outflow are not fully developed; and, (4) probabilistic computer modeling shows promise as a useful tool for initial evaluation of future designs.
The Oil Pollution Act has been very successful in reducing oil spills in U.S. waters. According to the Coast Guard, by 1999 the average number of oil spills over 10,000 gallons has dropped about 50 percent from 1991 levels. Also, the average number of gallons spilled per million gallons of oil shipped in the U.S. had been reduced by 64 percent by 1999. This success is due to the comprehensive system of oil spill prevention, response, liability, and compensation, as well as research and development programs established by the Oil Pollution Act. The phase-out of single hull oil tankers and barges is part of this environmental protection system.
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