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--> 1 Introduction The idea of transferring crude oil or petroleum products between two vessels that are under way, anchored, or drifting on the open ocean may seem risky. And yet, according to shipping companies and maritime accident statistics, this common practice—known as lightering—is safe, as long as certain conditions are met. More than 25 percent of the more than 7.5 million barrels of crude oil imported to the United States each day is lightered, or transferred from one vessel to another, before delivery to port.1 A comparable proportion of the 6.4 million barrels of oil per day produced domestically is carried by water and lightered (DOE, 1998). Few vessel accidents or spills that are directly attributable to lightering operations have ever occurred in U.S. waters. Nevertheless, public concerns about oil spills makes it important to maintain vigilance over lightering activities. Almost 30 years have passed since lightering first became a routine practice in the U.S. Gulf of Mexico and Delaware Bay, driven by increases in crude oil imports and in the size of ships (NRC, 1997). Over the past few decades, strong economic incentives have led to the use of very large tankers for the long hauls from the Persian Gulf and Africa. Because these ships are too deep and too wide to approach or enter most U.S. ports safely, the oil cargo is transferred to smaller vessels that deliver it to refineries. As the cost of the domestic oil supply has risen and its availability has declined, East Coast refiners have become dependent 1 Approximately 25 percent of imported oil is lightered offshore (outside the U.S. territorial sea), according to data for 1994 provided by the Maritime Administration Office of Statistical Analysis, Washington, D.C. Additional imported oil is lightered closer to shore, but the government does not maintain specific records on this activity. The committee's estimates are provided later in this chapter.
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--> A Typical Lightering Operation The lightering process begins with a service vessel making its approach to an STBL. At the final approach, the two ships are alongside each other, protected by fenders. After the vessels are moored together, hoses are passed from the service vessel to the STBL and connected to the cargo oil piping.
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--> In this case, the service vessel is equipped with a cargo crane to connect the transfer hoses. Photo Credit: Chevron Shipping Co. After the transfer is complete, the two vessels are unmoored, and the service vessel departs to deliver the oil. Two vessels are moored together during the transfer of cargo from the STBL to the service vessel.
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--> on imported crude oil. The frequency of lightering has led both the shipping industry and the U.S. Coast Guard (USCG) to take a number of steps to ensure the safety of this practice. Although these safety initiatives have been effective so far, several factors suggest that a review of the risks and practices of lightering is warranted. First, lightering activity levels or patterns could change in the near future, although no dramatic changes are expected. Oil imports into the U.S. Gulf of Mexico have been steadily increasing, and, if more imports are shipped across long distances, then lightering operations may become more frequent. Product and crude oil offshore lightering activity has also increased in recent years along the East Coast, and there is a possibility of continued small increases. 2 Second, lightering might be encouraged by the Oil Pollution Act of 1990 (OPA 90; P.L. 101–380), which prohibits certain tank vessels from approaching U.S. shores (NRC, 1997). Operators of these vessels will have to lighter their cargo instead. In any case, the lightering industry will have to maintain, or even improve, its existing high performance levels by continuously evolving the standards established at various levels by industry and national and international regulatory bodies. The U.S. Congress has also expressed concern about lightering safety. The present study was conducted to satisfy the requirements of the Coast Guard Authorization Act of 1996 (P.L. 104-324), Section 903, which requires an assessment of the risks of oil spills attributable to lightering operations off the U.S. coasts. This study evaluates statistics on oil spills and existing spill-prevention measures, examines current activities and future trends in offshore lightering, assesses the regulatory framework and standards and operations for lightering, and recommends measures to reduce the risk of oil spills and minimize environmental damage. The study does not address port and terminal activities, bunkering, or cargo spills that are not directly related to lightering. Nor does it assess the relative risks associated with alternative methods of transferring cargo, such as using deepwater ports or offshore pipelines. Lightering at a Glance For the purposes of this report, ''lightering'' is defined as the mooring of two vessels to transfer petroleum cargo,3 excluding bunkers, between the ship to be lightered (STBL) and the receiving vessel (the service vessel) for the purpose of either taking cargo from, or adding cargo to, the STBL (see Box 1-1). Most often the service vessel takes on cargo for delivery to a shore terminal. Lightering typically takes place either 12 or more miles offshore or at deepwater anchorages and other sheltered locations inshore. (The term "inshore" 2 Inshore crude oil lightering on the East Coast is not expected to increase. 3 Although many types of cargo can be lightered, this report focuses on crude oil and petroleum products to fulfill the statutory mandate of evaluating the risks of oil spills.
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--> BOX 1-1 DEFINITIONS Lightering: Lightering is the mooring of two vessels for the purpose of transferring petroleum cargo, excluding bunkers, from the ship to be lightered (STBL) to a service vessel. The process can be divided into three phases: the approach phase, the transfer phase, and the posttransfer phase. Vessels involved in Lightering: The STBL is generally either too large or has too deep a draft to enter the port or facility where the cargo is to be delivered. The service vessel may be of several types: all-purpose tankers, tankers specifically equipped for lightering, integrated tug-barge units specifically equipped for lightering, and standard all-purpose tug-barge units. Lightering processes: In the open ocean, the two vessels are moored and unmoored either while both are under way or while the STBL is at anchor. The process is completed without the assistance of tugboats or other vessels. During inshore lightering, the STBL is always at anchor and in a semi-protected or protected area. is defined here as inside the outer boundary of the contiguous zone, which the United States extends 12 miles from shore.) Lightering is usually necessary because the STBL is too large, or has too deep a draft,4 to enter the harbor or approach the terminal where the cargo is to be picked up or delivered. The service vessel may be an all-purpose tanker, a tanker equipped specifically for lightering, an integrated tug-barge unit equipped specifically for lightering, or a standard all-purpose tug-barge unit. Lightering operations in the open ocean may span a geographical area of many miles and may take several hours to a week or more, depending on the number of discharges and the volume of cargo discharged. Lightering takes place when both vessels are under way or drifting or when the STBL is at anchor. The process encompasses three phases: the approach phase, the transfer phase, and post-transfer phase. The approach phase begins when the two vessels are approximately three miles apart. Once they are moored together and cargo transfer begins, one "lift"—a discharge from an STBL to a service vessel—can take 10 to 24 hours to complete. Very large STBLs can require as many as eight lifts to transfer all cargo; thus, they may remain within a lightering area for as long as 20 4 The term "draft" refers to the depth of a vessel below the waterline. Large ships have deeper drafts than small vessels, and all vessels have deeper drafts (i.e., sit deeper in the water) when fully loaded with cargo than when empty or partially loaded.
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--> days to discharge their cargo completely. The process proceeds more quickly when service vessels are dedicated lightering vessels, which are permanently outfitted with the required equipment. Inshore lightering usually takes place at a dedicated, deepwater anchorage in a sheltered location, such as Delaware Bay, San Francisco Bay, or Long Island Sound. The STBL is always at anchor, with the service vessel (usually a tug-barge unit) maneuvering alongside, resulting in a very limited geographical scope of operations. The process entails the same three phases as in offshore lightering, but the transfer often takes less time—usually 8 to 15 hours, depending on the size and configuration of the service vessel and the type of cargo. A typical inshore lightering operation entails no more than three lifts, which lightens the STBL enough to allow it to continue to a terminal, where the remaining cargo can be offloaded. Lightering is usually done for economic reasons. Because of economies of scale, it is more economical to move oil in large tankers over the greatest distance possible and then, near the destination, transfer it to a smaller vessels than to move the same amount of oil the entire distance in six or seven smaller tankers. Shipping oil from the Arabian Gulf directly to a Gulf of Mexico port in service-sized vessels costs 70 percent more than moving the same amount of oil by lightering (von Zharen, 1994). Another economic reason for lightering is to avoid dead freight charges associated with "light loading" of a vessel bound for a port with a restricted depth. Cost is not the only reason for lightering, however. Lightering sometimes takes place between two vessels of the same size, not because cargo needs to be moved to another ship to reach port, but because the transfer is specified in the terms of the contract between cargo traders. Approximately 95 percent of the offshore lightering in U.S. waters takes place in the Gulf of Mexico, where restricted water depths keep large ships from entering most ports to deliver oil to refineries. Offshore lightering also takes place off Long Island, near the New Jersey and Virginia capes, off San Diego in California, and near the Bahamas. Inshore lightering takes place in the Delaware Bay and River, Long Island Sound, New York Harbor, and San Francisco Bay (see Figure 1-1). The largest tankers have only a few alternatives to lightering.5 In southern California and Hawaii, ships can stop at offshore moorings and use their own pumps to transfer oil to shore, and in the Gulf of Mexico they can use the only U.S. deepwater port, the Louisiana Offshore Oil Port (LOOP), which is 18 miles south of Grand Isle, Louisiana, in approximately 115 feet of water. Between 10 and 15 percent of U.S. oil imports are brought in through the LOOP (NRC, 1997), 5 The committee did not analyze alternatives to lightering, which would have been beyond the scope of this report. The committee felt however, that neither economics nor safety factors nor any business trends would force dramatic changes in current practices. However, if future trends indicate that major changes in lightering activities are likely, some site-specific alternatives could be analyzed.
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--> Figure 1-1 U.S. lightering operations. which has a capacity of approximately 1.4 million barrels per day. However, economics and the demands of the refineries supplied through the LOOP pipeline connections have limited use of the port to far below its original design capacity. The amount of imported crude oil currently passing through the LOOP is approximately 900,000 barrels per day, which is close to the maximum level achieved to date and represents a marked increase since the early 1990s (personal communication from Thomas P. James, general counsel, LOOP, Inc., April 7, 1998). Lightering activities in the United States are described in more detail in Chapter 2. This report does not deal with foreign operations, but it is important to note that lightering is a standard link in the worldwide petroleum supply chain that is used in many parts of the world, especially in the Far East (see Box 1-2). Safety Record Lightering involves a series of operations, including the approach maneuver, berthing, mooring, hose connection, cargo transfer, hose disconnection, and un-mooring. Lightering spills can occur for a variety of reasons, such as a ruptured hose, a tank overflow, or a collision, many of which can also occur when a vessel is unloading at a dock. The risks unique to lightering are associated with vessels coming close together (seafarers are generally trained to keep vessels apart); the breakaway procedure; severe weather; and problems with fenders, hoses, and other equipment. The greatest risk in lightering may be from human error, which
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--> BOX 1-2 Lightering Worldwide Lightering is common throughout the world. Generally two lightering methods are used: traditional side-by-side lightering, which is typical in the united States, and tandem lightering, in which floating storage units (mostly converted tankers) are permanently moored and connected to oil production and exporting facilities. Traditional lightering is used in Argentina, Venezuela, West Africa, East Africa, Fujairah, Korforkhan, Gulf of Kutch, Rangoon, Singapore, Sumatra, Thailand, Hong Kong, Taiwan, South Korea, Gibraltar, Malta, and the United Kingdom. Tandem lightering (associated with production facilities) is used in Iran, Oman, Australia, the Irish Sea, and Vietnam. As oil is produced, it is pumped from wells to offshore units and stored until the quantity is sufficient to export. At that point, a vessel is moored behind the unit; a floating hose is used to connect the two vessels. The operation requires special boats to handle the lines and hoses and sometimes a tugboat to keep the two vessels from coming into contact with each other. Tandem lightering is typically a continuous, permanent operation and is invariably backed by very large companies. has been implicated as a cause of 80 percent of maritime accidents in general (NRC, 1994; USCG, 1995; von Zharen, 1994). The committee also took note of some recent oil spills in Rhode Island, which have heightened public and congressional concerns about spills in general. Although these spills did not occur during lightering and were not in any way attributable to lightering, they caused environmental groups to question other tanker transportation practices, including lightering, especially practices about which public information was not generally available. Thus, lightering is cause for concern among certain environmentalists, and Senator John Chafee of Rhode Island sponsored legislation, which was ultimately passed by the U.S. Congress, that called for the present study. Yet even in Rhode Island, there is general agreement among decision makers that the safety record of local lightering is good. Nationally, the shipping industry stresses the benefits of lightering rather than the risks. For example, INTERTANKO, an organization that represents 250 independent tanker operators constituting much of the world fleet, contends that lightering is not only safe but also offers environmental benefits because it keeps large tankers away from shorelines and congested areas (personal communication from Jonathan Benner, INTERTANKO, August 5, 1997). The advantages and disadvantages of lightering in comparison to alternatives, such as delivery to deepwater ports, have been examined (e.g., USCG, 1993) and are not evaluated in the present study.
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--> Worldwide, oil spills from all causes have been declining in both numbers and volume since the early 1980s (Etkin, 1997). Most spills are small and result from routine operations, such as cargo loading and discharging. Major collisions and groundings cause much larger spills, and a few very large spills are responsible for most of the oil spilled (NRC, 1991; Etkin, 1997). The patterns are similar in U.S. waters, where the number of spills has been declining since the 1980s. This trend was accelerated by OPA 90, which imposed structural requirements, safety and training mandates, and substantial economic penalties for spills. The reduction in spills can be attributed in large part to economic liabilities in the provisions of OPA 90 and the growing awareness of these liabilities (NRC, 1997). Meanwhile, the volume of oil spilled in U.S. waters dropped dramatically in the early 1990s and has remained very low compared to the levels of a decade or two ago. The extent of the recent improvement is evident in Figure 1-2. Reliable data that can be used to assess the safety of lightering in U.S. waters are difficult to gather. An immense amount of information is available on maritime accidents, but identifying patterns and comparing data sets is problematic. The USCG's casualty database, recently renamed the Marine Investigation Module (MIN-MOD), is difficult to analyze, in large part because information on specific casualties is collected by local offices and is sometimes incomplete or is logged in inconsistent formats. Some spills that occur before or during lightering are not directly caused by, or related to, the lightering operation. For example, the tanker Mega Borg caught fire and spilled 3.9 million gallons of oil off the Figure 1-2 Oil spills of more than 10,000 gallons into U.S. maritime waters, 1970 to 1997. Source: Oil Spill Intelligence Report.
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--> Texas coast in 1990 during a lightering operation, but the fire was not directly related to lightering. The committee considered that an explosion-and-fire accident like the one in the pump room of the Mega Borg could just as easily have happened if the ship had been unloading in port, in which case the risk to life and environmental damage could have been even greater. The USCG provided the committee with MIN-MOD data on spills that occurred during lightering operations in U.S. waters from 1984 to 1996. The data have many limitations, most significantly that the causes of spills are either missing or are ambiguous. Despite these limitations, the committee made several general observations. First, few spills occurred during lightering operations in that time period (see Figure 1-3). Second, the average spill volume was only 26 barrels (1,095 gallons); a spill of less than 50 barrels is generally considered small. Recurring causes of spills that appear to be directly related to lightering include valve failures, tank overflows, and hose ruptures (see Figure 1-4 and Figure 1-5). The complete data are provided in Appendix C. A formal USCG analysis of its own and other federal and private records provides additional insight. Between 1986 and 1990, 15 lightering-related accidents, resulting in total spillage of 45 barrels, were reported in the Gulf of Mexico (USCG, 1993). For the 4,391 offshore transfers in the Gulf of Mexico in those years, an average of 3.4 accidents occurred per 1,000 transfers. The average spill volume was only three barrels (126 gallons). The USCG Marine Safety Office at Galveston reported only one small spill attributable to lightering during the early Figure 1-3 Location of lightering incidents.
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--> Figure 1-4 Lightering spills by secondary cause, 1984 to 1996. Figure 1-5 Lightering spills by secondary cause, 1984 to 1996. 1990s (USCG, 1993). The cause of that spill was a ruptured transfer hose. In general, the lightering safety record in the Gulf of Mexico appears to be excellent. Although the USCG data on lightering-related spills have some limitations, and some people claim that small spills offshore are less likely to be detected or reported than spills in port, the committee found no evidence of unreported lightering-related spills.6 Private analyses of maritime accidents (e.g., Etkin, 1997) and archives, such as those maintained by Lloyd's Register of Shipping, can be useful for some broader studies. These data are typically sorted, computerized, and subjected to 6 The committee's investigation included several meetings and workshops with representatives of industry, regulatory agencies, and environmental groups (See Appendix B for a complete list). Additional resources included correspondence with shipping and lightering companies and industry organizations and the extensive experience and personal contacts of committee members.
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--> quality assurance and quality control measures, so the records are likely to be easier to search and more reliable than the USCG database. However, private databases can also be costly to access and typically concentrate on large spills worldwide, which limits their utility for studies focusing on small spills in U.S. waters. The risks of lightering in U.S. waters have been addressed previously by independent investigators (e.g., NRC, 1991; Wilson, Gillette & Co., 1993; von Zharen, 1994), none of which found evidence of major accidents, catastrophic spills, or patterns of serious safety problems directly related to lightering. For the present study, accident statistics for a five-year period were collected from a variety of sources, including state agencies, shipping companies, and the Industry Taskforce on Offshore Lightering (ITOL). The committee informally checked industry data with local Coast Guard offices and/or state agencies. Data from these sources were necessary because the study focused on 1993 to 1997, which is too recent to be included in some databases, and because the committee needed detailed information for all three U.S. coasts, for both the open ocean and inshore waters. The data, which are summarized in the following sections, confirm the good safety record reflected in earlier studies. Gulf of Mexico According to ITOL data for five lightering companies7 operating in the Gulf of Mexico, out of approximately 5,000 lifts8 or 2.5 billion barrels lightered between 1993 and 1997, 8029 barrels were spilled in six accidents (see Table 1-1). Two spills occurred on deck, one from an expansion joint and one from a valve as a result of human error. Four spills went into the water: two were caused by overfilling tanks, one by an emergency breakaway, and one by a collision. The collision occurred in 1995 in the Galveston area, when the service vessel Skaubay was approaching the tanker Berge Banker to take off some of its cargo. Although no cargo was lost in the accident, a fuel tank was ruptured on the Berge Banker, and more than 850 barrels (more than 35,700 gallons) of fuel oil were spilled into the Gulf of Mexico.10 The USCG investigation concluded that the accident was caused by limited communications about expected maneuvers (see Box 1-3). This was the only substantial spill related to lightering since 1984, when the USCG began collecting data. One oil company reported an additional spill of one barrel in 1993, when an officer on the STBL opened the manifold valves too early, and 7 The five companies are Skaugen PetroTrans, Inc., American Eagle Tankers, Inc., and OMI Petrolink Corp., Aramco, and SeaRiver Maritime. 8 A "lift" is one complete transfer operation offloading oil from an STBL to a service vessel. 9 Most of the oil was spilled in a single accident in 1995 (the Berge Banker). 10 Initially, the spill estimated at approximately 800 barrels, the figure reported to the committee by ITOL in 1997. The official USCG investigation, released in 1998, revised the total spill estimate to more than 850 barrels, which is the figure that appears in the text of the present report.
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--> These vessels are preparing to begin a lightering operation in the Gulf of Mexico.
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--> BOX 1-3 A Case of ''Limited Communication'' On February 5, 1995, at 9:40 a.m. local time, the service vessel Skaubay collided with the STBL Berge Banker in the Galveston lightering area during the approach phase of lightering operation. The following account of the incident is based on the USCG marine casualty investigation report. The Berge Banker, a large single-hull tanker, was loaded in Saudi Arabia. The Skaubay, a small tanker, left Port Neches, Texas, on February 4, bound for the lightering site. It was expected to be the second vessel to lighter the Berge Banker. The weather was clear, winds were from the west at 10 to 15 knots, and seas were at one the three feet. The Skaubay was traveling at 10 knots as it approached the STBL. Using a hand-held radio, the mooring master aboard the Skaubay instructed the Berge Banker to maintain a course of 270 degrees and come up to a speed of 5.5 knots. When he determined the distance between the vessels to be one mile, he ordered the Skaubay to turn to starboard. He "gave this order without knowledge of the Berge Banker's current speed ... [he and the service vessel's captain then] realized that the Berge Banker was not going as fast as they thought it was ... [and the mooring master] ordered the Skaubay to reduce starboard rudder angle and engine speed. However, they did not communicate the risk of collision to the Berge Banker." The captain of the Berge Banker "was surprised at the Skaubay's course change but did not use his radar [or] radio equipment to confirm the Skaubay's intention. Based on his visual observations, he did not believe that there was a risk of collision until a few seconds before impact." The mooring master then "ordered the Skaubay to operate astern propulsion and its rudder amidships. The captain of the Berge Banker ordered his ship to "turn hard to port, sounded the ship's internal emergency alarm, and stopped his ship. Neither ship sounded the danger signal." When the vessels collided, the Berge Banker's fuel tank ruptured, spilling more than 850 barrels (35,700 gallons) of No. 6 fuel oil into the Gulf of Mexico. The Skaubay sustained a 25-foot gash on its port low, whereas the STBL sustained damage to a cargo tank and bunker tank. The Skaubay remained on scene for several days to serve as a helicopter landing platform for the pollution response operation, then sailed to Texas City of repairs. The Berge Banker, after completing the discharge of its remaining cargo, was repaired temporarily while at anchor in the lightering area. Permanent repairs were scheduled in Saudi Arabia.
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--> Because both vessels were Norwegian flag and the collision occurred outside the U.S. territorial sea, the government of Norway conducted the inquiry, in which the USCG participated. The collision was attributed to "limited communication between the vessels." Contributing factors included the failure of the Skaubay captain and mooring master to use all available means to determine whether there was a risk of collision when they turned their vessel tower the STBL and their failure to sound any maneuvering signal. The report also cited the failure of the Berge Banker's captain to sound a danger signal when the Skaubay turned toward his vessel. The USCG accident report recommended that the commandant establish specific requirements regarding how a service vessel should approach an STBL. This recommendation was acted on in the final version of the lightering zone regulations and incorporated into the most recent version of the lightering guidelines issued by OCIMF (1997). (USCG, 1998) TABLE 1-1 Lightering Incidents in the Gulf of Mexico, 1993 to 1997a Incident Type Number Notes (including causes and volume of spill) Vessel touching 16 13 vessel to vessel 3 workboat to vessel Emergency separation 1 result: spill on deck Spill on deck 2 1 expansion joint (2 gallons) 1 valve, human error (2 barrels) Spills to environment 4 1 collision (800+ barrels)b 2 tank overfilling (1 barrel) 1 breakaway (1 barrel) Injuries 3 not life threatening Near misses 5 2 fender failures 2 engine malfunctions 1 generator fire Other 1 1 STBL struck by workboat a These are the only incidents directly attributable to lightering activities. Some additional small spills may have occurred during lightering as a result of vessel leaks or other causes that were not directly related to the lightering operation. The incidents occurred out of approximately 5,000 lifts (3 per day on average) and 2.5 billion barrels of oil transferred. b This incident was the Berge Banker collision (see Box 1-3). The total spillage was later determined to be in excess of 850 barrels. Source: Industry Taskforce on Offshore Lightering
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--> Two vessels are lightering in Delaware Bay. Photo credit: John McGrail. residue spilled across the deck and into the Gulf of Mexico. The committee could not determine whether this spill was or was not included in the database in Appendix C, but it was a minor spill and would not change the overall numbers substantially. ITOL reported 16 vessel-to-vessel contacts between 1993 and 1997. STBLs came into contact with service vessels on 13 different occasions—six times during mooring, and seven times during unmooring. An additional three contacts involved workboats touching ships. Also during the same time period, five near-misses and one collision of a workboat and an STBL (with no spillage) were reported in the Gulf of Mexico. Two of these incidents were attributed to fender depressions, two to aborted moorings resulting from engine malfunctions, one to a generator fire, and one to the collision of an STBL and a workboat not involved in the lightering operations. ITOL describes the overall lightering safety record as "exemplary," noting that all incidents were followed up by the companies involved with lessons learned and risk-reduction measures. The data confirm the patterns described by the USCG (1993). East Coast No spills directly related to lightering were reported on the East Coast during the time period under study, according to the limited data obtained by the
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--> committee for Long Island Sound and Delaware Bay (see Appendix D). The MIN-MOD records indicate that two spills occurred along the East Coast during lightering operations between 1993 and 1997, but the causes were not recorded. More recent USCG reports indicate that several spills occurred during, but were not directly attributed to, lightering operations in Delaware Bay. In September 1997, the tanker Mystras was engaged in a lightering operation when it spilled an estimated 20,000 gallons of oil into Delaware Bay (8,000 gallons were recovered). The cause was the failure of a valve isolating the ballast system from the cargo system. Also in late 1997, the tanker Alandia Bay spilled less than 100 gallons of oil into Delaware Bay in several separate discharges. The vessel was engaged in lightering, but the spill was traced to a heat exchanger for a vacuum pump. In 1996, the tanker Anitra spilled 500 to 800 gallons of oil into Delaware Bay when it entered the bay to engage in lightering. This spill was the result of an obstruction that prevented closure of a valve, allowing cargo to reach the ballast sea chest lines.11 West Coast No lightering-related spills on the West Coast were reported for 1993 to 1997 by the California State Lands Commission, Washington Department of Ecology, or major oil companies (see Appendix E). Five gallons were spilled from a barge during one lightering operation in Long Beach, but the spill was attributed to a hull fracture, which was located by divers. The USCG MIN-MOD records reveal no spills during lightering operations along this coast since the 1980s. Overall U.S. Lightering Spill Record for 1993 to 1997 To provide a context for evaluating lightering-related spills, the committee collected data on the total volume of cargo lightered during the same time period. Data on offshore lightering volumes only were obtained from the Maritime Administration, which does not maintain records on inshore lightering. The committee collected information from a variety of sources to try to fill in this gap. The results, shown in Table 1-2, probably underestimate the volume lightered inshore because no data could be obtained for some areas. Nevertheless, this exercise provided a more complete picture of lightering in U.S. waters than has previously been available. More than two-thirds of inshore lightering, a fairly substantial volume, takes place on the East Coast. Table 1-2 also summarizes the combined data on spills, which show a strong safety record. Only seven spills were reported, all in the very busy Gulf of 11 A "sea chest" is an integral structural box with a grill opening to the sea built on the inside of a vessel's hull. It is connected to multiple pipes (thus minimizing openings in the hull) designed for either intake or discharge of seawater from various internal systems, such as ballast water piping.
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--> TABLE 1-2 Spills Attributed Directly to Lightering off U.S. Coasts, 1993 to 1997 Area Barrels Lightered Offshored Barrels Lightered Inshoree Total Spills Barrels Spilled Apparent Causes East Coasta 77.5 million (2.7%) 501 million (68%) 0 0 no spills West Coastb 23.5 million (0.8%) 237 million (32%) 0 0 no spills Gulf of Mexicoc 2.9 billion (96.5%) 0 7 > 850 (or > 35,700 gallons) 1 equipment failure 5 human error 1 unknown a Information on spills for the East Coast (Delaware Bay and Long Island Sound only) was obtained from the U.S. Coast Guard. No data could be obtained for the small amount of lightering activity in other East Coast areas. b Information on spills for the West Coast was obtained from the California State Lands Commission, Washington Department of Ecology, British Petroleum, Chevron, and Exxon. c Information on spills for the Gulf of Mexico was obtained from the Industry Taskforce on Offshore Lightering and Chevron. One collision accounted for almost the entire volume spilled. d Offshore lightering totals were estimated by the committee for the entire five-year period based on data for one year obtained from the Maritime Administration (1994). e Inshore lightering totals were estimated by the committee based on data obtained from the U.S. Coast Guard for Long Island Sound and Delaware Bay on the East Coast and San Francisco Bay on the West Coast. Almost all of the East Coast inshore lightering took place in Delaware Bay. About 1 million barrels were lightered in Long Island Sound in 1997; no data could be obtained for prior years. The San Francisco figure is an estimate based on data for 1995 to 1997. Mexico, and only one was substantial. Even more impressive, less than .003 percent of the total volume of oil lightered in the Gulf of Mexico was spilled. When the volume spilled in lightering-related incidents is compared to the overall U.S. spillage (shown previously in Figure 1-2), lightering accounted for approximately 0.5 percent of the spillage resulting from substantial incidents—those in which more than 238 barrels, or 10,000 gallons, were spilled—from 1993 to 1997. Summary The committee's assessment confirms the results of previous studies of lightering safety that very few spills are related directly to lightering and, with rare exceptions, they are small spills. Only one substantial spill—the Berge Banker—can be attributed directly to lightering in U.S. waters from 1993 to 1997. Several other large spills occurred during lightering but were not attributed directly to the lightering operation. The committee reviewed these incidents and
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--> concluded that they probably would have occurred even if the vessels had been engaged in other activities. Given the absence of a comprehensive, reliable database on spills directly attributable to lightering in U.S. waters, the committee was forced to collect information of varying degrees of completeness and reliability from various sources. The impression of a solid overall safety record conveyed by the resulting data was confirmed by the experience of individual committee members and by presentations and other comments by representatives of industry, government agencies, and environmental groups. The USCG's current approach to data collection and maintenance is not conducive to studies of this type. References DOE (U.S. Department of Energy). 1998. Petroleum Supply Monthly. May 1998, with Data For March 1998. Energy Information Administration. Etkin, D.S. 1997. Oil Spills from Vessels (1960–1995): An International Historical Perspective. Arlington, Mass.: Cutter Information Corp. NRC (National Research Council). 1991. Tanker Spills: Prevention by Design. Washington, D.C.: National Academy Press. NRC. 1994. Minding the Helm: Marine Navigation and Piloting. Washington, D.C.: National Academy Press. NRC. 1997. Double-Hull Tanker Legislation: An Assessment of the Oil Pollution Act of 1990. Washington, D.C.: National Academy Press. USCG (U.S. Coast Guard). 1993. Deepwater Port Study. Washington, D.C.: USCG Office of Marine Safety, Security, and Environmental Protection. USCG. 1995. Prevention Through People Quality Action Team Report. Washington, D.C.: U.S. Department of Transportation. USCG. 1998. Marine Casualty Investigation Report, Case MC95002001, 05 Feb 95. Washington, D.C.: U.S. Department of Transportation. Wilson, Gillette & Co. 1993. The Evaluation of Past and Future Crude Oil Lightering Operations in the U.S. Gulf Coast. Unpublished internal report by Wilson, Gillette & Co., Arlington, Virginia. von Zharen, W.M. 1994. Risk Evaluation of Ship-to-Ship Oil Transfer: An Assessment of Lightering as a Predictably Sound Environmental Risk: Inherent Relevant Concerns and Operational Safeguards. Galveston, Tex.: Maritime and Environmental Management Research, Inc., Texas A&M University Texas Institute of Oceanography.
Representative terms from entire chapter: