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EXECUTIVE SUMMARY Several states are considering regulations to control vapor emis- sions from the loading and ballasting of tankships and tank barges carrying liquids such as volatile hydrocarbons. These vapors, displaced by entering cargo or ballast as vessel tanks are filled, totaled 56,600 metric tons in the United States in 1985. About 95 percent were from crude oil and gasoline cargoes; two-thirds came from inland barges and the rest from tankships. These emissions amounted to about 0.2 percent of all volatile organic emissions nationally. For comparative purposes, this is about one-tenth the volume of the vapor emissions from automobile refueling. However, vessel hydrocarbon vapor emissions may be very important locally. State efforts to meet federal air quality standards have therefore focused on emissions from marine loading terminals, among other sources. Under current air quality regulations, these emissions are generally not subject to control. Nevertheless, hydrocarbon vapors are important contributors to ozone generation. Several states are considering con- trols as a way to meet federal air quality standards for ozone set by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act. A number of major metropolitan areas in the United States are not in attainment of National Ambient Air Quality Standards (NAAQS) for ozone. THE FEASIBILITY OF VAPOR CONTROL Technology for controlling these emissions is available and in use; vessels and marine terminals that load liquefied natural gas, acrylo- nitrile, and other hazardous fluids routinely capture and reuse or dispose of loading vapors. It is technically feasible to locate equip- ment for vapor recovery or disposal either on the vessel or at the shoreside terminal. Controlling vapors from hydrocarbon loading would require extending this practice broadly, and undertaking vapor control at higher loading rates than currently practiced. Handling potentially explosive vapors could present an added hazard at barge and tankship terminals. It would also entail substantial investments and operating costs in the tankship and barge industries. Loading terminals and vessels would need to install and operate the 1
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2 necessary systems. Terminals with low throughputs, inland barges, and smaller, older tankships would face greater cost impacts than larger units of the industry. Equipment needed for vapor control includes systems aboard vessels that make closed loading possible: devices to protect tanks from over- pressurization, level monitoring and alarm systems to prevent overfill- ing, and devices for final cargo gauging and sampling. Closed loading is done with hatches and ports shut, but it does not necessarily pre- clude venting of vapors to the atmosphere. Most tankships are equipped for closed loading, to maintain the required pressure of fire-preventive inert gas in cargo tanks. Tank barges generally do not use inert gas, and are usually open loaded. Terminals would need vapor transport piping, incinerators, or other equipment for disposal or recovery of vapors, and inert gas generating and piping systems to prevent the formation of flammable or explosive vapor-air mixtures in tanks and pipelines. Vessels would need piping and manifolds to collect vapors and carry them ashore or elsewhere for disposition. Tank gauging and alarms, detonation arrestors, and other inline safety devices on vessels and at terminals are needed to prevent overpressurization and prevent or limit the effects of fires and explosions. The complexity of these systems could challenge the engineering, operational, and personnel training standards of some sectors of the industry, especially at the lower technology end of the scale, such as inland barges and small product terminals. Some items of safety equip- ment, such as detonation arrestors, might require further development and testing at sizes appropriate to tank barge or tankship loading rates. SAFETY AND OPERATIONAL COMPLEXITY The loading of tank vessels with hydrocarbon cargoes presents three main hazards: (1) fire due to the ignition of spilled liquid or uncon- fined vapors, (2) explosion due to the ignition of vapor-air mixtures in confined spaces, (3) water pollution as a result of spills. An addi- tional consideration is possible personnel exposure to vapors. The addi- tion of vapor-handling systems, it has been suggested, could increase the risks of such events by adding to the operational complexity of loading operations, and in particular by requiring additional handling of potentially explosive vapors. Experience to date is too limited to justify firm conclusions, although it does suggest that proper personnel training and management can keep the risks of vapor control within the bounds of normal risks in the industry. Redundant safety systems would be required at terminals and on board vessels to ensure that the unnoticed failure of one system would not expose operations to undue risks. Certainly, vapor control would require raising operating and train- ing standards throughout the tank barge and tankship industries to the levels that obtain in the most technically advanced sectors of those industries. The operation of vapor control systems would entail stan
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3 cards of precision and care, for example, well above those considered normal in the industries. Control of hydrocarbon vapors from vessels would require raising standards of care and management to levels similar to those in the most technically sophisticated sectors of the marine transportation industry. Furthermore, human error is the major cause of industrial accidents, and management and training programs should address this fact. Tank barges generally, and tankships occasionally, are loaded with hatches and vents open, to allow visual inspection of cargo levels. Containing vapors will require closed loading, with closed-tank gauging systems, and will also require vapor collection systems to carry vapors to disposal or recovery facilities. Experience suggests that the neces- sary operations could be carried out with little or no increase in spills or other accidents. The U.S. Coast Guard would have to proceed on the basis of risk analysis while it and the industries involved gather the experience necessary to quantify the risks. Such a risk analysis has not yet been made. COSTS AND ECONOMIC IMPACTS The economic impacts of vapor control requirements could be substan- tial. First, vessel and terminal owners and operators would suffer the direct costs associated with installing and operating the necessary systems. The committee's assessment suggests that these costs would vary widely from vessel to vessel and terminal to terminal. For exam- ple, estimates indicate that an inland river barge would incur the same retrofit cost--$168,000--as a 70,000 deadweight-ton crude carrier with 25 times the cargo capacity. Case studies of two actual terminals (see Chapter 5) show added capital and operating costs that range from more than $5,000 per ton of emissions abated for a small terminal, loading 1.3 million barrels of gasoline per year, to less than $3,000 per ton of emissions for a larger terminal, loading 14.9 million barrels per year. In general, the committee's cost studies show that the cost effective ness of emission abatement improves with cargo throughput. This could put small terminals and small inland barge companies at a competitive disadvantage. Second, the hydrocarbon vapor control standards under consideration for marine terminals and vessels would affect the cost-competitiveness of tank vessels in relation to other forms of transport. Tank vessel carriage of petroleum cargoes is already declining. Third, the imposition of standards only in nonattainment areas for ozone, it has been suggested, would lead many vessel operators to limit their operations to areas where vapor control is not required, or where requirements are less stringent. This situation would be exacerbated by varying and possibly incompatible standards. Without detailed economic study, it is impossible to gauge the sizes of these economic impacts. Appropriate regulatory coordination, with attention to safety and uniformity, can minimize them, but not avoid them altogether.
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4 POTENTIAL REGULATORY CONFLICT Neither the Coast Guard nor the EPA has taken a major initiative to coordinate or standardize state regulatory development. However, with- out coordination between these two agencies, state air quality regula- tory bodies, and industry, a high potential exists for a clash of regulatory interest between marine safety and air quality goals. Marine vessels, unlike other mobile emissions sources such as auto- mobiles, are not expressly regulated by federal air quality legislation. It is unclear whether EPA may require states to regulate the emissions of so-called mobile sources (such as vessels) indirectly, by attributing them to their stationary gathering points (in this case, marine termi- nals). The agency has taken no positive action on hydrocarbon vapor emissions from vessels, beyond that involved in reviewing state ozone compliance plans. Its authority to coordinate state initiatives is limited. The Coast Guard, whose responsibility is marine safety, must ultimately approve the vapor control systems that may be installed on vessels and at terminals. Uncoordinated development of state regula- tions could increase risks by fostering a lack of standardization. Thus, the drive to clean up the air in this case raises the poten- tial for conflict of national interest between safety and environmental goals. The committee found that vapor control is technically feasible with available technology, that appropriate care by industry and regulators could satisfy the above concerns, and that uniformity of equipment and procedures is important. It recommends a coordinated national approach to developing regulations under the leadership of the Coast Guard, with the involvement of the EPA, states, and industry. Special attention should be directed to risk analysis, uniform technical standards, person- nel training and certification, and investigation of new technologies. CONCLUSIONS AND RECOMMENDATIONS 1. Of the estimated 56,600 metric tons of hydrocarbon vapor emis- sions from tank vessels in 1985 (about 0.2 percent of national volatile organic compound emissions), about 95 percent came from gasoline and crude oil loaded in tankships and tank barges. Almost all of these emissions were from vessels in domestic trade. About two-thirds were from inland tank barges, and the rest were from tankships. 2. Control and recovery of more than 90 percent of hydrocarbon emis- sions from tankships and tank barges are technically feasible with avail- able technology. Hydrocarbon vapor emissions may be abated by any of several technologies to recover or destroy hydrocarbons. Technologies vary in their efficiency of abatement, with destruction technologies generally higher in efficiency than recovery technologies. 3. Abatement of hydrocarbon vapor emissions from tank vessels raises legitimate concerns of safety, cost, economic impact, and operational reliability. With appropriate government and industry attention, these
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5 concerns can be addressed. There is as yet too little experience to project conclusively the safety of planned operations. RECOMMENDATION: In the absence of historical safety experience, the U.S. Coast Guard should employ risk analysis in assessing the safety of the various hydrocarbon vapor emission control alterna- tives. 4. Safe handling of hydrocarbon vapors will require standardized equipment and procedures, which include redundant, automated gauging and alarm devices to prevent overfilling and over or under pressuring, as well as in-line safety devices such as detonation arrestors. RECOMMENDATION : Development and testing programs should be pursued to advance the state of the art in gauging and alarm systems and also to assure and improve the reliability of large (> 6-in. diameter) detonation arrestors. The gauges and alarms program should include addressing the requirements of small, unpowered vessels, i.e., tank barges. 5. Safe hydrocarbon vapor emission abatement will require trained, experienced personnel and adequate control of operations by safety- conscious management. The level of operational control in the tankship industry is, in general, adequate. However, that in the barge industry will need to be strengthened. RECOMMENDATION: The U.S. Coast Guard should revise its per- sonnel certification requirements for tankermen to ensure that responsible personnel are fully qualified and trained to maintain the safety of vapor control operations. RECOMMENDATION: The tank barge industry should undertake a voluntary safety consciousness education campaign directed to operations. This campaign should complement any federal and state regulatory initiatives. 6. Controlling hydrocarbon vapors from vessels may be cost-effective in a particular nonattainment area for ozone if tank vessels are a signi ficant source of hydrocarbon vapor emissions and cargo-loading through put is sufficient to justify control measures. 7. The economic impact of vapor control regulations will be related to how the regulations are applied: their timing, the categories of ves sels or terminals that may be controlled, and the geographical locations in which the regulations are imposed. 8. If emission controls are to be put in place, a coordinated national approach is essential to ensure the implementation of uniform and effective safety practices, with appropriate regard for the effects on interstate and international commerce. The necessary coordination could be achieved by amendments to the Federal Clean Air Act, or by a cooperative interagency program of regulatory development.
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6 RECOMMENDATION: The U. S . Coast Guard should lead the develop- b ment and implementation of a coordinated program to ensure the safety and standardization of maritime hydrocarbon vapor emissions controls. Such an interagency program should involve, at a minimum the U.S. Coast Guard and the U.S. Environmental Protection Agency, operating according to appropriate federal rule-making procedures. Elements of the program should include: · vessel safety; · terminal safety; · control of emissions; and · industry safety education. l 9. New vapor control, recovery, and disposal methods may hold promise as replacements for currently available methods. RECOMMENDATION: A program of technical research, development, and testing should be directed to changes in operational procedures that may reduce emissions, to recovery and disposal technologies that may offer safer, less costly control measures, and to vapor barriers and foams that could help reduce hydrocarbon emissions by controlling vapor generation in cargo tanks.
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