Search

Liquefied natural gas (LNG) is a supercooled liquid form of natural gas. U.S. LNG imports are projected to increase to about 17 percent of natural gas supplies by 2030, from about 3 percent today. To meet this increase, energy companies have submitted 32 applications for new terminals. If a terrorist attack on an LNG tanker caused a spill, potential hazards, such as fire, asphyxiation, and explosions, could result. The Department of Energy (DOE) recently funded a study to conduct small- and large-scale experiments to refine and validate models that calculate how heat from large LNG fires would affect the public. This testimony is based on GAO's report, Maritime Security: Public Safety Consequences of a Terrorist Attack on a Tanker Carrying Liquefied Natural Gas Need Clarification (GAO-07-316). To prepare this report, GAO examined the results of six recent studies on the effects of an LNG spill and convened a panel of 19 experts to identify areas of agreement on the consequences of a terrorist attack on an LNG tanker. The six studies GAO reviewed examining the potential effect of a fire resulting from an LNG spill produced varying results; some studies also examined other potential hazards of a large LNG spill and reached consistent conclusions on explosions. Specifically, the studies' conclusions about the distance at which 30 seconds of exposure to the heat (heat hazard) could burn people ranged from less than 1/3 of a mile to about 1-1/4 miles. Sandia National Laboratories (Sandia) conducted one of the studies and concluded, based on its analysis of multiple attack scenarios, that a good estimate of the heat hazard distance would be about 1 mile. Federal agencies use this conclusion to assess proposals for new LNG import terminals. The variations among the studies occurred because, with no data on large spills from actual events, researchers had to make numerous modeling assumptions to scale up the existing experimental data for large LNG spills. Three studies considered LNG vapor explosions and concluded that such explosions are unlikely unless the vapors were in a confined space. Only the Sandia study examined the potential for the sequential failure of multiple tanks on the LNG vessel (cascading failure) and concluded that only three of the five tanks in a typical tanker would potentially be affected, and that such failure would increase the duration of the LNG fire. GAO's expert panel generally agreed on the public safety impact of an LNG spill caused by a terrorist attack, disagreed on specific conclusions of the Sandia study, and suggested future research priorities. Experts agreed that the most likely public safety impact of an LNG spill is the heat impact of a fire and that explosions are not likely to occur unless LNG vapors are in confined spaces. However, the experts did not all agree with the heat hazard and cascading failure conclusions reached by the Sandia study. Finally, they suggested priorities to guide future... [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) is a supercooled liquid form of natural gas. U.S. LNG imports are projected to increase to about 17 percent of natural gas supplies by 2030, from about 3 percent today. To meet this increase, energy companies have submitted 32 applications for new terminals. If a terrorist attack on an LNG tanker caused a spill, potential hazards, such as fire, asphyxiation, and explosions, could result. The Department of Energy (DOE) recently funded a study to conduct small- and large-scale experiments to refine and validate models that calculate how heat from large LNG fires would affect the public. This testimony is based on GAO's recently released report, Maritime Security: Public Safety Consequences of a Terrorist Attack on a Tanker Carrying Liquefied Natural Gas Need Clarification (GAO-07-316). To prepare this report, GAO examined the results of six recent unclassified studies on the effects of an LNG spill and convened a panel of 19 experts to identify areas of agreement on the consequences of a terrorist attack on an LNG tanker. The six studies GAO reviewed examining the potential effect of a fire resulting from an LNG spill produced varying results; some studies also examined other potential hazards of a large LNG spill and reached consistent conclusions on explosions. Specifically, the studies' conclusions about the distance at which 30 seconds of exposure to the heat (heat hazard) could burn people ranged from less than 1/3 of a mile to about 1-1/4 miles. Sandia National Laboratories (Sandia) conducted one of the studies and concluded, based on its analysis of multiple attack scenarios, that a good estimate of the heat hazard distance would be about 1 mile. Federal agencies use this conclusion to assess proposals for new LNG import terminals. The variations among the studies occurred because, with no data on large spills from actual events, researchers had to make numerous modeling assumptions to scale up the existing experimental data for large LNG spills. Three of the studies also examined other potential hazards of an LNG spill, including LNG vapor explosions and sequential failure of multiple tanks on the LNG vessel (cascading failure). All three studies considered LNG vapor explosions unlikely unless the vapors were in a confined space. Finally, the Sandia study examined the potential for cascading tank failure and concluded that only three of the five tanks in a typical tanker would potentially be affected, and that such failure would increase the duration of the LNG fire. GAO's panel of experts generally agreed on the public safety impact of an LNG spill caused by a terrorist attack, disagreed on specific conclusions of the Sandia study, and suggested future research priorities. Experts agreed that the most likely public safety impact of an LNG spill is the heat impact of a fire and that explosions are not likely to occur unless LNG vapors are in confined spaces. However, the experts did not all agree... [ABSTRACT FROM AUTHOR]

The United States imports natural gas by pipeline from Canada and by tanker as liquefied natural gas (LNG) from overseas. LNG--a supercooled form of natural gas--currently accounts for about 3 percent of total U.S. natural gas supply, with an expected increase to about 17 percent by 2030, according to the Department of Energy (DOE). With this projected increase, many more LNG import terminals have been proposed. However, concerns have been raised about whether LNG tankers could become terrorist targets, causing the LNG cargo to spill and catch on fire, and potentially explode. DOE has recently funded a study to consider these effects; completion is expected in 2008. GAO was asked to (1) describe the results of recent studies on the consequences of an LNG spill and (2) identify the areas of agreement and disagreement among experts concerning the consequences of a terrorist attack on an LNG tanker. To address these objectives, GAO, among other things, convened an expert panel to discuss the consequences of an attack on an LNG tanker. The six unclassified completed studies GAO reviewed examined the effect of a fire resulting from an LNG spill but produced varying results; some studies also examined other potential hazards of a large LNG spill. The studies' conclusions about the distance at which 30 seconds of exposure to the heat (heat hazard) could burn people ranged from less than 1/3 of a mile to about 1-1/4 miles. Sandia National Laboratories (Sandia) conducted one of the studies and concluded, based on its analysis of multiple attack scenarios, that a good estimate of the heat hazard distance would be about 1 mile. Federal agencies use this conclusion to assess proposals for new LNG import terminals. The variations among the studies occurred because researchers had to make modeling assumptions since there are no data for large LNG spills, either from accidental spills or spill experiments. These assumptions involved the size of the hole in the tanker; the volume of the LNG spilled; and environmental conditions, such as wind and waves. The three studies that considered LNG explosions concluded explosions were unlikely unless the LNG vapors were in a confined space. Only the Sandia study examined the potential for sequential failure of LNG cargo tanks (cascading failure) and concluded that up to three of the ship's five tanks could be involved in such an event and that this number of tanks would increase the duration of the LNG fire. GAO's expert panel generally agreed on the public safety impact of an LNG spill, but believed further study was needed to clarify the extent of these effects, and suggested priorities for this additional research. Experts agreed that the most likely public safety impact of an LNG spill is the heat hazard of a fire and that explosions are not likely to occur in the wake of an LNG spill. However, experts disagreed on the specific heat hazard and cascading failure conclusions reached by the Sandia... [ABSTRACT FROM AUTHOR]

Numerous invasive species have been introduced into U.S. waters via ballast water discharged from ships and have caused serious economic and ecologic damage. GAO reported in 2002 that at least 160 nonnative aquatic species had become established in the Great Lakes since the 1800s--one-third of which were introduced in the past 30 years by ballast water and other sources. The effects of such species are not trivial; the zebra mussel alone is estimated to have caused $750 million to $1 billion in costs between 1989 and 2000. Species introductions via ballast water are not confined to the Great Lakes, however. The environment and economy of the Chesapeake Bay, San Francisco Bay, Puget Sound, and other U.S. waters have also been adversely affected. The federal government has been taking steps since 1990 to implement programs to prevent the introduction of invasive species from ships' ballast water discharges. However, species introductions are continuing. This testimony discusses the legislative and regulatory history of ballast water management and identifies some of the issues that pose challenges for the federal government's program for preventing the introduction of invasive species via ships' ballast water. Congress recognized ballast water as a serious problem in 1990 with passage of the Nonindigenous Aquatic Nuisance Prevention and Control Act, legislation intended to help reduce the number of species introductions in the Great Lakes. A reauthorization of this law in 1996, the National Invasive Species Act, elevated ballast water management to a national level. As directed by the legislation, the federal government has promulgated several regulations requiring certain ships to take steps, such as exchanging their ballast water in the open ocean to flush it of potentially harmful organisms, to reduce the likelihood of species invasions via ballast water. Initially these regulations applied only to certain ships entering the Great Lakes; now they apply to certain ships entering all U.S. ports. In addition to these domestic developments, the United Nation's International Maritime Organization has recently adopted a convention on ballast water management that could affect the global fleet. Since 1998, Coast Guard data show that compliance with existing ballast water exchange requirements has generally been high. However, key agencies and stakeholders recognize that the current ballast water exchange program is not a viable long-term approach to minimizing the risks posed by ballast water discharges. The primary reasons for this are that: (1) many ships are exempt from current ballast water exchange requirements, (2) the Coast Guard has not established alternate discharge zones that could be used by ships unable to conduct ballast water exchange for various reasons, and (3) ballast water exchange is not always effective at removing or killing potentially invasive species. Developers are pursuing technologies to provide more reliable alternatives to ballast water exchange, some of which show promise. However, development of such technologies and their eventual use to meet ballast water regulatory requirements face many challenges including the daunting technological task of developing large scale water treatment systems that ships can accommodate, and the lack of a federal discharge standard that would provide a target for developers to aim for in terms of treatment efficiency. As a result, ballast water exchange is still the only approved method for treating ballast water despite the concerns with this method's effectiveness. Consequently, U.S. waters remain vulnerable to the introduction of invasive species via ships' ballast water. State governments and others have expressed frustration over the seemingly slow progress the federal government has made on more effectively protecting U.S. waters from future species invasions via ballast water. As a result, several states have passed legislation that authorizes procedures for managing ballast water that are stricter than federal regulations. [ABSTRACT FROM AUTHOR]

The U.S. surface and maritime transportation systems include roads, mass transit systems, railroads, and ports and waterways. One of the major goals of these systems is to provide and enhance mobility, that is, the free flow of passengers and goods. Mobility provides people with access to goods, services, recreation, and jobs; provides businesses with access to materials, markets and people; and promotes the movement of personnel and material to meet national defense needs. During the past decade, total public sector spending increased for public roads and transit, remained constant for waterways, and decreased for rail. Passenger and freight travel are expected to increase over the next 10 years, according to Department of Transportation projections. Passenger vehicle travel on public roads is expected to grow by 24.7 percent from 2000 to 2010. Passenger travel on transit systems is expected to increase by 17.2 percent over the same period. Amtrak has estimated that intercity passenger rail ridership will increase by 25.9 percent from 2001 to 2010. The key factors behind increases in passenger travel, and the modes travelers choose, are expected to be population growth, the aging of the population, and rising affluence. According to GAO's expert panelists and other sources, with increasing passenger and freight travel, the surface and maritime transportation systems face a number of challenges that involve ensuring continued mobility while maintaining a balance with other social goals, such as environmental preservation. These challenges include (1) preventing congestion from overwhelming the transportation system, (2) ensuring access to transportation for certain undeserved populations, and (3) addressing the transportation system's negative effects on the environment and communities. There is no one solution for the mobility challenges facing the nation, and GAO's expert panelists indicated that numerous approaches are needed to address these challenges. Strategies included are to (1) focus on the entire surface and maritime transportation system rather than on specific modes and types of travel, (2) use a full range of tools to achieve desired mobility outcomes, and (3) provide more options for financing mobility improvements and consider additional sources of revenue. [ABSTRACT FROM AUTHOR]