Chemical facilities manufacture a host of products—including basic organic chemicals, plastic materials and resins, petrochemicals, and industrial gases, to name a few. Other facilities, such as fertilizer and pesticide facilities, pulp and paper manufacturers, water facilities, and refineries, also house large quantities of chemicals. EPA has a role in preventing and mitigating accidental releases at chemical facilities through, among other things, the RMP provisions of the Clear Air Act. Under these provisions, EPA identified 140 toxic and flammable chemicals that, when present above certain threshold amounts, would pose the greatest risk to human health and the environment if released. According to EPA, approximately 15,000 facilities in a variety of industries produce, use, or store one or more of these chemicals beyond threshold amounts. The 2003 President’s National Strategy for the Physical Protection of Critical Infrastructures and Key Assets sets forth actions that EPA and DHS will take to secure the chemical infrastructure. The strategy directs EPA and DHS to promote enhanced site security at chemical facilities and review current practices and statutory requirements on the distribution and sale of certain pesticides and industrial chemicals to help identify whether additional measures are necessary. DHS is also charged with continuing to develop the Chemical Sector Information Sharing and Analysis Center, a partnership with industry to facilitate the collection and sharing of threat information, by promoting the Center and recruiting chemical industry constituents to participate. A presidential directive issued in December 2003 designates DHS as the lead federal agency for chemical security, a change from national strategies issued in July 2002 and February 2003, which named EPA as the lead. A number of other critical infrastructures have federal security requirements. All commercial nuclear power facilities licensed by the Nuclear Regulatory Commission are subject to a number of security requirements. The Aviation and Transportation Security Act of 2001 directed the Transportation Security Administration to take over responsibility for airport screening. The Public Health Security and Bioterrorism Preparedness and Response Act of 2002 requires community water systems serving more than 3,300 people to conduct a vulnerability assessment, prepare an emergency response plan, certify to EPA that the vulnerability assessment and emergency response plan have been completed, and provide a copy of the assessment to EPA. To improve security in our nation’s ports, the regulations implementing the Maritime Transportation Security Act of 2002 direct vessels and facilities—some of which are chemical facilities—to develop security plans. Congress is considering several legislative proposals that would grant DHS, or DHS and EPA, the authority to require chemical facilities to take security steps. S. 994 requires the Secretary of Homeland Security to promulgate regulations specifying which facilities should be required to conduct vulnerability assessments and to prepare and implement site security plans, a timetable for completing the vulnerability assessments and security plans, the contents of plans, and limits on the disclosure of sensitive information. S. 157 would direct EPA to designate high-priority chemical facilities based on the threat posed by an unauthorized release and require these facilities to conduct vulnerability assessments, identify hazards that would result from a release, and prepare a prevention, preparedness, and response plan. S. 157 would also require facilities to send these assessments and plans to EPA. EPA and DHS would jointly review the assessments and plans to determine compliance. S. 157 would also require that facilities consider inherently safer practices (referred to as inherently safer technologies), such as substituting less toxic chemicals. Experts agree that chemical facilities present an attractive target for terrorists intent on causing massive damage because many facilities house toxic chemicals that could become airborne and drift to surrounding areas if released. Chemical facilities could also be attractive targets for the theft of chemicals that could be used to create a weapon capable of causing harm. Justice has concluded that the risk of an attempt in the foreseeable future to cause an industrial chemical release is both real and credible. In fact, according to Justice, domestic terrorists plotted to use a destructive device against a U.S. facility that housed millions of gallons of propane in the late 1990s. In testimony on February 6, 2002, the Director of the Central Intelligence Agency warned of the potential for an attack by al Qaeda on chemical facilities. Some chemical facilities may be at higher risk of a terrorist attack than others because they contain large amounts of toxic chemicals and are located near population centers. Attacks on such facilities could harm a large number of people, with health effects ranging from mild irritation to death, cause large-scale evacuations, and disrupt the local or regional economy. No specific data are available on what the actual effects of successful terrorist attacks on chemical facilities would be. However, RMP facilities must submit to EPA estimates, including the residential population located within the range of a toxic gas cloud produced by a “worst-case” chemical release, called the “vulnerable zone.” According to EPA, 123 chemical facilities located throughout the nation have toxic “worst-case” scenarios where more than one million people could be at risk of exposure to a cloud of toxic gas. About 600 facilities could each potentially threaten between 100,000 and a million people, and about 2,300 facilities could each potentially threaten between 10,000 and 100,000 people within these facilities’ “vulnerable zones.” According to EPA, “worst-case” scenarios do not consider the potential causes of a release or how different causes or other circumstances, such as safety features, could lessen the consequences of a release. Hence, the “worst-case” scenario calculations would likely be overstating the potential consequences. However, under the Clean Air Act, RMP facilities must estimate the effects of a toxic chemical release involving the greatest amount of the toxic chemical held in a single vessel or pipe—not the entire quantity on site. Therefore, for some facilities it is conceivable that an attack where multiple chemical vessels were breached simultaneously could result in an even larger release, potentially affecting a larger population than estimated in the RMP “worst-case” scenarios. Other factors besides location and the quantity of chemicals onsite could also make a facility a more attractive target. For example, a facility that is widely recognizable, located near a historic or iconic symbol, or critical to supporting other infrastructures could be at higher risk. A 2002 Brookings Institution report ranks an attack on toxic chemical facilities behind only biological and atomic attacks in terms of possible fatalities. Currently, no one has comprehensively assessed security across the nation at facilities that house chemicals. According to a 1999 study by the Department of Health and Human Services’ Agency for Toxic Substances and Disease Registry (ATSDR), security at chemical facilities in two communities was fair to very poor. ATSDR observed security vulnerabilities such as freely accessible chemical barge terminals and chemical rail cars parked near residential areas in communities where facilities are located. Following visits to 11 chemical facilities, Justice concluded that some facilities may need to implement more effective security systems and develop alternative means to reduce the potential consequences of a successful attack. The ease with which reporters and environmental activists gained access to chemical tanks and computer centers that control manufacturing processes at chemical facilities in recent years also raises doubts about security effectiveness at some facilities. No federal laws explicitly require all chemical facilities to take security actions to safeguard their facilities against a terrorist attack. Although the federal government requires certain chemical facilities to take security precautions directed to prevent trespassing or theft, these requirements do not cover a wide range of chemical facilities and may do little to actually prevent a terrorist attack. For example, under EPA’s regulations implementing the Resource Conservation and Recovery Act of 1976, facilities that house hazardous waste generally must take certain security actions, such as posting warning signs and using a 24-hour surveillance system or surrounding the active portion of the facility with a barrier and controlled entry gates. However, according to EPA, these requirements would be applicable to only approximately 21 percent of the 15,000 RMP facilities. Regulations implementing the Maritime Transportation Security Act of 2002 also require vessels and port facilities—some of which are chemical facilities—to develop security plans. A number of federal laws also impose safety requirements on chemical facilities, but these requirements do not specifically and directly address security preparedness against terrorism. Several statutes, including the Occupational Safety and Health Act, the Clean Air Act, and the Emergency Planning and Community Right-to-Know Act, impose safety and emergency response requirements on chemical facilities that may incidentally reduce the likelihood and mitigate the consequences of terrorist attacks. All of these requirements could potentially mitigate a terrorist attack in a number of ways. First, because some of these requirements only apply to facilities with more than threshold quantities of certain chemicals, facility owners have an incentive to reduce or eliminate these chemicals, which may make the facility a less attractive target or minimize the impact of an attack. Second, both the Clean Air Act risk management plan provisions and the hazard analyses under the Occupational Safety and Health Act require facility operators to identify the areas of their facilities that are vulnerable to a chemical release. When facilities implement measures to improve the safety of these areas, such as installing sensors and sprinklers, the impact of a terrorist-caused release may be lessened. Third, the emergency response plans increase preparedness for a chemical release—whether intentional or unintentional. While these safety requirements could mitigate the effects of a terrorist attack, they do not impose any security requirements, such as conducting vulnerability assessments and addressing identified problems. While no law explicitly requires facilities to address the threat of terrorism, EPA believes that the Clean Air Act could be interpreted to provide it with authority to address site security from terrorist attacks at chemical facilities. Section 112(r) of the Clean Air Act—added by the Clean Air Act Amendments of 1990—imposes certain requirements on chemical facilities with regard to “accidental releases.” The act defines an accidental release as an unanticipated emission of a regulated substance or other extremely hazardous substance into the air. Arguably, any chemical release caused by a terrorist attack would be unanticipated and thus could be covered under the Clean Air Act.