Responding to Water Contamination Threats - Environmental Science

Responding to Water Contamination Threats. Matthew L. Magnuson ... U.S. Regulatory Environment and Planning for Water Security. Ravi Jain , Mary Kay ...
6 downloads 0 Views 280KB Size
Responding to WATER Contamination Threats Planning ahead is the key to

ANTHONY FERNANDEZ

dealing with potential terrorism.

M ATTHEW L . M AGNUSON STEV EN C. ALLGEIER U.S. EPA BART KOCH RICARDO DE LEON METROPOLITA N WATER DISTRICT OF SOUTHERN CALIFORNIA RONALD HUNSINGER EAST BAY MUNICIPAL UTILIT Y DISTRICT © 2005 American Chemical Society

W

ater terrorism—through intentional or threatened contamination of a drinking-water system— can undermine public health, economic well-being, societal functioning, and the environment. Not only can consumers become ill or die, but water contamination could also cut off water needed for other vital uses such as food preparation, sanitation, fire fighting, agriculture, and industry. Although some goals of water terrorAPRIL 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 153A

and other major water supply organizations. Regulatory, public health, and water utility officials as well as representatives from federal, state, and local drinking-water laboratories and organizations served as technical reviewers. Because the RPTB is a consensus document, it integrates many viewpoints. Thus, although specific opinions may differ, the RPTB is a unique source for providing practical, collective insight into how to respond to drinkingwater terrorism.

ism could be accomplished merely by threatening contamination, terrorists could also actually introduce a broad range of contaminants into the water supply—from widely available industrial chemicals to exotic, engineered microorganisms. Accordingly, an extensive range of affected groups, including the U.S. government, water utilities, and the general public, are increasingly aware that drinking water is a critical and interdependent component of the nation’s infrastructure. In 2003, a presidential directive on homeland security designated the U.S. EPA as responsible for protecting the nation’s drinking-water and water-treatment systems (1). In 2004, a second directive required EPA to establish surveillance and monitoring systems that safeguard water quality (2). Traditionally, drinking-water safety has been linked to water quality. The possibility of terrorism directed against the drinking-water supply has emphasized the link between water safety and water security (3, 4). The traditional paradigm in solving water-quality problems is to develop or adapt environmental technology, whether for prevention, remediation, control, analysis, or other goals. Can technology continue to provide us with the answers we need to respond to water terrorism? At first glance, the very reasonable answer would be a resounding “yes”, because responding to an intentional water contamination threat or incident seems to be straightforward and purely technological: The “event” is captured through appropriate sample collection, and the response follows directly from sample analysis. However, no reliable technology on the market today can rapidly and reliably provide the substantial amount of water-quality information needed to make a response decision based solely on analytical data. PHOTODISC

In the toolbox

In lieu of the perfect technology, EPA developed the Response Protocol Toolbox (RPTB) (5). This nonbinding guidance based on existing technology is designed to help water utilities and other organizations address the complex, multifaceted challenges encountered during planning for and responding to the threat or act of intentional contamination of drinking water. EPA developed the RPTB as part of its Water Security Research and Technical Support Action Plan (6) with the help of a working group, which included water utility professionals and officials from the American Water Works Association 154A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2005

The RPTB is divided into six modules. Each discusses a different aspect of the response process. Not every contamination threat or incident requires the use of all six modules. The modules can be used separately or in combination by groups such as water utilities, analytical laboratories, emergency responders, state drinking-water programs, source water protection programs, public health officials, EPA and other federal agencies, and law enforcement. Because it is important that all users be informed about the overall response process, modules aimed at a specific user group also briefly discuss relevant response aspects that are more fully described in modules tailored toward other user groups. Although the RPTB does not necessarily assess or recommend technologies from specific manufacturers, it lists a mixture of the currently available types, ranging from low- to high-tech. In addition, desired characteristics of emerging environmental technologies are discussed. For the sake of this article, low- and mid-tech approaches represent applications of fairly mature, reliable technologies, while high-tech methods involve cuttingedge engineering and science. Furthermore, “notech” refers to an approach that has no technology or uses technology in a simple manner. Water Utility Planning Guide. Module 1 is a water utility planning guide, which describes the activities that a utility could undertake to prepare for contamination threats and incidents (7). Most of these planning activities, which are summarized in Table 1, involve no- or low-tech approaches from an environmental technology standpoint, but modern electronic, information, and telecommunications technology can enhance planning. The planning activity of understanding a water system in terms of its construction, design, operation, personnel, and critical customers illustrates potential benefits of higher-tech approaches. Specifically, the use of high-tech geographic information system (GIS) and hydraulic models may benefit some systems. Setting up a baseline-monitoring program is a planning activity that may rely on mid-tech analytical environmental technology. If such a baseline is not established, a normal fluctuation may be mistaken for a water contamination incident. Baseline monitoring can rely on the diligent application of existing, mid-tech analytical environmental technology. However, a high-tech baseline-monitoring program could be developed with online devices to monitor potentially contaminated

ing EPA responsibilities under the homeland security presidential diPlanning activities and associated technology requirements rectives (1, 2). To successfully rePlanning activity Technology level required spond to all types of Establishing a communication and noMay use information and communicacrises, decision makers tification strategy to predefine comtion technology have historically relied munication pathways and notification on the principles of caresystems ful planning and evalEstablishing an incident command sys- May use information and communicauation of available infortem to delineate leadership and chain tion technology mation. Module 2 exof command prior to an actual threat tends these tried-andor incident (Ref. 21) true principles to water Performing training and conducting Little or no environmental technology contamination threat desk/field exercises to properly apply management, which inany emergency plans volves several interreEnhancing physical security to signifLittle or no environmental technology; lated activities: planning icantly reduce intrusions and false may use low- to high-tech security a management response alarms that would otherwise expend technology prior to an incident, evalutility resources uating the threat’s credDeveloping an information management Some environmental technology, mostly ibility, and making destrategy to provide timely and accuto reduce data to useful information cisions regarding approrate information for evaluating the priate actions to take in credibility of a threat and taking steps response to the threat. to protect public health as necessary Figure 1 on the next page Updating emergency response plans to Little environmental technology represents these interrecover terrorist threats, including inlated activities and illustentional contamination trates the fact that reDeveloping streamlined response guide- Little environmental technology sponse actions intensify lines to support responders and decias threat credibility insion makers in the midst of a crisis creases. As described in Establishing a program to monitor the Mid-tech environmental technology for the following few parabaseline, which accounts for normal most cases; high-tech needed if pergraphs, crisis managefluctuations in water-quality data or formed through online monitoring ment activities do not consumer complaints and which may necessarily inherently indicate a potential problem require technology, alUnderstanding water-system construc- Little environmental technology in most though contamination tion, design, operation, personnel, and cases; high-tech hydraulic and geothreat management may critical customers; applying this ingraphic information system modeling call upon the technoloformation to assess vulnerabilities to may be helpful gies described in other contamination threats modules of the RPTB. Using and understanding data from High-tech activity, especially in underThe first activity is online monitors of water-quality standing both water monitoring sysplanning a response to parameters, such as pH, chlorine tem fundamentals and the relationship unknown threats—a residual, and turbidity, to warn of between water-quality fluctuations and daunting task because potential water contamination the presence of specific contaminants such an immense number of potential biologiwater that rapidly travels through a system. Online cal, chemical, and radiological contaminants exist. monitors are appealing, but experts debate their efFortunately, as described by the World Health Orgafectiveness, costs, and benefits as a contaminant nization, it is neither possible nor necessary to plan warning system (8, 9). Many organizations, includfor an attack by all possible contaminants; rather, ing EPA’s National Homeland Security Research planning and preparation to counter the effects of Center (10) through its Distribution System Resuch an attack can provide the capabilities to deal search Consortium, are actively engaged in research with a wide range of possibilities (13). Accordingly, to advance the goal of online monitoring (11). Module 2 presents management planning activiContamination Threat Management Guide. ties, such as establishing roles and responsibilities Module 2 is the centerpiece of the RPTB (12). It preof various parties under different scenarios. These sents the overarching framework for managing parties must answer vital questions about who will contamination threats to the drinking-water supperform response activities at a particular location. ply. Because appropriate management is integral Management must also take the appropriate steps, to solving any water crisis, the response principles such as those outlined in Module 1, to improve prediscussed in Module 2 can guide activities beyond paredness and responsiveness at a particular water the primary focus of the RPTB, such as implementsystem. TA B L E 1

APRIL 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 155A

FIGURE 1

Overview of threat management activities Module 2 emphasizes careful planning and evaluation of available information and is considered the centerpiece of the Response Protocol Toolbox. Building on the strategies presented in Module 2, this diagram shows how response actions expand as threat credibility increases. Planning and preparation Threat warning Initial threat evaluation

Immediate operational response actions Site characterization and sampling Is threat credible? Public health response actions

Expanded response actions

Threat evaluation process

Is threat possible?

Sample analysis

Is incident confirmed?

Remediation and recovery

Evaluating the credibility of a threat, the second management activity, is a process that considers available information to determine whether a threat is possible, credible, or a confirmed incident. The time frames for determining each of these stages are 1 h, 8 h, and up to several days, respectively. Therefore, decisions frequently must be made without complete information, leaving threat managers to rely on a preponderance of evidence, not only from analytical technologies but also from careful evaluation of sources of information, such as law enforcement, the public health community, and observations at the suspected contamination site. In parallel to threat evaluation is the third management activity: making decisions regarding appropriate actions in response to the threat. Making these decisions effectively means skillfully balanc156A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2005

ing the benefits of the particular decision with the consequences. For example, isolating a potentially contaminated storage tank from a water system could keep people from becoming ill, but then that water may not be available for fire fighting and sanitation. Site Characterization and Sampling Guide. Module 3 describes how to gather information from the site of a suspected contamination incident at a drinking-water system (14). Site characterization activities include site investigation, field safety screening, rapid field-testing of the water, and sample collection for in-depth laboratory analysis. Most of the sampling activities described in Module 3 do not use advanced technology but rely on classic fieldwork techniques. One exception is a field sample concentrator for microbiological species, which is currently in development and testing (6). This midtech device uses routine technology but applies it to overcome the unique challenges of collecting representative samples from the site of a suspected water contamination incident. As an example, consider a waterborne pathogen with an infectious dose of 10–100 organisms, which might be consumed in 500 mL of water. The technological challenge is to sample a 250,000-gallon tank in a manner that can provide a meaningful result about whether the water is safe to use. The proposed solution includes using a field concentrator to sample a large volume of water and concentrate any organisms present by several orders of magnitude. Field safety screening can detect environmental hazards that might pose a threat to the site characterization team. For example, radioactivity can be monitored as the team approaches the site. Rapid field-testing involves water analysis during the site characterization to tentatively identify contaminants or unusual water quality. Table 2 lists the generic types of available field-screening and rapid field-testing kits. The target parameter for screening and rapid water testing may be a specific contaminant; a contaminant class; or a general indicator, such as chlorine residual, of potential changes in water quality. The core kit includes the equipment necessary to conduct the recommended minimum level of field safety screening and rapid water testing (Table 2). Note that these technologies are fairly well established, are considered highly reliable, and may be classified as low- to mid-tech. Additional, less-proven, higher-tech approaches that might be used for expanded field-testing are also listed in Table 2. One unfortunate characteristic of the high-tech expanded field-testing technologies is that they can have propensities for false positives and false negatives. An example is a recent study of rapid toxicity assays, which will not detect many contaminants of concern and yet respond to compounds such as copper and chlorine (15). Another study of field-testing technologies for drinking-water security investigations highlighted the need for further research and testing (16). Thus, the better available technology for field safety screening and field-testing can actually be low-tech, because high-tech solutions can create ad-

TA B L E 2

Core and expanded field-testing kits Core kit Target parameter

Purpose

Environmental technology

Comments

Radioactivity (, , )

Primarily a safety screen

Geiger–Müller probe and meter

May be expanded to water testing with a special probe

Cyanide

Water testing

Colorimetric or ionselective electrode

Tests water for cyanide ion but not combined forms

Chlorine residual

Water testing

Colorimetric

Absence of residual may indicate a problem

pH/conductivity

Water testing

Ion-selective electrode

Abnormal pH or conductivity may indicate a problem

Target parameter

Purpose

Environmental technology

General hazards

Safety screen

Hazard categorization kits (explosives, oxidants, etc.)

Should be performed by a trained hazardous materials responder

Volatile chemicals

Safety screen

Sniffer-type devices

Detect chemicals in air

Schedule 1 chemical weapons (VX, sarin, etc.) (Ref. 22)

Safety screen, water testing

Enzymatic/colorimetric

Many kits may also detect certain pesticides

Water quality parameters

Water testing

Variable (e.g., ion probes, colorimetric)

Kits available for a variety of common parameters

Pesticides (organophosphates and carbamates)

Water testing

Immunoassays

Quick and simple to use

Volatile organic compounds and semivolatile organic compounds

Water testing

Portable gas chromatography/mass spectrometry

Expensive but expands field capability for chemicals

Biotoxins (ricin, botulinum, etc.) Water testing

Immunoassays

Quick and simple to use

Pathogens (tularemia, anthrax, plague, etc.)

Water testing

Immunoassays and polymerase chain reaction

Preconcentration will increase sensitivity

Toxicity

Water testing

Inhibition of biological activity

Need to establish a baseline

Expanded kit

ditional problems and uncertainties in the analysis. Analytical Guide. Module 4 shows an approach to the analysis of samples collected from the site of a suspected contamination incident (17). It is not a detailed, prescriptive protocol but rather a flexible framework for developing a technological approach for the analysis of water samples containing an unknown contaminant. The framework is also designed to promote the effective and defensible performance of laboratory analysis. Table 3 (on the next page) lists the types of analytical environmental technology that may be the most useful for water security samples. As part of the overall analytical framework, Module 4 combines a number of highly reliable, low- and mid-tech approaches into a battery of standardized analytical methods designed to screen for contaminants of concern. Additional contaminant coverage is provided by the various test kits and high-tech handheld detection equipment for the chemicals, polymerase

Comments

chain reaction (PCR), reverse transcriptase PCR, and sequencing of microbiological contaminants. These high-tech approaches often must be customized to specific contaminants of concern, increasing the technological complexity of the analysis and, frequently, the uncertainty of the result. Public Health Response Guide. Module 5 deals with the public health response measures that could be used to minimize public exposure to potentially contaminated water (18). Specifically, it examines the role of the utility during a public health response action, as well as the interaction among the utility, the drinking-water primacy agency, the public health community, and other parties with a public health mission. The public health response has five major components: planning, including conducting drills and simulations; determining public health consequences of contamination; implementing any necessary response actions; notifying the public if appropriate; and providing an APRIL 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 157A

lizing alternative water supplies for fire fighting could take time; therefore, during that period of time, it may Analytical environmental technologies used to screen for be necessary to extinguish fires with various classes of contaminants contaminated water. The appropriate use of contaminated water for this or any other purpose should be carefully Contaminant type Analytical environmental technology evaluated in terms of its benefits and Organic Gas chromatography (GC) with various detectors, GC/ risks, along with any measures needmass spectrometry (MS), liquid chromatography ed to minimize those risks. (LC) with various detectors, LC/MS, immunoassay Remediation and Recovery Guide. test kits Module 6 describes the planning and Inorganic Ion chromatography, graphic furnace atomic absorpimplementation of remediation and tion, cold vapor atomic absorption, inductively courecovery activities that would be necpled plasma (ICP), ICP/MS essary following a confirmed contamination incident (19). The remeCyanides Ion-selective electrode, wet chemistry diation process involves a sequence Biotoxin Immunoassay test kits, GC/MS, LC, and LC/MS of several activities, including system Radiological Gross , , and ; radionuclide-specific technology; characterization, selection of remehandheld meters and equipment dy options, provision of an alternative drinking water supply during reSchedule 1 chemical GC/MS with direct injection, purge and trap, solidmediation activities, and monitoring weapons (VX, sarin, phase extraction/solid-phase microextraction, test to demonstrate that the system has etc.) (Ref. 22) kits, handheld equipment been remediated. Bacteria Culture in selective media, biochemical and serological The goal of remediation and retests, polymerase chain reaction (PCR), sequencing covery is to return the water supply system to service as quickly as posBacteria–spore-forming PCR, immunoassay, sequencing sible while protecting public health Protozoa Immunomagnetic separation, immunofluorescence and minimizing disruption to normal assay microscopy, sequencing life (or ensuring business continuity). Viruses Mammalian cell culture, plaque neutralization, PCR, During the remediation and recovery reverse transcriptase PCR , sequencing stage of the threat management process, the urgency of the situation has passed, and the magnitude of the realternative domestic water supply, if needed. Public medial action requires careful planning and implehealth response is an important subset of the overmentation. Although rapid recovery of the system is all threat management (Module 2). crucial, it is equally important to follow a systemInformation-sharing technology may be valuatic process that establishes remedial goals acceptable in terms of notifying the public, and high-tech able to all stakeholders, implements the remedial approaches such as hydraulic and GIS models may process in an effective and responsible manner, and be useful to predict the spread of the contaminant demonstrates that the remedial action was indeed through the water system. In addition to these sosuccessful. phisticated models, simpler approaches, such as In many respects, the model for remediation and hydraulic maps, may be helpful. In many cases, howrecovery presented in Module 6 resembles a Superever, the information necessary to assess potential fund program (20), although a contaminated water health consequences may be unknown or poorly system probably would not be classified as a Supercharacterized in the relatively short time frame in fund site. Why use the Superfund model? First, the which public health decisions must be made. This approach and technology are familiar to a wide reinforces the need for implementing Module 2’s variety of people in the United States, including state and federal regulators and remediation procrisis management approach. How alternative water supplies are provided may fessionals who would probably be involved in the also vary with respect to the level of technological response action. Second, the Superfund model is a sophistication, depending on the particular situascientifically sound and defensible process. Many tion and whether short- or long-term water supplies of these remediation activities rely on traditional are needed. In either time frame, many of the better environmental techniques—and are not necessarsolutions may be inherently low-tech, such as haulily cutting-edge technologies—but are applied ing water to consumers; connecting to a neighboraccording to carefully thought-out practices for esing, uncontaminated utility; or simply providing tablishing remedial goals (e.g., determining “how bottled water. Higher-tech solutions involve porclean is clean”) specific to each contaminant of table water treatment systems, complete with their concern. Applying these traditional environmenown power sources, storage capacity, and wastetal technologies to the remediation of the contamstream management components. Activities that inants of concern may present specific challenges demand large amounts of water, such as fire fightin terms of destroying or deactivating the contaming, can complicate the situation. In reality, mobiinants and disposal of any residuals from their TA B L E 3

158A ■ ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2005

destruction or deactivation. However, several organizations, such as the American Water Works Association Research Foundation and EPA’s Distribution System Research Consortium, are actively engaged in research to solve important problems in the remediation and recovery of drinking-water distribution systems (11).

The bottom line As with other environmental problems, decision makers may inherently tend to rely on environmental technology when responding to a contamination threat or incident. However, the RPTB illustrates that technology alone is not the solution. In fact, over-reliance on current technology can create its own problems, such as false positive responses from high-tech analysis. On average, the level of technology in the RPTB as a whole could probably be characterized as low, with many response activities that require no technology at all. The technology included in the RPTB is appropriate because it is generally quite reliable. High-tech, cutting-edge approaches could be of immense value during the response to a contamination threat if they were sufficiently reliable, but they are not necessarily critical to or appropriate for the successful application of the RPTB today. We hope that environmental technology will eventually become so advanced that it will be able to provide timely, objective, and complete answers during a contamination threat or incident at a drinking-water system. To achieve this goal, much more work is required. At present, however, if we were to operate under the usual belief that hightech solutions are by themselves capable of solving the problems, our response might be tragically ineffective. The bottom line is that for a timely response to a threat or incident, decision makers need to rely on careful planning and skillful evaluation of available information; these are tried-and-true techniques for responding to crisis. Technology of any variety is only one tool in this effort. Matthew L. Magnuson is a research chemist with the EPA Water Supply and Water Resources Division in Cincinnati, Ohio. Steven C. Allgeier is an environmental engineer with the EPA Water Security Division in Cincinnati, Ohio. Bart Koch is the Water Quality Laboratory Chemistry Unit manager and Ricardo De Leon is the Water Quality Laboratory Microbiology Unit manager with the Metropolitan Water District of Southern California. Ronald Hunsinger is the Manager of Water Quality with the East Bay Municipal Utility District in Oakland, Calif. Address correspondence regarding this article to Magnuson at magnuson.matthew@epamail. epa.gov.

Acknowledgments and Disclaimer

The authors thank the RPTB working group and technical reviewers, along with the many other individuals who provided additional support. Any opinions expressed in this paper are those of the authors and do not necessarily reflect the official position and policies of EPA. Any mention of products or trade names does not constitute recommendation for use by EPA.

References (1) Homeland Security Presidential Directive 7: Critical Infrastructure Identification, Prioritization, and Protection, 2003, www.counterterrorism.org/homelandsecurity-presidential-directive-7.asp. (2) Homeland Security Presidential Directive 9: Defense of United States Agriculture and Food, 2004, w w w.cou nter ter ror ism.org/homela nd-secu r it ypresidential-directive-9.asp. (3) Rose, J. B. Water Quality Security. Environ. Sci. Technol. 2002, 36, 246A–250A. (4) Luthy, R. G. Bioterrorism and Water Security. Environ. Sci. Technol. 2002, 36, 123A–123A. (5) Response Protocol Toolbox: Overview and Application; Document No. EPA-817-D-03-007, U.S. EPA: Washington, DC, 2003, www.epa.gov/safewater/watersecurity/ pubs/guide_response_overview.pdf. (6) The Water Security Research and Technical Support Action Plan; U.S. EPA: Washington, DC, 2004, www.epa. gov/nhsrc/pubs/bookActionPlan031204.pdf. (7) Module 1: Water Utilities Planning Guide; Document No. EPA-817-D-03-001; U.S. EPA: Washington DC, 2003, www.epa.gov/safewater/watersecurity/pubs/guide_ response_module1.pdf. (8) International Life Sciences Institute. Early Warning Monitoring to Detect Hazardous Events in Water Supplies; ILSI Press: Washington, DC, 1999, www.ilsi.org/ file/EWM.pdf. (9) Hargesheimer, E., Conio, O., Popovicova, A., Eds. Online Monitoring for Drinking Water Utilities; American Water Works Association Research Foundation and CRS PROAQUA: Denver, CO, 2002. (10) U.S. EPA National Homeland Security Research Center, www.epa.gov/nhsrc. (11) Herrmann, J.; Janke, R.; Rubiou, G. Achieving Water Security through a Collaborative Approach: The Distribution System Resource Consortium. In Proceedings of the American Water Works Association Water Security Congress, Charlotte, NC, April 26–28, 2004, www.epa.gov/ nhsrc/index.htm. (12) Module 2: Contamination Threat Management Guide; Document No. EPA-817-D-03-002; U.S. EPA: Washington, DC, 2003, www.epa.gov/safewater/watersecurity/ pubs/guide_response_module2.pdf. (13) World Health Organization. Public Health Response to Biological and Chemical Weapons: WHO Guidance; 2004, www.who.int/csr/delibepidemics/biochemguide/en/ index.html. (14) Module 3: Site Characterization and Sampling Guide; Document No. EPA-817-D-03-003; U.S. EPA: Washington, DC, 2003, www.epa.gov/safewater/watersecurity/ pubs/guide_response_module3.pdf. (15) ETV Advanced Monitoring Systems Center—Advanced Monitoring Systems (Water) Rapid Toxicity Testing Systems; U.S. EPA: Washington, DC, 2003, www.epa.gov/ etv/verifications/vcenter1-27.html. (16) States, S.; et al. Rapid Analytical Techniques for Drinking Water Security Investigations. J. Am. Water Works Assoc. 2004, 96, 52–64. (17) Module 4: Analytical Guide; Document No. EPA-817D-03-004; U.S. EPA: Washington, DC, 2003, www.epa. gov/safewater/watersecurity/pubs/guide_response_ module4.pdf. (18) Module 5: Public Health Response Guide; Document No. EPA-817-D-03-005; U.S. EPA: Washington, DC, 2003, www.epa.gov/safewater/watersecurity/pubs/guide_ response_module5.pdf. (19) Module 6: Remediation and Recovery Guide; Document No. EPA-817-D-03-006; U.S. EPA: Washington, DC, 2003, www.epa.gov/safewater/watersecurity/pubs/guide_ response_module6.pdf. (20) U.S. EPA. Welcome to Superfund, www.epa.gov/superfund. (21) FEMA IS-195 Basic Incident Command System: EMI Independent Study Program; Federal Emergency Management Agency: Washington, DC, 2003, http://training. fema.gov/EMIWeb/IS/is195.asp. (22) Chemical Weapons Convention. CWC Regulations, Supplement No. 1 to Part 712—Schedule 1 Chemicals, www. cwc.gov/Regulations/cfr-15/part-712-s1_html. APRIL 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 159A