Water Safety and Water Infrastructure Security

John G. Voeller

• Publisher: Wiley
• Year: 2014
• Print ISBN: 9781118651841
• eBook ISBN: 9781118652091
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Environmental Management
• Index: Technology & Engineering

Water Safety and Water Infrastructure Security features articles from the Wiley Handbook of Science and Technology for Homeland Security covering topics related to contamination of drinking water, prevention, monitoring, and decontamination. Emergency response planning for drinking water and wastewater systems are also discussed.

1 Potential Contamination Agents of Interest

Robert M. Clark

Cincinnati, Ohio

1.1 Introduction

There are nearly 60,000 community water supplies in the United States serving over 226 million people. Over 63% of these systems supply water to less then 2.4% of the population and 5.4% supply water to 78.5% of the population. Most of these systems provide water to less then 500 people. In addition, there are 140,000 noncommunity systems that serve schools, recreational areas, trailer parks, etc. [1]. Some of the common elements associated with water supply systems in the United States are as follows:

• Water source, which may be a surface impoundment such as a lake, reservoir, river, or ground water from an aquifer;
• Conventional treatment facilities, including filtration, which removes particulates and potentially pathogenic organisms, followed by disinfection, primarily for surface supplies;
• Transmissions systems, which include tunnels, reservoirs, and/or pumping facilities, and storage facilities;
• Distribution systems, carrying finished water through a system of water mains and subsidiary pipes to consumers.

1.2 Water System Vulnerability

Water systems are spatially diverse and therefore, have an inherent potential to be vulnerable to a variety of physical, chemical and biological threats that might compromise a systems’ ability to reliably deliver safe water. Community water supplies are designed to deliver water under pressure and generally supply most of the water for firefighting purposes. Therefore a loss of water or a substantial loss of pressure could disable firefighting capability, interrupt service, and disrupt public confidence. This loss might result from sabotaging pumps that maintain flow and pressure, or disabling electric power sources that might lead to long term disruption. Many of the major pumps and power sources in water systems have custom-designed equipment and could take months or longer to repair and/or replace [2].

Major areas of vulnerability include the following:

• raw water source (surface or groundwater);
• raw water channels and pipelines;
• raw water reservoirs;
• treatment facilities;
• connections to the distribution systems;
• pump stations and valves;
• finished water tanks and reservoirs.

Each of these system elements present unique challenges to a water utility in safeguarding water supply [3].

1.2.1 Physical Disruption

The ability of a water supply to provide water to its customers can be compromised by destroying or disrupting key physical elements of the water system. These elements include raw water facilities (dams, reservoirs, pipes, and channels), treatment facilities, and distribution system elements (transmission lines and pump stations).

Physical disruption may result in significant economic cost, inconvenience, and loss of confidence by customers, but has a limited direct threat to human health. Exceptions to this generalization include (i) destruction of a dam that causes loss of life and property in the accompanying flood wave and (ii) an explosive release of chlorine gas at a treatment plant. Water utilities should examine their physical assets, determine areas of vulnerability, and increase security accordingly. An example of such an action might be to switch from chlorine gas to liquid hypochlorite, especially in less secure locations which decreases the risk of exposure to poisonous chlorine gas. Redundant system components would provide backup capability in case of accidental or purposeful damage to facilities.

1.2.2 Contamination

Contamination is generally viewed as the most serious potential terrorist threat to water systems. Chemical or biological agents could spread throughout a distribution system and result in sickness or death among the consumers, and for some agents the presence of the contaminant might not be known until emergency rooms report an increase in patients with a particular set of symptoms. Even without serious health impacts, just the knowledge that a group had breached a water system could seriously undermine consumer confidence in public water supplies [4].

Accidental contamination of water systems has resulted in many fatalities. Examples of such outbreaks include cholera contamination in Peru [5], Cryptosporidium contamination in Milwaukee, Wisconsin (US) [6], and Salmonella contamination in Gideon Missouri (US). In Gideon the likely culprit was identified as pigeons infected with Salmonella that had entered a tank's corroded vents and hatches [7].

1.3 Microbial Threats

Waterborne pathogens have been recognized as a threat to human public health throughout history but the development of drinking water treatment techniques have controlled this threat since the beginning of the twentieth century. Although modern drinking water treatment has virtually eradicated waterborne disease from developed countries, drinking water treatment systems have been identified as a potential security vulnerability.

Water-related microbial pathogens can be categorized as water-based or waterborne pathogens. Water-based pathogens spend part of their life cycle in water to reach and infect a potential host. An excellent example of a water-based pathogen is malaria for which mosquitoes are a vector. Since water-based pathogens are not transmitted totally through water they are not potential agents of bioterrorism.

Waterborne pathogens, however, are those transmitted through ingestion of contaminated water primarily through the fecal-oral route. In this case water acts as a passive carrier of infectious agents. Some waterborne pathogens that can cause problems in drinking water include Campylobacter jejuni, pathogenic Escherichia coli, Yersinia enterocolitica, enteric viruses such as rotavirus, calicivirus, astrovirus, and parasites such as Giardia lamblia, Cryptosporidium parvum and Microsporidia sp. Table 1.1 provides useful summary information related to these organisms. Some species of environmental bacteria have demonstrated the ability to survive in drinking water biofilms and have been identified as opportunistic pathogens including Legionella spp., Aeromonas spp., Mycobacterium spp., and Pseudomonas aeruginosa [8–10].

Table 1.1 Pathogens of Public Health Significance^{a, b, c, d, e}

Pathogen	Disease	Incubation Period
Salmonella bongori and Salmonella enterica	Salmonellosis	12–36 h
Salmonella paratyphi A, B, and C	Paratyphoid fever	8–14 d
Salmonella typhi	Typhoid fever	1–3 wk
Shigella dysenteriae, S. flexneri, S. boydii, and S. sonnei	Shigellosis (bacillary dysentery)	1–7 d
Vibrio cholerae	Cholera	2–3 d
Vibrio parahaemolyticus	Gastroenteritis	8–48 h
Yersinia enterocolitica	Yersiniosis	3–7 d
Clostridium perfringens	—	10–12 h
Bacillus cereus	—	6–24 h
Escherichia coli enteropathogenic	Endemic diarrhea	9–12 h
Coxsackeivirus	Gastroenteritis	3–5 d
Hepatitis A virus	Hepatitis	28–30 d
Polio virus	Poliomyelitis	7–14 d
Cryptosporidium sp.	Cryptosporidiosis	7 d
Entamoeba histolytica	Amoebiasis	2–4 wk
Naegleria fowleri	Naegleriasis and Acanthamebiasis	3–7 d

^a Abbaszadegan and Alum [8].

^b Burrows and Renner [11, 12].

^c Clark and Deininger [2, 3].

^d American Public Health Association [13].

^e http://www.bt.cdc.gov/agent/agentlist.asp.

Bacterial pathogens can cause gastroenteritis, including cramps, diarrhea, nausea, vomiting, chills, and mild fever. Bacterial pathogens are generally sensitive to disinfectants such as chlorine and include the following [2, 3, 8, 14]:

• Salmonella;
• Shigella;
• Escherichia coli O157:H7;
• Yersinia;
• Vibrio;
• Campylobacter;
• Legionella.

Viral pathogens can pose a 10- to 10,000-fold higher infection risk then bacteria. Important waterborne viral pathogens include the following:

• Adenovirus;
• Astroviruses;
• Hepatitis A;
• Hepatitis E;
• Norovirus;
• Rotaviruses.

Parasitic pathogens are a significant threat to drinking water supplies. Nearly 20,000 protozoan parasites have been identified of which 20 genera are known to cause diseases in humans some of which include the following:

• Acanthamoeba,
• Cryptosporidium parvum,
• Entamoeba histolytica,
• Microsporidia, and
• Naegleria.

In general, the most effective mechanism for controlling these pathogens is disinfection, especially with chlorine. Table 1.2 summarizes the capacity o...

Table of contents

• Cover
• Title Page
• Copyright
• Preface
• 1 Potential Contamination Agents of Interest
• 2 Surveillance Methods and Technologies for Water and Wastewater Systems
• 3 Designing an Optimal Water Monitoring Systems
• 4 Emergency Response Planning for Drinking Water Systems
• 5 Treatability of Contaminants in Conventional Systems
• 6 Decontamination Methods for Drinking Water Treatment and Distribution Systems
• 7 Decontamination Methods for Wastewater and Stormwater Collection and Treatment Systems
• 8 Prevention of Contamination of Drinking Water in Buildings and Large Venues
• 9 Understanding the Implications of Critical Infrastructure Interdependencies for Water
• Index