Securing and Sustaining Water Systems Research
EPA's securing and sustaining water systems research focuses on developing tools and applications that can provide contamination warnings to water utilities in the event of terrorist attacks with chemical, biological, or radiological weapons.
EPA’s homeland security research provides water utilities with tools needed to improve water security and to recover from an attack or contamination incident involving chemical, biological, or radiological (CBR) agents or weapons.
The research tools and state-of-the-art science products assist in:
- improving water security through detection of contamination events caused by CBR agents
- minimizing exposure and damage to infrastructure from contamination events
- treating water and decontaminate water infrastructure
Many CBR agents that could be used in an attack have not been well studied. A variety of other agents or explosive materials could also be used, so researchers have begun prioritizing the most likely classes of materials (for example, pesticides, metals, bacterial toxins), in addition to the most likely individual CBR agents. EPA has been investigating the use of existing water quality sensors and commonly used measurements to see if they can indicate the presence of intentional contamination. By using existing sensor networks and software tools, water utilities will be able to optimally place sensors and create contamination warning systems.
EPA researchers are focused on developing software tools for utilities to use when designing and implementing contamination warning systems. In addition, other water security applications, which aid in the selection of valves to isolate regions of the water distribution system and hydrants to flush contaminants from the system, are being developed.
In other important work, EPA researchers are focused on improving the detection of microorganisms in water systems and treating and decontaminating water and wastewater distribution infrastructure following a homeland security or contamination event.
Water Infrastructure Protection Research
The Public Health Security and Bioterrorism Preparedness and Response Act requires community water systems serving more than 3,300 persons to conduct vulnerability assessments and develop emergency response plans. EPA and its research partners have developed tools and methodologies to help:
- identify and prioritize threats to drinking water and wastewater infrastructure
- evaluate vulnerabilities
- create a standard framework for the risk management process
- plan for countermeasures to reduce the risk of attacks
Desktop computer based software programs have been developed:
- to assess vulnerability of a utility to attack
- to help utility managers and security experts assess risks from deliberate contamination
- to estimate the damages from an attack with explosives
Contaminant Detection Research
EPA researchers use systems analysis and computer modeling to develop software programs that optimize the placement of water quality sensors in drinking water distribution systems. Researchers at EPA work closely with other agencies, industry groups, and research institutions to create cost-effective contamination warning systems (CWS) that water utilities can integrate into their existing distribution systems.
Being able to identify contamination events while minimizing false alarms is essential for contamination warning systems to work effectively. One approach is to integrate information from a variety of sources, including:
- data from online monitoring instruments and sensors
- results from water quality sampling required under the Safe Drinking Water Act
- solicited and unsolicited customer complaints about water
- public health reports on clusters of symptoms that could be related to water contamination
Other EPA research increases the chances of detecting low levels of microorganisms in water. Ordinarily, large volume samples of water (possibly containing disease-causing microorganisms) must either be analyzed in the field with cumbersome, delicate equipment or transported in multiple containers to a laboratory for analysis. Researchers at EPA have partnered with the Department of Energy’s Idaho National Laboratory to develop a rugged and automated field deployable sample concentration (ultrafiltration) device that greatly reduces the size of each sample, more easily transporting them to the laboratory.
Other detection research work includes testing commercially available water quality sensors to see what type of sensor measurement could indicate the presence of a particular CBR agent or class of contaminants. A number of different types of detection devices and technologies have been tested, ranging from test strips for detecting microorganisms or biotoxins to optical sensors that can be used in water distribution networks.
Contaminant Containment and Mitigation
Researchers in EPA are working on software tools that will help water utilities respond to contamination events, and help contain or mitigate the effects of these events. The tools can:
- aid in identifying the contamination source within a water distribution system
- incorporate real-time supervisory control and data acquisition systems (SCADA) data to better identify where a contamination plume will move
- help identify optimal locations within a distribution system where contaminant spread can be limited or contaminants can be removed through isolation or flushing
Researchers are also conducting studies to better understand the fate and transport of contaminants within a water distribution system, so as to identify appropriate water treatment and infrastructure decontamination strategies.
The software tools, plus related research, will be used to create a situational awareness software tool. This software tool will help the personnel at water utilities evaluate mitigation strategies in real-time, as well as identify sampling locations and populations at risk.
Water Treatment and Infrastructure Decontamination Research
EPA uses a testing and evaluation facility to work with pilot-scale projects that investigate the behavior of contaminants. By understanding how contaminants interact with pipes, how they move or attach to surfaces, and how long they can stay in place without being inactivated, EPA researchers can develop effective decontamination and treatment plans.
Researchers need to understand how chemical, biological, and radiological contaminants move through and within water distribution systems in order to devise treatment or decontamination plans for water distribution infrastructure (for example, pipes and tanks). By combining various factors, including water flow rate, pipe materials, quantity of corrosion products, or attached biologically active layers (biofilm), EPA researchers can simulate the behavior of CBR agents in distribution systems using computer models.
As facilities (buildings or distribution infrastructure) are decontaminated, large amounts of wastewater can be generated. This water needs to be collected and pre-treated before being released into treatment facilities or the environment. EPA is testing water treatment methods using spores that are similar in behavior to anthrax spores, but do not cause illness. Treatment methods and technologies that prove successful in the laboratory will undergo larger scale field testing.
- EPA: Water Security
- Water Research Foundation
- Centers for Disease Control and Prevention: Water Treatment
EPA works in close collaboration with other agencies and organizations to provide water utilities with tools and methods that can identify and prioritize threats to the nation’s drinking water and wastewater systems, as well as solutions to contamination threats or incidents.
The Public Health Security and Bioterrorism Preparedness and Response Act (Bioterrorism Act of 2002) requires drinking water utilities serving more than 3,300 people to conduct vulnerability assessments and develop emergency response plans. To help utilities meet the requirements of the Bioterrorism Act of 2002, EPA and its homeland security research partners have developed tools and methodologies that:
- identify and prioritize threats to drinking water and wastewater infrastructure
- evaluate vulnerabilities
- create standard frameworks for risk management
- plan for countermeasures to reduce the risk of attacks
In addition to deliberate contamination of water infrastructure, attacks on drinking and waste water systems with explosives are possible. The Blast Vulnerability Assessment (BVA) tool is a desktop computer-based tool that can be used with minimal training by engineers and other professionals. A variety of options allow different scenarios to run, providing estimates of damage that could occur from an attack using explosives. This tool is available on the Water Information Sharing and Analysis Center (WaterISAC) , which has a secure online platform and a controlled subscription list.
EPA has collaborated with the American Water Works Association (AWWA) to develop contingency plans in the event of a large-scale disaster. Planning for an Emergency Drinking Water Supply has recommendations on planning for alternative drinking water sources and water and wastewater treatment.
The possibility of terrorists or criminals intentionally contaminating drinking water with disease-causing microorganisms is a significant public health concern. The need to rapidly and effectively sample water to detect low concentrations of potentially dangerous microorganisms has led to the development of an ultrafiltration device that greatly reduces the size of samples, making it simpler and safer to transport them to the laboratory for analysis. Microbes occurring at low levels are more accurately detected in concentrated samples.
EPA researchers have partnered with the Department of Energy's Idaho National Laboratory to develop the ultrafiltration device, which is a rugged, automated, field deployable sample concentration device that greatly reduces the size of each sample. The ultrafiltration device can concentrate the microorganisms contained in a 26-gallon water sample into less than two cups of water in about an hour. The device is currently licensed for commercialization.
Most drinking water utilities use commercially available water quality sensors to monitor for changes in acidity, levels of free or total chlorine, total organic carbon, and other water quality indicators. EPA’s homeland security research program has been testing some of these commercially available and commonly used sensors to determine if they could detect accidental or intentional water contamination, in addition to detecting routine water quality variations.
Of the water quality measures tested, free chlorine and total organic carbon (TOC) were found to be the most sensitive indicators for the presence of selected chemical and biological contaminants.
Because commercially available TOC sensors are expensive and time-consuming to operate, a cost-effective sensor for total organic carbon is being developed. EPA is running pilot-scale tests on it. This sensor has been designed to meet water quality goals and potentially to serve as an indicator for chemical and biological contamination.
One major challenge in the use of sensors to monitor water quality is how to distinguish between the normal fluctuations in water quality (baseline) and changes due to contamination. EPA researchers are developing computer modeling programs that evaluate standard water quality data over time and use mathematical and statistical techniques to distinguish unusual water quality changes from normal water quality fluctuations.
Water Security Modeling and Simulation Research
EPA researchers use systems analysis and computer modeling to develop software tools and methods to help water utilities detect and respond to events.
EPANET is a software package that was developed by EPA’s National Risk Management Research Laboratory and is available to download at no cost. EPANET estimates flow and water quality in pressurized pipe networks for water utility distribution systems.
EPA researchers have been developing extensions to EPANET that will work in conjunction with the existing software to extend its capabilities. EPANET–MSX (Multi–Species eXtension) is a software package for modeling multiple interacting chemical and biological reactions in drinking water distribution systems. EPANET–RTX (Real–Time eXtension) enables real–time estimation of water demands using real–time hydraulic measurements of pressure and flow rates, and will improve contamination event detection, source identification, modeling of distribution systems and operations.
Threat Ensemble Vulnerability Analysis–Sensor Placement Optimization Tool (TEVA–SPOT) utilizes EPANET to simulate flow and water quality in water distribution systems. The software helps water utilities optimize the number and location of sensors needed to support a contamination warning system. The location of these online sensors is optimized to detect contamination incidents in time to mitigate both economic and public health consequences.
EPA researchers and Sandia National Laboratories have developed the CANARY Event Detection System software, which assists water utilities in interpreting large amounts of water quality data. It can automatically review incoming data, detect unusual conditions, and alert the water utility if further action is required. CANARY can detect unusual conditions resulting from contamination incidents, as well as detecting unexpected normal operating events, such as a sensor malfunction or a pipe break.
EPA is also working to integrate water quality data with public health information to create more robust contamination warning systems. Public health surveillances include monitoring poison center and 911 emergency calls, over–the–counter medication sales, and the number of patients reporting certain symptoms to doctors. Increases in any of these indicators could signal a disease outbreak. Integration of this information with water quality data could also indicate whether water contamination was the source of the outbreak. EPA researchers have been working to integrate an established public health surveillance system, the Electronic Surveillance System for the Early Notification of Community–based Epidemics (ESSENCE), with water quality data to improve the effectiveness of contamination warnings systems.
- Method Development and Verification
- Public Health Surveillance
- Sample Collection
- Sensor Studies
Containment and Mitigation
EPA researchers continue to develop software tools that will help water utilities respond to contamination events, as well as mitigate the effects of these events.
A response toolkit will help the water industry throughout the continuum of a water contamination incident by rapidly detecting and interpreting changes in water quality, evaluating different response scenarios, and optimizing and implementing response actions in real–time. Such a toolkit could include the ability to identify:
- a contaminant source
- optimal sampling locations
- optimal flushing locations
- valves that could be opened or closed to isolate the contaminant
- locations where disinfectants or decontaminating agents could be added
EPA researchers are also conducting studies to better understand the fate and transport of contaminants within a water distribution system and to identify appropriate water treatment and infrastructure decontamination strategies. This research will be used to create a situational awareness software tool to help personnel at water utilities evaluate mitigation strategies in real–time, as well as identify sampling locations and populations at risk.
EPA has collaborated with the American Water Works Association (AWWA) to develop contingency plans in the event of a large–scale disaster. Planning for an Emergency Drinking Water Supply has recommendations on planning for alternative drinking water sources and water and wastewater treatment.
Treatment and Decontamination
The water distribution system is the most vulnerable part of a drinking water system. Even if chemical, biological, or radiological weapons are not used, many other kinds of contaminants are readily available in quantities that could contaminate distribution systems and severely affect human health. The economic costs of recovery would be extremely high.
The ability to detect contamination events as they happen would allow water utilities to isolate a contaminant before public health is affected. Once a contaminant is isolated, decontamination and disposal plans could be put into action.
EPA has developed optimization models to use with the EPANET software and EPANET extensions, which model the flow and water quality in pressurized pipe networks. The ability to model water and quality and to perform simulations can assist with optimizing decisions throughout the continuum of a water contamination incident. From the simulations, the contaminant source location, optimal sampling locations flushing or isolation valve locations, locations where disinfectants or decontaminating agents could be added.
Focusing on treating water in houses, business, or other facilities, the use of point–of–use or point–of–entry devices can add to increased water security. Point–of–use devices are designed to treat only that portion of water that is used for drinking, dish washing, or cooking. Point–of–entry devices treat all water coming into houses or facilities.
EPA tested point–of–use and point–of–entry water treatment devices that used microfilters and other methods for treating water. EPA concluded that some water security benefit could be gained from using some of the treatment devices. Widespread use was not recommended because no device removes all contaminants, and it was not possible to know what contaminant could be present. In addition, even if water could be treated, without further intervention fixtures or appliances such as dishwashers or ice makers would remain contaminated.
Other challenges related to point–of–use devices include their cost and the need to properly maintain or upgrade them. Selective use of these devices in high–risk facilities, such as hospitals or sensitive facilities such as police and fire stations and military bases, was recommended as long as the devices could be maintained properly.
Another decontamination challenge is treating water contaminated through accidental or deliberate actions or as the result of decontaminating indoor or outdoor areas. This water needs to be treated before being released into treatment systems or the environment.
Although many microorganisms are inactivated by commonly used water treatments such as chlorination, some, like viruses or spore forming bacteria, are resistant. Inactivation studies on a variety of organisms and disinfectants used in water treatment continue.
Many contaminants that have been identified as likely threats to drinking water and distribution facilities can adhere to, or become embedded in, rusty or corroded pipes or biologically active layers (biofilm). In the real world, chemicals and biological organisms react with substances in the water and on the pipe walls. EPANET–MSX was developed to model the complex interactions of multiple reaction species, thus providing a more realistic prediction of water quality in a distribution system. EPANET–MSX enables users to model reactions of interest to water utility operators such as chlorine loss, the formation of disinfection byproducts, nitrification dynamics, disinfectant residuals, and adsorption to pipe walls. Homeland security researchers are particularly interested in modeling the fate and transport of toxic contaminants in drinking water distribution systems.
EPA studies found that contaminants can persist even after typical decontamination treatments. The studies have investigated different factors, including:
- various CBR contaminants
- different water flow rates
- different pipe materials used in distribution systems
- water acidity
- different decontamination methods
The challenge continues to be finding cost–effective methods in the laboratory that could be tailored to actual distribution system materials and water characteristics, taking into account the fate and transport of CBR contaminants. For example, studies using anthrax spore surrogates (similar to anthrax spores but not dangerous) to contaminate water in the laboratory can eventually be performed in the field to study how to optimize water treatment methods.