The Environmental Protection Agency recently released a guidance that provides a basic framework to help drinking water utilities plan for deployment of a contamination warning system. The guidance is based on a model developed under the EPA’s Water Security initiative (formerly known as WaterSentinel).
Initiated in response to Homeland Security Presidential Directive 9, the overall goal of the Water Security initiative is to design and deploy contamination warning systems for drinking water utilities through a phased approach that includes conceptual design, implementation at an initial pilot utility, expansion to additional pilot utilities, and ultimately development of guidance and tools to support implementation at drinking water utilities across the nation.
In 2005, EPA documented the conceptual design for contamination warning systems in WaterSentinel System Architecture and began implementation of the first WS contamination warning system pilot in partnership with the City of Cincinnati at the Greater Cincinnati Water Works (GCWW).
EPA recently requested applications for additional drinking water contamination warning system demonstration pilots as part of the next phase of the initiative. EPA’s goal is to provide approximately $31 million to fund up to four cooperative agreements for the demonstration pilots. However, utilities involved will have to provide a minimum 20 percent cost-share/match of the total project cost.
According to EPA’s guidance, monitoring the distribution system should be the primary focus of contamination warning systems. Water security experts have identified the distribution system as one of the most vulnerable components in a drinking water utility.
As an added benefit, a warning system can help utilities proactively manage their systems, detecting accidental contamination through crossconnections with non-potable water, permeation of contaminated water through leaking pipes in areas of the distribution system subject to low pressures, or chemical reactions or microbial growth within the distribution system pipes.
According to EPA, a contamination warning system is not merely a collection of monitors and equipment placed throughout a water system to alert of intrusion or contamination. It involves capturing, managing, analyzing, and interpreting information in a way that helps utilities recognize potential contamination incidents in time to respond effectively. While much data comes from traditional monitoring equipment, information can also be provided by people and agencies within the community at large.
A complete contamination warning system consists of the following monitoring and surveillance components, according to the EPA guideance:
- Online water quality monitoring - Stations located throughout the distribution system that measure chlorine, total organic carbon, conductivity, and other parameters. Software analyzes the monitoring data to establish a water quality base state. Possible contamination is indicated when a significant, unexplained deviation from the base state occurs.
- Sampling and analysis -- Collection of distribution system samples that are analyzed for various contaminant classes as well as specific contaminants. Sampling is both routine to establish a baseline and triggered to respond to an indication of possible contamination from another component. Analyses are conducted for chemicals, radionuclides, pathogens, and toxins using a laboratory network.
- Enhanced security monitoring -- This includes the equipment and procedures that detect and respond to security breaches at distribution system facilities. Security equipment may include cameras, motion activated lighting, door contact alarms, ladder and window motion detectors, area motion detectors, and access hatch contact alarms.
- Consumer complaint surveillance - This involves the collection and analysis of calls by consumers for water quality problems indicative of possible contamination. Consumers may detect contaminants with characteristics that impart an odor, taste, or visual change to the drinking water.
- Public health surveillance - The analysis of health-related data to identify disease events that may stem from drinking water contamination. Public health data may include over-the-counter (OTC) drug sales, hospital admission reports, infectious disease surveillance, emergency medical service (EMS) reports, 911 calls, and poison control center calls.
A copy of the Water Security Initiative: Interim Guidance on Planning for Contamination Warning System Deployment can be downloaded from the EPA website at: http://www.epa.gov/safewater/watersecurity/pubs/guide_watersecurity_securityinitiative_interimplanningpdf.pdf
