Over the past several years many advances have been made to monitor potable water systems for toxic threats. However,
the need for real-time, on-line systems to detect the malicious introduction of deadly pathogens still exists. Municipal
water distribution systems, government facilities and buildings, and high profile public events remain vulnerable to
terrorist-related biological contamination. After years of research and development, an instrument using multi-angle light
scattering (MALS) technology has been introduced to achieve on-line, real-time detection and classification of a
waterborne pathogen event.
The MALS system utilizes a continuous slip stream of water passing through a flow cell in the instrument. A laser beam,
focused perpendicular to the water flow, strikes particles as they pass through the beam generating unique light
scattering patterns that are captured by photodetectors. Microorganisms produce patterns termed 'bio-optical signatures'
which are comparable to fingerprints. By comparing these bio-optical signatures to an on-board database of
microorganism patterns, detection and classification occurs within minutes. If a pattern is not recognized, it is classified
as an 'unknown' and the unidentified contaminant is registered as a potential threat. In either case, if the contaminant
exceeds a customer's threshold, the system will immediately alert personnel to the contamination event while extracting
a sample for confirmation.
The system, BioSentry<sup>TM</sup>, developed by JMAR Technologies is now field-tested and commercially available. BioSentry
is cost effective, uses no reagents, operates remotely, and can be used for continuous microbial surveillance in many
water treatment environments. Examples of HLS installations will be presented along with data from the US EPA
NHSRC Testing and Evaluation Facility.
The events of September 11, 2001 represented an escalation in the means and effects of terrorist attacks and raised awareness of the vulnerability of major infrastructures such as transportation, finance, power and energy, communications, food, and water. A re-examination of the security of critical assets was initiated. Actions were taken in the United States to protect our drinking water. Anti-terrorism monitoring systems that allow us to take action before contaminated water can reach the consumer have been under development since then. This presentation will discuss the current performance of a laser-based, multi-angle light scattering (MALS) technology for continuous, real-time detection and classification of microorganisms for security applications in all drinking and process water applications inclusive of protection of major assets, potable and distributed water. Field test data for a number of waterborne pathogens will also be presented.
Naturally occurring outbreaks of bacteria have the potential to contaminate process water used in semiconductor manufacturing. Bacteria are normally filtered out in the water treatment process, however contamination can still occur from biofilm growth, filter or media break-through, and air vectors. Because there is seldom a residual disinfectant and system sanitation is intermittent, the manufacturer must rely on point of use filters to prevent contamination at critical points in the process. Particle counters in the distribution system can tell when the number of particles is increasing but cannot discriminate bacteria from small silica particles and often are unable to detect smaller gram-negative particles. If an on-line multi-angle light scattering system is used in place of particle counters or in conjunction with them, then the discrimination between silica particles and bacteria can be made and the proper action taken in the distribution system to help identify the contamination source, improve preventative maintenance, and ultimately increase yields. This paper describes the multi-angle light scattering method of detecting bacteria with the BioSentry<sup>TM </sup>system to provide an effective real-time on-line water monitoring sensor.