EARLY WARNING SYSTEMS TO ENSURE DRINKING WATER

SAFETY

Presentation Agenda

Vulnerability & sensitivity of drinking water sources

Health effects

Sources of contamination

Early Warning System - » Definition» Structure & Function» Design Consideration» Data Management & Interpretation» Response

AquaVerity - CheckLight’s comprehensive solution

Components

Competitive edge

Vulnerability and Sensitivity of Drinking Water Sources

Surface water

Runoff

Ground water infiltration

Ground water

Infiltration from the surface

Injection of contaminants

Naturally occurring substances

Health effects caused by contaminated source water

Acute health effects mainly by -

viruses

pathogenic bacteria

parasites

protozoa

cysts

Chronic health effects mainly by -

volatile organic chemicals (VOCs)

inorganic chemicals (IOCs)

synthetic organic chemicals (SOCs)

Vulnerability Within the Distribution System

Backpressure can cause backflow to occur when a potable system is connected to a non-potable supply operating under a higher pressure than the distribution system by means of a pump, boiler, elevation difference, air or steam pressure, or other means.

Backflow is any unwanted flow of used or non-potable water, or other substances from any domestic, industrial, or institutional piping system back into the potable water distribution system.

Cross-connections and backflow represent a significant public health risk (US EPA, 2000b) by allowing chemical and biological contaminants into the potable water supply (a conclusion of the Microbial/Disinfection Byproducts Federal Advisory Committee (M/DBP FACA)).

A wide number and range of chemical and biological contaminants have been reported to enter the distribution system through cross-connections and backflow. Pesticides, sewage, antifreeze, coolants, and detergents were the most frequent types of contaminants reported.

Sources of Contaminants with Acute and Chronic Health Effects

Acute: Industrial activities Animal feeding operations Agriculture Septic systems and cesspools

Chronic: Industrial & commercial activities Agriculture Landfills & surface impoundments Urban uses

Early Warning System (EWS) Structure & Function

An effective EWS is an integrated system for deploying the monitoring technology, analyzing and interpreting the results, and utilizing the results to make decisions that protect public health.

An ideal contamination warning system that monitors toxic events in water should have the following features:

RapidSensitiveWide detection spectrum

ReliableContinuous

Fit for field testing User-friendly Inexpensive

EWS - Core Criteria

Currently, an EWS with all of these features does not exist.

However, there are some technologies that can be used to build an EWS that can meet certain core criteria:

provide rapid response

screen for a number of contaminants while maintaining sufficient sensitivity

perform as automated systems that allow for remote monitoring

Any monitoring system that does not meet these minimum criteria should not be considered an effective EWS.

EWS Design Considerations

There are many issues and water system characteristics that need to be considered when designing an EWS:

Planning and Communication

System Characterization

Target Contaminants

Planning and Communication

The objectives of the program should be defined clearly, and a plan should be developed for the-

Interpretation Use Reporting of monitoring results.

The plan should be developed in coordination with -The water utilityLocal and state health departmentsEmergency response units Law enforcement agencies

Local political leadership

System Characterization

The system should be characterized with respect to -

Access points

Flow and demand patterns

Pressure zones

If not already available, a hydraulic model should be constructed.

System vulnerabilities should be identified and characterized, preferably through a formal vulnerability assessment.

Target Contaminants

Even the most complex array of monitoring equipment cannot detect the entire spectrum of agents that could pose a threat to public health via contaminated water.

Thus, the design of an EWS should focus on contaminants that are thought to pose the most serious threat.

Many factors may go into this assessment, including:

the concentration of a particular contaminant that is necessary to cause harm

the availability and accessibility of a contaminant

the persistence and stability of a contaminant in an aqueous environment

the difficulty associated with detecting a contaminant in the water

EWS - The Tiered Approach

A balance between the need for screening function of the system (i.e., the ability to detect a wide range of contaminants) and the need for specificity (i.e., the ability to positively identify and quantify a specific contaminant) can be achieved through tiered monitoring.

First tier - continuous, real-time screen for a range of contaminants utilizing a broad-based screening technology such as assays designed to detect changes in toxicity.

Second tier - a positive result from the first stage would trigger the second stage of confirmatory analysis using more specific and sensitive techniques.

A positive result from the confirmatory analysis would trigger a response action.

Tiered Response Model

Increasing:

Certainty

Response

Cost

Observed Water Quality Change

)determined by broad-based continuous screening(

Automated Sample Collection

Confirmation Bioassay

Chemical Analysis

If positive

Public health Regulatory or Remedial Action

If positive

Broad Based Continuous Screening

A major problem in the development of early warning water quality monitoring systems is that there are an almost unlimited number of potential contaminants that could threaten a water asset.

While many products have been developed that monitor for specific contaminants or specific types of contaminants, it is impractical to design a system that can detect every potential threat to water quality.

One approach is to use biological organisms as living "sentinels" that will warn operators of contamination.

Sophisticated continuous and automatic biomonitors are now available that detect and alert whenever a notable change occurs in the behavior of the sensing organisms (such as, bacteria, fish, algae, mussels, daphnia).

Bioassays - Applications & Benefits

Mapping to identify toxicity/concentration hotspots

Selection of samples for further/more expensive analysis

Mapping after pollution incidents/accidents

“While there are several different organisms that can be used to monitor for toxicity (including bacteria, invertebrates, and fish), bacteria-based bio-sensors are ideal for use as early warning screening tools for drinking water security because bacteria usually respond to toxics in a matter of minutes”. [EPA - Biological Sensors for Toxicity-Water and Wastewater Security Product Guide]

The Luminescent bacteria provided by CheckLight offer the unique advantage of both automatic and hand held testing capabilities.

EWS Technology Selection

Performance of the chosen field deployable monitoring technology must meet the data quality objectives of the monitoring program that were defined during the design of the EWS and include:

Specificity

Sensitivity

Accuracy

Precision

Recovery

False positives/negatives rates

Alarm Levels

For the alarms to be triggered at the appropriate levels, one must identify the concentrations at which the agents pose a threat to human health.

The basis for setting alarm levels will depend on the capability of the EWS employed.

The alarm should be triggered by a combination of events, not a single detection, which may be a false positive.

Sensor Location and Density

The location and density of sensors in an EWS is dictated by the results of the system characterization, vulnerability assessment, threat analysis, and usage considerations.

Proper characterization of the distribution system, including usage patterns, and the location of critical system nodes (e.g., hospitals, law enforcement and emergency response agencies, government facilities, etc.) is necessary to design an effective monitoring network.

However, even if sensors can be optimally located within a distribution system, there may not be sufficient time to prevent exposure of a portion of the public to the contaminated water.

At best, monitoring conducted within the distribution system will provide time to limit exposure, isolate the contaminated water, and initiate mitigation/ remediation actions.

Data Management, Interpretation, and Reduction

One of the challenges of a continuous, real- time monitoring system is management of the large amounts of data that are generated.

Use of data acquisition software and a central data management center is critical.

The data management system should be capable of performing some level of data analysis and trending in order to assess whether or not an alarm level has been exceeded and minimize the rate of false alarms.

At a minimum, the system should notify operators, public health agencies, and/or emergency response officials.

In some cases, it may be appropriate to program the data management system to initiate preliminary response actions, such as closing valves or collecting additional samples. However, these initial responses should be considered simple precautionary measures, and public officials should make judgments regarding decisive response actions.

Acknowledgement; this presentation was adopted in part from: Safeguarding The Security Of Public Water Supplies Using Early Warning Systems: A Brief Review .J Hasan et al. Journal Of Contemporary Water Research And Education Issue 129, Pages 27-33, October 2004.

Response

The possible responses when an EWS triggers an alarm may include-

Modification to the drinking water system (e.g., shutdown, addition of disinfectants, etc.)

Notification (e.g., boil water advisory) either to the general public or to target communities or Subpopulations

Additional data gathering or monitoring

Follow-on surveillance and epidemiologic studies

No action, or some combination of these

The type of response will be dependent on the nature of both the threat to and the nature of the drinking water system, including the population it serves.

The ETV-Verified ToxScreen Technology Serves

as the Basis for the

AquaVerity

The comprehensive Solution for Water

Utilities to Ensure Drinking Water Safety

and Quality

AquaVerity Components

CCB - Continuous Contamination Biomonitor

PCB - Portable Contamination Biomonitor

CAS - Control & Analysis Software package

SIS - Solution Implementation Service package

Tiered Response Model

Increasing:

Certainty

Response

Cost

Observed Water Quality Change

)determined by broad-based

continuous screening(

Automated Sample Collection

Confirmation Bioassay

Chemical Analysis

If positive

Public health Regulatory or Remedial Action

If positive

PCB-TOX SPOT

CCB-TOC

AquaVerity

xxx

CheckLight’s Value Proposition

Functional Benefits:

Early detection of contamination in drinking water

Enabling to pinpoint location & boundaries of contamination sources

Reducing direct & indirect costs of illnesses & deaths

Saving lives, pain & agony

Reducing liability

Emotional Benefits:

Providing a sense of safety & security

Reducing perceived risk of malpractice/liability

For deployment in monitoring stations positioned at

strategic locations

Includes various monitoring models & re-fill reagent kits

(for detecting chemical & biological contaminants)

Easily integrated with other systems

Suspicious samples are captured by an automatic

sampler for further analysis

Easy installation, operation and maintenance

No need for adjustments due to changing

environmental conditions

Remotely operated & controlled

Requires minimal operator intervention

CCB - Continuous Contamination Biomonitor

Enables remote operation and control of multiple

CCB units from a control center.

Provides tools for long term research and rapid

response during emergency situations

Software add-ons enable the integration and

communication of AquaVerity with 3rd party

devices & management systems (such as

SCADA/GIS).

CAS – Control & Analysis Software

Graphic display of response to potential heavy metal contaminants

Graphic display of response to potential organic contaminants

Contamination alert

Instrument malfunction

All clear

CAS – User Interface

How does the AquaVerity solution

compare to competitive offers on the

market?

EWS Matrix (1)- Detection & Warning Capabilities

FactorMulti-ParameterOther Biomonitors

CheckLight’sAquaVerity

Method5-6 sensors5-20 live organismsOne million luminescent bacteria

Detection spectrum5-6 parametersWide range of contaminants, including unknown types.

Determines toxicityNoYesYes

Discrimination between organic & heavy metals Contaminants

NoNoYes

Detection sensitivity

Medium (depends on the parameter)

HighHigh

ContaminationBoundaries assessment

PartialNoYes, by using the portable detectors

EWS Matrix (2)- Implementation

FactorMulti-ParameterOther BiomonitorsCheckLight’sAquaVerity

Installation & maintenance

Complex due to variability of sensors used

Complex & requires on going human supervision

Very simple to install & maintain. Unattended operation.

Adjustment to changing water environment

ComplexComplexNo adjustment needed.

Effective coverage in large water networks

Limited to wide distribution. Depends on parameters mix & complexity

Limited distribution due to complexity & costs

Wide distribution possible due to simple installation, minimal training & maintenance.

On-Going usageMedium – requires skills & training

Complex - Requires skilled personnel & special training

Effort is minimal - reagents replacement once a month.

Overall reliabilityMedium. Depends on parameters used.

Low to Medium. Depends on biota used & environment. conditions

Very high. Includes built-in control mechanism.

Future EnhancementsunknownUnknownUpgrade re-fill kits with enhanced detection capabilities

EWS Matrix (3) - Cost Effectiveness

FactorMulti-ParameterOther BiomonitorsCheckLight’sAquaVerity

Initial capital investment

Low to very highDepending on chosen parameters

Medium to very highMedium

On going costsMedium due to complexity of sensors arrays and baseline build up

High due to the required human supervision

Low due to minimal intervention

Total cost of ownership

Medium to highHighLow to medium

Positioning

Sensitive to a broad range of

contamination sources

Reliable

Cost effective

Easy to operate

Customer oriented

CheckLight Ltd

P.O. Box 72, Qiryat Tivon 36000, Israel

Tel: 972 4 9930530 Fax: 972 4 9533176

info@checklight.biz www.checklight.biz