United States

Environmental Protection

Agency

Technologies and Techniques for Early Warning 

Systems to Monitor and Evaluate Drinking

Water Quality: A State-of-the-Art Review

Office of Research and Development

National Homeland Security

Research Center

research report

 EPA/600/R-05/156

Technologies and Techniques for Early Warning Systems to Monitor and

Evaluate Drinking Water Quality: A State-of-the-Art Review

U.S. Environmental Protection Agency

Office of Water

Office of Science and Technology

Health and Ecological Criteria Division

August 25, 2005
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 i

DISCLAIMER

This document has been reviewed in accordance with U.S Environmental Protection Agency policy

and approved for publication and distribution. The research described here was managed under EPA

Contract 68-C-02-009 to ICF Consulting, Inc.

Mention of commercial products, trade names, or services in this document or in the references

and/or endnotes cited in this document does not convey, and should not be interpreted as conveying

official EPA approval, endorsement, or recommendation.

Questions concerning this document or its application should be addressed to:

Jafrul Hasan, Ph.D.

USEPA Headquarters

Office of Science and Technology, Office of Water

1200 Pennsylvania Avenue, NW

Mail Code: 4304T 

Washington, DC 20460

Phone: 202-566-1322

Email: hasan.jafrul@epa.gov
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 iii

ACKNOWLEDGMENTS

The research described here was funded by the National Homeland Security Research Center, Office

of Research and Development, and managed by the Office of Science and Technology, Office of

Water.

EPA gratefully acknowledges the contributions of the following persons and organizations to the

development of the main Report Technologies and Techniques for Early Warning Systems to

Monitor and Evaluate Drinking Water Quality: A State-of-the-Art Review.

EPA Work Assignment Manager: Jafrul Hasan

ICF Work Assignment Manager: David Goldbloom-Helzner

Co-Work Assignment Manager: Audrey Ichida

ICF staff: Tina Rouse and Mark Gibson

Subject matter experts consulted: Stanley States, Walter Grayman, and Rolf Deininger

Internal (EPA) Reviewers:

Jonathan Herrmann Office of Research and Development/National Homeland Security Research

Center

Irwin Silverstein Office of Water/Water Security Division and Office of Research and

Development/National Homeland Security Research Center

John Hall Office of Research and Development/National Homeland Security Research

Center

Roy Haught Office of Research and Development/National Risk Management Research

Laboratory

Robert Janke Office of Research and Development/National Homeland Security Research

Center

Alan Lindquist Office of Research and Development/National Homeland Security Research

Center

Matthew Magnuson Office of Research and Development/National Homeland Security Research

Center

Regan Murray Office of Research and Development/National Homeland Security Research

Center

Grace Robiou Office of Water/Water Security Division

Cesar Cordero Office of Water/Office of Science and Technology

Jafrul Hasan Office of Water/Office of Science and Technology
U.S. EPA Office of Water Early Warning Systems

August 2005 iv

External (non-EPA) Reviewers:

Ronald J. Baker U.S. Geological Survey 

Frank Blaha American Water Works Association Research Foundation 

Erica Brown Association of Metropolitan Water Agencies

Bill Clark Association of Metropolitan Water Agencies

Ricardo DeLeon Metropolitan Water District of Southern California

Wayne Einfeld Sandia National Laboratories

Lee Glascoe Lawrence Livermore National Laboratory

Kevin Morley American Water Works Association

My-Linch Nguyen American Water Works Association Research Foundation

Irwin Pikus University of Virginia

Connie Schreppel Mohawk Valley Water Authority

Alan Roberson American Water Works Association
U.S. EPA Office of Water Early Warning Systems

August 2005 v

TABLE OF CONTENTS

DISCLAIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

LIST OF EXHIBITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

ACRONYMS and ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

1. Report Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Desired Characteristics of Integrated Early Warning Systems (EWSs) . . . . . . . . . . . . . . 2

1.2 Conclusions and Recommendations .........................................3

1.2.1 General Conclusions and Recommendations .............................3

1.2.2 Specific Conclusions and Recommendations .............................4

2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.1 Concern for the Water Supply .............................................9

2.2 Role of EPA in Water Security and Early Warning Systems . . . . . . . . . . . . . . . . . . . . . . 9

2.2.1 National Homeland Security Research Center Research . . . . . . . . . . . . . . . . . . 10

2.2.2 Environmental Technology Verification (ETV) Program . . . . . . . . . . . . . . . . . . 11

2.2.3 Technology Testing and Evaluation Program (TTEP) . . . . . . . . . . . . . . . . . . . . . 11

2.2.4 American Society of Civil Engineers (ASCE) Guidelines for Designing

an Online Contamination Monitoring System . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2.5 Water Utility Users Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.2.6 Water Security Working Group (WSWG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.2.7 Water Contaminant Information Tool (WCIT) . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.2.8 Distribution System Research Consortium (DSRC) . . . . . . . . . . . . . . . . . . . . . . 12

2.2.9 EPA Resources/Guidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.3 Purpose of this State-of-the-Art Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.4 Approach for this State-of-the-Art Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5 Sources of Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5.1 Experts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5.2 Conferences and Seminars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.5.3 Published Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.5.4 Website Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.5.5 Workgroup Efforts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.6 Criteria for Selecting Products/Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3. Desired Characteristics and Features of Integrated Early Warning Systems . . . . . . . . 19

3.1 Desired Characteristics for Integrated Early Warning Systems . . . . . . . . . . . . . . . . . . . 19

3.1.1 Rapid Response Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.1.2 Range of Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.1.3 Automation and Remote Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.1.4 Affordable Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.1.5 Low Skill and Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
U.S. EPA Office of Water Early Warning Systems

August 2005 vi

3.1.6 Source of the Contaminant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.1.7 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.1.8 Minimal False-positives/False-negatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3.1.9 Robustness and Continuous Functioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.1.10 Third Party Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.2 Design Features of Integrated Early Warning Systems . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.2.1 Evaluate the Need for an Integrated EWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.2.2 Establish EWS Plan and Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.2.3 Determine Overall Approach to EWS Design . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.2.4 Develop Detailed Design of an Integrated Early Warning System . . . . . . . . . . . 32

4. Features of an EWS Related to Data Acquisition and Analysis; Contaminant Flow;

Sensor Placement; Alerts; Data Security; and Communication, Response, and

 Decision Making . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.1 Real-Time Data Acquisition and Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.1.1 Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

4.1.2 Demonstration Projects, Tests, and Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.2 Contaminant Flow Predictive Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4.2.1 State-of-the-Art Systems and Current Research and Development . . . . . . . . . . . 42

4.3 Sensor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4.3.1 Current Research and Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

4.3.2 State-of-the-Art Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4.4 Alert Management Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4.5 Integrating Water Distribution Modeling and Data Acquisition Systems . . . . . . . . . . . 47

4.6 Data Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

4.7 Communications, Response, and Decision Making . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

5. Multi-Parameter Water Quality Monitors as Candidates for Early Warning

Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

5.1 Descriptions of Various Multi-Parameter Water Quality Monitors . . . . . . . . . . . . . . . . 53

5.2 Efforts to Determine Performance of Multi-Parameter Water Quality 

 Monitors and Establish Water Quality Baselines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

5.2.1 Evaluate Sensor Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.2.2 Investigate Baseline for Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.2.3 Verify Sensor Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.3 Efforts to Provide Red Flag EWS and to Identify Specific Contaminants via

 Signature Using Multi-Parameter Water Quality Monitors . . . . . . . . . . . . . . . . . . . . . . 57

5.3.1 Sensor Response to Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

5.3.2 Multi-Parameter Response to Chemical or Biological Agent Simulants . . . . . . 58

5.3.3 Signature Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

5.3.4 Further Testing of Signature Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

5.3.5 Multi-Parameter Response to Actual Chemical and Biological Agents . . . . . . . 59

6. Technologies that Detect Chemical Contaminants for Early Warning Systems . . . . . . 61

6.1 General Introduction to Assays and Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

6.2 Available Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

6.2.1 Detection of Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
U.S. EPA Office of Water Early Warning Systems

August 2005 vii

6.2.2 Detection of Cyanide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

6.2.3 Gas Chromatography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

6.2.4 Enzyme-Based Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

6.2.5 Biosensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

6.3 Potentially Adaptable Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

6.3.1 Enzyme-Based Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

6.3.2 Organism-Based Biosensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

6.3.3 Infrared Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

6.3.4 X-ray Fluorescence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

6.3.5 Ion Mobility Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

6.3.6 Microchips for Portable Chemical Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

6.3.7 Microchip Surface Acoustic Wave (SAW) Technology . . . . . . . . . . . . . . . . . . . 75

6.3.8 Microchip Chemiresistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

6.4 Emerging Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

6.4.1 Organism-Based Biosensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

6.4.2 Eukaryotic Cell-Based Biosensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

6.4.3 Fiber Optic Cable-Based Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

6.4.4 Ion Mobility Spectroscopy (IMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

6.4.5 Surface Acoustic Wave (SAW) Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

6.4.6 Raman Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

7. Technologies that Detect Microbial Contaminants for Early Warning Systems . . . . . 81

7.1 General Introduction to Assays and Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

7.2 Available Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

7.2.1 Immunoassays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

7.2.2 Detection of Bacterial - ATP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

7.2.3 Flow Cytometry- and Micro-Flow-Based Technology . . . . . . . . . . . . . . . . . . . . 85

7.2.4 Bioparticulate Monitors - Light Scattering Technology . . . . . . . . . . . . . . . . . . . 86

7.3 Potentially Adaptable Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

7.3.1 Fiber Optic-Based Biosensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

7.3.2 Dye-Loaded Microspheres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

7.3.3 Detection of ATP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

7.3.4 Cell-Based Biosensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

7.3.5 Polymerase Chain Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

7.3.6 Bio-Optoelectronic Sensor Systems (BOSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

7.3.7 Surface Plasmon Resonance (SPR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

7.3.8 Electrochemiluminescence (ECL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

7.4 Emerging Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

7.4.1 Lateral Flow Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

7.4.2 Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

7.4.3 Magnetic Beads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

7.4.4 Flow-Through Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

7.4.5 Raman Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

7.4.6 Microelectrode Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

7.4.7 Microarray of Gel-Immobilized Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

7.4.8 Magnetic Microbeads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

7.4.9 DNA Microarrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
U.S. EPA Office of Water Early Warning Systems

August 2005 viii

7.4.10 Micro-Cantilever System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

7.4.11 Photoluminescent Biochips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

7.4.12 Polymer Microbeads - Taste Chip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

7.4.13 Molecularly Imprinted Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

7.4.14 Magnetoelastic Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

7.5 Concentration Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

7.5.1 Hollow Fiber Ultrafiltration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

7.5.2 Hydroxyapatite Whole Cell Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

7.5.3 Lectin and Carbohydrate Affinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

8. Technologies that Detect Radiological Contaminants for Early Warning Systems . . 105

8.1 General Introduction to Methods of Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

8.2 Available Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

8.3 Potentially Adaptable Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

8.4 Emerging Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

9. Technical Evaluation of Early Warning Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

9.1 Approach for Technical Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

9.1.1 Verification Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

9.1.2 Degree of Government Involvement, Support, and Development for

Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

9.1.3 Field Experience and Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

9.1.4 Other Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

9.1.5 Expert Opinions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

9.2 Evaluation of Various Operational Features of EWS . . . . . . . . . . . . . . . . . . . . . . . . . . 113

9.2.1 Issues and Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

9.2.2 Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

9.3 Evaluation of Multi-Parameter Water Quality Monitors . . . . . . . . . . . . . . . . . . . . . . . 115

9.3.1 Issue and Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

9.3.2 Conclusion and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

9.4 Evaluation of Chemical Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

9.4.1 Issues and Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

9.4.2 Conclusion and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

9.5 Evaluation of Microbial Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

9.5.1 Issues and Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

9.5.2 Conclusion and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

9.6 Evaluation of Radiological Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

9.6.1 Issues and Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

9.6.2 Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

10. Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

10.1 General Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

10.2 Specific Conclusions and Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

10.2.1 Data Acquisition and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

10.2.2 Flow Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

10.2.3 Sensor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

10.2.4 Alert Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
U.S. EPA Office of Water Early Warning Systems

August 2005 ix

10.2.5 Decision Making and Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

10.2.6 Multi-Parameter Water Quality Technologies . . . . . . . . . . . . . . . . . . . . . . . . . 154

10.2.7 Detection of Chemical Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

10.2.8 Detection of Microbial Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

10.2.9 Detection of Radiological Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

APPENDIX A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

APPENDIX B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

APPENDIX C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

APPENDIX D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

ENDNOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 xi

LIST OF EXHIBITS

Exhibit 3-1. Drinking Water Contaminant Classes and Examples . . . . . . . . . . . . . . . . . . . . . . . 22

Exhibit 3-2. Design Features of an Integrated Early Warning System . . . . . . . . . . . . . . . . . . . . 27

Exhibit 3-3. Conceptual Process for Designing an Early Warning System . . . . . . . . . . . . . . . . 28

Exhibit 3-4. Sample EWS Approach using First-Stage and Second-Stage Monitors . . . . . . . . 31

Exhibit 4-1. Examples of Water Distribution System Modeling Software . . . . . . . . . . . . . . . . 42

Exhibit 7-1. Lateral Flow Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Exhibit 9-1. Evaluation of Water Quality Parameter Monitors . . . . . . . . . . . . . . . . . . . . . . . . 118

Exhibit 9-2. Water Quality Monitors Comparison with Desired EWS Characteristics . . . . . . 120

Exhibit 9-3. Water Quality Monitors as EWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Exhibit 9-4. Chemical Sensors Comparison with Desired EWS Characteristics . . . . . . . . . . . 125

Exhibit 9-6. Microbial Sensors Comparison with Desired EWS Characteristics . . . . . . . . . . . 136

Exhibit 9-7. Microbial Sensor Technologies and Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 144

Exhibit 9-8. Radiological Sensors Comparison with Desired EWS Characteristics . . . . . . . . 146

Exhibit 9-9. Radiation Sensor Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 xiii

ACRONYMS and ABBREVIATIONS

 Angstrom

AFD Automated Food Device

AK Adenylate Kinase

AMS Advanced Monitoring Systems Center

AOAC AOAC International (historically Association of Official Analytical Chemists)

APDS Autonomous Pathogen Detection System

ASCE American Society of Civil Engineers

ASTM American Society for Testing and Materials

ASV Anodic Stripping Voltammetry

ATP Adenosine Triphosphate

ATR Attenuated Total Reflection

AWWA American Water Works Association

AwwaRF American Water Works Association Research Foundation

BADD BioWarfare Agent Detection Devices

BARC Bead ARray Counter

BCIP 5-Bromo-4-Chloro-3-Indolyl Phosphate Disodium Salt Hydrate

BEADS Biodetection Enabling Analyte Delivery System

BOSS Bio-optoelectronic Sensor Systems

BTA Bio Threat Alert®

CAD Computer-Aided Drafting

CBR Chemical, Biological, and Radiological

CBRTA Chemical, Biological, and Radiological Technology Alliance

CBS Case-Based Systems

CBW Chemical Biological Warfare

CCD Charge-Coupled Device

CDC U.S. Centers for Disease Control and Prevention

CFD Computational Fluid Dynamics

cfu Colony Forming Unit

Ci Curies

CIS Customer Information Systems

COD Chemical Oxygen Demand

cpm Counts Per Minute

CRADA Cooperative Research and Development Agreement

CWS Contamination Warning System

DARPA Defense Advanced Research Projects Agency

DHS Department of Homeland Security

DNA Deoxyribonucleic Acid

DO Dissolved Oxygen

DOD Department of Defense

DOE Department of Energy

DSRC Distribution System Research Consortium

DSS Distribution System Simulator

ECBC Edgewood Chemical Biological Center

ECD Electrolytic Conductivity Detector

ECL Electrochemiluminescence
U.S. EPA Office of Water Early Warning Systems

August 2005 xiv

EDS Event Detection Software

ELFA Enzyme-Linked Fluorescent Immunoassay

ELISA Enzyme-linked Immunosorbent Assay

ELOD Estimated Limit of Detection

EMPACT Environmental Monitoring for Public Access and Community Tracking

EOC Emergency Operations Center

EPA U.S. Environmental Protection Agency

EPS Extended-Period Simulation 

ETV Environmental Technology Verification

EWS Early Warning System

FBI Federal Bureau of Investigation

FDA U.S. Food and Drug Administration

FID Flame Ionization Detector

FPW Flexural Plate Wave

FT-IR Fourier Transform Infrared

GC Gas Chromatography

GC-MS Gas Chromatograph-Mass Spectrometer

GE Genomic Equivalent

GIS Geographic Information Systems

GMR Giant Magnetoresistive

HA Hydroxyapatite

HANAA Hand-Held Nucleic Acid Analyzer

HRP Horseradish Peroxidase

HSPD Homeland Security Presidential Directive

I-CORE Integrated Cooling/Heating Optics Reaction

ICS Incident Command System

ICWater Incident Commanders Water Modeling Tool

IDSE Initial Distribution System Evaluation

ILSI International Life Sciences Institute

IMS Ion Mobility Spectroscopy

INL Idaho National Laboratory

ISAC Information Sharing and Analysis Center

ISE Ion Selective Electrode

JBAIDS Joint Biological Agent Identification and Diagnostic System

LAN Local Area Network

LEMS Liquid Effluent Monitoring System

LIMS Laboratory Information Management System

LLNL Lawrence Livermore National Laboratory

LRAD Long Range Alpha Detection 

LRN Laboratory Response Network

MAGIChipTM Micro Array of Gel-Immobilized Compounds

MALS Multi-Angle Light Scattering

MALLS Multi-Angle Laser Light Scattering

MCL Maximum Contaminant Level

MEMS Micro-Electro-Mechanical System

MIP Molecularly Imprinted Polymers

MIT Massachusetts Institute of Technology
U.S. EPA Office of Water Early Warning Systems

August 2005 xv

MOEMS Micro Optical Electro Mechanical Systems

MS Mass Spectroscopy

MW Molecular Weight

NaI Sodium Iodide

NALOD Nucleic Acid Limit of Detection

NASA National Aeronautics and Space Administration

NDWAC National Drinking Water Advisory Council

NHSRC National Homeland Security Research Center

NNI National Nanotechnology Initiative

NRMRL National Risk Management Research Laboratory

NSF NSF International (historically National Sanitation Foundation)

NTA National Technology Alliance

OGWDW Office of Ground Water and Drinking Water/U.S. EPA

OHS Office of Homeland Security/U.S. EPA

OLM On-Line Liquid Monitoring System

ORD Office of Research and Development/U.S. EPA

ORNL Oak Ridge National Laboratory

ORP Oxidation-Reduction Potential

OW Office of Water/U.S. EPA

PCR Polymerase Chain Reaction

PDD Presidential Decision Directive

PEC Photosynthetic Enzyme Complex

pfu Plaque Forming Unit

pfu-e Plaque Forming Unit Equivalent

PID Photo Ionization Detector

PNNL Pacific Northwest National Laboratories

ppb Parts Per Billion

ppm Parts Per Million

ppt Parts Per Trillion

psi Pounds Per Square Inch

QA/QC Quality Assurance and Quality Control

QLFA Quantitative Lateral Flow Assay 

R&D Research and Development

RADACS Radiological Assessment Display and Control Software

RAPID Ruggedized Advanced Pathogen Identification Device

RBS Rule-Based Systems

RLU Relative Light Unit

RNA Ribonucleic Acid

ROC Receiver Operating Characteristic

SAIC Science Applications International Corporation

SAW Surface Acoustic Wave

SBIR Small Business Innovation Research

SCADA Supervisory Control and Data Acquisition

SDWA Safe Drinking Water Act

SERS Surface-Enhanced Raman Scattering

SIA Sequential Injection Analysis

SMARTTM Sensitive Membrane Antigen Rapid Test
U.S. EPA Office of Water Early Warning Systems

August 2005 xvi

SMP Submitochondrial Particles

SNL Sandia National Laboratories

SOPs Standard Operating Procedures

SPCE Surface Plasmon-Coupled Emission

SPME Solid Phase Microextraction

SPR Surface Plasmon Resonance

SSL Secure Socket Layer

TAM Thermo Alpha Monitor

TCD Thermal Conductivity Detector

TCR Total Coliform Rule

T&E Test and Evaluation

TEVA Threat Ensemble Vulnerability Assessment

TIGER Triangulation Identification Genetic Evaluation of Risks

T&O Taste and Odor

TOC Total Organic Carbon

TRA Technology Readiness Assessment

TTEP Technology Testing and Evaluation Program

UC Ultrafiltration Concentration

UHF Ultra High Frequency

UPT Upconverting Phosphor TechnologyTM

URL Uniform Resource Locator (also known as website address)

USACEHR U.S. Army Center for Environmental Health Research

USAMRIID U.S. Army Medical Research Institute of Infectious Diseases

USGS U.S. Geological Survey

UV Ultraviolet Light

VARA Vulnerability and Risk Assessments

VHF Very High Frequency

VOCs Volatile Organic Compounds

WaterISAC Water Information Sharing and Analysis Center

WATERS Water Assessment Technology Evaluation Research and Security

WCIT Water Contaminant Information Tool

WDM Water Distribution Monitoring

WERF Water Environment Research Foundation

WISE-SC Water Infrastructure Security Enhancements-Standards Committee

WLA Water Laboratory Alliance

WQS Water Quality System

WS-CWS WaterSentinel Contamination Warning System

WSD Water Security Division

WSTB Water Science and Technology Board

WSWG Water Security Working Group

WUERM Water Utility Emergency Response Manager
U.S. EPA Office of Water Early Warning Systems

Early Warning System or EWS is a term used throughout this document. The term is derived from the a

use of EWSs in monitoring source water. Detectors have been used to identify changes in source water

quality upstream of a water intake (e.g., in rivers or streams for chemical spills). In its truest sense, an

EWS would provide for an early warning of a contaminant prior to human exposures with public health

impacts (e.g., “detect to warn”). Such may not be the case in the first generation of contaminant warning

in drinking water distribution systems. An alternative term of art has evolved based on threat recognition,

that being a “contamination warning system.” A contamination warning system involves the active

deployment and use of monitoring technologies/strategies and enhanced surveillance activities to collect,

integrate, analyze, and communicate information to provide a timely warning of potential water

contamination incidents and initiate response actions to minimize public health and economic impacts.

Based on currently available technologies, a contamination warning system is weighted toward “detect

to treat.” However, with advances in technology and the ability to detect specific contaminants or

specific contaminant categories in near real-time, it is anticipated that a contamination warning system

will move toward “detect to warn.”

August 2005 1

1. Report Highlights

Terrorist attacks have heightened concern about intentional threats to the U.S. water system, whether

from physical destruction, computer interference, or chemical, microbial, or radioactive

contamination. Such intentional contamination events can have a profound impact on public health

and confidence in the nation’s water infrastructure. An Early Warning System (EWS) can be an a

important tool to avoid or mitigate the impacts of an intentional contamination event in time to allow

an effective local response that reduces or eliminates adverse impacts (ILSI, 1999). An integrated

EWS includes sensors to detect the contaminant; systems to transmit, compile, and analyze data;

links for communication and notification; and protocols for decision making and emergency

response.

The goal of this EWS document is to review the state-of-the-art technologies and techniques for

integrated EWSs for drinking water infrastructure, particularly for finished water supplies and

distribution systems. The report summarizes and evaluates current and emerging EWS technologies

for identifying general categories of chemical, microbial, and radiological contaminants. It also

identifies future directions, technical issues, and research gaps. Information was gathered from a

variety of sources, including company information, government information, verification studies,

field case studies, and expert opinions.

The basis of this project is outlined in the Water Security Research and Technical Support Action

Plan, Section 3.3e, which recommends testing and evaluation of drinking water and other EWSs, 1

focused on distribution systems. This study also supports the implementation of Homeland Security

Presidential Directive (HSPD)-9 even though the study was started before HSPD-9 was issued. 2

HSPD-9 directs the U.S. Environmental Protection Agency (EPA) to “develop robust,

comprehensive, and fully coordinated surveillance and monitoring systems, ... that provide early

detection and awareness of disease, pest, or poisonous agents.” To focus on the most promising

products and technologies in this relatively new and rapidly progressing area, criteria were

developed in this study to select technologies and products that are available now, are potentially

adaptable to EWSs for drinking water systems, or have the potential to emerge as EWSs in the

future.
U.S. EPA Office of Water Early Warning Systems

August 2005 2

In response to HSPD-9, EPA is working with technical experts and stakeholders in the drinking

water community to design a robust and comprehensive drinking water system monitoring program

that would provide early indication of an attack and minimize public health consequences. An

outcome of these efforts is WaterSentinel, which is a proposed demonstration project where EPA,

in partnership with select utilities and laboratories, would design, deploy, and evaluate a model

contamination warning system for drinking water security. A more detailed description of how the

thinking behind the WaterSentinel concept has evolved is included in Appendix A.

This document is a state-of-the-art review and reflects knowledge and information gathered through

May 2005. The fast pace of technology and technique development and the implementation of

EWSs for drinking water indicate that this document should be viewed as a snapshot in time. It will

be useful to utilities as they plan activities that provide early warning against potential threats and

attacks to their water systems. As the state-of-the-art advances, periodic updates of this document

will be necessary.

1.1 Desired Characteristics of Integrated Early Warning Systems (EWSs)

An EWS is an integrated system for monitoring, analyzing, interpreting, and communicating

monitoring data, which can then be used to make decisions that are protective of public health and

minimize unnecessary concern and inconvenience to the public. To become a widely used,

effective, and reliable part of a water distribution security and quality monitoring system, an ideal

integrated EWS should demonstrate a number of characteristics, such as the following:

• provide a rapid response

• include a sufficiently wide range of potential contaminants that can be detected

• exhibit a significant degree of automation, including automatic sample archiving

• allows acquisition, maintenance, and upgrades at an affordable cost

• require low skill and training

• identify the source of the contaminant and allows accurate prediction of the location and

concentration downstream of the detection point

• demonstrate sufficient sensitivity to detect contaminants

• permit minimal false-positives/false-negatives

• exhibit robustness and ruggedness in continually operating in a water environment

• allow remote operation and adjustment

• function continuously

• allow for third party testing, evaluation, and verification

When a utility considers the development of an integrated EWS, especially for a distribution system,

it should go through a structured process to determine the need for and approach to using an EWS.

Some experts in the field of EWS design for drinking water distribution systems advocate a “tiered”

approach with two stages. The first stage uses continuous real-time sensors that can provide a

generic warning or trigger an alarm when a contaminant is detected in the water. Examples of this

first stage include common multi-parameter online sensors typically used for monitoring water

quality (e.g., pH, conductivity, chlorine residual, etc.). A warning would trigger a second stage

using more specific and sensitive technology to confirm and identify the contaminant (ILSI, 1999;

Hasan et al., 2004). A second-stage technology might be located in the field or could be brought

to the site as a field portable unit. Another design could include first stage warnings in conjunction
U.S. EPA Office of Water Early Warning Systems

August 2005 3

with data from customer complaints and public health surveillance as triggers for confirmatory

testing. Although real-time continuous monitoring may be the ultimate long-term goal, there may

be intermediate EWS architectures that would be more effective until real-time monitors become

available.

1.2 Conclusions and Recommendations

The conclusions and recommendations are based on a scientific and technical evaluation of EWS

technologies. An expert review of qualitative, semi-qualitative, and quantitative information was

conducted using various sources including verification studies, government research, and expert

opinions.

The following are general conclusions and recommendations from this review of state-of-the-art

technologies and techniques for EWSs. These are followed by specific conclusions and

recommendations organized by the features of the EWS: data acquisition and analysis; flow

modeling; sensor placement; alert management; decision making and response; multi-parameter

water quality technologies; and detection of chemical, microbial, and radiological contaminants.

The recommendations include a list of near term and long-term knowledge and research gaps.

1.2.1 General Conclusions and Recommendations

Viable integrated EWSs that meet the desired characteristics and can be routinely used are several

years away. Some individual components are available currently; however, others need further

development. Designs of EWSs for water distribution systems are largely theoretical or in

preliminary stages. The systems that are in place do not have all the features of an integrated EWS,

as described by this report. Most sensor and EWS components have not been third party tested or

verified, and the types of contaminants and levels of exposure have not been well defined to support

selection of sensor technologies. Utilities will need verification and demonstration studies to

evaluate various manufacturer claims.

Short-Term Research Needs

• An in-depth review of EWS design and implementation should be conducted.

• Methods for vulnerability assessments should be adapted to focus on contamination

scenarios.

• Research on international efforts on EWS is needed.

• Grab-sampling protocols and analysis technologies should be developed quickly.

Long-Term Research Needs

• Survey case studies and analyses should be performed on monitors/sensors/detectors used

by utilities.

• EWS components need to undergo performance testing.

• Potential contaminants list should be reviewed on an ongoing basis.

• Concentrations that must be detected by a sensor should be reviewed on an ongoing basis.

• The fate and transport (including exposure levels, doses, and detectible concentrations) of

contaminants, especially toxic byproducts, should be examined.
U.S. EPA Office of Water Early Warning Systems

August 2005 4

• Results from laboratory research by various agencies on EWSs should be replicated and the

conclusions of EWS studies should be shared among government agencies and water utility

stakeholders.

1.2.2 Specific Conclusions and Recommendations

• Data Acquisition and Analysis

Data collection by Supervisory Control and Data Acquisition (SCADA) or other automated systems

is essential to handle the large volume of data from online sensors in an EWS. Much of the required

data acquisition software and hardware already exists. However, software for security (e.g.,

encryption) of SCADA systems for EWSs is still under development and needs verification, but can

probably be addressed by utilities simultaneously with general security issues.

Short-Term Research Needs

• Standardized methods/guidance for data analysis and interpretation are needed.

• Large-scale data storage and manipulation techniques are needed.

Long-Term Research Needs

• SCADA data security programs should be developed to link existing utility efforts with

security characteristics necessary for EWSs.

• Flow Modeling

Predicting the movement and flow of contaminants in a water distribution system is important not

only to prepare for a potential intentional contamination event, but also to improve the effectiveness

of the EWS design. Distribution system modeling in general, and contaminant flow predictive

systems in particular, are developing rapidly. Current contaminant flow models can also integrate

data from geographic information systems. Calibration has been increasingly used in distribution

systems. Consumption-of-water models are also being occasionally incorporated. Utility efforts

to validate and develop predictive flow models would meet the dual purposes of general planning

(expansion, upgrades, repairs, maintenance) and testing intentional contamination scenarios. These

models also assist in the general management of water quality in the distribution system. Although

there are currently no established calibration criteria in the U.S., static and dynamic calibration

methods exist (EPA, 2005). Also, a committee of the American Water Works Association (AWWA)

did propose a set of possible calibration guidelines in 1999 (ECAC, 1999). These possible

calibration guidelines should serve as a catalyst or starting point to move forward on developing

accepted calibration guidelines or standards. Utilities would need further education and guidance

to make use of such predictive flow models, including a better understanding on how they are

calibrated. EPA’s Threat Ensemble Vulnerability Assessment (TEVA) program incorporates flow

modeling (e.g., EPANET) in a probabilistic framework to evaluate contamination events.

Short-Term Research Need

• Improved contaminant flow models are needed.

Long-Term Research Need

• Flow models need to be verified and then used to improve EWS design.
U.S. EPA Office of Water Early Warning Systems

August 2005 5

• Sensor Placement

Because of both budgetary and technical constraints, utilities can make only a modest initial

investment in sensors within their distribution system, and therefore often want to determine the

most appropriate locations. Without resorting to sophisticated experimental optimization

techniques, the limited numbers of utilities that are beginning to design EWSs and put sensors in

place, usually determine sensor placement based first on logistical constraints (e.g., available power

source, access to communications) and second on larger pipes that serve the most customers.

Current research combining flow models and sensor technology is beginning to be developed, but

such models must be verified before difficult and costly decisions are made by the utilities.

Short-Term Research Need

• Hardware and materials to protect remote sensors are needed.

Long-Term Research Need

• Research into sensor placement parameters is recommended.

• Alert Management

Alert management systems typically consist of two general areas: (1) establishing parameters for

alert triggers and (2) reducing false alarms. Any anomalies in the comparison of sensor data to the

baseline trigger alert the operator. Establishing reliable baseline data is key especially when water

quality fluctuates. Alert management systems usually rely on strict data validation protocols or

specialized software to reduce false alarms. Several companies are working on alert management,

but are in preliminary stages of research, with often proprietary trigger algorithms.

Long-Term Research Need

• Alert management approaches/technologies should be examined and sensitivity to falsepositives and false-negatives should be quantified.

• Decision Making and Response

The process linking the analysis of contamination data with decision making and response is

outlined in EPA’s Response Protocol Toolbox; however, additional tools to effectively implement

the process are needed for water utilities. Tools to assist decision making and response, such as the

Water Contaminant Information Tool (WCIT), are being developed and will help fill a current void.

Long-Term Research Need

• Technology to support and implement decision making and response strategies are needed.

• Multi-Parameter Water Quality Technologies

There is ongoing research on the use of the multi-parameter water quality monitors as part of an

EWS for distribution systems. Multi-parameter water quality technology includes readily available

water quality sensors that when analyzed together may be able to identify a physical or chemical

change in water quality. Such a change may suggest that a contaminant has been accidentally or
U.S. EPA Office of Water Early Warning Systems

August 2005 6

intentionally added. Standard water quality parameters include chloride, specific conductance,

turbidity, free chlorine, oxidation-reduction potential (ORP), pH, dissolved oxygen (DO),

temperature, and sometimes total organic carbon (TOC). Parameters that appear, from EPA’s

preliminary tests, to be useful for monitoring in distribution systems include chloride (ion selective

electrode, ISE), specific conductance (electrode), turbidity (nephelometric), free chlorine, and ORP

(EPA, 2004). TOC is also helpful, but may be too expensive to be widely used. The multiparameter approach has not been sufficiently evaluated to recommend widespread use. For example,

no tests have been performed on chloraminated systems. Also, there is concern about falsepositives. However, full-scale testing by the U.S. Geological Survey (USGS), EPA, and a

participating water utility company over the next 12 to18 months may help shed light on falsepositives and whether a system can work with the fluctuations of normal water quality.

Several equipment manufacturing companies are attempting to identify contaminants or classes of

contaminants through water quality parameter signatures. It is difficult to independently validate

or replicate the activities of these companies because their methods and algorithms are proprietary,

which indicates that caution should be used regarding these methods at this juncture. Also, the

examination of water quality parameters in detecting and identifying contaminants is still being

evaluated by EPA, USGS, the Army, and other organizations. There has yet to be a field-scale test

of an EWS with these water-parameter components.

Short-Term Research Needs

• Verified baseline data to calibrate EWS alarm triggers are needed.

• Contaminant specific signatures are needed.

• Validation of event detection algorithms is needed.

Long-Term Research Needs

• Costs and benefits of using TOC sensors should be determined. More affordable and reliable

TOC sensors should be developed.

• Detection of Chemical Contaminants

Portable field kits and devices are available for conducting analyses of grab samples for onsite

detection of many possible chemical contaminants. In contrast to portable field technology, online

detection technologies for specific chemical contaminants are not reasonably available or are not

cost-effective. In the next several years, the field should show further development in terms of costeffective and reliable devices. A few new technologies (e.g., microchip-based technology) could

revolutionize the chemical detection field for drinking water. Disinfectant residuals normally

present in treated drinking water (in the U.S.) may present a problem for many of the technologies

(e.g., biomonitors) that detect toxins. A few technologies are mature enough to be recommended

as good candidates for EPA Environmental Technology Verification (ETV) studies.

Short Research Need

• The impact and removal of disinfectant residuals on accuracy of detection should be

examined.

Long-Term Research Needs

• Reliable field kits should be developed.
U.S. EPA Office of Water Early Warning Systems

August 2005 7

• Existing state-of-the-art detection technologies should be adapted for use in EWSs.

• Detection of Microbial Contaminants

Development of an online microbial detection technology appears to be years away. The lightscattering methodology shows some promise, but most methods are not suited for continuous online

monitoring or for differentiating among microbes. However, to confirm the presence, viability, and

concentration of a contaminant using a portable field unit with grab samples, there are several

potentially adaptable methods from which to choose, including immunoassay, polymerase chain

reaction (PCR), and adenosine triphosphate (ATP). These methods have not yet been exploited to

their full potential, so will likely continue to be incorporated into new monitoring devices and

systems. Grab sampling could include sampling at scheduled intervals or taking composite

samples (e.g., collecting small volumes of sample continuously over time). In any sampling, the

microbial integrity must be ensured. For drinking water, the challenge for most methods is the issue

of concentrating the sample. A few methods of concentration show promise including the hollow

fiber and the micropump. In general, concentration does not seem to be an insurmountable obstacle

for some methods. One recommended approach was to screen a sample with a generic detector

(e.g., multi-parameter probe or perhaps light scatter), then use an immunoassay device in tandem

with another method for identification. ATP detection kits are promising for detecting microbial

contamination, but current products have not been verified for treated drinking water. In the future,

microchips have great potential for advancing online measurement of contaminants, but presently

the field is not sufficiently mature to provide devices that would meet the needs of drinking water

utilities.

Short-Term Research Needs

• Extraction and concentration technologies need improvement. 

• Methods to distinguish concentrated interferants from target contaminants are needed.

• Further development of field-stable reagents is needed.

• ATP detection products should be third party evaluated for EWS application.

Long-Term Research Needs

• Antibodies for unique epitopes (present on threat agents) that show less cross-reactivity

should be developed.

• Research on additional approaches and technologies that can detect emerging, evolving, and

engineered microbes is needed. 

• Detection of Radiological Contaminants

There are demonstrated technologies for examining radiation in wastewater, but the transfer or

adaptation to drinking water has not yet taken place. Only a few products claim applicability to

water, some on a grab-sample basis. More products are being developed by a few vendors, but it

is still unclear whether the threat merits use of these expensive products on a real-time basis. The

few items that are commercially available should be verified either by EPA or by a national

laboratory that specializes in radiation. All of the radiological monitoring devices mentioned in this

study usually require specialized expertise for installation, set-up, and routine calibration—even if

they are labeled maintenance-free. Thus, early warning for radiation detection is not currently
U.S. EPA Office of Water Early Warning Systems

August 2005 8

available for finished water or distribution systems, and the market forces for such development may

not be strong.

Short-Term Research Need

• Beta- and gamma-radioactivity detectors should be developed and verified for drinking water

monitoring applications.

Long-Term Research Needs

• Low-cost, online radioactivity monitors are needed.

• Monitors should be developed that are specifically intended for water distribution systems.
U.S. EPA Office of Water Early Warning Systems

August 2005 9

2. Introduction

This chapter first presents background on the general concern for the water supply including the

threat of intentional contamination of the water supply and the potential benefits of an EWS. It then

describes the EPA’s role in water security and EPA’s efforts on EWS. Further, it outlines the

objective of this study, which is to review the current and emerging technologies and techniques for

integrated EWSs for drinking water infrastructure, particularly for finished water supplies and

distribution systems. The chapter identifies current capabilities, future directions, technical issues,

and research gaps. Finally, it presents the approach used to conduct the review.

2.1 Concern for the Water Supply

Terrorist attacks have heightened concern about intentional threats to the U.S. water system, whether

from physical destruction, computer interference, or chemical, microbial, or radioactive

contamination. Such intentional contamination events can have a profound impact on public health

and confidence in the nation’s water infrastructure. An EWS can be an important tool to avoid or

mitigate the impacts of an intentional contamination event, reliably identifying a high impact

contamination event in source or finished drinking water in time to allow an effective local response

that reduces or eliminates adverse impacts (ILSI, 1999).

2.2 Role of EPA in Water Security and Early Warning Systems

EPA has a lead role in protecting the water supply and specifically to support efforts to develop

EWSs. This role is outlined in several regulations, national strategies, and presidential directives,

including the following:

• Presidential Decision Directive (PDD) 63, signed May 22, 1998, designates EPA as the lead

for security of the national water infrastructure.

• The National Strategy for Homeland Security (July, 2002), designates EPA as responsible 3

for protecting our national water supply. 

• The Public Health Security and Bioterrorism Preparedness and Response Act of 2002 (the

Bioterrorism Act), requires that community water systems serving > 3,300 people conduct

vulnerability assessments and prepare emergency response plans. Also, the Act charges

EPA with reviewing current and future methods to prevent, detect, and respond to the

intentional introduction of chemical, biological or radiological contaminants into community

water systems.

• HSPD-7 on Critical Infrastructure Identification, Prioritization, and Protection (HSPD-7),

signed December 17, 2003, also reinforces EPA’s role as the sector specific agency for the

water infrastructure.

• HSPD-9, signed on February 4, 2004, instructs the federal agencies responsible for 4

agriculture, food, and water security to “develop robust, comprehensive, and fully

coordinated surveillance and monitoring systems ... that provide early detection and

awareness of disease, pest, or poisonous agents.” This study, although initiated before

implementation of HSPD-9, supports the efforts of HSPD-9.

In response to HSPD-9, EPA is working with technical experts and stakeholders in the drinking

water community to design a robust and comprehensive drinking water system monitoring program
U.S. EPA Office of Water Early Warning Systems

August 2005 10

that would provide early indication of an attack and minimize public health consequences. An

outcome built upon existing efforts is WaterSentinel, which is a demonstration project proposed in

the Fiscal Year 2006 budget where EPA, in partnership with select utilities and laboratories, would

design, deploy, and evaluate a model contamination warning system for drinking water security.

A contamination warning system involves the active deployment and use of monitoring

technologies/strategies and enhanced surveillance activities to collect, integrate, analyze, and

communicate information to provide a timely warning of potential water contamination incidents

and initiate response actions to minimize public health and economic impacts.

Although EPA is continually refining its conceptual design for the program, WaterSentinel would

adopt a four-fold approach to detecting contamination involving, first, the monitoring of water

quality parameters; second, the direct monitoring and laboratory analysis of high priority chemical,

biological, and radiological contaminants; third, the integration of water system data with existing

public health surveillance systems; and fourth, active surveillance of customer complaints. In

addition to other critical sources of information, such as intelligence threat analysis and reports from

local law enforcement, WaterSentinel would harness and leverage an array of data streams in

supporting a robust contamination warning system. A more detailed description of how the thinking

behind the WaterSentinel concept has evolved is included in Appendix A. 

Since 2001, EPA has formed the Water Security Division (WSD) in the Office of Water (OW) and

the Office of Homeland Security (OHS). EPA has published the Strategic Plan for Homeland

Security. To spearhead the research efforts on homeland security, EPA formed the National

Homeland Security Research Center (NHSRC) in the Office of Research and Development (ORD ). 5

The Water Security Research and Technical Support Action Plan (Action Plan), prepared by

NHSRC and WSD, emphasizes the need for improving analytical monitoring and detection of

biological, chemical, and radiological threats in drinking water systems as part of securing drinking

water supplies and systems. The NHSRC has been working with the Department of Homeland

Security (DHS), other government agencies, national laboratories, water stakeholders, and the utility

industry to coordinate and conduct research on various issues including EWSs (Appendix B). EPA

has initiated many efforts related to EWSs; they are included below.

2.2.1 National Homeland Security Research Center Research

EPA/ORD’s National Risk Management Research Laboratory (NRMRL) has multiple above-ground

distribution system simulator (DSS) units, located at the Test and Evaluation (T&E) Facility in

Cincinnati, Ohio. The Water Assessment Technology Evaluation Research and Security (WATERS)

Center is located at the T&E Facility and has access to NRMRL’s DSS units. EPA has six different

DSS units in operation at the facility. The DSS units are designed and fabricated to evaluate and

understand the dynamics that influence water quality within water distribution infrastructure systems

in the U.S. and abroad. All DSS units are designed and fabricated above ground to permit easy

access to the entire pipe distribution system. The DSS units consist of six individual pipe-loop

circulating units, three single-pass dead-end units, and two decontamination research loops. EPA

is currently conducting research at the WATERS Center to evaluate various sensor and monitoring

technologies, distribution system modeling, disinfection and decontamination, and data acquisition

systems. The sensors and monitoring technologies are currently being evaluated to see how they

respond to accidental and intentional contamination events and threats in a distribution system

(Haught and Goodrich, EPA, personal communication).
U.S. EPA Office of Water Early Warning Systems

August 2005 11

2.2.2 Environmental Technology Verification (ETV) Program

The ETV Program operates as a public/private partnership through agreements between EPA and

private testing and evaluation organizations. The goal of ETV is to provide credible performance

data for commercial-ready environmental technologies to speed their implementation for the benefit

of vendors, purchasers, permitters, and the public. Of the six ETV centers, three are working in

water security relevant areas: ETV Advanced Monitoring Systems Center (AMS - Battelle), ETV

Drinking Water Systems Center (NSF International), and ETV Water Quality Protection Center

(NSF International ). Some testing areas formerly performed by ETV are being transferred to 6

NHSRC’s Homeland Security Technology Testing and Evaluation Program (TTEP). 7

2.2.3 Technology Testing and Evaluation Program (TTEP)

The TTEP was developed by NHSRC in 2004 to rigorously test technologies against a wide range

of performance characteristics. TTEP’s mission is to service the needs of water utility operators,

building and facility managers, emergency responders, consequence managers, and regulators by

providing reliable performance information from a trusted source. The technology categories of

interest include detection, monitoring, treatment, decontamination, computer modeling, and design

tools for protecting water and wastewater infrastructures and the outdoor environment. When

possible, technologies will be tested for their ability to detect chemical, biological, radiological

(CBR), and warfare agents. As an outgrowth of the ETV, many aspects of TTEP are similar to ETV.

However, TTEP does not offer verification statements or endorsements to the vendors and it may

test technologies with or without the involvement of the vendor.

2.2.4 American Society of Civil Engineers (ASCE) Guidelines for Designing an Online

 Contamination Monitoring System

Under a cooperative agreement with EPA, the American Society of Civil Engineers/Water

Infrastructure Security Enhancements-Standards Committee (ASCE/WISE-SC) has developed

interim voluntary security guidance that covers the design of online contamination monitoring

systems to detect intentional contamination events (Phase I of the project ). Phase II of the project 8

was to develop appropriate training materials for use in the water sector. Phase III of the project is

to develop community consensus voluntary best practice standards for designing an EWS.

2.2.5 Water Utility Users Group

The AWWA has convened a group (formerly known as the Water Contaminant Detection Working

Group) of water utilities to offer their opinions and experiences in contaminant detection. This

group has met on several occasions in the past year (2004 to 2005) and representatives from EPA

have been invited to participate in those meetings. Of particular interest to the Users Group is

EPA’s TEVA Research Program for Drinking Water Distribution System Security. The TEVA

Research Program is developing software tools, methodologies, and strategies for assessing the

public health consequences of chemical and biological attacks on drinking water, and for designing

and evaluating mitigation and response strategies. Partnering with a small group of AWWA water

utilities, the TEVA Research Program will use network models and water quality data gathered from

the utilities to validate and improve TEVA. An interdisciplinary team of researchers from EPA,

several Department of Energy (DOE) National Laboratories, and universities are collaborating to
U.S. EPA Office of Water Early Warning Systems

August 2005 12

develop these tools. Ultimately, the products of the TEVA Program will be useful for designing

EWSs specific to an individual utility. This information will be aimed at evaluating strategies for

sensor locations in drinking water distribution systems, and for optimizing response and recovery

activities in the aftermath of a contamination event (Murray et al., 2004).

2.2.6 Water Security Working Group (WSWG)

The National Drinking Water Advisory Council (NDWAC) is comprised of members of the general

public, state and local agencies, and private groups concerned with safe drinking water. The

NDWAC advises EPA on the Agency’s programs related to drinking water. NDWAC has several

working groups that make recommendations to the full council, which in turn advises EPA on

individual regulations, guidances, and policy matters. One group, the WSWG, has been charged by

EPA to (1) identify, compile, and characterize active and effective security practices and policies

for drinking water and wastewater utilities and provide an approach for considering and adopting

these practices and policies at a utility level; (2) consider mechanisms to provide recognition and

incentives that facilitate a broad and receptive response within the water sector to implement these

active and effective security practices and policies, and make recommendations as appropriate; and

(3) consider mechanisms to measure the extent of implementation of these active and effective

security practices and policies, identify the impediments to their implementation, and make

recommendations as appropriate. The WSWG began meeting in July 2004, and delivered a draft

report on these issues to the NDWAC in June 2005. In June 2005, the NDWAC unanimously

approved and adopted the WSWG’s findings unchanged and elevated these findings to the status of

recommendations to the EPA.

2.2.7 Water Contaminant Information Tool (WCIT)

EPA’s 2004 Homeland Security Strategy calls for the deployment of WCIT to provide easy access

to key information on priority contaminants, and to develop components of the Tool, including data

on treatability and toxicity levels. In this program, detailed information is to be made available to

utilities during a confirmed contamination event when the utility calls EPA’s National Response

Center. The information is then faxed to the utility. The Strategy recommends that the WCIT

should be revised periodically, as new information becomes available.

2.2.8 Distribution System Research Consortium (DSRC)

Formed in June 2003, the DSRC is led by the EPA’s NHSRC. The DSRC includes federal

employees from a number of agencies with experience in water infrastructure, the water industry,

EPA Program Offices and Regions, and other interested organizations. The DSRC provides a forum

for information exchange on a diverse set of water distribution system security topics. Topics have

included EWS research (e.g., sensors, field studies, sensor placement) and treatment and

decontamination research.

2.2.9 EPA Resources/Guidance

EPA/OW/Office of Ground Water and Drinking Water (OGWDW) maintains a Water Infrastructure

Security website that includes various guides including the Response Protocol Toolbox (e.g., Site

Characterization and Sampling Guide, Analytical Guide), a Security Product Guide, Standardized 9
U.S. EPA Office of Water Early Warning Systems

August 2005 13

Analytical Methods for Use During Homeland Security Events (on NHSRC website), and a list of

Sensors for Monitoring CBR Contamination.

2.3 Purpose of this State-of-the-Art Review

EWSs are needed for drinking water distribution systems because contamination of drinking water,

especially in distribution systems, is an important concern. Research and development of

technologies applicable to EWSs are rapidly progressing, making up-to-date reviews of the EWS

field challenging.

The basis of this project is outlined in the Water Security Research and Technical Support Action

Plan, Section 3.3e, which recommends testing and evaluation of drinking water EWSs and, if 10

applicable, EWSs from other sectors amenable to application in the water environment, focused on

distribution systems. More specifically, Action Plan Section 3.3e has the following four sequential,

yet interdependent tasks:

1. Conduct a survey to gain improved understanding of EWSs that could be employed in

protecting finished water supplies and distribution systems;

2. Perform pilot-scale testing and evaluation of EWSs that could be used by water utilities to

give an early warning of a contaminant threat or accidental contaminant event;

3. Perform field-scale testing and evaluation of EWSs that could be used by water utilities to

give an early warning of a contaminant threat or accidental contaminant event; and

4. Prepare a handbook on the application of EWSs for drinking water supply and system

protection.

This report is intended to fulfill Task 1 of the Action Plan. It includes a comprehensive review of

current and emerging EWS technologies and techniques, and evaluates their state-of-the-art so as

to identify future directions, research gaps, and technical issues. An EWS for finished water

presents a special set of challenges, compared with an EWS for source water. Finished water

includes various treatment chemicals, including chlorine residual. The finished water also flows

through miles of distribution system pipes, which makes the placement of EWS components

difficult. The other three tasks would be addressed by programs such as WaterSentinel. All four

tasks above are being addressed as part of an overall integrated approach being managed by

EPA/NHSRC. Additional information on technologies available for ground water monitoring can

be found in A Review of Emerging Sensor Technologies for Facilitating Long-Term Ground Water

Monitoring of Volatile Organic Compounds (EPA, 2003).

Information is needed on how specific contaminants (microbial, chemical, radiological) affect the

water quality parameters measured by some currently used online monitoring systems, particularly

with regard to which current technologies will best detect a contamination event. A number of

monitoring technologies and products are available that could potentially serve as an EWS, and a

number of suppliers of conventional monitoring systems have begun to advertise them as water

security monitoring systems. However, in most cases, the performance of these systems has not

been fully or independently evaluated. Without basic performance information (such as detection

limits, sensitivity, selectivity, rates of false-positives and false-negatives), it will be difficult to

interpret monitoring results and derive the information necessary to make appropriate public health

decisions.
U.S. EPA Office of Water Early Warning Systems

August 2005 14

Implementation of a minimally evaluated monitoring technology or EWS may result in a false sense

of security, since there is no assurance that it is capable of meeting EWS requirements. It could also

result in false-positive alarms that undermine the effectiveness of any monitoring program, or falsenegatives that would discredit an EWS. A significant amount of research is underway to adapt

existing and develop new technologies that may be suitable as EWSs for water systems.

As promising technologies continue to be developed and brought into the commercial market, there

is a need for a mechanism to evaluate and verify EWS performance that includes field evaluation

and testing sites. Ideally, such testing should be conducted according to a standard protocol by an

independent third party, and the subject technology should be evaluated against standardized

methods. This would provide water utilities with the data necessary to make informed decisions

regarding the implementation of a specific technology in an EWS. EPA’s TTEP can provide this

independent testing. The TTEP process follows strict quality assurance procedures to evaluate

technology performance. Stakeholders are involved in identifying and selecting technologies for

testing, and in developing testing plans and reviewing evaluation reports.11

Design of an EWS for finished water in the drinking water distribution system is not simple, as there

are many issues and water system characteristics that need to be considered. The issues that should

be addressed in the effective design of an EWS include planning and communication, characterizing

the system, determining the target contaminants for the EWS, selecting an appropriate EWS

technology, establishing appropriate alarm levels and monitoring frequency, employing hydraulic

models to optimize the number and placement of sensors, selecting parameters to be monitored, and

conducting data management and analysis.

Three recent projects complement the scope of this report. In the first project, the ASCE-WISE-SC

white papers and guidance, mentioned earlier in this report, seek to provide specific guidance to

utilities about the design and implementation of an online contaminant monitoring system (ASCE,

2004). In contrast, this study reviews the state-of-the-art EWS technologies and techniques and

provides recommendations (e.g., research needs) to further the development of an integrated EWS.

In the second project, the National Technology Alliance (NTA), through the Chemical, Biological,

and Radiological Technology Alliance (CBRTA) released a report entitled Water Monitoring

Equipment for Toxic Contaminants Technology Assessment (Black & Veatch, 2004). The NTA

leverages commercial investment in technology to meet U.S. security and defense needs. The NTA

report focuses on monitoring technologies for both source and finished water. In contrast, this study

focuses on the components of an integrated EWS (e.g., monitoring, data acquisition, flow modeling),

and specifically addresses finished water monitoring for distribution systems. An article by the

AWWA entitled “Contamination Warning Systems for Water: An Approach for Providing

Actionable Information to Decision-Makers” provides an easy to read summary of monitoring

technologies, monitoring locations, data transmission, alarms, and response (Roberson and Morley,

2005).

The purpose of this study was to provide a current state-of-the-art review (i.e., snapshot in time).

In the process, it also identifies areas of research needed in the short-term and long-term to develop

workable EWSs. This study, however, was not able to address all of the issues associated with

EWSs. The following are limitations in the scope of the study. This study does not discuss in detail

the specific types of drinking water contaminants, and instead focuses on three categories of

contaminants: chemical, microbial, and radiological. These categories are useful on a broad level
U.S. EPA Office of Water Early Warning Systems

August 2005 15

to evaluate monitoring technologies. Specific information, such as the concentrations at which a

contaminant is detectible or effective in impacting human health, is important in evaluating a

specific instrument or set of instruments. However, much of the detailed information and research

efforts on the types and concentrations of contaminants is either not publically available or is

undergoing collection and review. Detection limits for the different technologies are provided when

available from the vendor, government agency, or testing/verification entity. Limits of detection

may not be provided for emerging technology because of the newness of the technology.

The design of an EWS is a complex issue, and the design and development of EWSs for water

distribution systems are still at an early stage and continue to evolve. This study summarizes the

basic design and features of an EWS, but does not cover the topic in detail. For example, the study

does not provide detailed criteria for selecting instruments, locating instruments, setting alarm

levels, and integrating other independent data streams such as public health surveillance and

consumer complaints monitoring. This document is not a guidance document, but instead a state-ofthe-art review. As mentioned above, the ASCE has provided some guidance, including a ranking

of the desired characteristics of the EWS (Carlson et al., 2004). Reviewers of early drafts of this

study suggested that a more detailed treatment of design and implementation of an EWS is needed.

To accomplish this, another multi-stage project would be necessary to further develop an adequate

treatment of design possibilities and issues. Such a project should engage the water sector

stakeholders, including utilities, equipment designers and manufacturers, researchers, and policy

officials.

There are many technologies and products covered in this report. EPA does not recommend or

endorse the specific products mentioned in this report. In addition, much of the information

provided on specific technologies are from vendors and have not been independently verified unless

otherwise indicated. Efforts were made to use more than one source to verify the information;

however, EPA is not responsible for errors in company-provided information. The status of the

technology (e.g., pilot, concept), as well as estimates for field implementation are based on vendor

or government authorities, as indicated. It is particularly difficult to accurately predict when

emerging technologies will evolve into reliable and marketable products.

This project’s objective is to conduct a comprehensive review of the state-of-the-art technologies

and techniques for integrated EWSs for drinking water infrastructure, particularly for finished water

supplies and distribution systems. It seeks to identify the status of current and emerging EWS

technologies and future directions, research gaps, and technical issues. Chapter 1 provides report

highlights. Chapter 2 introduces the concept of an integrated EWS and discusses the approach used

to conduct this state-of-the-art review. Chapter 3 presents a description of desired characteristics

and component features that define EWSs. Chapter 4 addresses overall design and operation of

EWSs, including data management and analysis, predictive flow modeling, sensor placement, alarm

management, data security, and response communications. Chapter 5 presents the concept of using

general water quality parameters as indicators for contamination events. Details of efforts being

undertaken to develop multi-parameter water quality signatures for specific contaminants are also

presented in Chapter 5. Chapters 6, 7, and 8 cover chemical, microbial, and radiological detection

methods and technologies, respectively. These chapters are organized in a similar format, with a

general description of a technology followed by specific example products that are available or

could be adapted for drinking water, followed by emerging technologies that are more in the

developmental stage. Chapter 9 addresses the evaluation of the technologies discussed in Chapters
U.S. EPA Office of Water Early Warning Systems

August 2005 16

5 through 8. Chapter 10 explains the conclusions and recommendations from the evaluation of EWS

state-of-the-art. Tables are presented as Exhibits and are labeled by chapter number followed in

chronological number as they appear in the text.

2.4 Approach for this State-of-the-Art Review

This review document on EWSs covers technologies and techniques that may be applicable for many

different water monitoring needs, as well as specific EWS needs. The stepwise approach for

reviewing and evaluating EWS components includes several forms of information gathering and

critical review. Information was gathered from published literature, conferences, seminars,

workgroups, and consultation with experts in the field. The review and evaluation protocol

consisted of the following six steps:

Step 1: Identify experts on contamination issues for distributions systems to assist with the

technical writing of this background document, with emphasis on intentional

contamination events.

Step 2: Summarize characteristics and features for EWSs and the justifications for those criteria

and features.

Step 3: Develop an inventory, and descriptions of function and status, of rapid detection

technologies that might be appropriate components of an EWS. Methods are described in

general terms, then specific products are presented. Technologies include water quality

parameter monitors, and detectors for chemical, biological, or radioactive contaminants.

Step 4: Develop an inventory and report on the status of integrated EWS design and operation.

General water quality monitors and specific detection assays combined with data relay,

analysis, and display technologies are all part of EWS design. Where these technologies

are located, how they interact, and how they are made secure and reliable are also integral

parts of EWS design and operation.

Step 5: Identify and discuss research, gaps, information, and technical advancements needed to

build future EWSs.

Step 6: Evaluate technologies for their capabilities and issues.

For the EWS commercial products identified in Steps 3 and 4, information collected includes a

general description of the product, the extent to which it is a comprehensive EWS for real-time

monitoring in a distribution system (e.g., detector only, not notification), method of detection,

contaminants detected, limits of detection, level of verification, potential for piloting, current use,

and other critiques. Complete information was not available for all the technologies and products

discussed. See Appendix C for a list of products and manufacturers mentioned in this report.

2.5 Sources of Information

2.5.1 Experts

Government, industry, academia, and water utility experts in the field were consulted at various

conferences, seminars, workshops, and by telephone and e-mail. Subject matter experts provided

their experience and knowledge on the subject of EWSs (See Acknowledgments). In many cases,

company representatives were contacted directly via e-mail and/or telephone for information

regarding products and the application of their products. In general, information about products or
U.S. EPA Office of Water Early Warning Systems

August 2005 17

programs that was obtained through e-mail or telephone is cited as personal communication. All

correspondence took place between July 2004 and July 2005.

2.5.2 Conferences and Seminars

EWS design and its component technologies are part of the emerging field of water security. As

with all fields experiencing rapid growth, much valuable information is available from conferences

and seminars. Materials from several conferences were compiled and reviewed for building the

content of this state-of-the-art review. Conferences and seminars attended by the primary authors

for the purpose of gathering information for this review, are listed below:

• Water Security Congress, AWWA (April 2004, April 2005)12

• AWWA-sponsored seminar on Contamination Monitoring Technologies (Richmond,

Virginia; May 2004)13

• Water Infrastructure Security Enhancement Workshops Guidelines for Designing an Online

Contaminant Monitoring System for Water Utilities (May 19, 2004)14

• Rapid Detection Technologies for Water Supply Safety and Security (Washington, DC; June

2004)15

2.5.3 Published Literature

Information from peer-reviewed published literature, government agency publications, vendor

literature, and results of verification tests was gathered and critically reviewed for inclusion in this

report. The information sources include the following:

• articles, publications (e.g., Water Environment and Technology)

• reference texts such as Design of Early Warning and Predictive Source Water Monitoring

Systems (e.g., the American Water Works Research Foundation (AwwaRF))

• EPA Performance Verification Testing of commercially available rapid toxicity monitoring

systems

• Studies from other federal agencies working in this area (e.g., Department of Defense

(DOD), National Aeronautics and Space Administration [NASA])

2.5.4 Website Resources

Several hundred websites were evaluated for content applicable to this review. Electronic archives

and hard copies of websites cited were collected for future reference because web content evolves

so rapidly. The URLs are cited as endnotes throughout this report and were current as of April 2005.

2.5.5 Workgroup Efforts

Information from workgroups focused on EWSs was obtained, including EPA workgroups and the

Water Contaminant Detection Working Group.
U.S. EPA Office of Water Early Warning Systems

August 2005 18

2.6 Criteria for Selecting Products/Technologies

The goal of this EWS document is to report on the state-of-the-art technologies and techniques for

detecting contaminants, particularly chemical, microbial, and radiological contaminants in drinking

water distribution systems. To focus on the most promising products and technologies in this

relatively new area, criteria were developed for including technologies and products in this

document. Most technologies and products that were either only conceptual or were not currently

envisioned to apply to water were omitted. A complete discussion of the criteria used to select

technologies, as well as a list of the products and technologies investigated, can be found in

Appendix C.

Three categories of technology development were designated: (1) available now (being used, offthe-shelf technology, or could be used by water utilities) for use in EWSs; (2) potentially adaptable

technology for use in EWSs (in use, but needs additional steps to address specific challenges for use

with water distribution system); and (3) emerging technologies that may be applicable for use in

EWSs.

In this report, technologies are classified based on the three categories above (e.g., available,

potentially adaptable, emerging), and details are provided on the level of verification, if the

information was available. For most products, except where noted, manufacturer’s claims have

not been evaluated by independent sources and products mentioned are not endorsed by EPA.
U.S. EPA Office of Water Early Warning Systems

August 2005 19

3. Desired Characteristics and Features of Integrated Early Warning Systems

An EWS is much more than a collection of monitoring technologies. It is an integrated system for

deploying the monitoring technology; analyzing, interpreting, and communicating the results; and

using the results in making decisions that are protective of public health while minimizing

unnecessary concern and inconvenience within a community. EWSs should be viewed as a critical

part of the operation of a water system in general. EWSs can be used to identify intentional

contamination events and other non-intentional situations where water quality is impaired. To

become a widely used, effective, and reliable part of a water distribution security (and water quality

monitoring) system, there are characteristics that integrated EWSs should exhibit.

3.1 Desired Characteristics for Integrated Early Warning Systems

To become a widely used, effective, and reliable part of a water distribution security and quality

monitoring system, an ideal integrated EWS should demonstrate a number of characteristics, such

as the following (adapted from ILSI, 1999; Grayman, 2004a; Hasan, 2004):

• provide a rapid response

• include a sufficiently wide range of potential contaminants that can be detected

• exhibit a significant degree of automation, including automatic sample archiving

• allow acquisition, maintenance, and upgrades at an affordable cost

• require low skill and training

• identify the source of the contaminant and allows accurate prediction of the location and

concentration downstream of the detection point

• demonstrate sufficient sensitivity to detect contaminants

• permit minimal false-positives/false-negatives

• exhibit robustness and ruggedness to continually operate in a water environment

• allow remote operation and adjustment

• function continuously

• allow for third party testing, evaluation, and verification

Currently, an EWS with all of the above characteristics does not exist. However, there are parts of

an EWS that can meet certain core characteristics: (1) provide rapid response, (2) screen for a

number of contaminants while maintaining sufficient sensitivity, and (3) operate as an automated

system that allows for remote monitoring. Any EWS system that does not demonstrate these three

core characteristics could not be considered an effective EWS. Although emphasis is placed on

these three core characteristics, the other characteristics presented below cannot be ignored in the

design of an EWS. For example, consideration should be given to the rate of false-positive/falsenegative results and method sensitivity when interpreting the results. System operation and

maintenance costs, sampling rate, and reliability should be considered in the design of an EWS.

Furthermore, utilities are reluctant to invest in technologies that have not been third party verified.

3.1.1 Rapid Response Time

Response time for an EWS is typically from the time when the contaminant contacts the sensor to

when a result is reported and a response is initiated (Mays, 2004). An ideal EWS would detect,

interpret, and communicate the warning in sufficient time to take mitigation response actions before
U.S. EPA Office of Water Early Warning Systems

August 2005 20

human health is jeopardized (ILSI, 1999). It is especially desirable that the EWS is rapid between

contamination occurrence and detection and identification of the contaminant. This time may be

influenced both by the technologies used and the overall approach to identification of the

contaminant. For example, an approach could involve an initial warning by one technology

followed by a confirmation by another technology. In most of the current literature, the speed of a

rapid detection technology refers mainly to the time between sample collection and final

interpretation of the results. The ILSI reportEarly Warning Monitoring to Detect Hazardous Events

in Water Supplies considers results in two hours or less to be rapid (ILSI, 1999). Some

manufacturers call their field portable grab sample kits (or devices) rapid detection technologies.

In these cases it is important to note that even if a technology boasts a 2-minute assay time, if the

equipment is in storage and requires 30 minutes of set-up time before the sample is tested, then the

effective time is really 32 minutes. In addition, the time it takes for the sample to be collected from

the field will affect the overall response time.

Response time can also include the time to inform the decision makers of the results of the

contaminant analysis, initiate the response decision making process, and initiate the implementation

of the response plan. Since the definition of sufficiently rapid EWSs includes “sufficient time for

action,” the desired outcome of the action should be defined. For example, the desired outcome

could require actions as demanding as prevention of the contaminant reaching taps by mitigation

measures or pump shut down or a more simple response of issuing a boil-water notice.

Although detection, data analysis, decision making, and response implementation all factor into the

EWS’s overall response time, it seems reasonable that the detection technology should not be the

bottleneck in the response process. Rapid detection technology should ideally have high throughput

(collecting data or samples every few minutes or less), rapid assay, and brief analysis time. In a

best-case scenario, a contaminant is detected, a decision is made, and a response is implemented

before the contaminant has time to reach consumer taps. In this sense, an EWS should strive to

“detect to protect” (incident detected and exposure prevented; may be instant) and “detect to

warn”(incident detected before significant exposure or manifestation of public health indicators; may

take hours). Systems that can only “detect to treat” (incident detected after exposure occurs or

manifestation of public health indicators, may take hours to days) qualify as contamination warning

systems but may not meet the rapid criteria of an EWS (Roberson and Morley, 2005). However,

with improvements in technology and the ability to detect specific contaminants or specific

contaminant categories in near real-time, it is anticipated that a contamination warning system will

move toward “detect to warn.”

3.1.2 Range of Contaminants

It is impractical and probably unproductive to focus on specific drinking water contaminants when

designing an EWS. In addition, long and exhaustive lists of agents can give a misleading impression

of the extent of possible threats (WHO, 2004 ). Because the potential lists of contaminants and 16

potential threats are very large, it is unreasonable to expect to have a separate detection technology

in place for each contaminant or threat. The unlimited range of existing and emerging contaminants

would tax the resources and technical capacity of any water distribution system. Instead, there needs

to be an ongoing process of grouping known contaminants by such properties as their

physicochemical traits, source, public health impact, or the probability that they may be used to

disrupt a water distribution system. Characteristics like these can be useful because they help
U.S. EPA Office of Water Early Warning Systems

August 2005 21

determine the appropriate type, placement, and cost of monitoring technologies. It is necessary,

therefore, that a suite or panel of technologies be capable of detecting broad groups of contaminants

and other threats, instead of separate detection technologies for each contaminant. Toxic chemicals,

radiological contaminants, and microbial pathogens are broad categories that require particular

detection and identification strategies. Additional subcategories with examples are provided in

Exhibit 3-1 (EPA, 2003/2004). 

3.1.3 Automation and Remote Operation

Automated systems have several advantages over manual sampling assays. Sampling intervals are

easier to dictate and track with automated systems. Although human error and variability introduced

due to different human operators remain factors for automated systems, they are much reduced

compared to manual assays. With automated systems, remote monitoring is more feasible because

personnel do not need to travel to the sampling site each time a sample is taken. Remote operation

of the technology is also valuable. There are devices that are automated and can be placed remotely,

but if parameters need to be adjusted, calibrated or validated, then personnel must travel to the

devices. Performance optimization is cumbersome if traveling to each device is required to adjust

parameters. Systems amenable to adjustment, calibration, or validation via a central command

location are desirable but not available for many sensors used for detecting contaminants.

“Online” implies a certain degree of automation, remote control, and real-time capability. Online

at a minimum refers to the capability of a device to be permanently installed. “Continuously online”

can be used to emphasize real-time capability. This term should not be confused with “in-line” or

“in-pipe” which refers to the placement of a device within a pipe, so distribution system water does

not have to be re-routed out of the distribution system to be sampled. In-line or in-pipe technologies

are also online.

Automatic sample archiving is necessary when confirmatory testing is desired. When an alarm is

triggered, an automated sample collection device should store a grab sample so that the water sample

that triggered the alarm can be analyzed either in the field with portable devices or in a laboratory

for more sophisticated analysis. If automated sample collection is not in place, then it is problematic

to determine if a monitor detected a transient spike in contamination or if there was a false alarm.

Although flow rates vary throughout the distribution system, it is not unreasonable to predict that

some contamination spikes of concern could pass by sensors before response teams could make it

to the monitor location to perform a manual grab sample. Even if data from multiple sensors are

integrated with flow models to predict downstream contamination location and concentration, it may

still be desirable to have archived samples, particularly if a criminal investigation results from the

event.
U.S. EPA Office of Water Early Warning Systems

August 2005 22

Exhibit 3-1. Drinking Water Contaminant Classes and Examples

Category Examples

MICROBIOLOGICAL CONTAMINANTS

Bacteria Bacillus anthracis, Brucella spp., Burkholderia spp., Campylobacter spp.,

Clostridium perfringens, E. coli O157:H7, Francisella tularensis, Salmonella typhi,

Shigella spp., Vibrio cholerae O1, Yersinia pestis, Y. enterocolitica

Viruses Caliciviruses, Enteroviruses, Hepatitis A/E, Variola, Venezuelan equine encephalitis

virus

Parasites Cryptosporidium parvum, Entamoeba histolytica, Toxoplasma gondii

CHEMICAL CONTAMINANTS

Corrosives and caustics Toilet bowl cleaners (e.g., hydrochloric acid), tree-root dissolver (e.g., sulfuric acid),

drain cleaner (e.g, sodium hydroxide)

Cyanide salts or cyanogenics Sodium cyanide, potassium cyanide, amygdalin, cyanogen chloride, ferricyanide

salts

Metals Mercury, lead, osmium, their salts, organic compounds, and complexes (even those

of iron, cobalt, copper are toxic at high doses)

Nonmetal oxyanions, organononmetalsArsenate, arsenite, selenite salts, organoarsenic, organoselenium compounds

Fluorinated organics Sodium trifluoroacetate (a rodenticide), fluoroalcohols, fluorinated surfactants

Hydrocarbons and their oxygenated

and/or halogenated derivatives

Paint thinners, gasoline, kerosene, ketones (e.g., methyl isobutyl ketone), alcohols

(e.g., methanol), ethers (e.g., methyl tert-butyl ether or MTBE), halohydrocarbons

(e.g., dichloromethane, tetrachloroethene)

Insecticides Organophosphates (e.g., Malathion), chlorinated organics (e.g., DDT), carbamates

(e.g., Aldicarb) some alkaloids (e.g., nicotine)

Malodorous, noxious, foul-tasting,

and/or lachrymatory chemicals

Thiols (e.g., mercaptoacetic acid, mercaptoethanol), amines (e.g., cadaverine,

putrescine), inorganic esters (e.g., trimethylphosphite, dimethylsulfate, acrolein)

Organics, water-miscible Acetone, methanol, ethylene glycol (antifreeze), phenols, detergents

Pesticides other than insecticides Herbicides (e.g., chlorophenoxy or atrazine derivatives), rodenticides (e.g.,

superwarfarins, zinc phosphide, -naphthyl thiourea)

Pharmaceuticals Cardiac glycosides, some alkaloids (e.g., vincristine), antineoplastic chemotherapies

(e.g., aminopterin), anticoagulants (e.g., warfarin). Includes illicit drugs such as

LSD, PCP, and heroin

Schedule 1 Chemical Weapons Organophosphate nerve agents (e.g., sarin, tabun, VX), vesicants, [nitrogen and

sulfur mustards (chlorinated alkyl amines and thioethers, respectively)], Lewisite

Biotoxins Plant, animal, microbial, and fungal derived toxins 

(e.g. ricin, botulinum toxin, aflotoxins)

RADIOLOGICAL CONTAMINANTS

Radionuclides Does not refer to nuclear, thermonuclear, or neutron bombs. Radionuclides may be

used in medical devices and industrial irradiators (e.g, Cesium-137, Iridium-192,

Cobalt-60, Strontium-90). Class includes both the metals and salts.
U.S. EPA Office of Water Early Warning Systems

August 2005 23

3.1.4 Affordable Cost

Affordability is essential. Although what is considered affordable will vary for different water

utilities, the desired characteristics and features of EWSs outlined in this chapter can serve as a

checklist to compare systems to each other and to buyer requirements. In addition, other factors will

likely be considered by potential users, such as how soon the equipment will become outdated,

supply and maintenance costs, and budget demands from other high priority areas. A cost-effective

EWS should allow for future growth and improvements. This might be accomplished by a modular

design that could be upgraded stepwise on a planned schedule to incorporate new technologies as

they become available. This type of spiral development should keep EWSs evolving, both in terms

of performance and cost. Besides the capital costs, there are ongoing operation and maintenance 17

costs.

3.1.5 Low Skill and Training

Skill level and training requirements will factor into the cost of the detection technologies and the

EWS as a whole, and will impact the effective use of the system. Complicated technologies that

require initial training along with further practice and hands-on experience for proper

implementation will suffer from periods of shut down if personnel turnover is too rapid. In contrast,

technologies that require a low skill level and minimal training to run effectively are more likely to

yield results on a consistent basis. Skill and training required should be considered for both the

actual sampling or assay technology, as well as the necessary software needed for analysis and

interpretation.

3.1.6 Source of the Contaminant

It is desirable that the site of introduction of contamination be identified as quickly as possible.

Although it is unlikely that an EWS will be able to pinpoint the point of entry, it should provide

guidance for investigation of the event and narrow the possible locations. Where contamination is

ongoing, this is valuable for halting contaminant entry. In the case of intentional contamination, the

entry site would be subject to criminal investigation protocols. Sites of accidental transient entry

would also need to be evaluated. Site locations for monitoring equipment throughout the system and

special contaminant flow models will assist in tracing a contaminant to its point of entry. In

addition, it is important to accurately predict the location and concentration of contaminants once

they pass the detector site. This is valuable for knowing where an intervention, grab sample, or

other response might be effective, for determining the particular users at risk, and for predicting

exposures.

3.1.7 Sensitivity

Sensitivity of an assay or test impacts the utility and often the cost of the detection technology.

Assays that can only reliably detect relatively high levels of contaminants would not be useful if

lower levels need to be detected. Often assays that can detect very low levels of contaminants are

swamped by high levels and may be more expensive than other appropriate options. An assay that

can quantitate a broad range of concentrations, however, is likely to be prohibitively expensive. For

regulated contaminants, an assay should be sensitive enough to detect concentration levels that
U.S. EPA Office of Water Early Warning Systems

August 2005 24

bound the regulatory levels. For potentially hazardous contaminants, such as CBW agents, the

chosen thresholds of detection should be scientifically based and protective of public health.

3.1.8 Minimal False-positives/False-negatives

False-positives and false-negatives can make a system effectively useless. False-positive and falsenegative rates can be defined for individual monitors within the integrated EWS and for the EWS

as a whole. False-negatives lead to decreased protection because contaminants present at relevant

levels escape detection. This could result in catastrophic public health consequences and/or loss of

confidence in drinking water supplies. False-positives from devices or assays can slow down the

effective response time, because each time a positive result is obtained, it must be confirmed by

additional tests. If the consequences of a true positive are grave enough, then the initial presumptive

positive result would trigger a response. Any response has an associated cost measured in labor time

and direct costs. If the initial result is subsequently determined to be a false-positive, then money

has been spent needlessly and in some cases public trust is eroded. Each contamination warning that

the public finds inaccurate will increase the rate at which future warning are ignored, which would

increase the health impacts in a real contamination event. In many cases, the time needed to confirm

a result is added before any response plan is initiated.

Appropriate data analysis and event correlation techniques can reduce the false alarm rate for the

EWS. Only systems with either very low false-positive/negative rates or very rapid confirmation

methods should be considered early warning. The Defense Advanced Research Projects Agency

(DARPA) Chemical and Biological Sensors Standards Study presents methods for evaluating

sensors by capturing the performance trade-offs between sensitivity, probability of correct detection,

false-positive rate, and response time (DARPA, 2004). Hrudey and Rizak (2004) have developed

a statistical framework for hazard detection and judgment of the evidence to provide insight and

mathematical justification to decisions regarding balancing false-positive and false-negative errors

in the drinking water security context. In addition, Bravata et al. (2004) describe how sensitivity,

specificity, and pre- and post-test probability are reported in receiver operating characteristic (ROC)

curves to graphically communicate predicted false-positive and false-negative information. The

authors also suggest that published guidance for evaluating clinical diagnostic tests can be adapted

for evaluating detection systems because diagnostic test guidelines are well established and promote

study designs that provide unbiased estimates of both sensitivity and specificity (or likelihood ratios)

relative to an acceptable standard. Manufacturers and parties involved in third party verification

should quantitate the false-positive and false-negative rates.

Sources of false-positives and false-negatives can be due to human error, such as inaccurate

pipetting or mixing techniques. There are also common chemicals or conditions in the water

distribution system that can interfere with some types of assays. For example, the chlorine residual

can interfere with detection because chlorine itself may be measured as a toxin by some of the

assays. Chlorine can also be toxic to biomonitors (e.g., fish, bacteria). Copper and other metals can

affect the chemistry of some assays. Biofilms (microbial communities that coat the inside of pipes)

commonly occur in the distribution system, and can naturally slough off, releasing microorganisms

into the finished water. Microbial detection technologies could confuse this background level of

microbial occurrence with an intentional contamination event. Such interferents are discussed in

more detail in Chapter 9. 
U.S. EPA Office of Water Early Warning Systems

August 2005 25

The rates of false-positives and false-negatives for individual devices and assays should be

distinguished from the overall false rates of the EWS system. Although individual technologies may

have false-positive and false-negative rates that can be compensated for by overall design of the

EWS through the use of confirmatory and backup tests, the overall EWS should have a very low rate

of false-positives and false-negatives. If a response plan includes calling in emergency responders

from other community sources, utilities should consider that some local governments may have fines

in place for organizations and individuals that exceed a certain number of false alarms in a given

time period.

3.1.9 Robustness and Continuous Functioning

EWSs and the associated technologies should be resistant to damage or inaccuracies caused by

human error or environmental conditions, such as continuous exposure to the water environment.

This robustness decreases maintenance costs and provides increased reliability. These criteria apply

to both the hardware and the software. Human error during maintenance should be easily detectable.

Equipment that is highly sensitive to jarring, shaking, or falling has reduced utility and probably

higher maintenance costs. Environmental conditions such as humidity and temperature will

fluctuate, even in locations that are sheltered from direct sunlight and precipitation. Software that

is prone to crashing or is overly complicated to master compromises the usefulness of the system.

Battery life should be considered for hand-held units. For online units, automatic restart after a

power interruption is desirable, particularly for remotely operated devices. Continuous, predictable,

year-round functioning is a top priority for EWSs.

3.1.10 Third Party Verification

Third-party verification evaluation is desired to determine if specific devices and methods perform

as they are intended and advertised. EPA’s ETV Program and TTEP provide third-party verification

evaluation reports for several products related to EWSs. Another organization that provides third

party verification is the AOAC International, whose mission statement is to serve “the communities 18

of analytical sciences by providing the tools and processes necessary for community stakeholders

to collaborate and, through consensus building, develop fit-for-purpose methods and services for

assuring quality measurements.”

3.2 Design Features of Integrated Early Warning Systems

The design of an integrated EWS requires a conceptual framework of all its component parts.

Exhibit 3-2 outlines the component features of an integrated EWS. An integrated EWS is more than

just selecting sensors. It includes determining sensor locations, acquiring data, conducting data

analysis, developing communication and notification links, establishing decision making procedures,

and developing response protocols. Although public health surveillance, monitoring, consumer

complaints, and consequence management are features of a more broadly defined contamination

warning system (see Appendix A), this study focuses more on the use of contaminant

sensors/detectors and the associated data and communication networks in the drinking water

distribution system.

When considering an integrated EWS, especially for a distribution system, a utility should go

through a structured decision making process. Exhibit 3-3 presents a conceptual process for
U.S. EPA Office of Water Early Warning Systems

August 2005 26

designing an EWS. The utility should (1) determine the need for an EWS, (2) conduct the proper

and necessary planning and coordination, (3) prepare the overall EWS approach, and (4) develop

the details of the EWS design. These steps are described in more detail below. Much of this

information on the EWS design process has been reviewed by Hasan and colleagues in Water

Resources Update (Hasan et al., 2004). In a related effort called the WaterSentinel Initiative (see

Appendix A), EPA is designing a contamination warning system. Furthermore, EPA, in partnership

with drinking water stakeholders, is developing a concept of operations which will be further

designed and piloted for deployment by select water utilities.
U.S. EPA Office of Water Early Warning Systems

August 2005 27

Contamination

Monitoring

Sensors, grab samples,placements models

Secure Data

Transmission

Direct wire, phone line,radio, satellite

Data Acquisition,

Validation, Storage,

and Analysis

SCADA, alarmmanagement, flowmodels, geographicinformation systemssoftware, smart systems

Decision Makers,

Notification, and

Response

Decision software, EPA

Response Toolbox,

confirmation testing,

emergency response,

communication

Exhibit 3-2. Design Features of an Integrated Early Warning System
U.S. EPA Office of Water Early Warning Systems

August 2005 28

Exhibit 3-3. Conceptual Process for Designing an Early Warning System

Evaluate Need for EWS

• Determine Vulnerability/Threat (Contaminant List)

• Consider EWS and Possible Alternatives and Backups

Establish EWS Plan

• Obtain Management Commitment and Establish Teams

• Define Objectives and Performance of EWS Plan

• Examine Distribution System and Vulnerabilities

Determine Overall Approach to EWS Design

Develop Detailed Design of EWS

• Select EWS Detection Technology

• Determine Alarm Levels

• Conduct Studies on Fate and Transport of Pathogens and

Chemicals

• Determine Sensor Location and Density

• Select Systems for Data Management, Interpretation, and

Reduction

• Establish Response Communication Links, Notification, and

Decision Making

3.2.1 Evaluate the Need for an Integrated EWS

In evaluating the need for an integrated EWS, the utility should perform or revisit its vulnerability

assessment, especially with regard to the distribution system’s vulnerability to intentional

contamination events. The vulnerability assessment should consider the threat of such an event, the

consequences of an event, and the status of the facility to prevent, identify, and respond to such an

event. Additionally, the utility should characterize the distribution system to determine if there is

a reasonable way for the utility to provide early warning to protect users. The utility’s size, usage

patterns, and vulnerability should be factors. The utility should also weigh the cost-benefits of

integrating customer complaint monitoring and public health surveillance with contaminant

sensors/detectors and the associated data and communication networks. The utility should consider
U.S. EPA Office of Water Early Warning Systems

August 2005 29

the cost and reliability of current EWS technologies. Although the protection of public health is the

primary goal of an EWS, public perception of the effectiveness of the warning system should also

be considered. Not only must the public actually be protected, the majority of the public should be

made to feel protected to the extent possible. In this regard, utilities should consider the appropriate

level of information to be released to the public. Although the level of information should be enough

to allow confidence in the EWS and deter attacks, it should not compromise the effectiveness of the

EWS. Utilities may choose to include additional design features that address the concerns of their

customers.

The size of the water utility could greatly influence the appropriate design for an EWS. Large,

medium, and small water utilities have significant differences that should be considered. For

example, the number and strategic placement of sensors in a finished water system will depend on

the size of the utility including the miles of pipeline in the distribution system, the populations

served, and the flow dynamics. The types of contamination threats may also differ from large to

medium to small systems so the EWS design should also reflect these differences. In addition, water

utilities of differing size will have vastly different budgets to spend on integrated EWSs. For

example, small or medium systems may need to rely mostly on lower cost screening techniques in

conjunction with some water quality monitors and customer complaint data rather than investing in

expensive online systems or confirmatory kits. Small systems may not have the more sophisticated

data collection and analysis systems such as SCADA. Thus, other EWS designs may be needed with

less automated or even manual data collection/analysis techniques.

3.2.2 Establish EWS Plan and Coordination

A decision to develop an EWS capability requires a commitment from management. The planning

for an EWS usually requires the utility to assemble a team, which may include personnel from the

water utility, the local and state health department, emergency response units, law enforcement

agencies, and local political leadership. An EWS plan should be developed that outlines the

objectives for the EWS which should be clearly defined. The plan should also include how the

monitoring results or data will be interpreted, used, and reported. The plan can set performance

criteria and some essential design elements. The team should consider legal and regulatory issues

and the plan should define a budget and time line for the project. Note that the planning and

coordination for an EWS for finished water may be a separate, but linked, effort with an EWS for

source water contamination.

In developing the plan, the team should characterize the distribution system to be monitored. For

example, a distribution system should be characterized in terms of flow, pressure, access points,

water demand and usage patterns, extent of pipeline, and the locations of pipeline and pump stations.

A hydraulic model may be useful in this characterization.

Additionally, the team should specifically examine the vulnerability of the distribution system to

intentional contamination. Previously conducted vulnerability assessments, required by the

Bioterrorism Act, can be extremely helpful in evaluating aspects of physical security. An expanded

vulnerability assessment can help identify the contamination scenarios that could occur (e.g., pump

to overcome pipe pressure), as well as the insertion location and method (e.g., dump over a short

period; bleed, pump, or dissolving matrix over longer times). The duration of a contamination event

is an important parameter for an EWS. Hydraulic modeling may be useful in identifying those
U.S. EPA Office of Water Early Warning Systems

August 2005 30

portions of the distribution system that, if compromised, would have the most time-sensitive

consequences. The vulnerability assessment should also help to identify target contaminants.

System vulnerabilities and the ability of existing treatment barriers to remove or neutralize specific

contaminants should be considered in choosing the contaminants of concern. The list could include

groups of contaminants that cover a broad range of specific contaminants. Lists of contaminants are

available from various agencies, including EPA. This step is important because different

components of the EWS may be chosen to detect toxic, microbial, or radiological contaminants.

During planning for an EWS, there should be a discussion of system maintenance requirements,

housekeeping, system administration issues, human resource requirements including security and

training, exercising the system and its human participants, and upgrading the system when improved

technology is available.

3.2.3 Determine Overall Approach to EWS Design

There are many ways to approach development of an effective EWS design. While real-time

continuous monitoring may be the ultimate long-term goal, there may be intermediate EWS

architectures that would be more effective until real-time monitors are available. Under the

proposed Fiscal Year 2006 budget, EPA will launch WaterSentinel, a proposed demonstration

project by which EPA, in partnership with select utilities and laboratories, would design, deploy,

and evaluate a model contamination warning system for drinking water security. EPA and its

partners will thus gain operational and tactical experience that can assist in developing standardized

and cost-effective approaches to coordinated surveillance and monitoring of drinking water. Until

this program is implemented and lessons learned however, a few possible approaches to EWS design

and some brief discussion on their capabilities and limitations are provided below.

• Some experts in the field of EWS design for drinking water distribution systems advocate a

“tiered” approach with two stages. The first stage uses continuous real-time sensors that can

provide a generic warning or trigger an alarm that a contaminant is in the water. Initial detection

could occur within seconds, if first-stage monitoring is effective and located properly. This

would trigger a second stage using more specific and sensitive technology to confirm and

identify the contaminant (ILSI, 1999; Hasan et al., 2004). A second-stage technology might

either be located in the field or be brought to the site as a field portable unit. Analysis could take

minutes or hours depending on the method of detection and the location in the distribution

system. This tiered approach addresses the current situation where limited or no technology

exists that allows for affordable, online, real-time monitoring, and identification of hundreds of

specific contaminants. The first screening stage alone of a monitoring system does not constitute

an EWS. Thus, confirmatory analyses used to verify a positive result from a screening analysis

should be integrated into the overall design of the EWS. A more complete discussion of a firststage/second-stage approach to an EWS is provided in Exhibit 3-4. Other experts are concerned

about the possibility of obtaining many false-positives for certain first-stage technologies that

could be sensitive to normal fluctuations in water quality (Wayne Einfeld, Sandia National

Laboratory, personal communication).
U.S. EPA Office of Water Early Warning Systems

August 2005 31

Exhibit 3-4. Sample EWS Approach using First-Stage and Second-Stage Monitors

First-Stage Monitoring

A system that continuously monitors for general water quality parameters (e.g., turbidity,

temperature, pH, ORP, conductivity) in the distribution system has the potential of providing firststage monitoring for contamination events (intentional or accidental). Some, but not all,

contamination events can cause detectable changes in water quality parameters that are sufficient

level to provide an alarm. An intentional contamination event could even create changes in water

quality parameters that present a more specific fingerprint/signature indicating a possible group

of contaminants. In the laboratory, using confined distribution systems, online water quality

monitoring, and controlled spiking of known contaminants and contaminant cocktails, data are

being produced on how water quality parameters respond during contaminant influx. However,

an important concern is that baseline fluctuations in water quality parameters would need to be

determined before an anomaly in readings could be identified. This concern is the subject of

current research by EPA and other agencies. Some patterns in fluctuations may be associated

with storm events or certain operational conditions. It is likely that considerable experience with

daily, seasonal, and event-related fluctuations will be required for a specific finished water

distribution system before the monitoring system can be maximally useful for detecting

contamination events. Thus, false-positives are a large concern of utilities. Chapter 5 reviews

the specific technologies and research projects that are involved in developing first-stage

monitoring capabilities. Note that first-stage monitoring is not limited to traditional water quality

parameters; it could in the future also include biologically-based monitors.

Second-Stage Detection Confirmation

After routine first-stage monitoring has “raised a red flag,” second-stage confirmation can be used

to verify detection and/or characterize specific contaminants. Second-stage confirmation differs

from first-stage monitoring in that second-stage technologies are not as amenable to high

throughput continuous sampling. For first-stage monitoring, speed is measured in seconds, while

for second-stage confirmation speed is more appropriately measured in minutes (~10 to 120

minutes). Because second-stage confirmation is often not in continuous operation, set-up time

(solution mixing, equipment warm-up), sample capture time (time to obtain an appropriate sample

to be tested), and assay and analysis time should all be included in the estimate for how much

time it will take from the initial “red flag” until second-stage confirmation is complete. The

information gained from second-stage confirmation is more specific and should assist in choosing

between more targeted response options. Rapid identification of the specific contaminant may

also help mitigate adverse health outcomes for potentially exposed populations.

Note: “Stage” refers to levels of detection within the same EWS. It does not refer to near-term

EWS design and long-term EWS design goals.
U.S. EPA Office of Water Early Warning Systems

August 2005 32

• Another approach, perhaps an intermediate EWS design, is to (1) use multiple water quality

monitors to provide a red flag for contaminants, (2) perform frequent grab sample analysis by

rapid contaminant-specific monitors (e.g., arsenic/cyanide), and (3) take automated weekly

samples of water that can be analyzed for a suite of contaminants. The water samples could be

screened by field methods or analyzed with laboratory instruments, which are more developed

than online contaminant detectors. This approach has the advantage of monitoring for generic

warnings while using some established technology that is now available (e.g., chemical monitors

for continuous monitoring, automatic samplers, and established microbial tests). The approach

provides some intermediate level of EWS monitoring.

• Another more advanced EWS design is to use multi-parameter water quality monitors and

routine composite/grab sampling in conjunction with data collected from customer complaints

and public health surveillance as triggers for confirmatory testing. This design provides a

mechanism to identify potentially large scale events that are in the process of occurring.

Regardless of the approach, a properly designed EWS should include all other elements of a

monitoring program necessary to inform decision officials responsible for public health protection.

An EWS can be designed to be part of an overall water safety and security program for the utility.

In addition to providing warning for intentional contamination, the EWS fills a dual role of

providing water safety through routine and compliance monitoring. Other information sources such

as customer complaints could be indicative of intentional as well as accidental contamination events.

Utilities may want to consult with other utilities with additional experience, as well as keep informed

on the latest research development and test results. Such discussions need to be part of the overall

approach to EWS design.

3.2.4 Develop Detailed Design of an Integrated Early Warning System

This step is really a series of interrelated substeps, because the information from one may affect the

other. For example, a decision about which EWS detection technology to choose may depend on

the location and number of units to purchase. Whereas the alarm levels chosen may influence the

selection of EWS technology (i.e., make and model). Thus, all of these substeps will be discussed

together.

• Select EWS Detector Technology 

Once target contaminants for the EWS have been identified, and the range of concentration

necessary to detect them has been established, it is necessary to select a monitoring technology for

the particular contaminant or class of contaminants. This assumes that a monitoring technology that

meets the core requirements of an EWS currently exists. Furthermore, the monitoring technology

should be capable of dealing with complex water matrices. This may require an extraction step to

remove the material from the water matrix and/or a concentration step to enhance detection and

quantification. Although techniques for isolating, concentrating, and purifying microbial and

chemical substances have been developed for many laboratory methods, they may not necessarily

be transferable to field deployable monitoring devices. The technology considered for use in an

EWS should be evaluated to ensure that all steps of the methodology perform correctly and can

detect the target contaminant(s) without excessive interference. Identifying a field-deployable

technology with an acceptable methodology is only the first step. Performance of the monitoring
U.S. EPA Office of Water Early Warning Systems

August 2005 33

technology must also be adequate to meet the data quality objectives of the monitoring program.

These data quality objectives should be defined during the design of the EWS and include

specificity, sensitivity, accuracy, precision, and recovery, as well as rates of false-positives and

negatives. If the monitoring technology cannot meet the data quality objectives, then another

technology should be selected. If no technology can be identified that meets the objectives, then

either the EWS should not be implemented, or the data quality objectives will need to be revised.

If the later approach is taken, it will be necessary to modify the manner in which the results are used

to be consistent with revised data quality objectives. There are a great variety of EWS detection

technologies available (see Chapters 6 and 7). Certain technologies can be used online and provide

more real-time capability.

• Determine Alarm Levels

The basis for setting alarm levels will depend on the previously determined levels at which

contaminants need to be detected (based on human health risks) and on the type of EWS employed.

The response that is initiated by an alarm must be established before the EWS is deployed.

Automated systems with online monitoring especially should have alert capabilities. Operators

should be able to set threshold values so the system automatically triggers an alarm if readings move

outside of the range that has been defined as safe. Performance optimization of the system should

allow for alarm trigger rates that minimize false alarms, but still detect contamination events that

could pose a health risk. If a false alarm leads to a decision to issue a notice to the public to stop

using the water, public health as well as public confidence could be impacted. 

• Conduct Studies on Fate and Transport Modeling of Pathogens and Chemicals

Chemical and microbial contaminants can behave in a variety of ways as they migrate through a

water system. Environmental conditions, the presence of oxidants or other treatment chemicals, and

the hydraulic characteristics of the system will affect the concentration and characteristics of these

contaminants. If information is available on contaminant characteristics that affect the

contaminants’ fate and transport, it should be factored into the design of an EWS. For example, if

a target contaminant is known to chemically degrade at a certain rate in the presence of free chlorine,

it may be possible to use a hydraulic/chemical model of the distribution system to predict the

concentration profile through the system. This information in turn can be used to select optimal

locations for sensors. 

• Determine Sensor Location and Density

Choosing the location or site of sensor placement within a distribution system is a complex task.

The location and density of sensors in an EWS is dictated by the results of the system

characterization, vulnerability/threat assessment, usage considerations, risk minimization, and cost.

Thus, the easiest site to place a sensor may not be a site that yields the most useful information. The

size of the population downstream from the sensor may be a defensible criterion for choosing a site,

but might not be the best site for system modeling. Due to the complexity and dynamic nature of

distribution systems, it may be beneficial to develop a hydraulic model of the system to assist in the

placement of sensors. Real-time integrated pressure and flow data can be used to build flow models

that have well characterized predictive capabilities. Other factors to determine sensor location could

be location of isolation valves, location of critical nodes (hospitals, emergency response), and
U.S. EPA Office of Water Early Warning Systems

August 2005 34

physical security of the location. 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 and remediation actions.

• Select Systems for 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. This will require that individual sensors deployed in the system be equipped with

transmitters, modems, direct wire, or some other means to communicate the data to the acquisition

and management systems. Furthermore, the data management system should be capable of

performing some level of data analysis and trending in order to assess whether an alarm level has

been exceeded. The use of “smart” systems that evaluate trends and can distinguish between

genuine excursions and noise could minimize the rate of false alarms. A decision will also have to

be made regarding the action that is taken when the data management system detects an excursion

above the alarm level. At a minimum, the system should notify operators, public health agencies,

and/or emergency response officials. If possible, redundant communication should be used (e.g.,

notifying multiple individuals through multiple routes such as telephone and fax). 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 response decision makers should make

decisions regarding decisive response actions. Integrated analysis of the data gathered on many

different parameters and contaminant detectors is what makes an integrated EWS more than a

collection of detection technologies and assays. Data validation helps ensure the integrity of data

by requiring that appropriate quality assurance and quality control (QA/QC) procedures are

followed, and that adequate documentation is included for all data generated. Data validation

guidance may be different for different types of data and the stringency depends on the planned

utilization of the data. Data security is also an essential part of the integrity of the system. It is

important during the transmission of data and during the analysis and storage of information. For

obvious reasons, it is important that data being transmitted from a remote sensor to a command

center be free from tampering or accidental degradation. Because previously obtained data are

accessed by the system to look for patterns, it is also important that old data be free from tampering

or accidental degradation.

• Establish Response Communication Links, Notification, and Decision Making 

An integrated EWS would also include network and communication links between command center

operators and any people designated as response decision makers. The communications network

should assist with the rapid relay of critical information to the utility decision makers who

implement the response. The response may include the utility informing outside parties, such as

public health officials, police force, or other emergency responders. Utilities can refer to local

ordinances and laws to determine when they are required to inform outside parties. In general,

threats should be deemed credible before other agencies are alerted. Many responses are possible

when an early warning monitoring system triggers an alarm. Monitoring devices may report data

to a command center that will relay information to utility decision makers. In turn, the response may

use the same secure communications links to take actions in the distribution system (e.g., shut
U.S. EPA Office of Water Early Warning Systems

August 2005 35

isolation valves). Further actions may include monitoring and sampling for the contaminant at

appropriate locations in the distribution system and monitoring for surrogate parameters that may

indicate contamination (e.g., increased chlorine demand, changes in pH). The EPA Response

Protocol Toolbox (EPA, 2003/2004) greatly assists with planning this part of the response.

After developing this comprehensive strategy for an integrated EWS, the utility is ready to develop

an implementation strategy that includes buying and installing the equipment; providing

maintenance and operation procedures; and providing training, testing, and exercises for systems

and personnel.
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 37

4. Features of an EWS Related to Data Acquisition and Analysis; Contaminant

Flow; Sensor Placement; Alerts; Data Security; and Communication,

Response, and Decision Making

The purpose of this chapter is to characterize the state-of-the-art features of EWSs that are not

related to sensors. These EWS features include real-time data acquisition and analysis; contaminant

flow predictive systems; sensor placement; alert management; security enforcement; and

communication, response, and decision making. These features of EWS design and operation should

be part of an overall plan for the interpretation, use, and reporting of monitoring results (Hasan et

al., 2004).

4.1 Real-Time Data Acquisition and Data Analysis

4.1.1 Basics

Continuous, real-time water quality monitoring systems for an EWS have the potential to generate

large amounts of raw data, which can be unmanageable without the use of a data acquisition and

management system. Water utilities are already familiar with collecting information on water

quality and operating their drinking water treatment plant and distribution systems. Over 75 percent

of drinking water utilities already operate online analyzers for water quality parameters such as

chlorine and turbidity. However, not all of these utilities have monitors within the distribution

system. The 75 percent figure includes utilities that have monitors only at the drinking water

treatment plant (AwwaRF, 2002). Utilities often use the supervisory control and data acquisition

system known as SCADA. A SCADA system links monitoring instruments, remote telemetry units,

programmable logic controllers, and a host computer in order to integrate data collection and

processing into a single system-wide control center that can be accessed from various locations

(Carlson et al., 2004). Large utilities usually use a SCADA system for controls in the distribution

system. Such a SCADA system can often incorporate data from online or remote sensors in a cost

effective manner (Mays, 2004). The system triggers the collection of data. Remote locations could

use microprocessor-based “smart” SCADA systems. Although slower and more expensive than

programmable logic controller-based systems, the “smart” SCADA systems save on communication

media costs, maintenance, and travel. The simplest SCADA systems only include three or four

input/output channels for monitoring (Mays, 2004). SCADA systems that are already in operation

for daily water quality monitoring purposes may not be configured so that they can serve all the

locations where EWS detectors are needed (see Section 4.3 for discussion of sensor placement).

Various approaches taken and systems used for data transmission, validation, and analysis are

described below.

• Data Transmission

Data transmission to the central database occurs through either hardwired or wireless systems.

Hardwired transmission requires the physical connection of cable or wire, and can utilize either

coaxial or fiber optic technology. In some cases it may be difficult to hardwire remote locations.

Wireless transmission can use a variety of methods, including microwave, UHF or VHF radio, basic

telephone modems, cellular telephone modems, or satellite. Wireless transmission may require a

direct line of sight between the transmitter and receiver, or the use of re-transmitters (also known

as repeaters and amplifiers) (AWWA Workshop, 2004). The least expensive transmission systems
U.S. EPA Office of Water Early Warning Systems

August 2005 38

are typically phone lines or direct wire. A combination of data transmission approaches could be

used throughout the distribution system, as long as the command center can achieve integration of

the information. The data transmission method must be compatible with monitoring equipment and

data acquisition equipment. In most cases, utilities would be expanding monitoring capabilities by

adding to existing equipment and the existing SCADA system so newer upgrades need to be

compatible with existing equipment and SCADA (AWWA Workshop, 2004). For water security

applications, the existing monitoring system would need to be evaluated for its vulnerability to direct

physical attack (e.g., wire cutting), and to cyber attack (e.g., tapping). Transmission of unencrypted

data is a security risk, so hardware and software should have encryption capabilities. Traditionally,

utilities have not seen a need to encrypt data from water quality monitors, however monitoring for

security applications would require data encryption to reduce vulnerability.

The quantity of data that needs to be transmitted should be considered. Factors that influence data

quantity are the number of instruments in the system, the number of data points each instrument

generates in a given time frame (e.g., sampling rate of 1/second or 1/minute or 1/hour), and bits per

sample. Some monitoring equipment may generate a relatively manageable quantity of data,

whereas some equipment (e.g., video) may generate data that require considerably more

transmission capability.

Currently, data transmission capacity, computer data storage capacity, and software support are

adequate for online monitoring of contaminants. The water industry is not generally considered a

large market force; thus, similarly developed systems in other markets may push development of

technology for the water industry. For example, SCADA systems based on analog signals require

special drivers to accept data from monitors (e.g., particle counters) with digital signals. Products

for conversion between analog and digital formats are commercially available. Expected future

developments will probably alleviate this concern (AwwaRF, 2002).

• Data Verification

Manual verification of sensor data will not usually be an option with a continuous, real-time

monitoring system due to the large amount of raw data collected. Therefore, automated data

validation processes are indispensable to ensure accurate results from data analysis. A simple yet

effective protocol is to compare data received from monitoring sites with data stored at the sensor

locations to ensure accuracy and completeness (Carlson et al., 2004). Traditional SCADA systems

perform data validation processes such as range checking and data filtering (e.g., moving window

averaging). Other approaches under development for data validation are simple outlier detection

by commercial off-the-shelf data mining software and finding formal correlations among spatial and

temporal data attributes (e.g., pH, temperature, DO, specific conductivity, turbidity, chlorophyll)

(Mays, 2004). Data verification is part of an overall quality assurance plan which is a systematic

procedure for determining that all aspects of the EWS are functioning as expected.

• Data Analysis

Once obtained, the data may go through quality assessment and validation, aggregation,

transformation, and analysis (AwwaRF, 2002). Data analysis is performed by specialized software

and can take the form of univariate and multivariate analysis, Rule-Based Systems (RBS), or

Case-Based Systems (CBSs). Univariate analysis targets one parameter at a time, in order to note
U.S. EPA Office of Water Early Warning Systems

August 2005 39

changes in a specific parameter or instrument response in the event of a change in water quality.

This separate monitoring of instrument response is useful in determining instrument sensitivity to

different contaminants, and in confirming the validity of other similar instrument responses when

considering potential false alarms (Carlson et al., 2004). Multivariate analysis uses inputs from all

instruments simultaneously to detect data anomalies. The benefits of multivariate analysis are the

potential to detect contamination events sooner and the means to learn more about the type of

contaminant that generated the alarm. RBSs are characterized by IF-THEN rules, which provide

real-time reasoning by looping through rules and polling for new data on a programmed schedule.

CBSs operate by comparing a collection of current measurements to a database of historical

measurements. Any deviations of the current state from past data will notify the operator, who can

run a predictive WHAT-IF model to evaluate scenarios (Carlson et al., 2004). The development of

logic systems (e.g., artificial neural networks and fuzzy logic) to interpret the data that are produced

by an EWS may be an integral part of some EWS designs. As more and more information is

collected by an array of instrumentation, there must be a dependable system developed to interpret

all the data produced. One example of such a project was published by IHT Delft, entitled Use of

Artificial Neural Networks and Fuzzy Logic for Integrated Water Management: Review of

Applications.

19

When online instruments provide a stream of data from which the utility will need to manage and

potentially use for response decisions, the data quality has to be handled and analyzed carefully

(AwwaRF, 2002). The utility should consider the performance characteristics of the instrument, so

that the proper degree of validity of the online measurements can be determined. Online data

aggregation and the handling of those data should be considered so that large amounts of data can

be processed effectively.

For online data, a predictable percentage of the data will be dropped or lost, particularly for remote

sites. For these cases some methods for data validation include gap filling, range checking (when

data out of range, check along full working range of sensor), rate of change check (peaks/outliers

usually a result of disturbance of the sensor), and variance check (check small variations in

repeatability). Cross validation methods explore the connection between online measurements. This

is particularly valuable for detectors with multi-parameters. Highly correlated parameter measures

can be programmed into a model and used for determining confidence in measures. 

An EWS may generate real-time data for quick analysis and decisions and action. There are various

techniques for assisting in real-time reporting and decision support. They include data filtering,

operational indexes (commonly used by operators to calculate measures that represent trends for

routine operational performance), short-term prediction using software sensors, and classification

and state description to reduce information overload. Predictive modeling can also be used for

assisting with data validation (AwwaRF, 2002).

Short-term and long-term data storage and backup needs also must be assessed. For some

parameters, baseline characterization may require a full year’s worth of data. Data storage needs

will depend on how the utility wishes to use the data. The monitors discussed in Chapter 5

potentially serve the dual purpose of general water quality monitoring for operations and of red flag

alert for potential security threats. Although data analysis for the purpose of determining immediate

security threats may not require long-term storage of data, there may be other secondary uses for the

data that would warrant longer term storage. For example, older data could be released to the
U.S. EPA Office of Water Early Warning Systems

August 2005 40

utility’s systems modeling contractors or to the research community to answer future research

questions. A standard minimum storage of data for at least several years is not unreasonable to

expect. Utilities should consider developing a policy that maximizes the usefulness of the gathered

data, while also addressing the concerns of their legal counsel, and the budgetary constraints of data

storage and access.

4.1.2 Demonstration Projects, Tests, and Products

EPA recently conducted a project to evaluate and demonstrate the usefulness of SCADA systems

for real-time monitoring of water sensors within distribution systems (EPA, 2004). The test was

conducted at the WATERS Center in Cincinnati, OH. Within the WATERS Center, there are two

DSSs, which were designed and fabricated to evaluate and interpret the dynamics that influence

water quality within water distribution infrastructure systems typical in the U.S. and abroad. EPA 20

concluded that a SCADA system is a critical feature for handling the data from online sensors in the

distribution system. Analyzing the data from multiple sensors is too difficult and time-consuming

without a centralized SCADA. If the data were collected separately from different sensors, the data

would have to be downloaded, processed with a computer, and analyzed. This would not provide

an effective real-time alert.

A centralized SCADA system also provides a time-stamp on the measurement for comparative

analyses. The EPA report also addressed the frequency of sampling for multi-parameter water

quality monitors. The EPA report suggested a frequency of between 2 and 10 minutes depending

on the ability of the SCADA system to take the data (based on SCADA system setup and

bandwidth), the location of the sensor, and the water flow rate. This sampling frequency would also

help utilities to establish trends in water fluctuations so as to reduce false alarms. Also, during the

test, a number of problems occurred in processing 4 to 20 milliampere signals through the SCADA

system so the report recommends purchasing monitors with the option of RS232 outputs, as these

are not subject to ground loop problems and other electrical interferences. Further challenges that

were identified are the need for regular maintenance and calibration schedules for the sensors and

that operator experience and expertise with the sensors and SCADA system are essential. It is

important to note that there are technologies other than SCADA that are available for combining and

integrating data.

Remote monitoring has applications to an EWS for finished water. An operation can monitor the

water quality on line for intentional contamination. A demonstration project conducted by EPA a

few years ago examined remote monitoring of drinking water treatment. The remote monitoring

system consisted of the sampling units and an associated data acquisition unit. The SCADA units

were programmed to monitor, record, and control water treatment and distribution system operation

in three locations: Washington, DC; McDowell County, WV, and a distribution system simulator

(DSS-1) at EPA’s T&E Facility in Cincinnati. In Washington DC, online instruments measured

temperature, turbidity, pH, and residual chlorine at locations within the distribution system. In West

Virginia, EPA collaborated with the McDowell County Public Services Division to implement a

smart SCADA in 1998. The smart SCADA unit observed trends in pressure, chlorine, turbidity, and

flow at 15 minute intervals. The system also was programmed to provide an alert if certain

conditions were met. The project showed that remote monitoring can be a practical option for small

rural utilities (AwwaRF, 2002). Details on EPA’s research in Cincinnati on online instruments are

discussed in Sections 5.2 and 5.3.
U.S. EPA Office of Water Early Warning Systems

August 2005 41

There are several commercial products currently available on the market to help acquire and manage

sensor data remotely to improve water security. One company, PDA Security Solutions (Greer, SC),

is marketing the Hydra Remote Monitoring System. It captures data from sensing devices located

remotely throughout the water distribution system. It includes trend analysis tools, and it

continuously compares real-time water quality data against benchmark water profiles. Alarms are

programmed to alert operations and security personnel. Biometric login and data encryption are part

of the system. EPA has a Cooperative Research and Development Agreement (CRADA) with PDA

to develop a nationwide water quality surveillance project. Under the Federal Technology Transfer

Act, EPA can form CRADAs with the private sector in order to speed the development of

technologies for various programs. Currently, EPA’s NHSRC and NRMRL are developing

CRADAs for the development of technologies specifically to accomplish the nation’s homeland

security initiatives.21

During the 2002 Olympic Games in Salt Lake City, UT, the Hach Company (Loveland, CO)

demonstrated the remote transmission of data from a dozen continuously monitoring sensor

platforms in the distribution system. The data were transmitted through unbroken cellular telephone

data transfer or directly to the SCADA system. The data were monitored around the clock with

provisions for triggering alarms.22

An emerging technology project in Copenhagen, Denmark is integrating information from existing

data sources for a water distribution network in a utility. In the pilot project, the data from real-time

sensors are provided to a SCADA system. The sensor information is stored in a database allowing

for analysis. Automated checks of the system compare against baseline measurement. Data are

validated with standard modules that will flag potentially suspect or corrupt data. The project began

in 2001 and is expected to be completed somtime in 2005.

One commercial vendor, PureSense Environmental Inc. (Moffet Field, CA), has a PureSense System

which covers the full spectrum from data acquisition to alert and notification. The system includes

four components. The PureSense iNodeTM is a remote data communication device that uses cellular

and Wi-Fi services to collect monitoring data and send commands to remote sensors. The PureSense

iWatchTM is an internet data management system that enables the integration of disparate data sets,

including data from remote online sensors. The PureSense iServeTM allows automated analysis of

real-time data, while PureSense AlertNetTM provides automated alerts. EPA had entered into a

CRADA with PureSense Environmental to test the system.

4.2 Contaminant Flow Predictive Systems

From the beginning of the planning phase, an EWS for water distribution systems should develop

the capability to predict the movement of flow and contaminants in the system. This predictive

ability is important not only to prepare for a potential contamination event, but also to determine the

effectiveness of the monitoring system.

Contaminant flow predictive systems are used to predict how a contaminant would move through

the distribution system. Such systems are built upon hydraulic and water quality modeling

technology known as water distribution system models that are now in wide use within the water

industry. This capability could be applied to accidental contamination events (e.g., backflow,

cross-connections) or intentional contamination.
U.S. EPA Office of Water Early Warning Systems

August 2005 42

Hydraulic modeling dates back to the 1930s when Professor Hardy Cross of the University of

Illinois developed an iterative procedure for predicting flow and head within a distribution system

(Cross, 1936). This manual procedure was used throughout the water industry for almost 40 years.

With the advent of computers, computer-based models using the Hardy Cross methodology and

improved solution methods were developed and were in widespread use by the 1980s. These models

have become ubiquitous within the water industry and are an integral part of most water system

design, master planning, and fire flow analyses. In the 1980s and 1990s, hydraulic analysis was

extended to include the ability to model water quality, water age, and source tracing in distribution

systems. The usability of these models was greatly improved in the 1990s with the introduction of

the public domain EPANET model (Rossman, 2000) and other Windows-based commercial water

distribution system models (ASCE, 2004). Exhibit 4-1 provides examples of current water

distribution system modeling software.

In order to apply a hydraulic/water quality model to reliably predict the movement of a contaminant

in the distribution system, a calibrated, extended-period simulation (EPS) model is needed. An EPS

model represents the normal temporal variation in demands and operation. Such a model can be

used for planning purposes as part of vulnerability studies and emergency response plans, and as a

real-time tool during an actual contamination event. Another challenge is the effort to incorporate

pipe networks into the modeling framework, although geographic information systems (GIS) are

assisting utilities with this effort

Exhibit 4-1. Examples of Water Distribution System Modeling Software

Network Modeling

Software

Company URL

AQUIS Seven Technologies http://www.7t.dk/company/default.asp

EPANET U. S. EPA http://www.epa.gov/ORD/NRMRL/

wswrd/epanet.html

InfoWater/H2ONET/H2OMAP MWHSoft http://www.mwhsoft.com

InfoWorks WS Wallingford Software http://www.wallingfordsoftware.com/

MikeNet DHI, Boss International http://www.dhisoftware.com/mikenet/

Pipe2000 University of Kentucky http://www.kypipe.com/

PipelineNet SAIC, TSWG http://www.tswg.gov/tswg/ip/Pipeline

NetTB.htm

SynerGEE Water Advantica http://www.advantica.biz/

WaterCAD/WaterGEMS Haestad Methods http://www.haestad.com

4.2.1 State-of-the-Art Systems and Current Research and Development

Distribution system modeling in general and contaminant flow predictive systems in particular are

developing rapidly. Work is being sponsored by governmental agencies, professional organizations

such as ASCE and AwwaRF, and private companies. Predictive modeling is more extensively

integrated into European utilities than U.S. utilities. The state-of-the-art in contaminant flow

predictive models and some current active areas of research include the following:
U.S. EPA Office of Water Early Warning Systems

August 2005 43

• Integration of models with GIS and computer-aided drafting (CAD) software packages has been

and continues to be an active area of research and development. GIS and CAD were initially

used to help build water distribution system models. Present research and development is

directed towards complete integration of distribution system models into the GIS or CAD

platform in order to facilitate modeling, display, and assessment. PipelineNet, an integration of

EPANET and ArcView GIS, and commercial integration packages such as WaterGEMS and

InfoWater provide direct capabilities to assess impacts of contamination events. Additional

efforts by EPA are to expand EPANET to account for multiple interacting species and to better

involve hydrologists and biologists (DSRC Meeting, 2004).

• Calibration of a model involves adjustments in model parameters so that the model reflects

observed field behavior. Optimization techniques for calibrating hydraulic models based on

genetic algorithms and other mathematical methods have recently become part of many

commercial models (Walski et al., 2003). Continued research in this area is underway to expand

the use of these tools to extended period simulation calibration and calibration of water quality

parameters. Another area of development in the calibration field is the use of tracer studies in

distribution systems. A conservative tracer substance such as sodium chloride is injected into

the distribution system and monitored using online conductivity meters. The resulting dataset

can be used to calibrate and validate hydraulic models. Although there are currently no

established calibration criteria in the U.S., static and dynamic calibration methods exist (EPA,

2005). Also, a committee of the AWWA did propose a set of possible calibration guidelines

(ECAC, 1999). These guidelines have not been officially accepted however, there is no active

process underway to adopt them. Using these possible calibration guidelines as a catalyst or

starting point, it would be recommended to move forward on developing accepted calibration

guidelines or standards.

• Existing modeling software is being applied and advanced modeling-based tools are currently

under development to assist in evaluating the vulnerability of a distribution system to

contaminant events. Carlson et al. (2004) demonstrated the use of existing hydraulic models by

creating three case studies of the movement of a contaminant through a distribution system. The

capabilities of PipelineNet have been demonstrated through a series of applications in actual

distribution systems (Bahadur et al., 2003a). It has been applied as a modeling tool for use in

emergency response to contamination of a distribution system. TEVA, a probabilistic

distribution system simulation model, is being developed by EPA to evaluate both vulnerability

and sensor placement in distribution systems (Murray et al., 2004). Van Bloemen Waanders et

al. (2003) have developed a nonlinear programming method for tracing an observed

contamination event in a distribution system back to where it was introduced.

• Recent studies have recognized that there are both uncertainty and variability associated with

distribution system modeling. Application of such models in a purely deterministic framework

where all parameters are assumed to be known with certainty does not provide the information

needed for decision making. Baxter and Lence (2003) present a general framework for the

analysis of performance risk in a water supply. Kretzmann and van Zyl (2004) incorporated

uncertainty through a stochastic analysis of water distribution systems. Grayman et al. (2004b)

used Monte Carlo simulation in estimating contaminant exposures while reconstructing an

unintentional contamination event. The aforementioned TEVA system incorporates a

probabilistic framework for a large range of contamination senarios. 
U.S. EPA Office of Water Early Warning Systems

August 2005 44

• Consumption (demand) is an important factor in affecting movement of water and contaminants

in a distribution system. Typically, monthly or quarterly meter readings and approximate diurnal

water use patterns are used in estimating demands in models. This is recognized as inadequate

for detailed contaminant flow models and is being addressed through ongoing research and

development in demand models, demand metering, and customer information systems (CIS).

Li and Buchberger (2004) have developed and applied models using a Poisson Rectangular Pulse

method to simulate fine time scale demand patterns. Metering systems that will measure

customer water use at fine time scales and transmit the information to central locations are on

the market. CISs provide a mechanism for managing consumption data so that they can be used

as a basis for providing better demand data for distribution system models.

• Real-time use of water distribution system models is an active area of development with

applications in the improved operations of water systems leading to savings in energy usage and

water quality, and as a response tool to contamination events (Jentgen et al., 2003). This is

being accomplished through integration of models with SCADA systems that provide

information on operation of a water system on a continuous and real-time basis. Commercial

water distribution system software companies and companies offering SCADA systems are the

primary developers of such systems (Fontenot et al., 2003).

• Tanks and reservoirs have been identified as key elements in water systems that are especially

vulnerable to purposeful contamination. If a contaminant enters a tank in the inflow or through

direct contamination of the tank contents, the manner in which it mixes with the ambient water

in the tank and how it subsequently exits on the outflow affect how and when customers will be

exposed to the contaminant. Various mathematical modeling techniques have been developed

to assist in predicting the mixing within tanks. These include both detailed computational fluid

dynamics (CFD) models and conceptual systems models (Grayman et al., 2004c).

• Water quality models have most commonly been used to represent conservative substances,

chlorine residual, and trihalomethanes. Current research is directed towards improving the

capability to model disinfectants and disinfectant by-products and expanding models to include

bacteria and non-conservative substances that may be introduced in purposeful attacks (Powell

et al., 2004). An upgrade to EPANET will allow the simultaneous simulation of multiple

interacting chemicals in a distribution system (Uber et al., 2004b). For example, this will allow

a simultaneous simulation of both chlorine and a contaminant whose concentration is affected

by the chlorine residual.

• Incident Commanders Water Modeling Tool (ICWater) extends the capability of a previously 23

developed RiverSpill modeling tool to allow an incident commander to analyze and react quickly

to chemical and/or biological contaminants introduced into surface water sources. ICWater will

allow “plug-and-play” with existing incident commander and emergency response tools such as

the Chemical Biological Response Aide, Consequence Assessment Tool Set, Natural Hazard

Loss Estimation Methodology, and the EPA Emergency Response Analyzer.

• The hydraulic portion of flow contaminant models are still based largely on the methods and

assumptions of Hardy Cross developed over 75 years ago. More sophisticated representations

of the hydraulics may be required to adequately predict the behavior of water quality
U.S. EPA Office of Water Early Warning Systems

August 2005 45

contaminants in the distribution system. The research community is starting to re-examine some

of the basic assumptions concerning hydraulic representation of phenomena such as dispersion,

pipe mixing, and flow dynamics (Li et al., 2005).

4.3 Sensor Placement

Historically, monitors and sensors have been placed in distribution systems to meet regulatory

requirements. Their locations have been determined based on ease of access and a general intuitive

assessment of representative locations. Lee et al. (1991) proposed a method for locating monitors

based on the concept of coverage, which is defined as the percentage of total demand that is sampled

by a set of monitors. Various other researchers further addressed this issue using alternative

mathematical methods (Kessler et al., 1998). Though widely cited, these methodologies have rarely

been applied in actual practice. However, following the events of September 11, 2001, there has

been a renewed interest in sensor placement primarily as a mechanism for detecting purposeful

contamination of distribution systems.

4.3.1 Current Research and Development

Many current studies are applying optimization techniques to determine the optimal placement for

monitors in distribution systems based on a defined objective function. Ostfeld (2004) and Ostfeld

and Salomons (2004) provide reviews of past work in this area and present example mathematical

formulations using genetic algorithm solution techniques. Their methodology finds an optimal

layout of an early warning detection system comprised of a set of monitoring stations aimed at

capturing deliberate external intrusions through sources, nodes, or tanks under an extended period

of unsteady conditions. The optimization considers the maximum volume of contaminated water

exposure at a concentration higher than a defined safe level. Berry et al. (2004) used an integer

programming optimization technique to place a limited number of perfect sensors in the pipes or

junctions of a water network so as to minimize the expected amount of damage to the public before

detection, assuming the attack occurs on a typical day. Watson et al. (2004) used a mixed-integer

linear programming model for the sensor placement problem over a range of design objectives.

Using two case studies, they showed that optimal solutions with respect to one design objective

(e.g., population exposed) are typically highly sub-optimal with respect to other design objectives

(e.g., time to detection). The implication is that robust algorithms for the sensor placement problem

must carefully and simultaneously consider multiple, disparate design objectives. Uber et al.

(2004a) describe an iterative numerical solution methodology using the “greedy heuristic” algorithm

for the sensor location problem.

In general, the optimization methods described above are experimental approaches that have been

applied only to hypothetical or small water systems and are based on assumptions about the

availability of monitoring technology, ability to define explicit objective functions, and limited

incorporation of the variability of water system operation. Further research, development, and

practical applications are needed before this technology is ready for routine use.

Research and development of formal methods for locating monitors in water distribution systems

are likely to continue in parallel with the development of monitors that can be effectively placed in

distribution systems. Though most of the cited research is related to monitors to be used to detect

intentional contamination events, related research efforts on sensor location are likely in the future
U.S. EPA Office of Water Early Warning Systems

August 2005 46

to support future water quality regulations. For example, the Initial Distribution System Evaluation

(IDSE) component of the Stage 2 Disinfectants and Disinfection Byproducts Rule that is

approaching promulgation by EPA requires additional routine monitoring in distribution systems.

Similarly, re-evaluation of the existing Total Coliform Rule (TCR) will also focus on sampling

requirements. An AwwaRF sponsored study that is just commencing as this report neared

completion, Methodologies for Assessing and Improving Water Quality Sampling Programs in

Drinking Water Distribution Systems, will focus in part on sensor location in a probabilistic

framework (see Appendix D, Project #3017).

Sandia National Laboratories (SNL) is conducting a project to develop algorithms to identify and

quantify the threat to water systems, and thus determine optimum sensor placement locations. An

additional purpose of the project is to determine the contaminant source location in real-time. The

research team has identified the challenge of determining population density at any node and how

it changes throughout the day. Under an interagency agreement with EPA, SNL is planning to

develop a new set of mathematically based tools for designing an EWS. Scalability to very large

networks and the general uncertainty in the input parameters may be other issues (DSRC Meeting,

2004).

EPA’s TEVA program is developing software and tools to examine system vulnerability and help

design response strategies. TEVA has developed a model to indicate sensor location, based on

protecting the greatest number of people. The TEVA program is comparing its model to other

models that have different sensor placement objectives, such as fastest warning or minimizing the

number of attacks that would be missed (system coverage, not based on population served). The

TEVA model uses a statistical approach, by simulating thousands of scenarios (different

contaminant injection locations) and calculating average impact for the entire set of simulations.

The comparative analysis should be completed in 2005.

There is a National Science Foundation project effort underway entitled Placement and Operation

of an Environmental Sensor Network to Facilitate Decision Making Regarding Drinking Water

Quality and Security. The objective of the project is to develop drinking water quality models for

multiple potential chemical and biological threats. It should also improve spatial and temporal

resolutions for sensor collection networks.24

Online sensors are typically installed using special sample taps that require interruption of water

flow through pipes. New installation techniques are being developed to enable installation without

interrupting the water flow or requiring major excavation. Sensors also need to be able to withstand

the harsh environment of different locations (AwwaRF, 2002).

4.3.2 State-of-the-Art Systems

With sophisticated models at their disposal, Bahadur et al. (2003b) pioneered a technique using

PipelineNet in which GIS data and hydraulic model results guide the manual placement of monitors

in order to fulfill certain general criteria. In a case study conducted with personnel at a water utility,

25 potential monitor sites were identified and subsequently reduced to the two best sites using the

GIS/PipelineNet framework. This approach is more closely related to the traditional methods for

locating monitors than are the optimization techniques currently in the research and development

stage.
U.S. EPA Office of Water Early Warning Systems

August 2005 47

Due to budgetary and technical constraints, many water utilities will face a common situation— the

utility wishes to make a modest initial investment in sensors within its existing distribution system

and wants to pick the most appropriate locations. Without resorting to the sophisticated

experimental optimization techniques that have been previously described, a two-stage procedure

is typically followed. In the first stage, likely sites for sensors are determined based on

technological constraints for available sensors. Most current sensors require an external power

source, a secure location with protection from the elements, access to communications, and easy

accessibility for maintenance. These constraints typically result in a limited number of potential

sensor locations. In the second stage, the potential sites are evaluated in terms of the “information

content” that will be provided if a sensor is placed at that location. This typically translates into

placing sensors throughout the system on larger pipes that serve the most customers. This process

can be done informally by operations personnel who know and understand the distribution system

or more formally, using hydraulic models to identify high flow pipes. This procedure, in effect,

emulates the methodology developed by Professor Deininger at the University of Michigan (Lee et

al., 1991) based on the concept of coverage that is defined as the percentage of total demand that is

sampled by a set of monitors.

4.4 Alert Management Systems

Alert management systems consist of two general areas: (1) establishing parameters for alert triggers

and (2) reducing false alarms. During the data analysis phase, new data points are compared to

baseline data values. The baseline should incorporate all potential variations due to seasonal water

quality fluctuation and cover typical operational changes (Carlson et al., 2004). It may be necessary

to incorporate up to a year’s worth of data into the baseline for it to adequately capture these

variations. The baseline must also differentiate between single data versus multiple data streams

(i.e., one physical/chemical parameter versus multiple parameters), but the amount of baseline data

needed will vary according to the technology used and the statistical variance of the data (AWWA

Workshop, 2004). Any anomalies in the comparison of new data to the baseline trigger alerts to the

operator. For example, Hach Company (Loveland, CO) has developed a trigger algorithm to create

an alarm when conditions in water depart from expected baseline parameter values. Because utilities

regularly experience changes in water quality, there are always concerns regarding false-positives.

Alert management systems usually rely on strict data validation protocols or specialized software

to reduce false alarms. PureSense Environmental, Inc. (Moffet Field, CA), for example, created a

software product to reduce false-positive and negative readings in standard water quality sensors.

EPA had entered into a CRADA with PureSense Environmental to test the system to determine if 25

the software can reduce false signals in EWS in water distribution networks. PureSense systems are

currently in use in public water systems and in the U.S. military.

4.5 Integrating Water Distribution Modeling and Data Acquisition Systems

The following systems comprise the state-of-the-art in integrating water distribution modeling and

data acquisition to support the goals of an EWS.

MIKE NET-SCADA unites EPA modeling software and SCADA systems in an effort to optimize

system performance to recognize and respond to alarm conditions. The system’s online module

performs real-time comparisons of the measured and calculated data, automatic data pre-processing
U.S. EPA Office of Water Early Warning Systems

August 2005 48

for the off-line module, and pressure/flow calculations at any point of the system. The model results

are stored back into the SCADA database and the online viewer is used to display detailed model

results (Fontenot et al., 2003). In addition, the online module features automatic data validation

procedures, in which all measurements are automatically checked and validated with standard

modules. These modules will tag questionable data and, if possible, fill in gaps in the time series.

This ensures that only validated data will be transferred and used as boundary conditions in the

strategic model, decreasing the potential for false alarms (Fontenot, 2003).

MIKE NET-SCADA’s off-line module models IF-THEN scenarios, models system breakdowns, and

predicts system behavior using demand and control rules prediction. It uses Microsoft Access to

store and maintain model alternatives. Coupling the online and off-line results of MIKE

NET-SCADA allows the operator to quickly detect abnormalities and help analyze ways in which

the abnormality can be remedied or its impact minimized (Fontenot, 2003).

Clarion Sensing Systems’ (Indianapolis, IN) SentinalTM is a remote computing platform that features

logical data processing at the monitoring sites and compatibility with various forms of wireless and

wired data transmission. The system integrates sensor data into a single display that presents

information through the Internet, a local area network, or a local terminal. The data are presented

in a web page format with analytical and historical data storage capability. Each monitoring site has

its own Internet Protocol address and serves its own web page to allow for specific site monitoring

and remote configuration of the water quality profile of the site. The SentinalTM system can be

integrated into an existing system such as SCADA, and its software is compatible with spiral

development approaches, since new sensor technologies can be integrated into the system (Martin

Harmless, Clarion Sensing Systems, personal communication).

AQUIS is a water network management system designed for both on- and off-line, real-time

monitoring. The software, produced by Seven Technologies (Denmark), is used to create models 26

to efficiently manage water resources. The models allow utility managers to minimize the impact

of operational disruptions in order to maintain continuity and quality of service. The software also

allows managers to explore strategies for responding to emergencies, including the introduction of

contaminants and increased demands placed on the system by extensive fire-fighting or other surge

demands. AQUIS is currently in use in 1,500 cities worldwide.

AQUIS offers a Contingency Management Software Package that has five modules designed to

establish a point of entry for contaminants, determine a method for limiting the spread of the

contaminant, and determine methods to mitigate any harmful effects. The modules include a model

manager for GIS data management and a hydraulic module for modeling throughout the distribution

system. A water quality module tracks the chemical composition of the water throughout the

system, and a diagnostic module identifies the source of contaminants. Finally, a flushing module

facilitates cleaning the distribution network.

4.6 Data Security

Utility management is provided routine characterization of water through daily, weekly, and

monthly reports. Monitoring data are often collected by SCADA information and then analyzed.

A major concern is that most data are not secure or encrypted by SCADA and could be subject to

security breaches. Thus, security enforcement is a major issue for all EWSs to ensure the integrity
U.S. EPA Office of Water Early Warning Systems

August 2005 49

of the system. There are a number of security considerations related to the design of an EWS.

Hardwired data transmission systems have the benefit of being more secure than wireless, because

it is harder to obtain the physical connection to the cable required for data interception (AWWA

Workshop, 2004). Hardwired systems also may be more robust during a crisis situation because

there could potentially be issues with wireless network availability. A number of wireless

transmission systems rely on an outside network, which makes it difficult to ensure their security.

Similarly, Internet-based software applications like those in the Sentinal system are vulnerable TM

to viruses and hackers. Ideally, the SCADA system should be isolated from other systems to avoid

competition for bandwidth and prevent potential system crashes (Carlson et al., 2004).

In addition to a secure design, the water distribution facility should establish security policies to be

followed by all personnel and develop a security module for the EWS. Policies should restrict data

sharing and document access to the public, especially concerning sensitive information such as

individual sensor locations. Need-to-know requirements and data quality and integrity objectives

form the basis for these security policies (Mays, 2004).

The security module includes three areas of protection:

• Authentication. A password-based authentication mechanism should be employed for users

to access the sensor data and document databases.

• Access Control. A fine-grained access control system is capable of specifying access control

permissions based on the users’ credentials, which are verified electronically.

• Secure Data Transfer. Encrypted communication using protocols such as SSL (Secure

Socket Layer) helps ensure confidentiality and integrity of the sensor data and documents

during their transit from the sensors to the system, as well as from the system to the users.

4.7 Communications, Response, and Decision Making

EPA’s Response Protocol Toolbox (EPA, 2003/2004) provides guidance to utilities and response

agencies for evaluating, communicating, and responding to threats to the water system. Managing

the threat is based on the Incident Command System (ICS) in which the utility names a Water Utility

Emergency Response Manager (WUERM) to be the initial Incident Commander. EPA’s guidance

specifically outlines a threat management system in which three main threat levels occur, “possible,”

“credible,” and “confirmatory.” At each level, there are evaluation, notification, and response

suggestions. Although information from many sources (e.g., outside law enforcement) can elevate

the threat from one level to another, the focus in this study is on how information on water

contamination provided by EWSs or subsequent laboratory analysis elevates the threat level.

A “possible” threat exists with the first sign of unusual water quality that significantly differs from

established baseline data. This information could be provided by multi-parameter water quality

monitors. The data should be compared with other monitoring locations to determine if changes in

source water could be the cause of the unusual data. Such possible classifications result in

notifications within the utility. Response may include identifying sites and initiating a site

characterization in order to rapidly test the water and collect samples for possible delivery to a

laboratory. Other responses include investigating unusual consumer complaints and consulting with

external information sources.
U.S. EPA Office of Water Early Warning Systems

August 2005 50

A “credible” threat exists when additional information collected during the site characterization, as

well as other factors, corroborate the threat warning. Evaluation at this stage should determine if

the unusual data are substantially different from other water quality episodes, if the unusual water

quality is indicative of a specific contaminant, and if the unusual water quality is clustered in a

specific area. “Credible” threats result in notification of the drinking water primacy agency, state

and local public health agencies, local law enforcement, and the Federal Bureau of Investigation

(FBI). At this stage, appropriate response should estimate the affected area and isolate it if possible,

implement appropriate public health protection measures, and further analyze samples from the site

characterization in a laboratory.

“Confirmation” represents the transition from a credible contamination threat to a confirmed

contamination, based on definitive information that the water has been contaminated. Often at this

stage, the contaminant information is available. Emergency response agencies, as well as the

National Response Center, are notified. The WUERM is no longer responsible for incident

command at this stage, but still plays a vital role in helping other agencies. An external source that

may help determine the “confirmatory” stage is the WCIT, which is currently in development by

EPA. At this point, the local Emergency Operations Center (EOC) may be fully activated in order

to support an effective and coordinated response. All of the participating organizations will likely

be coordinated under existing incident command structures designed to manage emergencies at the

state or local level. One agency will be designated as a lead agency and will be responsible for

incident command. Public health protective measures are revised as necessary and may include a

“boil-water” notice, a “do not drink” notice, or a “do not use” notice, which involves consideration

of an alternate water supply for consumption, sanitation, and other uses.

Water utilities and public health officials should develop specific criteria for making important

notifications and to identify key contacts within each agency. These criteria will ensure that

effective communications occur and appropriate public health response actions are taken in the event

of a water-related public health incident. EPA recommends the use of the Water Information

Sharing and Analysis Center (WaterISAC) for rapid information exchange. The WaterISAC has 27

secure portals and established protocols for handling information. A WaterISAC security analyst

follows up on incident reports. When responding to the threat, three factors should be considered:

(1) the credibility of the threat, (2) the potential consequences of the contamination incident, and

(3) the impact of the response action on consumers.

AwwaRF, with its partner the Water Environment Research Foundation (WERF), is conducting

research to assist utilities in efforts to communicate, respond, and make decisions during a disaster

such as a terrorist attack. In one research effort, AwwaRF/WERF is developing written and oral

message statements to be used by public agencies and elected officials to communicate with the

public in the event of a water contamination threat (see Appendix D, Project #3046). They will also

include an action plan for working with the public to increase public awareness of potential public

health risks, and appropriate responses. Another research effort is to provide a decision support

system for water distribution system security. The effort, involving Colorado State University and

Advanced Data Mining, will provide a broad and substantial knowledge base for utilities about the

impact of a toxicological attack on a distribution network and cost-effective approaches for detecting

and mitigating such attacks (see Appendix D, Project #3086).
U.S. EPA Office of Water Early Warning Systems

August 2005 51

Summary reports containing monitoring data could assist in the response. Such reports are

increasingly being developed in electronic format. To support the communications of contamination

information, there are the beginnings of web-based communication of results to critical response

agencies (AwwaRF, 2002). Data communication between online monitors is becoming part of a

“knowledge-based” management environment (Rosen et al., 2003). Furthermore, water utilities

serving more than 3,300 people have developed emergency response plans under the Public Health

Security and Bioterrorism Preparedness and Response Act of 2002. These plans help in facilitating

response and decision making.
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 53

5. Multi-Parameter Water Quality Monitors as Candidates for Early Warning

Systems

As noted elsewhere in this report, a first-stage approach to online screening for contaminants has

typically been the use of readily available online sensors that measure simple physicochemical

parameters typical for monitoring water quality (e.g., temperature, pressure, pH, conductivity,

chlorine residual). A second-stage is analysis that confirms and identifies the contaminant. Exhibit

3-3 provides a more complete discussion of the Stage One/Stage Two approach to an EWS.

Technologies to continually measure basic water quality parameters have been commercially

available and widely used by utilities for some time. They are used for process control and to ensure

regulatory compliance. These technologies are rapid and relatively easy to use on a continuous basis

via remote access to data and are available from a variety of manufacturers. Vendors have

developed panels of sensors that monitor multiple water quality parameters. The most basic

application for such sensors is to detect a physical and/or chemical change in water quality (e.g.,

change in state) that might suggest that a contaminant had been accidentally or intentionally added

to the water. The goal is to use multi-parameter water quality monitors to provide an online early

warning or red flag of an unspecified contaminant. This has been referenced by some in the field

as a Stage One EWS (Hasan et al., 2004).

A more advanced application for the use of routine physicochemical sensors is the attempt to

establish a characteristic pattern of changes in multiple parameters that might be used to actually

presumptively identify the contaminant. Such a characteristic pattern is often termed a contaminant

signature. This application is currently in the development and testing phase and is being actively

pursued by several manufacturers and government research groups. Applications utilizing routine

multi-parameter water quality monitors (e.g., simple detection of change of state as well as

establishment of a contaminant signature) are described in this section.

5.1 Descriptions of Various Multi-Parameter Water Quality Monitors

Typical multi-parameter water quality sensors for finished water have the following types of water

monitoring methods:

• colorimetric and membrane electrode for chlorine

• thermistor for temperature

• membrane electrode or optical sensors for DO

• potentiometric method for ORP

• glass bulb electrode for pH

• nephelometric method or optical sensor for turbidity

• conductivity cell method for specific conductance

3, 4 • ion-selective electrodes for Cl , NO and NH - +

In addition to basic screening of single parameters by individual sensors, some vendors are now

offering preassembled packages consisting of several conventional water quality sensors. The

following are a few example multi-parameter platforms of water quality sensors. All of these are

considered available technologies except for STIP-Scan, which is designed for wastewater

applications but is potentially adaptable for drinking water. EPA does not endorse or recommend
U.S. EPA Office of Water Early Warning Systems

August 2005 54

any of the following technologies. The summary information below was obtained from company

websites, promotional literature, and personal communication with company representatives.

The Hach Corporation (Loveland, CO) is marketing the Water Distribution Monitoring Panel. This

panel combines established instrumentation into a preconfigured system for more comprehensive

monitoring. The basic model includes the following:

• Hach CL17 Chlorine Analyzer

• Hach 1720D Low Range Turbidimeter

• Hach/GLI pH Controller

• Hach/GLI Oxidation Reduction Potential Controller

• Hach/GLI Conductivity Controller

• GEMS Pressure Sensor

The expanded model also includes a Hach Astro UV TOC analyzer and an American Sigma 900

MAX auto sampler that can be activated to collect and archive samples when pre-specified setpoint

values are exceeded for any of the parameters being measured. The Hach Distribution Monitoring

Panel is designed to continually measure these six to seven physicochemical parameters from a side

stream of water in a municipal distribution system, and the results can be reported directly to the

utility SCADA system.29

In addition to the system

designed to continually sample a

side stream of water, the Hach

Corporation is also marketing a

multi-parameter probe that is

installed directly into a water

distribution pipe. The Hach

Water Distribution Monitoring

PipeSonde In-Pipe Probe can be

installed into any water pipe (at

least eight inches in diameter),

via a two-inch corporation stop

(ball valve), and is designed to withstand water pressures of up to 300 psi. The Pipe Sonde can

measure the following parameters: pressure, temperature, conductivity, turbidity, ORP, DO, and

chlorine concentration. A sample port is available for attachment of an autosampler and a TOC

analyzer. As was the case with the Hach Water Distribution Monitoring Panel, the PipeSonde InPipe Probe can be configured to communicate directly with a utility’s SCADA system. The Hach

Event Monitor Trigger System allows for real-time analysis of data from the Water Distribution

Monitoring Panel, PipeSonde In-Pipe Probe, and the online TOC analyzer. It triggers an alarm when

water quality deviates from a baseline. It can thus profile and catalog events. The trigger signal and

all parameter measurements can be viewed from the main touch screen interface . (Image 30

reproduced with permission from Hach Company.)

Dascore, Inc. (Jacksonville, FL) markets a multiarray sensor called Six-CenseTM. The Six-CenseTM

system, like Hach’s Pipe Sonde, is designed for permanent insertion into a pressurized water main.

However, unlike the Hach products, Six-CenseTM consists of electrochemical sensors mounted on
U.S. EPA Office of Water Early Warning Systems

August 2005 55

a one square inch ceramic chip layered with gold. Measurement is accomplished via

electrochemical methods, rather than through the use of reagents. The system can continuously

monitor six parameters including chlorine or chloramine, DO, pH, ORP, conductivity, and

temperature. The system can be operated remotely with data reported to the utility SCADA

system.31

Emerson Process Management - Rosemont

Analytical (Columbus, OH) is marketing a

continuous-monitoring system for freshwater and

water distribution networks. The Model WQS

Multi-Parameter Electrochemical/Optical Water

Quality System (Model 1055 Solu Comp II)

continually analyzes a low flow (< 3 gal/hr) side

stream of water. No reagents are utilized. Six

parameters are analyzed by electrochemical

methods (pH, conductivity, ORP, DO, free

chlorine, and monochloramine). Two parameters

are assayed via optical methods (turbidity and

particle index). The particle monitor counts

particles utilizing optical laser technology, and

reports particle concentration as a particle index.32

(Image reproduced with permission from Emerson Process.)

YSI Environmental, Inc. (Yellow Springs, OH) produces standard

equipment to monitor drinking water for ORP, DO, pH, specific

conductance, and temperature. In addition, YSI systems measure turbidity,

and levels of chloride, ammonia nitrogen, and nitrate nitrogen. YSI

currently uses its technology in surface water applications. (Image

reproduced with permission from YSI Environmental.)

Analytical Technology, Inc.’s, (Collegeville, PA) Series C15 Water

Quality Monitoring system allows the user to choose those parameters for

which monitoring is desired and to integrate those components into a

monitoring package suitable for continuous monitoring, alarming, and data

collection. System components are currently available for free chlorine, combined chlorine (for

chloramine treated systems), dissolved ozone, pH, ORP, conductivity, and temperature. In addition,

DO and turbidity modules will be added to the

system in the future.33

Clarion Sensing Systems’ (Indianapolis, IN)

SentinalTM integrates sensor data into a single

display which can be viewed remotely (e.g., over

the Internet). Clarion sells the complete system

including sensors, or can integrate a utility’s

existing sensors from a variety of manufacturers.

The system is modular, so utilities can select to

monitor various parameters including: chlorine,
U.S. EPA Office of Water Early Warning Systems

August 2005 56

pH, temperature, flow, pressure, conductance, turbidity, ORP, DO, radiation, TOC, VOCs, and

certain chemical weapons. The SentinalTM software is compatible with spiral development

approaches, since new sensor technologies can be integrated into the system. The system can run

off of AC current or solar power and automatically re-boots if power is interrupted. Data can be

transmitted via LAN or satellite link (Martin Harmless, Clarion Sensing Systems, personal

communication) (Image reproduced with permission from Clarion Sensing Systems.)34

STIP-scan from STIP Isco GmbH (Germany) analyzes multiple wastewater parameters with a single

device. Although designed for wastewater applications, the equipment is potentially adaptable for

drinking water distribution systems. Designed to operate in municipal and industrial wastewater

treatment plants at the inlet, in the aeration basin, and in treated effluent, the STIP-scan UV/Vis

spectroscopic sensor is capable of simultaneous measurement of nitrate, chemical oxygen demand

(COD), TOC, spectral absorption coefficient (SAC254), total solids, sludge volume, sludge volume

index, and turbidity. It can also be used for river monitoring. In addition to these parameters, the

STIP-scan measures absorption in any specified range within the wavelength spectrum from 190 to

720 nm for detection of other compounds. No sample filtration or preparation is required, and the

wiping action of the piston seals cleans the measuring cell on each cycle. The controller is equipped

with analog outputs and a bidirectional serial interface to transmit data. A color display presents the

data as continuous daily graphs of nitrate, COD, TOC, or SAC254. Data intervals are two minutes

and can be stored up to 14 days.35

5.2 Efforts to Determine Performance of Multi-Parameter Water Quality Monitors and

Establish Water Quality Baselines

During the process of developing a workable EWS based on multi-parameter water quality monitors,

there are various validation steps that are occurring simlutaneously. These include efforts to

determine the performance of multi-parameter water quality monitors as well as establishing

operating water quality baselines so that anomalies can be spotted. Several tests have and are being

performed at EPA. Some efforts have occurred under CRADAs. Under the Federal Technology

Transfer Act, EPA can form CRADAs with the private sector in order to speed the development of

technologies for various programs. In forming these CRADAs, EPA is aiming to continue research

into the detection and identification of contaminants, response and mitigation, and prevention and

protection. Private industry, as well as state and local governments, can utilize CRADAs to access

federal laboratory equipment, personnel, and services.36

EPA has used its T&E Facility in Cincinnati, OH, for much of the past research. The specific center

is called the WATERS. Within the WATERS Center, there are multiple DSSs, which were designed

and fabricated by the NRMRL to evaluate and understand the dynamics that influence water quality

within water distribution infrastructure systems typical in the U.S. and abroad. EPA research 37

investigators selected a platform array of real-time online sensors and instrumentation that represent

the various types of technologies currently used by utilities to monitoring water quality.

Experiments are underway to evaluate the selected online water monitoring sensors in the various

DSS units for their ability to detect changes in water quality due to chemical, physical, and microbial

contaminants at concentrations that would present a public risk in a distribution system. Water

quality sensors utilized for the EPA WATERS Center studies can be classified in two

groups—traditional sensors and continuous monitors. EPA is conducting studies to evaluate the

sensitivity, response, limit of detection, reproducibility, potential for false-positives/false-negatives,
U.S. EPA Office of Water Early Warning Systems

August 2005 57

and other limitations of the selected sensors. The individual conclusions of these evaluations are

discussed in Chapter 9. 

5.2.1 Evaluate Sensor Performance

An important part of developing a first stage EWS is to evaluate whether the normal operation of

water distribution systems can be documented in terms of sensor response. At the WATERS Center,

EPA has conducted tests to understand which sensors can determine a baseline water quality and

if sensor drifting takes place. A basic conclusion was that specific-conductance, TOC, and free

chlorine monitors drift very little when properly calibrated and serviced, and therefore these sensors

are ideal for characterizing normal or safe conditions (EPA, 2004).

5.2.2 Investigate Baseline for Water Quality

The USGS New Jersey District, EPA, and a local water utility, under an Interagency Agreement,

will plan a study to implement and test an EWS in an actual water distribution system. The study

will test sensors, optimize the sensor location, and develop a baseline water quality profile of the

distribution system (DSRC Meeting, 2004). AwwaRF has two projects that analyze online water

quality data to address normal fluctuations in water quality parameters and develop methods to

differentiate them from contamination events (see Appendix D, Projects #3035 and #3086).

5.2.3 Verify Sensor Performance

Another series of tests is currently being conducted at the EPA WATERS DSS facility to verify the

capability of multi-parameter water monitors for normal daily operation of distribution systems. The

testing is being performed under the auspices of EPA through the ETV Program. The work is being

performed by Battelle Laboratories (Columbus, OH), which is managing the ETV AMS Center

through a cooperative agreement with EPA. Vendor representatives are installing, maintaining, and

operating their respective technologies throughout the test (Ryan James, Battelle, personal

communication ) A CRADA with EPA will test YSI technology in water distribution systems to 38

determine how applicable the technology is to online monitoring of water distribution. This project

is separate from the research project described below, because the sensors are being verified for their

ability to perform as basic water quality monitors, and their response to injected contaminants is not

being tested.

5.3 Efforts to Provide Red Flag EWS and to Identify Specific Contaminants via Signature

Using Multi-Parameter Water Quality Monitors

There is an increasing level of activity to examine the use of multi-parameter water quality monitors

to provide a red flag EWS and to identify the actual contaminant using signatures. Historically,

utilities have invested in multi-parameter water quality monitors to enhance the management

capabilities of drinking water treatment plants’ and distribution systems’ daily operations. If these

same monitors prove to be useful for detecting even a subset of intentional contamination events,

then the monitors would serve dual purposes. If the same equipment can be used for both daily

operations and for detecting system perturbations due to intentional contamination, then their value

to utility companies would be enhanced. Further details of the evaluation are provided in Chapter 9.
U.S. EPA Office of Water Early Warning Systems

August 2005 58

5.3.1 Sensor Response to Contaminants

At the WATERS Center, EPA investigated whether various sensors could identify contaminants.

The conclusion was that certain sensors can provide only a general indication of the contaminant

class (such as inorganic, organic, or a reactive species producing chlorine demand) (EPA, 2004).

5.3.2 Multi-Parameter Response to Chemical or Biological Agent Simulants

Another study at EPA’s WATERS Center investigated the response of a combination of off-the-shelf

sensors to detect changes caused by the injection of wastewater, groundwater, a chemical mixture,

and individual chemicals. The sensor system showed promise for providing quick detection of water

quality changes caused by these contaminants. With additional optimization, a system of sensors

may be used as an EWS (EPA, 2004). However, because the range of contaminants was narrow,

additional types of contamination and scenarios should be examined to further test this conclusion.

5.3.3 Signature Development

An advanced application of conventional physicochemical sensors for security monitoring is the

presumptive identification of a specific contaminant through interpretation of a characteristic pattern

of changes (signature) in multiple parameters. Typically, the interpretation of such a pattern of

changes is accomplished with the help of a computerized data system. Just as in the previously

described effort to infer the occurrence of an unidentified contaminant by observing a

physicochemical change, a reliable parameter baseline must first be established for successful

interpretation of sample results. Furthermore, when attempting to actually identify a contaminant

through observation of a characteristic pattern of changes in parameter values, it is also necessary

to characterize the expected changes in multiple parameters ahead of time. The signature data for

the characterization would need to be obtained empirically. Several manufacturers are exploring

this signature approach for water contaminant monitoring. One company, Hach (Loveland, CO),

has tested this signature approach. The signatures being developed by Hach and others to identify 39

contaminants or classes however, are difficult to independently validate because their methods and

algorithms are not available to the public. Also, the examination of water quality parameters for use

in detecting and identifying contaminants is still being evaluated by EPA, USGS, the Army, and

other organizations, and there has yet to be implemented a field-scale test of a full EWS with these

water parameter components. These add to the caution in currently recommending use of these

water quality parameter-based EWSs.

5.3.4 Further Testing of Signature Concept

To quickly facilitate the development and use of multi-parameter water quality monitors as part of

an integrated EWS for water distribution systems, EPA has entered into a CRADA with Hach

Company. Hach Company currently produces a real-time water distribution monitoring panel that

is composed of several different types of sensors. The CRADA will determine if this technology

can be adapted to real-time monitoring of water distribution systems to detect contaminants such as

pesticides, herbicides, industrial chemicals, and wastewater.
U.S. EPA Office of Water Early Warning Systems

August 2005 59

5.3.5 Multi-Parameter Response to Actual Chemical and Biological Agents

Working with EPA, the Edgewood Chemical Biological Center (ECBC) is planning to test multiparameter water quality monitors using actual CBR Agents. 
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 61

6. Technologies that Detect Chemical Contaminants for Early Warning Systems

6.1 General Introduction to Assays and Sensors

The technologies presented in this chapter are for the detection of chemical contaminants. However,

several of the technologies are also capable of detecting microbial pathogens. For EWSs, secondstage confirmation technologies can come mostly in the form of portable field kits or hand-held

sensor devices. Online and kit assay biomonitors that measure effects on biological organisms are

also included even though they do not identify specific contaminants. Online gas chromatography

and mass spectroscopy (GC-MS) is also included, and although it may be too expensive for

continuous operation, it would be valuable for remote identification when triggered by a stage one

alarm (e.g., red flag). Kits are generally portable versions of bench top assays that require pipetting,

mixing, and reaction containers. They may also require a reader device for monitoring the assay

reaction. Sensors and detection devices can be based on a variety of technology platforms, many

of which are described in this chapter and Chapter 7, and can be of a suitcase, backpack, or handheld size.

EPA does not endorse or recommend any of the following technologies. Much of the summary

information below was obtained from company websites, promotional literature, personal

communication with company representatives, and some government sources.

6.2 Available Technology

6.2.1 Detection of Arsenic

To evaluate the presence and concentration of arsenic in water there are two basic types of

technologies that are used in commercially available tests, which have been third party verified by

EPA’s ETV Program (see Chapter 9 for verification results). Both types of technologies are used

in portable devices designed for onsite rapid analysis of arsenic in water. The first type involves a

color reaction kit in which a water sample is mixed with a series of reagents producing a color

change in an indicator, which is then compared to a standard color gradient that corresponds to the

concentration of arsenic in the water. 

Industrial Test Systems, Inc. (Rock Hill, SC) offers five QuickTM test reaction kits that identify

arsenic levels at varying concentrations, depending on which kit is used. For these products the

indicator strip, in addition to being read visually, can be read with the hand-held instrument or with

a portable scanner and laptop system. Both operate on the same principle as a colorimeter, provide

a quantitative result, and are available separate from the test kits. All five QuickTM tests are easy

to use and easily transportable to the field. The time to analyze one sample is approximately 15

minutes. Peters Engineering (Austria) offers the AS 75 arsenic test kit, another color reaction kit,

which is also field portable. It measures the color change in a filter after reagent tablets are dropped

into the sample by visual comparison to a color chart, or by the battery operated AS 75 tester.

Another color reaction test kit is the As-Top Water test kit offered by Envitop, Ltd. (Oulu, Finland).

The kit is easily transportable to the field and analysis takes 35 minutes (EPA-ETV, 2004).

A second type of test to evaluate arsenic concentrations employs anodic stripping voltammetry

(ASV), which can be used to analyze various analyte metal ions. The measurement is performed
U.S. EPA Office of Water Early Warning Systems

August 2005 62

in an electrochemical cell. A reducing potential is applied to the working electrode. When the

electrode potential exceeds the ionization potential of the analyte metal ion in solution (in this case,

arsenic), it is reduced to the metal which plates on the working electrode surface. The analyte is

then stripped (e.g., oxidized) off the electrode by an applied potential. The electrons released by this

process form a current, which is measured and can be plotted as a function of applied potential to

give a “voltammogram.” The current at the oxidation/stripping potential is read as a peak, and to

determine analyte concentration the height or area of the peak can be measured and compared to that

of a known standard solution (EPA-ETV, 2004).

Monitoring Technologies International Pty., Ltd. (Perth, Australia) offers the PDV 6000 portable

analyzer which measures arsenic in water using ASV. For this device, the sample concentration

result is provided as a digital readout on a hand-held controller, or can be measured using VAS

Version 2.1 software. The PDV 6000 portable analyzer is easily transported from the field to a

storage shed where samples are analyzed. Instrument setup and calibration takes about 30 minutes

and analysis time per sample is about five minutes. Another device that employs ASV technology

is the Nano-BandTM Explorer made by TraceDetect (Seattle, WA). This device has a three-electrode

cell which combines a Nano-BandTM Explorer electrode with a reference and auxiliary electrode.

The samples take one hour to prepare prior to analysis, then the concentration is detected within

seconds and displayed in real-time using software run on a laptop computer. The Nano-BandTM

Explorer is optimized for trace metal analysis and allows for detection of some metals as low as

0.1 parts per billion (ppb). The Nano-BandTM Explorer measurement system includes Explorer

software, but not a laptop computer (EPA-ETV, 2004).

6.2.2 Detection of Cyanide

To evaluate the presence and concentration of cyanide in water there are two basic types of

technologies in use by commercially available tests, both of which have been third party verified by

EPA’s ETV program (see Chapter 9 for verification results). Both types of technologies are used

in portable devices designed for onsite rapid analysis of cyanide in water. The first is a portable

colorimeter in which a sample and reagent(s) are mixed producing a color whose intensity is

proportional to the cyanide concentration. The color is measured photometrically to provide a

quantitative determination of cyanide in the sample (EPA-ETV, 2004).

The VVR V-1000 multi-analyte photometer was used with the V-3803 cyanide module and selffilling reagent Vacu-vial® ampoules, all by CHEMetrics, Inc. (Calverton, VA) to test for cyanide

concentrations. The CHEMetrics VVR operates on four AA batteries, was easy to operate, and was

easily transported to the field. The 1919 SMART 2 Colorimeter with the 3660-SC Reagent System

by LaMotte Company (Chesterton, MD) was also tested by ETV. The LaMotte SMART 2 operates

at 120V/60Hz and was easy to use and transport to the field. Analysis for one sample takes

approximately 22 minutes. The Mini-Analyst Model 942-032 by Orbeco-Hellige (Farmingdale, NY)

also operates on four AA batteries. Analyzing one sample takes approximately 18 minutes. The

AQUAfast® IV AQ4000 colorimeter by Thermo Orion (Beverly, MA) automatically identifies the

species to be measured and selects the method, wavelength, and reaction time. It also operates on

four AA batteries and can measure cyanide concentration when used with AQ4006 cyanide reagents.

The AQ4000 was easily transported to the field and clear instructions assured easy operation.

However, sample throughput for only one sample would take approximately 17 minutes (EPA-ETV,

2004).
U.S. EPA Office of Water Early Warning Systems

August 2005 63

The second basic technology type that is used to measure cyanide concentrations in water is found

in a device that consists of a solid sensing element containing a mixture of inorganic silver

compounds bonded to the tip of an epoxy electrode body. When the sensing element is in contact

with a cyanide solution, silver ions dissolve from the membrane surface. Silver ions within the

sensing element move to the surface to replace the dissolved ions, establishing a potential difference

that is dependent on the cyanide concentration in the solution. Upon calibration with solutions of

known cyanide concentrations, these potential differences are converted to concentrations and

displayed on the digital readout at milligrams per liter (mg/L) (EPA-ETV, 2004).

One device that employs this technology is the Thermo Orion Model 9606 Cyanide Electrode with

the Model 290A+ Ion Selective Electrode Meter, which operates on a 9-volt battery. The Thermo

Orion ISE was easily transported to the field and the instruction manual for its use was clear and

concise. Sample preparation takes 1-2 minutes per sample, calibration takes between 15 to 20

minutes and each sample took approximately 5 minutes to attain a reading. The Cyanide Electrode

CN 501 with the Reference Electrode R503D and Ion Pocket Meter 340i (WTW ISE) by WTW

Measurement Systems (Ft. Myers, FL) operates on four AA batteries and was easily transported and

used in the field setting (EPA-ETV, 2004).

6.2.3 Gas Chromatography

GC can be used to analyze for a wide variety of organic chemicals such as industrial chemicals and

components of fuel oils. Individual organic compounds are separated as the compounds are carried

by a carrier gas (e.g., nitrogen, helium, argon, hydrogen) through a packed or coated column

containing a stationary phase. The columns are coiled in an oven. At the beginning of the coil, the

compound is vaporized into a gas. The compounds separate from each other within the column due

to differing affinity among the sample compounds for the gas and liquid phases. As a result, the

individual compounds travel through the column at different speeds. The time required to pass

completely through the column and reach the detector varies from compound to compound. The

components of a complex sample matrix can be separated, compared to known standards, and the

concentrations then quantified. For smaller devices, photolithographic machining techniques are

used to produce injection and detection systems on silicon microchips (see Section 6.3.5 for general

description of microchips). GC alone can only provide tentative identification. For more definitive

identification, traditional and microfabricated GC columns can be coupled to detectors such as

thermal conductivity detector (TCD), surface acoustic wave (SAW) detector, electrolytic

conductivity detector (ECD), electron capture detector, flame ionization detector (FID), photo

ionization detector (PID), and mass spectrometer. Volatile organic compounds (VOCs) can be

extracted and concentrated from water samples using purge and trap technology. The volatile

compounds are initially purged from the water sample using a purge gas such as helium and are

sorbed onto an organic resin trap. The compounds are subsequently desorbed from the trap by flash

heating and enter the GC column. Purge and trap gas chromatography has been used for years to

monitor raw waters such as the Ohio River and Rhine River for industrial spills (ILSI, 1999). In

some cases analyses are conducted on grab samples one or more times each day. In other cases

sample collection has been automated and occurs at regular intervals throughout a 24-hour period.

The units require skilled operators and regular maintenance.

One commercially available automated gas chromatograph that is being used as a continuous online

monitoring system for the analysis of VOCs is the Scentograph CMS500 manufactured by INFICON
U.S. EPA Office of Water Early Warning Systems

August 2005 64

(East Syracuse, NY). It can operate automatically and unattended providing real-time

measurements. The system can measure concentrations ranging from parts per million (ppm) to

parts per trillion (ppt) with sampling and reporting of results at programmable intervals. The

Scentograph CMS500 analyzes VOCs in water using a modified EPA purge and trap protocol (the

SituProbe). Since no pumps, valves, or cells are exposed to the water matrix, there is no need for

sample pretreatment or filtration, allowing the analysis of even complex water samples. Currently,

a medium-sized U.S. city is using an automated gas chromatograph (INFICON Scentograph

CMS500) in its water distribution system to detect trihalomethanes and other chemicals.

Portable versions of GC instruments are also available. INFICON’s, Scentograph CMS200 is a

portable version of the online instrument described above. INFICON’s HAPSITE® GC/MS is used

in 15 different countries for military and homeland security applications. It is backpack portable,

can be operated by individual soldiers, and yields results in minutes. Constellation Technology 40

Corporation’s (Largo, FL) CT-1128, is also a portable GC-MS, but weighing 70 pounds, is set up

from the back of a truck . (Images reproduced with permission from INFICON and Constellation 41

Technology.)

6.2.4 Enzyme-Based Detection

• Inhibition of Cholinesterase

The Severn Trent Field Enzyme Test (distributed by Capital Controls a division of Severn Trent

Services, Fort Washington, PA) was developed for qualitative detection of nerve agents in a field

setting. The test is based on the inhibition of the enzyme cholinesterase. A membrane disk is

saturated with cholinesterase and dipped into a water sample for one minute. If no pesticide/nerve

agent is present in the water sample, the cholinesterase on the membrane disk hydrolyzes esters

resulting in the formation of a blue color. If sufficient concentrations of pesticide/nerve agent are

present, the cholinesterase on the membrane is inhibited, the ester is not hydrolyzed, and there is no

change in color (i.e., remains white). The detection limits cited by the manufacturer for pesticides

are: carbamates (0.1 to 5 mg/L); thiophosphates (0.5 to 5 mg/L); and organophosphates (1 to

5 mg/L). No data are available for detection limits for nerve agents.42
U.S. EPA Office of Water Early Warning Systems

August 2005 65

• Inhibition of Horseradish Peroxidase - Indicated by Decreased Chemiluminescence

A chemiluminescence detection technique based on the reaction of luminol and an oxidant in the

presence of the enzyme horseradish peroxidase (HRP) can be used to indicate the presence of toxins

in a sample. The HRP mediated reaction produces light that is measured by a luminometer.

Phenols, amines, heavy metals, or compounds that interact with the enzyme reduce light output and

indicate contamination.

EcloxTM, developed by Severn Trent Services (Fort Washington,

PA), is a broadband chemiluminescence test that qualitatively

assesses a water sample to determine contamination by a variety

of chemical and biological agents. The EcloxTM portable

kit/luminometer is applicable for both laboratory and field use

(EPA-ETV, 2004, photo from ETV Report 2003/2004).43

AquanoxTM, developed by Randox Laboratories (Co. Antrim,

United Kingdom), is a hand-held water quality-monitoring

instrument based on enhanced chemiluminescent technology.

AquanoxTM offers onsite analysis of water and effluent waste

testing in a range of industrial applications including chemical

wastewater treatment plants.44

6.2.5 Biosensors

Biosensors work to identify toxic substances in the water using whole-organism or cellular response

approaches. Biosensors measure changes in physiology or behavior of living organisms resulting

from stresses induced by toxins. This type of biosensor does not identify the specific toxin, but

indicates that there is an unusual condition in the water. The overall rationale is that the organism

can respond with sensitivity to all the factors that contribute to stress. Fast acting toxins associated

with acute effects are most quickly detected. However, slower acting toxins or toxins with chronic

effects would not be rapidly detected if they do not also have acute effects. It is important to note

that the biosensors presented are not effective for detecting human pathogens because pathogens are

often species- or tissue-specific and require incubation times (typically days or weeks) before

disease symptoms are noticeable.

Biosensors have used bacteria (prokaryotic cells) and eukaryotic cells, as well as organisms such

as daphnia, mussels, algae, and fish. Organisms or cells that have been genetically modified to

contain specific response elements and reporter constructs such as bioluminescence can be designed

to respond to specific contaminants. Because the living organisms are sensitive to chlorine and other

water treatment chemicals, many biosensors are currently limited to raw water application. If such

treatment chemicals are sufficiently removed from the sample, the biosensors have the potential to

be used at critical points in the water distribution system. Portable sensors can be used to monitor

grab samples.
U.S. EPA Office of Water Early Warning Systems

August 2005 66

• Bacteria-Based Biosensors

Biosensors using bacterial responses show promise for use in early warning screening because

bacteria can rapidly react to toxins (biological or chemical). The metabolism of bacteria is disrupted

as a result of exposure to toxins. Some detection techniques work by monitoring for reduction in

bioluminescence. Some bacteria have natural or engineered bioluminescence, which emits light

when the cells are healthy. This bacterial bioluminescence is closely tied to respiration, so that

changes in the cellular metabolism or disruption of the cell structure decreases luminescence, which

is measureable. Kits come with freeze-dried or customer-activated bioluminescent bacteria. The

reconstituted or cultured bacteria are exposed to the water sample and the luminescence is compared

to bacteria exposed to control water. A decrease in bioluminescence (light reduction) suggests the

presence of toxins. Other detectors monitor bacterial metabolism based on color changes or on

bacterial oxygen demand. Substances that interfere with such bacterial monitoring include chlorine,

chloramine, and copper.

There are currently several commercially available bioluminescent bacterial monitoring systems that

have been verified under EPA’s ETV Program, including Tox Screen II (Check Light, Ltd), 45

BioToxTM (Hidex Oy), MicroTox®/DeltaTox® (Strategic Diagnostics Inc.), ToxTrakTM (Hach

Company), and POLYTOXTM (InterLab Supply, Ltd.). Brief descriptions of these technologies are

provided below.

ToxScreen-II

ToxScreen-II Rapid Toxicity Testing System was

developed by CheckLight, LTD (Qiryat Tivon, Israel).

The basis for this technology rests on bacterial metabolism

as indicated by bioluminescence. This product uses the

luminous bacteria Photobacterium leiognathi and special

assay conditions to detect toxins in water samples. There

are two assay buffers designed to discriminate between

organic pollutants and metal toxins at sub-mg/L

concentrations. Changes in bioluminescence indicate

water toxicity. The system involves a series of steps

including sample preparation and a 90-minute incubation

period. Results are captured using a portable luminometer, which can

be integrated with a personal computer for data acquisition,

evaluation, and storage. The ToxScreen-II test kit costs $300 and 46

luminometer costs $2,895 (EPA-ETV, 2004, photo from EPA-ETV,

2004).47

BioToxTM

BioToxTM Rapid Toxicity Testing System was developed by Hidex Oy

(Turku, Finland) and bases its technology on bacterial metabolism as

indicated by bioluminescence. The test uses the photobacteria Vibrio

fischeri, which reduce their bioluminescent output when exposed to

toxic chemicals. The BioTox Flash Test is an improved Vibrio TM
U.S. EPA Office of Water Early Warning Systems

August 2005 67

fischeri test for rapid screening of water and sediment samples. The detection process is the same

as BioTox , but BioTox Flash automatically corrects for color/turbidity interference and can TM TM

screen the majority of the samples within a few seconds. The system uses freeze-dried BioToxTM

reagent ($128 for entire kit) together with the Hidex Oy Triathler (portable combination liquid TM

scintillation counter, luminometer, gamma counter, totaling $8,900 with injector) Results take 48

from 5 to 30 minutes. The product is small enough to be portable, but can only be operated on

110-volt AC electricity (EPA-ETV, 2004, photo from EPA-ETV, 2004).49

DeltaTox®

DeltaTox®, developed by

Strategic Diagnostics Inc

(Newark, DE), is the portable,

field-applicable version of

MicroTox®, a laboratory testing

system based on bacterial

metabolism as indicated by

bioluminescence. Both 50

products can detect multiple

kinds of toxins by measuring the

light output of the photobacteria

Vibrio fischeri. The organisms’

metabolism and thus light output are reduced in the presence of toxins, indicating sample

contamination. Results are obtained in 5 to 15 minutes. DeltaTox® is a self-calibrating photometer

that incorporates a photomultiplier tube, a data collection and reduction system, and software. The

system costs $5,900 and the test kit is $370. MicroTox® Model 500 costs $17,895 and the reagents

are $360. The DeltaTox® lacks the temperature control chambers of MicroTox® (EPA-ETV,

2004). Both MicroTox® and DeltaTox® are sensitive to chlorine, which makes them difficult for 51

use in water distribution systems. The maker of MicroTox® is developing a commercial online

system that can remove the chlorine residual. (Image reproduced with permission from Strategic

Diagnostics Inc.)

ToxTrakTM

ToxTrakTM Rapid Toxicity Testing System was developed by the

Hach Company (Loveland, CO) as a colorimetric test based on

resazurin dye chemistry. The basis for this technology is bacterial

metabolism as indicated by a color change. The process uses

resazurin reduction to measure respiration, a critical pathway for

cell viability. Resazurin is a redox-active dye which, when reduced,

changes color from blue to pink. Substances that are toxic to

bacteria can inhibit their metabolism and thus, inhibit the rate of

resazurin reduction. The test indicates the presence of a toxic

substance if the color of the dye does not change; a colorimeter or

spectrophotometer must be used to determine color changes (not

included in the kit). ToxTrakTM costs $280 for the kit, $100 for the reagent set, and

spectrophotometer cost approximately $3,950 (EPA-ETV, 2004, photo from EPA-ETV, 2004 ). 52
U.S. EPA Office of Water Early Warning Systems

August 2005 68

The Hach Company supports the use of this system as a cost effective and wide scope monitoring

method for use as an EWS by drinking water utilities.

POLYTOXTM

POLYTOX , developed by InterLab SupplyTM, Ltd (The TM

Woodlands, TX) uses the respiration of microorganisms to

indicate the toxicity of a water or wastewater stream,

including the presence of chemical and biological

contaminants. When activated in water, the mixture of 53

bacterial cultures in POLYTOX breathe in oxygen and TM

respire carbon dioxide at a rate that can be monitored and

measured as milligrams (mg) of oxygen consumed per liter

per minute. A change in respiration rate is an indication of

toxins in the sample. The portable dissolved oxygen probe

and meter cost $1,600 and the test kit costs $147 (EPA-ETV,

2004, photo from EPA-ETV, 2004).54

microMAX-TOX

None of the preceding technologies is designed for use in water distribution systems. However, a

system called microMAX-TOX Screen is being adapted to distribution systems. Tox Screen is

manufactured by SYSTEM Srl. (Italy) and is based on the measurement technology developed by

an Israeli company (Check Light, Inc.). It is similar to MicroTox® but applied in continuous online

mode. It has two online analyzers, one colorimetric and the other ion selective. The detection

mechanism uses freeze-dried bioluminescent bacteria. It is fully automated to activate alarms and

conducts the analysis every 30 to 60 minutes (grab samples).

Every two weeks, the instrument is re-supplied with a new set

of liquid buffers and a freshly hydrated suspension of bacteria.

The interfering chlorine residual is continuously removed by

sodium thiosulfate. It is expected to be commercially available

in 2005 (Grayman et al., 2003).

• Organism-Based Biosensors

MosselMonitor®

Mussels will change their behavior in response to toxins, such

as closing their shells to reduce exposure to the toxin. Thus,

the frequency of valve opening and closing can be monitored

to indicate toxin avoidance behaviors. Delta Consult

(Netherlands) has a commercially available MosselMonitor®

that can be used to monitor chlorinated drinking water by

applying a thiosulphate pre-treatment to remove chlorine.

Thiosulfate does not remove all disinfectants used in finished

water, therefore systems that use chloramines would not be

able to use this technology. For drinking water applications,
U.S. EPA Office of Water Early Warning Systems

August 2005 69

an Automated Food Device (AFD) is used to provide a continuous supply of nutrients. The

MosselMonitor® can be run online continuously for up to two to three months before replacement

of mussels is necessary. The data presentation software allows for near real-time graphical

presentation at a remote location or on the Internet. Only eight mussels are required because each

mussel’s behavior is analyzed against its own previous behaviors, then the combined results from

all eight mussels are analyzed. The MosselMonitor® has been used with five different bivalve

species (three for freshwater and two for marine water ). The MosselMonitor® has been used by 55

Waterworks of Budapest, Hungary, to monitor chlorinated drinking water. Although the company

recommends replacement of mussels every three months, in the Budapest installation the mussels

survived 10 months before needing to be replaced (Jan de Maat, Delta Consult, personal

communication). (Images reproduced with permission from Delta Consult.)

Fish Bio-sensor®

Biological Monitoring, Inc. (Blacksburg, VA) makes

Bio-Sensor®, which monitors the bioelectric field of 8-12 fish to

assess if abnormal behavior indicates the presence of a toxin.56

Concurrent automated and continuous physicochemical

monitoring enhances the reliability of the results. In an event

when a toxin is indicated, an alarm is generated both locally and

remotely, so as to inform the users. A water sample is also

automatically collected should advanced (chemical) analytical

verification be desired. A dechlorination module can be added if

Bio-Sensor® is installed in the distribution system. An automated

feeder reduces the maintenance interval to a recommended once

monthly. Bio-Sensor® is currently installed in distribution

systems in Singapore, Australia, and South Africa (Joe Rasnake,

Biological Monitoring Inc., personal communication). (Image

reproduced with permission from Biological Monitoring Inc.)

6.3 Potentially Adaptable Technology

Several technologies that have been developed for other applications, such as monitoring in source

water or air, may be adaptable for use in distribution systems.

6.3.1 Enzyme-Based Detection

• Inhibition of Photosynthetic Enzyme Complexes

(PEC)

LuminoTox developed by Lab_Bell Inc. (Shawinigan,

Canada) utilizes either photosynthetic enzymes isolated

from plants, or detection of photosynthetic activity of

algae, to detect toxic analytes. Photosynthetic enzyme

complexes (PECs) isolated from plants are stabilized by

vacuum evaporation for storage. The LuminoTox system

using PECs can detect toxic molecules such as
U.S. EPA Office of Water Early Warning Systems

August 2005 70

herbicides, hydrocarbons, phenols, divalent cations, polycyclic aromatic hydrocarbons (PAHs), and

aromatic hydrocarbons. LuminoTox used with photosynthetic algae allows for the specific detection

for herbicides, organic solvents (e.g., gasoline, hydrocarbons), ammonia nitrogen and organic

amines. In the urban and industrial effluents the company has tested, toxicity can be measured in

10 to 15 minutes, while sensitivity of detection can be increased by lengthening the incubation time.

The hand-held portable luminometer allows the system to be field portable. In 2005, the company

introduced an online version called Robot LuminoTox, which is self-cleaning, monitors pH and

temperature, and records a toxicity measurement every 30 minutes. The data are stored in an Excel

file. Robot LuminoTox is operated via Windows and can be processed via a SCADA system . 57

(Images reproduced with permission from Lab_Bell Inc.)

Researchers from the Institute of Microbiology (Czech Republic) have demonstrated that

Photosystem II complexes coupled to a screen-printed electrode can detect triazine and phenylurea

herbicides. The biosensor is reusable with a half-life of 24 hours and limit of detection of

approximately 10 M for diuron, atrazine, and simazine (Koblizek et al., 2002 ). However, this -9 58

system is at the research stage.

• Inhibition of Submitochondrial Particles

Harvard BioScience, Inc. (Holliston, MA) produces a toxicity detection kit called MitoScan that uses

fragmented inner mitochondrial membrane vesicles isolated from beef heart. The submitochondrial

particles (SMPs, called “micelles”) contain complexes of enzymes responsible for electron transport

and oxidative phosphorylation that are inverted from their in vivo orientation. The enzymes in the

SMPs produce a hydrogen ion gradient which is used to produce ATP from adenosine diphosphate,

and this process (oxidative phosphorylation) is coupled to electron transport as it occurs in vivo.

Progress of this reaction is directly proportional to the redox state and can be monitored

spectrophotometrically at 340 nm. When specific inhibitors or toxicants are added to the SMPs the

reactions are slowed or inhibited. The SMP vials from the MitoScan kit need to be stored at -20oC

and are viable for up to four weeks. For longer storage, SMPs should be stored at -80oC. The test

kits include all necessary reagents and SMPs in 100μl or 500μl vials. MitoScan bioassays can be

configured for microwell plate readers or for manual cuvette formats using single-beam

spectrophotometers. Cuvettes with a portable spectrophotometer capable of running kinetic assays

at 340 nm make the kit field portable. The assay also requires cuvettes, sample dilution tubes,

pipettors, and pipettor tips. MitoScan tests can be formatted to provide results in less than 30

minutes. The kit has not yet been third party verified. 59

6.3.2 Organism-Based Biosensors

Several biomonitors are available and used for monitoring surface water. They are not currently

used in treated water distribution systems because the chlorine residual is toxic to the organisms.

Thus these may be adaptable for use in distribution systems if chlorine can be removed, similar to

what been done with MosselMonitor® and Bio-Sensor®. 

• Daphnia-Based Biosensors

Daphnia (water fleas) are small free-swimming organisms that are very sensitive to toxins. A

daphnia toximeter consists of daphnids contained in a glass chamber through which sample water
U.S. EPA Office of Water Early Warning Systems

August 2005 71

continuously flows. The swimming behavior is monitored by closed circuit TV and analyzed via

integrated computer. Variations in speed, altitude, and frequency of turning can indicate a potential

contaminant. Sometimes the method for measuring toxins is based on feeding the daphnids

fluorogenic food, which when metabolized by healthy daphnids, generates a fluorescent glow. In

either identification method, the setup requires high maintenance (e.g., changing daphnia

periodically) and the daphnia are sensitive to changes in temperature. The method was extensively

used in Europe and during the 2002 Salt Lake City Olympic Games. The method is primarily used

to monitor raw water because the daphnids are sensitive to the chlorine in finished water. This

makes the method more difficult for use in treated water distribution systems.

The IQ Toxicity TestTM kit for grab samples was developed by Aqua Survey, Inc. (Flemington, NJ)

and detects various chemical and biological contaminants, including nerve agents and biotoxins, in

potable water. This method is based on fluorescent tagging and metabolism of live multicellular 60

organisms. In the presence of toxins, the metabolism of Daphnia magna is reduced, blocking their

normally visible light emittance. Test preparation includes growing and feeding Daphnia magna

a fluorescent sugar reagent, while the test itself takes 75 minutes. Aqua Survey, Inc., has packaged

the IQ Toxicity TestTM into a product called Threat Detection KitTM, which the company claims can

detect 9 different toxins at levels 2 to 20 times below the human lethal threshold. Based on EPA’s

ETV study, IQ-ToxTM can detect both nerve agents and biotoxins (EPA-ETV, 2004). However, the

results also may suggest that the test is too chlorine sensitive for use in finished water and

distribution systems.61

The Daphnia Toximeter, developed by bbe moldaenke (Kiel-Kronshagen, Germany), is used on line

with a measuring cycle of 30 minutes. Toxicity is assessed based on monitoring the behavioral

parameters, swimming speed, swimming altitude, turns and circling movements, growth rate, and

number of live daphnia. Allowable temperature range is between 0 to 30°C. The maintenance

interval is greater than seven days.62

• Algae-Based Biosensors

Algae can be used to detect the presence of toxic compounds by

monitoring chlorophyll fluorescence. An Algae Toximeter (bbe

moldaenke) cultures algae in a fermenter that regulates the concentration

and activity of the algae. A water sample is automatically injected with

standardized algae and monitored for changes in fluorescence. Activity

of the algae is constant if no toxic substances are present. Monitor

maintenance is required, at most, once every seven days. The Algae 63

Toximeter has not been adapted for use with finished drinking water.

(Image reproduced with permission from bbe moldaenke.)

• Fish-Based Biosensors

The German company that manufactures daphnia and algal toximeters (bbe moldaenke) also makes

a Fish Toximeter and a combined Fish and Daphnia Toximeter. The system uses zebrafish and

daphnia which are both fed by an integrated algae fermenter. Both toximeters use visual monitoring

for analysis of behaviors to assess organism health. Parameters measured are speed, altitude, turns,

circling movements, growth, and number of living fish. The presence of toxins is indicated by
U.S. EPA Office of Water Early Warning Systems

August 2005 72

changes in behavioral parameters. The measuring cycle is 1 to 30 minutes and the maintenance

interval is greater than seven days . (Images reproduced with permission from bbe moldaenke.) 64

• Dinoflaggelate-Based Biosensor

Because human cells are eukaryotic (contain a nucleus and organelles), eukaryotic cell responses

could be better models for toxicity to humans than bacterial cell responses. The only eukaryotic

cell-based biomonitor currently commercialized for use with water is the dinoflaggelate-based

Lumitox®. Lumitox® (Lumitox Gulf L.C., River Ridge, LA) uses bioluminescent dinoflaggelate

mutants to detect the presence of toxins in the ppb range. It is field portable and the company

indicates it is unaffected by a broad range of pH, turbidity, and salinity. The American Society for

Testing and Materials (ASTM) has published a guide (ASTM E1924-97) for using Lumitox®. It

can test both marine and non-marine fluids, soils, and chemicals (either water-soluable or

lipophylic). The patented TOX BOX® testing instrument is considered easy to operate, and no

computer is required. Grab sample screening can be completed in two to four hours.65

6.3.3 Infrared Spectroscopy

HazMatIDTM is the newest product from SensIR Technologies (now

merged with Smiths Detection, Edgewood, MD) for identification of 66

a variety of weapons of mass destruction, toxic industrial chemicals,

narcotics, and explosives. This is a portable tool using Fourier

transform infrared (FT-IR) attenuated total reflection (ATR)

spectroscopy for field identification of analytes in the solid or liquid

phase. HazMatIDTM features an integrated computer system with

wireless remote control capabilities to instantly compare the

spectroscopy of the unknown contaminant against an onboard

spectroscopy database of known substances. Its Bio-CheckIR software

can alert the user when at least 10 percent of the sample is composed of

proteins, indicating that a possible biological material is present (Mark

Norman, Smiths Detection, personal communication). The sample

interface is a diamond sensor with integrated video monitoring and is operational in extreme weather

and temperatures. Since infrared analysis is limited in aqueous samples containing less than 10

percent product, SensIR has developed an accessory product to HazMatIDTM, called ExtractIRTM.

This portable tool physically removes nonvolatile organic chemicals from the interfering water
U.S. EPA Office of Water Early Warning Systems

August 2005 73

matrix. By doing this, chemical levels as low as 100 ppm in water can be identified. ExtractIRTM

can be used in a hot zone by a responder in full Level A protective gear, and the entire process takes

about 10 minutes. The suitcase unit can be operated in extreme temperatures and can be totally 67

immersed in water for decontamination. (Image reproduced with permission from Smiths 68

Detection.)

6.3.4 X-ray Fluorescence

ITN Energy Systems, Inc. (Littleton, CO) has been given an EPA Small Business Innovation 69

Research (SBIR) Phase I award for the period of March 1, 2005 to August 31, 2005. The ultimate 70

project goal is to adapt ITN’s x-ray fluorescence technology to provide a smart, automatic early

warning sensor for trace levels of toxic metals in water on a ppb scale. This technology has been

proven in solar cell manufacturing where the sensor continuously monitors very small amounts of

metal in products and automatically provides feedback to process control. The sensor is capable of

simultaneously detecting multiple metals, including mercury, arsenic, and lead. In Phase I, the

feasibility of this approach will be demonstrated by showing the sensor can detect 20 ppb of mercury

in water without interferences from other metals, chemical state of the metals, or organic material.

6.3.5 Ion Mobility Spectroscopy

Ion Mobility Spectroscopy (IMS) is a technique for identifying and measuring volatile compounds.

An ambient air or vapor sample is drawn over a semi-permeable membrane. Smaller volatile

compounds pass through the membrane into the detection cell, where the sample is ionized by a

weak plasma formed by a nickel-63 radioactive source. The ionized sample molecules drift through

the cell under the influence of an electric field. An electronic shutter grid allows periodic

introduction of the ions into a drift tube where they separate, based on charge, mass, and shape.

Smaller ions move faster than larger ions through the drift tube and arrive at the detector sooner.

The amplified current from the detector is measured as a function of time and a spectrum is

generated. A microprocessor evaluates the spectrum for the target compound, and determines the

concentration based on the peak height. IMS is used in explosives detection equipment at airport 71

security check points. There are several portable IMS sensors for chemical detection but all have 72

been designed for use with air/vapor samples. One example is described below. 73

Smiths Detection produces a hand-held chemical vapor detector

called the SABRE 4000, that utilizes IMS and can detect and

identify over 40 threat substances (explosive, chemical warfare

agent, toxic industrial chemical, or narcotic substances) in

approximately 15 seconds. It takes 10 minutes to warm-up and

weighs seven pounds including the four-hour battery. The Sabre 74

4000 can be used in two modes, vapor mode or direct thermal

desorption mode. In the latter mode, the Sabre 4000 can test liquid

or solid samples. Either temperature controlled ramping to

evaporate the sample or a fiber solid phase microextraction

(SPME) probe are needed to measure aqueous samples. IMS technology can detect volatile organic

and inorganic compounds (MW < 1,000) above about 5 to 10 ppb concentrations. The technology

could be used to detect many different substances, but only about 40 to 50 profiles can be saved in
U.S. EPA Office of Water Early Warning Systems

August 2005 74

the current versions of the sensor devices (Rachel Kohn, Smiths Detection, personal

communication). (Image reproduced with permission from Smiths Detection).

6.3.6 Microchips for Portable Chemical Sensors

Not all portable sensors are based on microchip technology, but many are. The name, microchip,

is derived from the micrometer dimensions of the individual components that comprise microchips.

Any technology that can be minaturized to the micrometer scale could be mounted on a solid

platform and form the basis of a microchip technology. Minaturization is a key development for

making small portable sensors. When semiconductor devices (e.g., transistors and resistors) were

minaturized into the form of microprocessors, the computer industry was revolutionized. Since the

early 1990s, other technologies have been adapted to microchip dimensions and technologies that

would not be feasible on a macro level have also been invented for microchip platforms. This newer

class of microchips is often referred to as “lab-on-a-chip,” because the kinds of data generated by

the microchips are comparable to data that would have previously required bench-top sized

equipment to gather. “Lab-on-a-chip” generally refers to microetched chambers that can contain

nanoliter volumes of liquid to carry out multiple, small-scale, side-by-side chemical and/or

biological reactions. Microfluidics technology which allows minute quantities of liquids (reagents

and sample) to be manipulated and delivered to microchip components is an essential part of any

chip design that utilizes aqueous solutions.75

“Microarray” refers to microchips that have zones of unique characteristics. Current technology can

allow for as many as 100,000 distinctly unique zones or elements in a microarray. Each element

within an array can be designed to react with or respond to a different sample component. For

example, if the microarray has elements that recognize different DNA sequences, when a sample

of mixed DNA sequences is delivered to the microarray elements, only a subset of the elements will

respond to the sample. The response of the elements is detected or “read” by a chip reader device.

For example, the chip transducer could be based on optical, piezoelectric, magnetic, electrochemical,

or thermometric mechanisms. Although there are many different technologies for reading

microchips, the microchip design and the microchip reader device are designed as a single system

and in some cases are fully integrated. Microchips may or may not be reuseable. Several companies

offer custom designed microchips, which means they will incorporate subsets of elements specific

for the particular targets the customer wants to identify.

Micro-Electro-Mechanical System (MEMS) microchips have miniaturized mechanical and electrical

components. Microcantilevers and magnetoelastic sensors are examples of MEMS. Research and 76

development of MEMS-based technologies is a large field covering many potential applications.

As this field grew out of the integrated circuit field, much of the technology is built on silicon

wafers.77

Biochips, which often come in the form of microarrays, are based on biological reactions using

biological components such as nucleic acid hybridization, antibody reactions, and enzymatic

reactions. Biomolecules are also used for bioelectronic applications in a microchip format.

Biochips could be designed to detect biological molecules (DNA, RNA, proteins, biotoxins), or nonbiological chemicals. It’s important to note that the term “biochip” refers to the biological basis 78

of the chip and does not limit the class of targets to those that are biological. Because enzymes,
U.S. EPA Office of Water Early Warning Systems

August 2005 75

DNA, and antibodies all work in aqueous environments, microfluidics is an essential part of biochip

technology.

There are many kinds of prototype microchips demonstrating proof of concept that have not been

commercialized. Commercialized microchips are common in research and diagnostic laboratories,

however the support equipment to use the microchips, such as microfluidics stations and chip

readers, requires a laboratory setting, including trained personnel. Although microchips are a highly

developed technology for genomics, they are an emerging technology for other applications, such

as medical devices and environmental sensing.

Because of programs like the National Nanotechnology Initiative (NNI, a federal R&D program 79

established to coordinate multiagency efforts in nanoscale science, engineering, and technology) and

the intense interest and promise in the field in general, it is likely that micro- and nano-based

technologies will significantly contribute to product development and commercialization in the near

future.

6.3.7 Microchip Surface Acoustic Wave (SAW) Technology

SAW technology has been used for decades in transceiver technology and cell phone technology.

For chemical detection, SAW sensors can be configured in a microarray, with each element uniquely

coated. Mass changes in a subset of elements due to interaction with a particular volatile chemical

causes surface acoustic waves (~10 Å in amplitude, 1 to 100 micrometers in wavelength) which are

detected by piezoelectric materials. The subset of elements that respond to a specific VOC can be

recognized by software included in the sensor, allowing for a diverse list of detectable analytes.80

HAZMATCAD , from Microsensor Systems, Inc. (Bowling TM

Green, KY), features three 250 MHz SAW sensors in a hand-held

portable Chemical Agent Detector instrument. Each sensor is

coated with different polymers that provide a multi-pattern sensor

response (fingerprint) to indicate the presence of contaminants in

vapor samples. HAZMATCAD detects and identifies trace 81 TM

amounts of chemical warfare agents, including nerve and blister

agents, and can be configured to detect phosgene and/or hydrogen

cyanide. HAZMATCAD Plus supplements the SAW technology TM

with electrochemical sensors for additional detection of up to four

classes of toxic industrial chemicals, specifically hydride, halogen,

choke, and blood agent vapors. The system operates on 20 to 120

second analysis cycle, depending on the mode selected, and the

typical time to alarm is less than 60 seconds in “Fast Mode.” This

device has price range of $4,850 to $7,950 and has been evaluated

by the Army. (Image reproduced with permission from 82

Microsensor Systems Inc.)
U.S. EPA Office of Water Early Warning Systems

August 2005 76

6.3.8 Microchip Chemiresistors

CyranoTM Sciences, now a part of Smiths Detection

(Edgewood, MD), has developed miniature “electronic 83

nose” sensors using conductive polymer films deposited

in an array on a ceramic substrate. Each individual

detector of the sensor array is a composite material

consisting of conductive carbon black homogeneously

blended throughout a non-conducting polymer. The

detector materials are deposited as thin films on an

alumina substrate that lie across two electrical leads,

which create conducting chemiresistors. The output from

the device is an array of resistance values as measured

between each of the two electrical leads for each of the detectors in the array. The polymer

composite chemiresistors, are designed to absorb a diversity of analytes. The manufacturers claim

that the polymer composite sensors respond to a wide range of organic compounds, bacteria, and

natural products in a vapor form. The signature of 100 different analytes can be stored in the

memory of the Cyranose® 320 hand-held device, which is commercially available. A penny sized

version called the NoseChip is being used to develop future products called ChemAlert and TM TM

ChemBioAlert , which will be integrated into online sensor networks. Although these “electronic TM

noses” are not able to directly measure water samples, if used with vaporizing technology, they

could be adapted for water sampling (Rachel Kohn, Smiths Detection, personal communication).

(Images reproduced with permission from Smiths Detection.)

6.4 Emerging Technology

Although the biosensor, IMS, and SAW technologies discussed above (Section 6.3) have

commercially available products on the market for surface water or vapor media, these technologies

are also being used to develop the next generation of sensors so they can also be considered an

emerging technology. In addition, fiber optic cables, which are being designed to serve as

continuous sensors, are discussed below. These emerging technologies are being developed by

companies, national labs, and other research institutes.

6.4.1 Organism-Based Biosensors

• Clam Biomonitor

Similar to MosselMonitor®, discussed previously, other groups are investigating using clam

responses to detect water quality issues that affect clam behavior. However, these approaches have

been limited to source water monitoring. The University of North Texas, Little Miami, Inc.

(Milford, OH), and EPA have a joint project to develop a Clam Biomonitoring System. The gape

of 15 clams is measured at one-minute intervals and is plotted along with temperature, pH,

conductivity, and dissolved oxygen. A cellular modum is used to connect to the Internet for data

relay. The system is installed on the Little Miami River in Miamiville, OH. This system has not 84

been tested in chlorinated drinking water. 
U.S. EPA Office of Water Early Warning Systems

August 2005 77

• Fish Biomonitors

The Great Lakes Water Institute, a University of Wisconsin research group, is developing a

biosensor system using transgenic zebrafish to monitor water distribution systems. The embryos

of zebrafish are injected with pollution responsive reporter genes shortly after fertilization. The

transgenic fish are designed to detect 18 chemical contaminants, including the biological warfare

agents paraoxon and parathion, which are relatives of sarin. The contaminants trigger the pollution

response elements, which then activate the production of luciferase in the fish. The enzyme causes

the fish to emit light, thereby signaling the presence of a toxin in the water. The fish can be used

to repeatedly analyze the same site as the monitoring process does not kill the fish.85

The U.S. Army Center for Environmental Health Research (USACEHR) has developed an

automated biomonitor-based on bluegill (Lepomis macrochirus) ventilatory and body movement

patterns. It was developed to monitor toxins in treated wastewater but has not been adapted for 86

chlorinated drinking water.

6.4.2 Eukaryotic Cell-Based Biosensors

There are emerging technologies that incorporate eukaryotic cells or tissues in assays on microchip

platforms for biosensors. The B-cell, cardiac-cell, and fish-cell systems described in this section

have not yet been commercialized and are not being developed specifically for drinking water.

These emerging technologies could be utilized for drinking water monitoring provided that sample

volume concentration and disinfectant residual issues are addressed.

Fish cells could be used to detect toxins through changes in color and movement of chromatophores

(primary cells). The cells are stored in disposable cartridges which can be monitored by a video

camera through a microscope. The data would be analyzed by a computer for the changes described

above. Such a system could show changes within 1 to 100 minutes and could be used in continuous

or grab sample mode (Grayman et al., 2003). A prototype system, SOS Cytosensor system, is being

developed by Adlyfe, Inc. (Rockville, MD).87

A biosensor-based on mammalian cells (cardiac cells) is being developed by Dr. Gregory Kovacs

at Stanford University. The cells are cultured on disposable microelectrode arrays. The toxins are

detected by changes in electrical discharge, beat rate, and signal propagation velocity. The system

is being designed for grab sample analyses using portable hand-held equipment. The Portable CellBased Biosensor is in the prototype stage. Mammalian neuronal cells have also been explored as

a biosensor by the U.S. Naval Research Laboratory. The neuronal cells are carried in a transportable

cell cartridge which is placed in a monitoring device for continuous monitoring for up to two days.

A computer program evaluates changes in electrical patterns such as mean spike rates. The system

called Portable Neuronal Microelectrode Array is commercially available (Shaffer et al., 2003).88

6.4.3 Fiber Optic Cable-Based Sensors

The Great Lakes Water Institute, a University of Wisconsin research group, is developing a real-time

water distribution system monitor utilizing fiber optic cables. The Water Security Division of the

Great Lakes Water Institute is supported in part by the Water Harvesting and Water Purification

Program at DARPA. The monitor consists of a fiber optic cable run through the water conduit, and
U.S. EPA Office of Water Early Warning Systems

August 2005 78

various chemical receptors and a fluorescent group are attached to a gel coating the cable. When

a toxin binds to a receptor, the characteristics of the fluorescent group, or fluorophore, are altered.

Laser pulses passing through the cable detect the change in the fluorophore, providing for detection

from a central monitoring station. Spatial maps are generated, based on the data from the laser

pulses. The Institute is developing technology to add both biological and chemical receptors to the

cable in order to provide a more complete monitoring system, since the only toxins that are detected

are the specific ones that the system is designed to detect.89

Intelligent Optical Systems, Inc.’s (Torrence, CA) DICAST® technology is composed of fiber optic

cables that have a glass core coated with a permeable indicator-doped cladding to achieve chemical

sensitivity over their entire length. Instead of having several sensors at various locations along its 90

length, the entire length of the fiber is a sensor. Thus, it has more sensing area and less probability

of missing a target molecule. Although DICAST® has been developed for sensing in air, it could

be modified to work in water. The applications of this and other fiber optic sensors include

monitoring water for dissolved gases, pH, bio-content, and toxic chemicals and their byproducts

such as cyanide (Steven Cordero, Intelligent Optical Systems, Inc., personal communication).

6.4.4 Ion Mobility Spectroscopy (IMS)

Sionex Corporation’s (Waltham, MA), MicroDMxTM, technology is based

on IMS in a MEMS format, but is referred to as differential mobility

spectroscopy because a varying radio frequency field pulls the ions in a

zigzag pattern increasing the distance they travel thereby increasing their

separation. The company has prototype hand-held and online products 91

in development for detection of VOCs in air. The company also has

research projects ongoing for adapting the prototypes for water matrices

(Joe Santos, Sionex, personal communication). (Image reproduced with

permission from Sionex Corporation.)

6.4.5 Surface Acoustic Wave (SAW) Technology

S-CAD, developed by Science Applications International Corporation (SAIC; San Diego, CA), is

a portable, hand-held chemical agent detection system for air. This product features the dual

detection power of an IMS cell and a SAW sensor, combined with a data fusion algorithm to reduce

false alarms without affecting detection performance. The system can both identify and specify the

concentration of different chemical agents, including nerve, blister, and blood agents. S-CAD has

the capability to gather and store data for future analysis, and its modular design allows easy

integration with nuclear and biological agent detectors and/or other application specific sensors.92

The company is currently examining issues regarding adaptation for water sampling (Steven Haupt,

SAIC, personal communication).

Sandia National Laboratories (SNL) has developed the Micromachined Acoustic Chemical Sensor

to detect VOCs, explosives, illicit drugs, and chemical warfare agents. These miniature sensors 93

(as small as 0.5 mm) incorporate a micromachined flexural plate wave (FPW) device as a general

purpose chemical sensing platform. FPW technology uses polymer films to selectively absorb the 94

analyte of interest and is compatible with both gases and liquids. These devices are analogous to

the SAW sensor, which is an extremely sensitive gravimetric detector that can be coated with a film
U.S. EPA Office of Water Early Warning Systems

August 2005 79

to collect chemical species of interest down to ppm and ppb levels of airborne contaminants. The 95

Micromachined Acoustic Chemical Sensor can be fabricated on silicon with integrated

microelectronics to complete the sensor capability. Although none of these technologies has been

integrated into a commercially available product nor has been designed for use in water distribution

systems, SNL believes the technology has high potential for in situ chemical detection applications.

SNL has also developed two field prototypes for portable chemical

analysis systems, called μChemLab, which researchers hope to

combine into one complete system by 2008 (μChemLab/CBTM ). 96

The Gas-Phase μChemLab uses a combination of GC channels

coupled with an array of SAW sensors to monitor volatile and semivolatile organic species in air. This product can detect chemicals at

levels as low as 10 to 100 ppb and analysis takes just seconds-tominutes. The Liquid-Phase μChemLab hand-held analyzer utilizes

various chip-based technological innovations such as microfluidics,

capillary gel, and zone electrophoresis columns that are combined

with small laser-induced fluorescence detectors. The detectors can

analyze biotoxins and other inorganic and high MW chemical contaminants. SNL scientists plan

to further develop the system so it can detect viruses and bacteria. Nanodetex (formerly MCL 97

Technologies, Albuquerque, NM) is an SNL spin-off company licenced to develop μChemLab for

chemical warfare agents, drug detection, and health monitoring. There is also ongoing research to

adapt the Gas-Phase μChemLab to water applications, including automated onsite measurement of

trihalomethanes, petroleum hydrocarbon contaminants, and chemical warfare agents and their

hydrolysis products. The ultimate goal is to develop a low-cost, quickly deployable, and real-time

discriminatory sensor for water quality determination as well as online versions of the equipment.

This technology is funded under the DOE’s Chemical and Biological Non-Proliferation program and

is also a candidate system for the DOD’s Joint Chemical Biological Agent Water Monitor project

(Wayne Einfeld, SNL, personal communication). SNL, CH2M Hill (Colorado), and Tenix

Investments (Australia) have signed an agreement that calls for an online water monitoring

prototype, based on μChemLab, to be developed and begin testing by June 2005. The first phase 98

of testing will focus on detecting ricin and botulinum toxin. The development team eventually also

hopes to address viruses, bacteria, and parasites. (See Appendix B for summaries of SNL research

projects related to detection technologies; photo from SNL website.)

Pacific Northwest National Laboratories (PNNL; Richland, WA) has designed a SAW-based sensor

system to detect chemical warfare agents in the field. The SAW sensors have chemically selective

polymer coatings to provide rapid, reversible analysis of multi-component chemical vapors.

Chemometric analysis is used to distinguish between multiple vapor signals, which is the application

of mathematical, statistical, graphical, or symbolic methods to maximize chemical information

which can subsequently be extracted from data. The system is integrated with computer control and

data acquisition and has been deployed and demonstrated in the field. PNNL researchers have also

improved the sensitivity of traditional SAW sensors by coating them with synthesized novel

hydrogen bonding organic/inorganic copolymers. The sensors reach 90 percent of full response

within six seconds of the first indication of response when exposed to nerve agent simulants and

organic solvents. In tests using actual nerve agents, response sensitivity was increased at least four

times over traditional sensing polymers. PNNL’s new copolymers are currently being used in
U.S. EPA Office of Water Early Warning Systems

August 2005 80

commercially available chemical sensors for the detection of nerve agents. Copolymer technology

is available for licensing.99

6.4.6 Raman Spectroscopy

Real-Time Analyzers, Inc. (East Hartford, CT) has recently been received an EPA Small Business 100

Innovative Research (SBIR) Program Phase I award for the period of March 1, 2005, to August 31,

2005, to provide the Agency with a chemical sensor that can be multiplexed into water distribution

systems to provide an EWS capability. Surface-enhanced Raman scattering (SERS) sensors will be

coupled to a central Raman analyzer via fiber optics. The objective of the project is to develop

sensors that will selectively detect several chemical agent hydrolysis products, toxic industrial

chemicals, and pesticides at concentrations below 1 mg/L in flowing streams in 10 minutes or less.
U.S. EPA Office of Water Early Warning Systems

August 2005 81

7. Technologies that Detect Microbial Contaminants for Early Warning Systems

7.1 General Introduction to Assays and Sensors

Currently, microbial culture methods are relatively slow, requiring at least 24 to 48 hours before

results are available. With traditional techniques, growth of the target organisms in culture is

required for identification. Ideally, microbial monitoring methods should be rapid, providing results

in two hours or less. The methods presented in this chapter begin to meet these criteria. Sensors

for living organisms can target detection of genetic material (nucleic acids), proteins, or other

components or activities of living cells such as adenosine triphosphate (ATP). Most sensors for

detecting microbes are based on biological interactions, so they have biological components

incorporated into the sensor technology. The sensor components that interact directly with sample

components are called capture or recognition components. Capture molecules can be DNA,

antibodies, or other molecules that bind or react with sample components. The sample component

that will be detected is called the target. Generally, target refers to the actual molecule that interacts

with the capture molecule, but in some cases it is used to refer to the whole organism that is

indicated by the presence of the target molecule. Examples of target molecules are specific DNA

sequences and antigens. Target molecules can also be chemicals. There are some sensors presented

in this chapter that can detect both pathogens and chemicals, but detection of chemicals is not the

primary application of the technology. 

The specificity of a sensor is determined by how reliably and firmly capture molecules bind or

interact with the specified target. The capture molecule-target molecule interaction is detected

through various mechanisms such as light production or mass change. The sensitivity of a sensor

is based both on how well the capture molecule and target interact and on how many molecules need

to interact before the reaction can be detected. The reaction kinetics (binding and release of target

molecules) requires that targets be relatively concentrated, so methods for concentrating microbes

from larger volumes of drinking water are needed. In the case of intentional contamination, a

sample concentration step may not be needed. The above discussion applies to multiple sensor

platforms, such as immunoassay strips, microchips, and solution phase systems.

EPA does not endorse or recommend any of the following technologies. The summary

information below was obtained from company websites, promotional literature, and personal

communication with company representatives.

7.2 Available Technologies

7.2.1 Immunoassays

The principle behind rapid immunoassay technologies is to detect the antigen-antibody reaction.

Specific antigens in the water are bound to corresponding antibodies through targeting of specific

proteins. The presence of a microbial contaminant is “seen” when specific antigen proteins in the

sample bind with the corresponding antibodies. Immunoassays have been used since the early 1980s

for many research, clinical, and safety/quality control applications. A familiar example of a strip

type immunoassay is a home pregnancy test. Classic examples of immunoassays are the enzyme- 101

linked immunosorbent assay (ELISA) and the enzyme-linked fluorescent immunoassays (ELFA).

Immunosorbent refers to the immobilization of the capture molecules on a surface, such as a
U.S. EPA Office of Water Early Warning Systems

August 2005 82

membrane (Alberts, 1994). The capture molecules can be either antigens or antibodies. The target

molecules in the sample are antibodies if antigens are immobilized and antigens if antibodies are

immobilized. Another antibody that recognizes either the sample antigens or sample antibodies,

called the secondary antibody, is added. The secondary antibody is conjugated (linked) to an

enzyme that forms a colored precipitate (for ELISA) or gives off light (for ELFA) in the presence

of substrate. Each enzyme molecule acts catalytically, thereby amplifying the signal of a successful

binding interaction. When the assay consists of capture antibodies recognizing antigens, which are

in turn recognized by secondary antibodies, it is called an antibody sandwich assay. ELISAs for

quantitative assays are commonly done in microtiter plates in laboratory settings and may require

time consuming pipetting. However, the technology has been advanced for strip assays for onsite

uses. One of the issues for many immunoassays is cross reactivity with other microbes which leads

to high false-positives rates. This can be addressed with the use of specific epitope targeted

monoclonals that have been verified for low cross-reactivity with other potential sample

components. Immunoassay methods have primarily been developed for grab samples, but have not

been applied for online water distribution monitoring systems. Variations on the basic ELISA and

ELFA concepts have also been incorporated into microchip designs.

Immunoassays designed for onsite grab sample screening for intentional chemical or microbial

contamination of air, food, and water are desirable because the method can determine the presence

of a specified microbial contaminant or contaminants and can be completed in less than 15 minutes.

Test strips are generally not quantitative, so the results usually need to be confirmed by other

methods.

• Strip Tests - Lateral Flow Assay

The lateral flow assay is a general technique for detecting antigens. It is a simplified version of 102

ELISA. The test strip is an absorbent membrane mounted on a stiff (plastic) backing, often

contained in a plastic cassette. A liquid sample is applied to one end of the strip, the sample diffuses

along the length of the strip, passing several stripes (narrow regions) impregnated with high

concentrations of specific antibodies, which are labeled with colored dyes or fluorescent agents.

When the antigen-labeled antibody complex migrates to the test stripes, a color change or

fluorescent signal indicates the presence of the target antigen. A control stripe beyond the test stripe

serves as a positive control, indicating proper diffusion and appropriate functioning of strip reagents

(Exhibit 7-1). Home pregnancy tests are lateral flow assays. Traditional lateral flow assays 103

produce color changes that can be detected with the naked eye. Newer fluorescent and

phosphorescent reporters require excitation light and/or light detection devices.

A commercially available lateral flow assay test strip is Bio Threat Alert® (BTA) made by Tetracore

(Gaithersburg, MD ). Samples are put on the test strip and move along the strip membrane. A 104

reddish band that can be seen with the naked eye on the positive line indicates the presence of

specific contaminants. The following are the currently available tests and detection limits, expressed

as colony forming units per milliliter (cfu/ml) (images reproduced with permission from Tetracore):

• Bacillus anthracis (1 x 10 cfu/mL) 5

• Yersinia pestis (2 x 10 cfu/mL) 5

• Francisella tularensis (1.4 x 10 cfu/mL) 5
U.S. EPA Office of Water Early Warning Systems

August 2005 83

Exhibit 7-1. Lateral Flow Assay

(image from: http://spaceresearch.nasa.gov/general_info/homeplanet.html)

• Botulinum toxin (10 ppb)

• Staphylococcal enterotoxin B (2.5 ppb)

• Ricin (50 ppm)

New Horizons Diagnostics’ (Columbia, MD) SMARTTM (Sensitive

Membrane Antigen Rapid Test) Tickets use a similar method. The

detection is provided by immuofocusing of colloidal gold-labeled

antibodies and their corresponding target antigens onto small

membranes. Two red lines on the strip indicate positive control and

positive sample and the test is complete in 15 minutes. SMARTTM tests

currently available are the same as BTA with the inclusion of Vibrio

cholerae O1. The detection limits of bacteria are 10 cfu/mL and for biotoxin is 50 ppb. 5 105

SMARTTM Tickets have been incorporated into Bio-HAZTM (EAI

Corporation, Abingdon, MD), a portable field kit for sample

collection and analysis to detect the presence of biological

contaminants (ECBC, 2002). Designed primarily for use by

emergency response and forensics evidence personnel, the kit

contains materials needed for liquid, solid, and air sampling and

onsite biological screening. Fluorometry, luminescence,

colorimetry, and sample-specific analyses, performed with handheld equipment, identify the presence of biological contaminants
U.S. EPA Office of Water Early Warning Systems

August 2005 84

in the field. Ruggedized for field use, the kit also includes instructions to assure evidentiary

integrity. (Image reproduced with permission from EAI Corporation.) 106

ADVNT (Phoenix, AZ), immunoassay detection strips called BioWarfare Agent Detection 107

Devices (BADD), have been used by U.N. weapons inspectors in Iraq. BADD strips are 108

self-contained, qualitative assays for screening environmental samples for the presence of anthrax,

botulinum toxin, and ricin. After a sample is transferred to the BADD test strip, dye-labled

antibodies detect trace amount of the contaminant and show its presence with two bands. After 15

minutes, the results are read visually.

RAMP Anthrax Assay by Response Biomedical Corporation (Vancouver, Canada) is a rapid

immunochromatographic system. The system has a portable fluorescence reader and test cartridges

for detecting anthrax, botulinum toxin, ricin, and smallpox. The cartridge is a lateral flow

immunoassay device with a test and control line. The detector is an antigen-specific antibody

attached to a fluorescent bead. The RAMP instrument detects the presence of fluorescent beads that

attach to the capture assay line. The RAMP Anthrax Assay has not been tested for use in drinking 109

water systems.

7.2.2 Detection of Bacterial - ATP

A common indicator for microbial presence used in the food and beverage industry is ATP. Tests

for ATP are now being used for rapid detection of microbes in water, such as cooling towers. A

small volume of water (typically < 20 milliliters) is required and the test takes between 30 seconds

and a few minutes depending on the kit. Either free ATP or microbial ATP can be measured. To

measure microbial ATP, cells in the water sample are lysed to release ATP into the solution. To

detect only ATP contained within living bacterial cells, the water sample must first be filtered to

collect the cells and rinse away non-bacterial ATP, then the cells are lysed to release ATP.

An enzyme, luciferase, and a substrate, luciferin, are present in the reaction solution. The reaction

catalyzed by luciferase, that breaks down ATP and releases a photon of light from luciferin. A small

hand-held/portable luminometer reads the quantity of light emitted from the reaction. The light

intensity is directly related to the concentration of ATP in the sample, which is in turn an

approximate indicator of biomass in the sample. The ATP test requires users to purchase a 110

luminometer and consumable supplies (enzyme, substrate, and sample container). The ATP reaction

can be amplified with adenylate kinase (AK) to measure very low numbers of cells.111

The concentration of ATP in microbes depends on species, strain, environmental, and metabolic

factors. Therefore, ATP is only an approximate indicator of biomass. Using bacteria-spiked water

samples, the kits available have lower detection limits, around 1,000 cfu/mL. Since all living cells

have ATP, microbial ATP needs to be separated from non-microbial ATP. However it cannot

differentiate between bacterial species. In general, a single relative light unit (RLU) reading is not

adequate for assessing the degree of microbial presence in a sample. It is important that routine

testing establish a baseline trend for ATP results, then subsequent fluctuations in ATP can indicate

a change in microbial status for the system. ATP from the human user can also be a source of falsepositive readings. Numerous companies have products on the market, a few that design products

for water are presented below. No third party verification was indicated for any of the products.
U.S. EPA Office of Water Early Warning Systems

August 2005 85

A few products that can detect total

ATP are included because they may be

useful for monitoring highly pure water

samples that do not have background

sources of ATP. AMSALiteTM

(Antimicrobial Specialists and

Associates, Inc., Midland, MI) sells 112

an ATP detection kit that is specifically

for industries using high purity water,

such as printing. The luminometer 113

costs about $2,000 and several versions

of the kit available. The WaterGieneTM

(Charm Sciences, Inc., Lawrence,

MA) test swab has a chamber with a cell lysing agent to expose cellular ATP, but it does not first 114

rinse extracellular ATP away. (Images reproduced with permission from AMSA Inc.)

Bio Trace International (Bridgend, UK) sells an online Continuous

Flow ATP Detector that can be used to discriminate between 115

background ATP and bacterial ATP. The company claims “near realtime” results and a testing capacity that provides readings every

second.

New Horizons Diagnostic Corporation’s (Columbia, MD) Profile®-1

uses its FiltravetteTM disposable cartridge system to remove nonbacterial ATP arising from somatic cells (other sources of nonbacterial ATP) and other interfering compounds. This system has 116

been demonstrated to be useful for measuring only bacterial ATP in

distribution system water by Deininger and Lee (2001). The

FiltravetteTM allows for the free ATP to be rinsed away before the

bacterial ATP is released into the assay solution. (Image reproduced

with permission from New Horizons Diagnostics Inc.)

7.2.3 Flow Cytometry- and Micro-Flow-Based Technology

Flow Cytometry is a general technique that has been used in laboratories since the 1960s for analysis

of cells. More recently, flow cytometry has been used in medical applications and analysis of

environmental microbial populations. A monodisperse suspension of cells flows past a laser beam

(or in some more complicated instruments, multiple laser beams) and the device measures properties

of each cell, such as size, granularity, green fluorescence, red fluorescence, and far red fluorescence

intensities. Fluorescent tags can be used for a variety of general or specific cell components, such 117

as DNA, RNA, proteins (antigens), or other target molecules. Some microorganisms can be

distinguished on the basis of differential light scatter properties with the addition of fluorescent tags.

Dyes that stain only live cells can be added to samples so that the flow cytometer can quantify the

level of live versus dead cells. Nucleic acid intercalating dyes can be used to determine DNA/RNA

ratios and adenine-thymine/cytosine-guanine content which helps further characterize the cells in

a sample and could be used to identify microorganisms in some cases. Fluorescently labeled

antibodies can be used to identify specific organisms in aerosols, water, soil, and food.
U.S. EPA Office of Water Early Warning Systems

August 2005 86

Alternatively, attachment of specific antibody to fluorescent microspheres can detect both toxins and

viruses in multicolor assays. The same technology that can “see” and sort individual cells can also

be used to analyze micro particles.

Microcyte Aqua® and Microcyte Field® by BioDetect (Houston, TX)

 are suitcase sized flow cytometers that can be used in the field to 118

characterize particles and identify microbes if used in conjunction with

fluorescent tags. Microcyte Aqua® is targeted at routine analysis of

algae and other microorganisms in water. BioDetect claims that the

minimal sample preparation makes the system suited for integration into

an online, continuous water surveillance system. The instrument can

differentiate between biological and non-biological particles, which is

important for applications where correlation between the total number

of particles and microorganisms does not always exist. (Image used

with permission from BioDetect.)

Brightwell Technologies (Ottawa, Canada)119

produces an automated Micro-Flow Imaging

instrument that acts as a particle counter but

actually captures digital images of the particles in

the water sample. The sample is drawn through

a micro-fluidic flow cell. One digital image per

second is taken of the sample and images are

stored that meet user-defined parameters. It

takes about 5 minutes to analyze 1 mL of sample.

Particles as small as 1 μm can be seen by the

camera, which has a 0.2 μm resolution. Particle

sizes and concentrations are analyzed and the

data are presented graphically. The system requires no sample preparation and can be run

continuously or intermittently for hours. The company has tested the system in drinking water and

wastewater treatment applications. (Image reproduced with permission from Brightwell

Technologies.)

7.2.4 Bioparticulate Monitors - Light Scattering Technology

Light scattering technology is a simple scanning procedure that provides information about the

presence of particles of a certain size. When a laser beam is sent through flowing water, the laser

light is scattered at right angles by the presence of particles in the water. Optical devices such as

photodiodes collect the scattered light, which can be analyzed to determine the size and number of

particles present in the water sample.

An alert to the presence of particles in the water is useful because it can quickly alert water operators

of a possible contaminant. However, the technology does not allow for the determination of specific

information about the identity of the particle; furthermore, it can only detect particles within a

certain size range. It often cannot differentiate between a grain of sand and a harmful

microorganism. As a result, there can be a high false-positive rate associated with the technology.120
U.S. EPA Office of Water Early Warning Systems

August 2005 87

Online turbidimeters, which measure the cloudiness of water using continuous light scattering

technology, are well known and used within the water utility industry. Turbidimeters use heated

tungsten filaments, light-emitting diodes, or lasers. Turbidity monitoring is required on any water

produced for public consumption, and tests alert water operators that filters are failing or that the

water is more conducive to bacterial growth. The same technology that supports turbidimeter 121

technology can also be applied to continuous online monitoring of drinking water distribution

systems to screen for the intentional introduction of pathogens. Optical techniques can overcome

many of the shortfalls of traditional detection methods, which are slow, labor-intensive, and can

have high variability and low recoveries.

An AwwaRF research project determined that Multi-Angle Light Scattering (MALS) can distinguish

between Cryptosporidium and finished water matrix particles at a level great enough to serve as an

early warning tool for water systems. The identification rate of Cryptosporidium parvum oocysts

varied from 11 percent to 45 percent, and false-positive rates varied from 0.3 percent to 3 percent.

The MALS system may be tuned by the user, who must understand that a higher identification rate

will be accompanied by a higher false-positive rate. MALS was also able to differentiate between

different physical states of Cryptosporidium oocysts, including oocysts treated with ozone, heat

treated, or excysted from live untreated oocysts. The technology uses optical fingerprints in order

to identify the different types of oocysts. This finding is important to water system operators

because it allows users to determine if the potential harm from Cryptosporidium oocysts has been

reduced by mitigation actions. The limit of detection was such that MALS could be used as an early

warning tool for water contamination outbreaks. For purified water, the estimated limit of detection

(ELOD) was found to be 7, 0.7, and 0.1 oocysts/mL in 1, 10, and 60 minutes, respectively. For

finished drinking water samples, the ELOD was 75, 7.5, and 1 oocysts/mL in 1, 10, and 60 minutes,

respectively. The researchers concluded that MALS technology has suitable applications to water

distribution system monitoring (Quist et al., 2004 ). It was tested at the San Diego State University 122

“Shadow Bowl,” which was organized to test new rapid-response measures to deal with a potential

national security emergency during the 2003 Super Bowl.123

The AwwaRF research project on MALS was developed into a

commercial product called BioSentryTM, by JMAR Technologies, Inc.

(Carlsbad, CA; formed from LXT Group and PointSource

Technologies). BioSentryTM beta units have been field tested and the

product is scheduled for commercial production in late 2005. The

system is composed of multiple, laser-illuminated sensor units that are

networked together to provide continuous, real-time monitoring of

water distribution systems. It uses 660 nm wavelength laser light and

a charge-coupled device (CCD) detector to collect the scattered light.

The technology uses Mie scattering, which is measured from the

direction of the incoming light and is not dependent on the specific

wavelength of the light. Although mie scattering has been used in

other particle counting technology, this is the first application to water

monitoring. The light is then collected from multiple angles, allowing

for the compilation of more information about the particles than is possible with a single collection

point. Desktop computers at a central location utilize LXT’s proprietary algorithms to analyze the

shape, size, index of refraction, and internal structure of particles in order to identify the

contaminant. The analysis of all of the factors helps reduce false-positives generated by systems that
U.S. EPA Office of Water Early Warning Systems

August 2005 88

examine particle size alone. BioSentryTM also has the ability to alert system operators to the

presence of unknown or unrecognized contaminants. (Image reproduced with permission from

JMAR.)

The two main challenges facing this technology are false-positives and the level of sensitivity. The

application of light scattering technology using multiple collection angles and complex algorithms

will yield a lower false-positive rate than its predecessor technology that simply counts particles of

a certain size. However, in order for the system to be effective in protecting humans from

contaminated water, the technology must be sensitive enough to detect microorganisms well below

dangerous levels, perhaps one spore in 100 liters. JMAR hopes to be able to more accurately assess

the effectiveness of BioSentryTM upon completion of field tests at water utilities in 2005.124

Rustek, Ltd. (UK) has developed a Multi-Angle Laser Light Scattering (MALLS) technology that

combined with pattern recognition techniques increases the technology’s ability to monitor for

microbial contaminants. The Computing Research Centre at Sheffield Hallam University, 125

(Sheffield, UK), is using the MALLS device patented by Rustek, Ltd. The technology is currently

being used to detect bacteria in different elements of the water industry, including water companies,

the bottled water industry, and breweries; in addition, the technology has applications in the medical

field. The device analyzes how light is scattered in order to determine the particle content in the

water sample. When a laser beam is projected through a sample, it is disrupted by particles. The

resulting light picture, or how the laser beam appears after it is disrupted by particles, will vary in

both the direction and speed of the light beams. Thus, the fluctuation in amplitude and frequency

of intensity are measured to determine the amount of microbes present in the sample.126

7.3 Potentially Adaptable Technology

The technologies presented in this section are potentially adaptable for finished water and

distribution systems, but have not reached the fully commercial stage or undergone third party

verification. The technologies either have been developed originally for source water or for nonwater media (e.g., air).

7.3.1 Fiber Optic-Based Biosensor

RAPTORTM, developed by the U.S. Naval Research Laboratory and

Research International (London, UK), is a portable, rapid, automatic

fluorometric assay system for monitoring biological contaminants,

toxins, explosives, and chemical contaminants. The self-contained 127

instrument integrates optics, fluidics, electronics, and software and is

suitable for laboratory and field assays. It performs user-defined,

multi-step assay protocols for monitoring fluorescently labeled

chemical reactions occurring on the surface of each of the system’s

four disposable optical waveguide sensors. Research International’s

biosensor systems are based on monolayer receptor-ligand reactions

taking place on the surface of injection molded polystyrene

waveguides. The baseline protocol used to identify specific pathogens is called the “sandwich

format” fluoroimmunoassay. Toxins and bacteria such as ricin and B. anthracis have been detected

at levels below <1.0 ng/mL and 100 cfu/mL, respectively. According to Research International,
U.S. EPA Office of Water Early Warning Systems

August 2005 89

RAPTORTM is capable of real-time detection of microbial pathogens with or without conventional

culture. The portable unit can simultaneously process four analytes in 7 to 12 minutes. The handheld model in development will be capable of 12 to16 simultaneous assays (Bunk, 2002). (Image

reproduced with permission from Research International.)

Daniel Lim’s laboratory (University of South Florida) was involved in the development of

RAPTORTM and is currently in the process of placing a prototype array biosensor linked to a

filtration/concentration system for automated, continuous online monitoring of potable water at a

local water utility. The filtration/concentration system uses a hollow fiber filter that concentrates

microorganisms from large volumes of water. The system will be back flushed and the back flush

will be sent directly to the biosensor. It is anticipated that the biosensor will be able to identify

specific microorganisms in the distribution system, including biothreat agents, should they occur

(Daniel Lim, University of South Florida, personal communication).

7.3.2 Dye-Loaded Microspheres

The Luminex® Corporation’s (Riverside, CA) xMAP®

system consists of 5.6 micrometer polystyrene

microsphere particles that are loaded with red and

infrared fluorophores in ratios that allow for 100

distinct color-codes. Each microsphere can be coated

with a separate capture molecule which can be

involved in either nucleic acid hybridization, antibody

recognition, a receptor-ligand reaction, or an enzymatic

reaction. The reaction times are about three times

faster than standard microarrays because the

microspheres are in solution have 3-D exposure allowing for nearly solution-phase kinetics, whereas

flat microarrays are limited by solid-phase kinetics. The microspheres pass through the detection

chamber single file and are optically measured. Luminex® markets bench top readers for 128

genomics and proteomics applications. Researchers from Lawrence Livermore National Laboratory

(LLNL) utilized Luminex® technology to develop an Autonomous Pathogen Detection System

(APDS). The system has an automated sample preparation module, based on sequential injection

analysis (SIA). The APDS interfaces aerosol sampling with multiplexed microsphere immunoassayflow cytometric detection. The system performed well over five days of unattended continuous

operation (Hindson et al., 2004). (Image reproduced with permission from Luminex Corp.) 129

7.3.3 Detection of ATP

Several ATP detection systems are available for use with water samples. Another commercially

available system deserves note because it has a long-standing history of use in the food and beverage

industry and may be applicable for finished drinking water. Celsis-Lumac (Landgraaf, The

Netherlands) sells a cellular ATP detection system, RapiScreenTM, that can be used to measure

bacteria on the surfaces of meat products and in beverages. Hygiena (Camarillo, CA), which also 130

markets some of the Celsis-Lumac technology, has developed liquid stable reagents and freeze-dried

reagents for ATP bioluminescence applications.131
U.S. EPA Office of Water Early Warning Systems

August 2005 90

7.3.4 Cell-Based Biosensor

The Massachusetts Institute of Technology

(MIT) developed Cellular Analysis and

Notification of Antigen Risk and Yields

(CANARYTM), which was licensed to

Innovative Biosensors, Inc. (College Park,

MD), and is now marketed as the BioFlashTM

System. With this system, transgenic B-cells

express antibodies against target antigens.

When the target antigen is present in the test

sample, the B-cells emit light (via green

fluorescent protein), which is detected by a

portable luminometer. Either liquid or solid samples can be tested. The assay protocol for liquid

samples has five steps, which collectively take about 5 minutes to complete, including reading time.

The sample preparation removes inhibitors such as chlorine (Hollie Kephart, Innovative Biosensors,

Inc., personal communication). The original development paper cites the sensitivity as 200 cfu for

Y. pestis (in 20 μL reaction volume), 1,000 cfu B. anthracis (from a swab rinsed in 1 mL of

extraction buffer), and 500 pfu vaccinia virus (in 20 μL reaction volume) (Rider et al., 2003). A

separate cell line must be developed for each target antigen. This system has not been verified by

a third party. The company markets CANARYTM as having broad applications in food testing,

animal health, biodefense, and human health care, including drug discovery and development, and

disease diagnosis. (Image reproduced with permission from Innovative Biosensors, Inc.) 132

7.3.5 Polymerase Chain Reaction

Polymerase chain reaction (PCR) is an analytical technique that detects/identifies organisms by

targeting their nucleic acids (DNA/RNA). PCR is a highly developed technology for molecular

biology applications. It has broad applicability for almost any situation where DNA needs to be

detected and identified.

Nucleic acids are synthesized in great numbers and subsequently identified by various techniques.

In terms of security applications, it can be used to detect and identify biological contaminants. The

following illustrates the PCR process:

• Microbial cells are disrupted to expose the DNA/RNA. Disruptive techniques include use

of lytic enzymes, freeze-thaw cycles, or bead-beating.

• DNA/RNA is extracted and purified to remove interferences such as folic acids.

• Various reagents are added (e.g., DNA primers, excess nucleotide bases, and enzymes to

produce DNA).

• DNA is synthesized in great numbers via thermal cycling. The amplification of DNA

occurs through a series of 30 to 45 temperature cycles producing billions of copies.

• The amplified target DNA is detected using various methods including electrophoresis,

fluorescent gene probes, and fluorescence melting curves.

PCR is a sensitive and potentially rapid detection method. It can detect any organism that contains

nucleic acids, including viruses, bacteria, and protozoa. The assay is selective, can be used to screen
U.S. EPA Office of Water Early Warning Systems

August 2005 91

for selected contaminants, and is getting easier to conduct using prepackaged reagents. However,

the method cannot distinguish between live and dead microorganisms and can be negatively affected

by natural interferences such as soil-derived humic and fulvic acids. Because PCR reactions are also

carried out in small volumes, samples need to be reduced to microliter volumes. Several portable

PCR-based identification devices are available.

The Ruggedized Advanced Pathogen Identification Device (RAPID), developed by Idaho

Technologies (Salt Lake City, UT), has been used extensively by the military. It can screen up 133

to eight contaminants simultaneously, uses a closed system to reduce contamination, and all reagents

are freeze-dried for convenience. It is an automated system which includes cell disruption and DNA

extraction-purification necessary for PCR. Reaction volume is 10 to 20 μL. The thermal cycler has

preprogrammed tests and automatic data interpretation. It is field deployable weighing 35 pounds

and can analyze samples in 30 minutes. The microbes that can be detected by the RAPID System

are listed below. The nucleic acid limit of detection (NALOD) is indicated where available in

parenthesis (units are genomic equivalent [GE] or plaque forming unit equivalents [pfu-e]; Tuck et

al., 2005):

• Bacillus anthracis (5 GE)

• Brucella spp. (10 to 20 GE)

• Salmonella spp. 

• Yersinia pestis (5 to 40 GE)

• Francisella tularensis (2.3 to 7 GE)

• E. coli O157:H7

• Listeria monocytogenes

• Campylobacter

• Clostridium botulinum

• Orthopox (200 to 350 GE)

• Smallpox (40 to 125 GE)

• Q fever (5 to 31 GE)

• Typhus (10 GE)

• Glanders (5 GE)

• Ebola virus (260 to 706 pfu-e)

• Marburg virus (1.9 to 4 pfu-e)

• Easter Equine Encephalitis virus (20 to 5,000 pfu-e)

RAPID can be used to detect pathogens in water samples. The unit costs around $55,000 with each

test costing $50. EPA and the Army are developing a prototype for water. Currently, EPA’s ETV

program is investigating the sensitivity, interferences, and cross-reactivity of the unit. In 134

September 2003, Idaho Technology was awarded the Joint Biological Agent Identification and

Diagnostic System (JBAIDS) contract. In March of 2005, RAPID underwent a two-week 135

operational test at Brooks City-Base, TX. The Air Force Operational Test and Evaluation Center,

based at Kirtland Air Force Base, NM, took the lead on the exercise, while the Army Medical

Department provided training and technical assistance. After validation by a joint-service Data

Authentication Group, the operational test results will be forwarded to the Joint Program Executive

Office for Chemical and Biological Defense for final approval. If approved, JBAIDS will enter

full-rate production in September 2005 and the DOD will distribute 450 systems throughout the

services over the next three years. (Image reproduced with permission from Idaho Technologies.) 136
U.S. EPA Office of Water Early Warning Systems

August 2005 92

Idaho Technology’s latest

portable PCR device, called

RAZOR, comes with

prepackaged freeze-dried

reagents for 12 different targets

already loaded into the clear

flexible plastic PathFinderTM

reaction pouches. Reagent

grade water is required but the

sample ports attached to the

reaction pouches are designed

so that volume measuring is not required. The reaction pouches are loaded into the cycling device

and results are obtained after about 30 minutes. The device weighs nine pounds, including

battery. (Images reproduced with permission from Idaho Technologies.) 137

Bio-Seeq , developed and commercially available through Smiths TM

Detection (Edgewood, MD), is a hand-held PCR-based biological

detector. A sample preparation cartridge allows samples to be

taken in the field and tests run on the spot. All the necessary

reagents, filters, and mixing chemicals required to process a

biological or viral sample are inclued in the sample prep cartridge,

eliminating the need for pipettors, tips, and sample vials. The unit

has six detection modules (thermocycler/optics modules) that

perform the thermal cycling, optical reading, and alarm detection

for each test. Each module has two independent optical channels

that can be used during a single test. With suitable reagents, these

channels can allow the user to run a target sample with a positive control in the same tube,

eliminating the need to prepare a separate positive control. The device is capable of detecting 1 cfu

(in ~28 μL sample volume) in 30 minutes and costs $25,000. (Image reproduced with permission 138

from Smiths Detection.)

LLNL has developed a “hand-held nucleic acid analyzer” (HANAA) based

on real-time PCR (TaqMan). This specific technology has been licensed to

Cepheid, a Sunnyvale, CA-based company that is developing biosensors for

the U.S. Postal Service. HANAA can identify an organism in less than 10

minutes (Perkel, 2003). It requires the operator to prepare the sample by 139

adding reagents to a reaction tube and selecting which pathogen will be

targeted. Water Environment Research Foundation (WERF) has tested

HANAA with the waterborne pathogens, Cryptosporidium parvum and

E. coli O157:H7 (photo from LLNL website).

Cepheid, Inc. (Sunnyvale, VA) Smart Cycler® XC is a portable PCR

machine that uses the company’s patented I-CORE (integrated cooling/heating optics reaction)

modules to amplify up to four targets simultaneously from one sample. The amplification is

monitored in real-time and can be completed in as little as 30 minutes. The company’s newer

GeneXpert System includes a cartridge-based sample preparation system that takes about five

minutes to prepare. In 2001, the U.S. Centers for Disease Control and Prevention (CDC) 140
U.S. EPA Office of Water Early Warning Systems

August 2005 93

developed and validated test

kits for several bio-threat

agents optimized for use with

the Smart Cycler®. The

Laboratory Response

Network (LRN), uses the

CDC validated kits and Smart

Cycler® to provide

nationwide screening and

reference testing to respond

to a bioterrorism event. In

2002, Cepheid, Inc.,

delivered to the U.S. Army

Medical Research Institute of Infectious Diseases (USAMRIID) field-ready DNA test kits for rapid

detection of four bio-threat agents, Bacillus anthracis (anthrax), Yersinia pestis(plague), Francisella

tularensis (tularemia), and Clostridium botulinum (botulism). Developed in collaboration with

USAMRIID under a DOD contract, the tests combine DNA sequences identified and validated by

USAMRIID for bio-threat agent detection with Cepheid’s proprietary reagent formulations and

“freeze-dry” processing for prolonged stability and ease-of-use. This technology is being used 141

in many post office sorting facilities throughout the United States. The system has a sensitivity of

< 30 spores/reaction in water or buffer, a false-positive rate target of < 1:500,000 samples (99.9998

percent), no cross-reactivity with nearest neighbor organisms, and a non-determinate rate of

< 1 percent. The anthrax assay has been validated by third party government agency evaluations.

In 2005, the company expects to introduce a triplex cartridge for anthrax, tularemia, and plague, and

a separate Orthopox cartridge (Jaymee Rosenberger, Cepheid, personal communication). For use

with drinking water samples, concentration techniques would be needed to reduce large sample

volumes to appropriately smaller volumes. (Images reproduced with permission from Cepheid, Inc.)

The PathAlertTM Detection System from Invitrogen Federal

Systems (Frederick, MD), in conjunction with the 2100

Bioanalyzer micro-fluidics based electrophoresis system from

Agilent Technologies (Palo Alto, CA), is a PCR based system 142

that is able to detect biothreat agents in a single agent assay or

multi-agent assay formats. Existing products include single agent

assays for B. anthracis, Y. pestis, vaccinia, and F. tularensis with

multiple target loci for each reaction. In addition, a multi-agent

single reaction assay is available for the detection of these four

agents. Under development are assays for additional water borne

pathogens such as E. coli O157:H7, Cryptosporidium parvum,

Giardia lambia, Salmonella species, Shigella sp., and others. The product is available in

prepackaged or custom formats, where the user is able to pick four to six targets of choice for

inclusion in a single multi-agent assay. PathAlertTM was tested in June 2004 as part of EPA’s ETV

program. During this testing, the system was able to overcome environmental inhibition from fulvic

and humic acids. The system is able to operate in a standard stationary or mobile laboratory

environment (Willem Folkerts, Invitrogen Federal Systems, personal communication). Although

PathAlertTM is not marketed as portable, it is included in this report because the developers have

specifically addressed biothreat agents and the technology has been tested in EPA’s ETV program,
U.S. EPA Office of Water Early Warning Systems

August 2005 94

as well as in a technology readiness assessment (TRA) conducted at the U.S. Army’s Dugway

Proving Ground. (Image reproduced with permission from Invitrogen.)

One method developed around DNA base

composition and PCR, that has successfully

demonstrated proof-of-principle, is called

Triangulation Identification Genetic Evaluation of

Risks (TIGER). TIGER has been developed by

Isis Pharmaceuticals, Inc. (within their Ibis

Therapeutics program, Carlsbad, CA), in

collaboration with SAIC, and funded by

DARPA. The TIGER biosensor system can 143

identify a broad range of infectious organisms,

including known, unknown, non-culturable, or

bioengineered elements, within a few hours. PCR primers are designed to place unknown organisms

with their related neighbors, and multiple primer pairs target multiple locations within pathogen

genomes. Mass spectrometry is used to obtain mass signature data. RoboDesign International, Inc.

(Carlsbad, CA) is developing TIGER 2.0, which will be an automated system and will require

minimal intervention from a technician (Bunk, 2002). The footprint will be ~ 8 x 8 feet and is being

transitioned to USAMRIID and CDC. The culture-independent methodology allows for flexibility

with respect to the types of starting sample that can be used (e.g., blood, urine, soil, other

environmental samples) (Kumar Hari, Ibis Therapeutics, personal communication). Although this

technology is not field portable or online, it presents an advancement beyond standard PCR

approaches where primers are designed for detecting only one known pathogen at a time. (Image

reproduced with permission from Ibis Theraputics.)

7.3.6 Bio-Optoelectronic Sensor Systems (BOSS)

DARPA funds the bio-optoelectronic sensor systems (BOSS) center, which includes team members

from the University of California at Berkeley, Colorado State University, Columbia University,

Georgia Institute of Technology (Georgia Tech), the University of Illinois at Urbana-Champaign,

the University of Michigan at Ann-Arbor, and the University of Texas at Austin, who collaborate

to develop technologies to detect chemical and biological warfare threats. Georgia Tech’s, 144

Applied Sensors Laboratory is using fiberoptic evanescent wave spectroscopy in the mid-infrared

region to sense capture-target molecule interactions. The sensing area is coated with a thin polymer

layer (can be a molecularly imprinted polymer; see Section 7.4.13) that forms a hydrophobic

membrane, serving both as an extractor phase to enrich hydrophobic analytes in close vicinity of the

sensor surface and as a suppressor of matrix interference by water absorptions. Georgia Tech has 145

developed sensors for marine and groundwater applications (EPA, 2003). The developers claim that

“the sensor is fast, highly sensitive, and provides real-time direct measurement with no additional

steps or consumable reagents...[and is] capable of detecting a wide variety of chemical and

biological species in air, water, and biological samples” (Bodurow, 2005).

7.3.7 Surface Plasmon Resonance (SPR)

Surface plasmon resonance (SPR), detects changes in mass by measuring changes in refractive

index. The sensor chip consists of a glass support surface coated with a thin layer of gold. The 146
U.S. EPA Office of Water Early Warning Systems

August 2005 95

gold surface can be modified in a variety of ways to immobilize different compounds. For example,

if the gold surface is modified with a carboxmethylated dextran layer, various biomolecules can be

attached to this hydrophilic layer without causing denaturation. When a sample is passed over the

chip surface (via microfluidics), molecules that bind/interact with the immobilized target are

captured. Interactions between proteins, nucleic acids, lipids, carbohydrates, and even whole cells

can then be studied. When binding occurs, the mass increases, and when disassociation occurs, the

mass deceases. These changes in mass can be detected as they occur and yield quantitative

information such as kinetics, affinity, and concentration of the molecule in the sample. Binding of

molecules as small as 100 Daltons can be detected. Portable instruments are being developed (Karl

Booksh, DMS Lab, University of Washington ). A related technique, called surface plasmon- 147

coupled emission (SPCE), is being developed at the University of Maryland, and has the potential

to improve sensitivity 1000-fold over other fluorescence technologies.148

Nomadics® Advanced Instrumentation Group

(Stillwater, OK) offers a Surface Plasmon

Resonance (SPR) Evaluation Module for

researchers interested in studying specific

chemical and biological contaminants on a

portable SPR platform. The Nomadics 149

Evaluation Module is based on Texas

Instruments’ (Dallas, Texas) SpreetaTM

biosensor that enables real-time quantitative

measurement of bio-molecular interactions.

The Module contains 50 sensors (chips), a flow

cell with an electronic PC interface control, and a Windows based operating system. Spreeta’s design

encapsulates the entire SPR optical system making the device compact and able to be integrated into

various instrument designs. The sensor can be used to detect and quantify the presence of specific

contaminants for applications such as agriculture, water quality, medical, and food safety

applications. Researchers at Stanford University tested Spreeta and conclude that the sensor 150

“shows promise as an inexpensive, portable, and accurate tool for bio-analytical applications in

laboratory and clinical settings” (Whelan et al., 2002). The same research team reported that the 151

analyte concentration in their test method corresponds to the detection of 90 fmol IgG (Whelan and

Zare, 2003). In 2006, Nomadics anticipates launching a Spreeta-based Life Science platform.

(Images reproduced with permission from Nomadics.)

7.3.8 Electrochemiluminescence (ECL)

ECL is a detection technology that utilizes light generated by the oxidation and reduction of a

ruthenium metal ion as a labeling system. Capture molecules (e.g., antibodies) are absorbed onto

a support surface, such as magnetic beads or a microarray plate. The addition of target molecules

from the sample and ruthenylated antibodies creates an antibody sandwich which is detected when

the ruthenylated antibodies are stimulated to glow with an electrode. Background signal is limited

because the electrodes only stimulate nearby ruthenium, quenching is not a problem with the 620 nm

emitted light. As with other antibody-based technologies, volume reduction would most likely 152

be required for ECL technologies to be adapted for distribution systems.
U.S. EPA Office of Water Early Warning Systems

August 2005 96

ECL was developed by BioVeris (formerly IGEN; Gaithersburg, MD).

BioVeris’ BioVerify Tests utilize two antibodies which recognize the

pathogen or toxin, one immobilized on paramagnetic microparticles and

the other labeled with BioVeris’ BV-TAGTM label. The sample mixed

with the antibody reagents is loaded into the flow based M1M Analyzer,

which transports this assay mixture into a measurement cell and collects

the microparticles on an electrode. The electrode stimulates the

BV-TAGTM labels bound (via the antibodies and the spore) to the

microparticles and the emitted light is measured. Assays that are

available for M1M include Botulinum neurotoxins (A, B, E, F), anthrax,

ricin, Staphylococcal enterotoxins A and B, E. coli O157:H7, Salmonella,

Listeria, and Campylobacter. The M1M comes packed in a transportable

suitcase with a separate reagent suitcase. The company markets the 153

system for biodefense applications and claims it can be used for research

and environmental samples.

Meso Scale Defense (Gaithersburg, MD), a division of Meso Scale Discovery, also sells systems 154

utilizing ECL technology. The company’s MULTI-ARRAYTM and MULTI-SPOTTM microplates

have electrodes integrated into the bottom of the plate. Capture molecules are immobilized onto the

plates, then sample and MSD-TAGTM are washed over the array. Antibody sandwiches, which are

formed when target molecules are present, are detected by a reader. Meso Scale Defense has

benchtop readers on the market and is designing a portable cartridge reader for first responders.155

7.4 Emerging Technology

The emerging technologies are prototype field or laboratory devices as well as technological

advancements that could be integrated into a system. Systems discussed include advancements in

immunoassays, proof-of-concept and prototype microchip technologies, micro beads, and light

scattering technology. Immunoassay technology in general is described in Section 7.2. Some of the

microchip technologies presented are used in commercial products for other applications such as

genomics research or clinical analysis. The potential range of applications of these technologies for

other uses is diverse and includes sensors for drinking water monitoring. Whether or not any of

these technologies are ever used to develop products specifically for use with drinking water

depends mostly on cost. Because it is beyond the scope of this document to analyze economic

factors, technologies that could be developed into products for use in drinking water distribution

systems will be presented regardless of whether costs might eventually prevent their development

for water application. In addition, it is difficult to determine what the potential detection limits

could be for these technologies because detection limits are based on specific contaminants in a

specified matrix and these technologies have not been adapted for distribution system water or the

range of threat agents that are of concern.

7.4.1 Lateral Flow Assay

NASA’s Jet Propulsion Laboratory has developed a quantitative lateral flow assay (QLFA) for

testing drinking water samples in space. Depending on the design and the specific antibodies 156

used, the test strip yields a rough count of the total cfus in the water sample, and a preliminary

classification as to the types of organisms present—for example, viruses versus different major
U.S. EPA Office of Water Early Warning Systems

August 2005 97

classes of bacteria. The test takes only minutes to conduct and does not require growth of bacteria.

Relatively low levels of antigens can be detected using newer fluorescent dyes, such as Qdots®,

which are much brighter than traditional fluorescent labels (see more below ). 157

7.4.2 Labels

Quantum Dot Company’s (Hayward, CA) Qdots® are nanocrystal

spheres that fluoresce at a variety of different wavelengths. The exterior

surface can be coated with biological molecules such as DNA,

antibodies, or receptors. Although colloidally dispersed pigments occur

naturally and have been used in paints for centuries, the breakthrough has

been creating fluorescent versions that are water soluble and non-toxic

to cells. Qdots® are currently being marketed for labeling subcellular 158

components of living cells for imaging applications. Other researchers 159

are also developing quantum dot technologies (Gorman, 2003).160

Quantum dots have the ability to quantitatively detect biological

molecules in samples. The EPA Office of Ground Water and Drinking

Water (OGWDW) Technical Support Center located in Cincinnati, OH, is using quantum dots to

as part of a sensor technology for determining the occurrence and prevalence of cyanobacteria and

their toxins in surface and finished water (Gerald Stelma, EPA, personal communication). The

biosensor EPA is developing will be portable for use in the field and eventually adapted for

continuous monitoring. The goal of EPA’s research is to develop molecular methods to detect

cyanobacteria and to simultaneously extract and detect cyanotoxins of interest to the Agency.161

(Image reproduced with permission from Quantum Dot Co.)

Another newer labeling technology is Upconverting Phosphor TechnologyTM (UPT). SRI

International (Menlo Park, CA), in collaboration with OraSure Technologies (Bethlehem, PA) and

under DARPA support, has developed a lightweight, battery operated, hand-held sensor to detect

multiple pathogens (bacteria, viruses) and their toxins simultaneously. The system uses UPTTM 162

to color-code multiple pathogens simultaneously in a lateral flow immunoassay test strip. The 163

upconverting phosphor reporters emit visible light upon excitation by near infrared light and have

the advantages of (1) single particle detection sensitivity, (2) multiplexing, (3) no autofluorescence,

and (4) no photobleaching. SRI has thus far developed ten UPTTM phosphors, each producing a

different color, which allows for the simultaneous detection of several contaminants in the same

sample. The sensor can detect 10 to 1,000 picograms (pg)/mL of small (e.g., virus, toxin) target 164

antigen in < 15 min with a sample volume of less than 300 μL. For spores and bacteria, the

sensitivity is as low as 1000 cfu/mL. So far, this technology has been developed for sampling of

biological fluids (oral fluids, blood, etc.) but future research aims to apply UPTTM to environmental

testing, including drinking water. OraSure Technologies owns commercial rights and may 165

develop the technology for other emerging applications, such as biological warfare defense,

combinatorial chemistry, biomolecular screening, medical diagnostics, and drug testing.

7.4.3 Magnetic Beads

Dynabeads®, developed by Dynal Biotech LLC (Oslo, Norway), is a product used for rapid

separation and detection of microbes, nucleic acids, proteins, and other biomolecules in liquid or

viscous samples. Dynabeads® technology is based on immunomagnetic separation. The polymer
U.S. EPA Office of Water Early Warning Systems

August 2005 98

shells of these microscopic (1 to 4.5 μm) beads can be coated with a variety of ligands (antibodies,

oligos, proteins, DNA/RNA probes, etc.) that will bind to specific targets. The resulting target-bead

complexes are then isolated using magnetic attraction and detected using an ultraviolet laser

system. The variable combinations of bead-size and ligand type facilitate detection and 166

identification of a wide variety of targets. This method has successfully detected E. coli in water

samples in less than five hours (Pyle et al., 1999). Although Dynabeads® are not being marketed

by Dynal as tools for CBW detection, they could be used in flow cytometry devices and other

technology that can detect small labled particles.

7.4.4 Flow-Through Columns

The Biodetection Enabling Analyte Delivery System (BEADS), developed by the PNNL (Richland,

WA), is a portable, automated front-end sample preparation device for pathogen detection. The

system features micro-sized glass, polymer, or magnetic beads coated with antibodies specific to a

chemical or biological species of interest. The beads are color-coded to differentiate their specific

chemistries for extracting and detecting multiple pathogen signatures. Liquid samples flow over

renewable bead-based immunoassay columns, which serve to isolate and concentrate whole cells,

proteins, nucleic acids, and/or chemicals as they bind with the beads. In addition to sample

purification and concentration, BEADS has its own PCR detector, or can be linked to other detector

technologies. No human interaction with the system is required for sample preparation or analysis,

and field test results can be sent electronically to a remote location. The BEADS system has

successfully detected trinitrotoluene (TNT), pesticide/herbicide, botulinum toxin, E. coli, and

anthrax in a process that takes about four hours to complete (ACS, 2002). This technology has 167

not been third party verified.

7.4.5 Raman Spectroscopy

Biopraxis (San Diego, CA) is developing a reagentless, portable, biosensor, whose first version is

known as “Doodlebug.” The biochip has biomolecules immobilized on a surface-enhanced

Raman scattering (SERS)-active metal surface. When a sample is added to the surface of the chip, 168

the immobilized capture biomolecules selectively bind their ligands. The chip reader, a Raman

microscope, illuminates the surface of the chip with a laser and the scattered light is collected. The

wavelengths and intensities of the scattered light are used to analyze the unique molecular structure

of the cross-reactions. The technology can detect chemicals (including explosives) and biologicals.

Biopraxis is developing a biochip to detect 8 to 10 different targets at the same time (Bunk, 2002).

A WERF study showed that Doodlebug could distinguish between six Legionella species, recently

passaged (fresh) oocysts from six C. parvum Genotype 2 strains, three Genotype 1 strains, a

C. meleagridis strain, and a Giardia sample. Results take about 60 seconds to obtain. Experiments

involving the impact of environmental and water treatment conditions suggested that this technology

will be able to differentiate between viable and nonviable, and possibly injured, organisms. The

SERS fingerprint may even be useful in determining the “age” of an oocyst (e.g., whether it is too

old to be infectious). The sensitivity of the technique eliminates the need for amplification

techniques, such as PCR, fluorescent labels, and enzymatic reactions, thereby greatly reducing the

potential for false responses from sample constituents that either mimic or inhibit the signals from

labels or interfere with enzymatic reactions (Grow et al., 2003). Several other companies have 169

portable Raman spectroscopy-based instruments.170
U.S. EPA Office of Water Early Warning Systems

August 2005 99

7.4.6 Microelectrode Arrays

The CombiMatrix Corporation (Mukilteo, WA) is in the

process of testing its biothreat detection system, Sen-ZTM,171

a hand-held, portable, self-contained unit that captures and

electronically detects a range of threat agents (e.g., anthrax

spores, smallpox virus particles, ricin, and saxitoxin).

CombiMatrix’s core technology consists of microarrays of

1,000 to 12,000 microelectrodes in one cm . Overlaying each 2

microelectrode is a porous reaction layer which serves as a

reaction “flask.” The microelectrode creates a local change

in pH, which dictates where on the microarray capture

molecules are synthesized or deposited. CombiMatrix

microarrays have been made to detect DNA hybridization and antigen-antibody reactions. Some

of the key features of the Sen-ZTM are multiplex immunochemical assays; a platform that can be

quickly configured to detect a broad range of threat agents; real-time fluorescent-free electronic

detection of signals by electrochemical methods; automated hands-free sample collection,

preparation, detection, and analysis; and high sensitivity (ricin at 60 pg/mL). At the present time,

this technology focuses on air sampling, but the company believes that the integration of agent

isolation and processing technology could adapt this product for a water monitoring system (David

Danley, CombiMatrix, personal communication). (Image reproduced with permission from

CombiMatrix.)

7.4.7 Microarray of Gel-Immobilized Compounds

The Biochip Technology Center at Argonne National Laboratory developed a reuseable “Micro

Array of Gel-Immobilized Compounds” (MAGIChipTM) that can perform thousands of biological

reactions in a few seconds. MAGIChipTM is a small glass slide with up to 10,000 3-D gel pads that

serve as micro-test tubes. Robots load the pads with DNA or protein fragments from bacteria,

viruses, or chemicals. Bench top equipment is required to analyze the chips. Researchers at

Argonne’s Biochip Technology Center are developing new applications for the biochip, writing

faster sample analysis programs, and working to shrink portable biochip readers. This technology

has been used for gene expression, diagnosis and

monitoring of genetic diseases, microbial analysis in

environmental cleanups and agriculture, routine protein

analysis of blood and urine, exploration for life in outer

space, and forensic DNA testing. Although they have 172

the potential for detecting biological contaminants in an

EWS context, they have not yet been adapted for this

use. In addition, volume reduction would most likely be

required for this technology to be adapted for

distribution systems.

7.4.8 Magnetic Microbeads

The Bead ARray Counter (BARC) chip, developed at

the Naval Research Laboratory, consists of an array of
U.S. EPA Office of Water Early Warning Systems

August 2005 100

DNA spots immobilized on a surface. Hybridization of sample DNA with chip immobilized DNA 173

is detected by magnetic beads 1 to 3 μm in diameter. The chip’s magnetic field microsensors are

μm-scale, wire-like structures made with giant magnetoresistive (GMR) material, which can detect

individual magnetic beads and is more sensitive and more compact than the optical detectors

required for fluorescence-based techniques (Whitman et al., 2001; Tamanaha et al., 2002; Rife et

al., 2003 ). The developers envision that millions of sub-micrometer GMR elements enabling 174

simultaneous detection of thousands of DNA sequences with high sensitivity and dynamic range will

be possible as the technology advances. This technology is not yet field ready. (Photo from NRL 175

website.)

7.4.9 DNA Microarrays

DNA microarrays (DNA chips) can contain 100,000 different spots of DNA printed on a glass

microscope slide (Fitzgerald, 2002). Alternatively, photolithography and solid-phase chemistry can

be used to produce microarrays containing 500,000 oligonucleotide (single stranded DNA) probes

within 1.28 cm (Affymetrix Genechip®). When a sample with unknown DNA is exposed to the 2 176

spots, it will hybridize (match-up) with the spots of DNA that are complementary. The sample DNA

is labeled (through a PCR reaction) so a chip reader device is able to detect where on the microarray

hybridization occurs. The microarrays could be designed to detect a multitude of sequences that

would be unique to specific pathogens of concern. There are several companies producing and 177

custom designing microarrays. Microarrays are widely used for genomics research, but face 178

sample volume reduction problems for use with environmental samples and drinking water.

7.4.10 Micro-Cantilever System

The VeriScanTM 3000 System, produced by Protiveris

(Rockville, MD), utilizes technology licensed from 179

Oak Ridge National Laboratory. The bench-top 180

system can conduct 64 simultaneous assays using a

proprietary Micro-Electro-Mechanical System181

(MEMS)-based biochip, a patented laser reader

technology, microfluidics, and advanced custom analysis

software. The biochip has an array of microcantilevers

that can detect interactions between proteins, antibodies,

antigens, or DNA. The system, which does not require

labels or amplification, delivers data in real-time as the

binding interactions take place. The lower limit of detection is 0.2 ng/mL, making it competitive

with the more traditional ELISA assay (Daviss, 2004). As with other technologies for detecting

microbes on microchip platforms, sample volume reduction for the concentration of cells would be

necessary before the technology is viable for drinking water. (Images reproduced with permission

from Protiveris.)

7.4.11 Photoluminescent Biochips

IatroQuest’s (Verdun, Canada) Bio-AlloyTM biochips are made of silicon-based semiconductor

materials that are nanostructured and chemically modified to bind to a variety of molecules,

including antibodies, enzymes, nucleotides, and chemicals as recognition elements. The underlying
U.S. EPA Office of Water Early Warning Systems

August 2005 101

detection principle, based on a photoluminescence response, relies on quantum confinement and

changes in the surface energy state when the material is excited with low-power blue LED light.

Upon affinity binding of target contaminants to the recognition elements linked to the surface,

surface energy perturbations result in an immediate change in the photoluminescence response,

which is detected as an increase in green light intensity. Different formats of the material can be

produced, including chips, particles, or microspheres for more end-product versatility. IatroQuest

has a portable demonstration system, but no products are yet developed. The company has been 182

awarded a $3 million (Canadian dollars) development contract from the CRTI Counter-Terrorism

Initiative.

7.4.12 Polymer Microbeads - Taste Chip

Scientists at the University of Texas at Austin have

developed the “electronic taste chip,” based on a system of

polymer microbeads that mimic human taste buds. The 183

system has been licensed to LabNow, Inc., for commercial

product development. This multi-sensor array technology

can generate digital fingerprints of complex fluids in nearreal-time. The device functions by using a combination of

micromachining, nano-chemistry sensing schemes, molecular

engineering of receptor sites, and pattern recognition

protocols to detect a variety of biological and chemical

contaminants (e.g., electrolytes, toxins, drugs, metabolites,

bacteria, blood products). Taste chips can be adapted within months to respond to new analytes,

which provide for customized applications such as drinking water analysis. Their analytical

characteristics (sensitivity, selectivity, detection thresholds, assay variance) have been shown to be

comparable to or better than many well-established macroscopic analytical methods (Goodey and

McDevitt, 2003; McCleskey et al., 2003; Kirby et al., 2004). Fully developed prototype instruments

and customized microchip sets have been designed, constructed, and tested in numerous application

areas including homeland defense, where hand-held units have been sent to the Defense Threat

Reduction Agency for further testing (John T. McDevitt, U. Texas, personal communication; image

reproduced with permission).

7.4.13 Molecularly Imprinted Polymers

Molecularly imprinted polymers (MIP) are synthetic receptors which can be designed for a range

of toxins and some microorganisms. MIPs have greater stability, being able to withstand climate 184

extremes and larger sensitivity ranges, than antibodies (Haupt, 2002). The technology is being 185

incorporated into the UK Ministry of Defense’s development of an integrated biological detection

system for battlefield use against biowarfare agents (Bunk, 2002). Some analytes for which MIPs

have been developed include the algal toxins, domoic acid, and microcystin, and the fungal toxins,

aflatoxin B1, and ochatoxin A. MIPs are used very successfully in “at home” glucose detection 186

devices for diabetics. Further refinement of MIPs for CBW detection is being pursued by multiple

laboratories (Mays, 2004; Pesavento et al., 2004).
U.S. EPA Office of Water Early Warning Systems

August 2005 102

7.4.14 Magnetoelastic Sensors

Mass-sensitive magnetoelastic sensors can be used to detect antibodyantigen interactions. However the mass change must be amplified by

biocatalytic precipitation. The sensor platform has immobilized

capture antibodies, which recognize target antigens, then alkaline

phosphatase-labeled antibodies are added to form an antigen-antibody

sandwich complex. The mass of the sandwich complex is amplified by

the precipitation of 5-bromo-4-chloro-3-indolyl phosphate disodium

salt hydrate (BCIP). In response to an externally applied time-varying

magnetic field, steady-state or pulse, the ribbonlike magnetoelastic

sensors mechanically vibrate at a characteristic resonance frequency.

These mechanical vibrations can be detected in several ways: optically from the amplitude

modulation of a reflected laser beam, acoustically using a microphone or hydrophone, and by using

a pickup coil to detect the magnetic flux emitted from the sensor. E. coli, enterotoxin, and ricin 187

have been detected with laboratory prototypes (Ruan et al., 2003, 2004a, 2004b). Although, this

laboratory prototype sensor will not likely be adapted for water in the near future, its very low cost

makes it an attractive technology. (Image reproduced with permission from Craig Grimes.)

7.5 Concentration Methods

Two AwwaRF research papers scheduled for publication in 2005 (Extraction Methods for

Early/Real-Time Warning Systems for Biological Agents - Project A and B; see Appendix D)

address methods for extracting biological contaminants from large sample volumes.

AwwaRF Project #2985 seeks to develop a large-volume extraction method for biological

contaminants that takes less than three hours and has at least a 60 percent to 70 percent recovery

efficiency. CDC is a project partner. The project builds on research being done by the DOD on the

Joint Service Agent Water Monitor, which serves all of the DOD services (e.g., Army, Navy, Air

Force, Marines). The objective of the program is to develop a water monitor that is portable,

preferably hand-held, near real-time, and capable of detecting all agents harmful to service members

in the field, while providing no false-positives. Because intentional contamination of water has

historically been a concern for the military, DOD has the most focused and developed information

concerning purposeful contamination of drinking water.

AwwaRF Project #2908 (see Appendix D) seeks to screen three to five different water extraction

methods for biological contaminant surrogates. DOD is a research partner. AwwaRF indicates that

release of the final report may involve a special protocol that requires signing a non-disclosure

agreement.

7.5.1 Hollow Fiber Ultrafiltration

A persistent challenge for many detection methods is the need to concentrate the contaminants

before identification and quantification. Hollow fiber ultrafiltration is a technology to

simultaneously concentrate viruses, bacteria, and protozoa from large volumes of water. The

ultrafiltration method can concentrate 100 liters of drinking water into 250 mL within 1 to 2 hours.

The water is circulated through a filter system to catch certain molecule sizes. The retentate can be
U.S. EPA Office of Water Early Warning Systems

August 2005 103

further subdivided to permit detection of various microorganisms. This method may still have to

remove concentrated inhibitors that can interfere with certain assay tests like PCR. The method is

currently being developed by EPA, CDC, Army, and the Metropolitan Water District of Southern

California. A study of the hollow fiber techniques on source water from four water districts showed

a mean recovery of approximately 48 percent of Cryptosporidium oocysts. The results were

comparable to the Envirochek filter. The conclusion was that hollow-fiber ultrafiltration can

efficiently recover oocysts from a variety of surface waters (Kuhn and Oshima, 2002).

EPA-NHSRC and the Idaho National Laboratory (INL) have an interagency agreement to develop

and produce a next generation prototype of the Ultrafiltration Concentration (UC) device previously

developed by NHSRC and other stakeholders. The UC benchtop device concentrates microbial

pathogens within a 100 L municipal drinking water sample into a 250 mL volume in approximately

a 2-hour time frame (400-fold concentration). INL hopes to uses the benchtop UC system that has

been tested at the NHSRC in Cincinnati, OH, to redesign/repackage and automate the components

such that the new device can be operated in the field as a near-commercial, or field prototype system

(Vincente Gallardo, EPA, personal communication).

7.5.2 Hydroxyapatite Whole Cell Capture

Hydroxyapatite (HA) whole cell capture is a technology that could be applied to concentrate

microbiological contaminants in water supplies in order to detect them. For both pathogenic and

non-pathogenic organisms, the presence of anionic polymers on cell surfaces can be used to capture

both Gram-positive and Gram-negative eubacteria. Hydroxyapatite is a form of calcium phosphate

that can bind to bacterial cells with high affinity. It has been demonstrated by Berry and Siragusa

(1999) that positively charged HA particles can concentrate and purify bacteria from complex

matrices such as suspensions of ground beef and bovine feces. The bacteria would then be ready

for identification by PCR analysis. Because the cell capture is based on van der Waals and

electrostatic interactions between the bacteria cells and the HA particles, the affinity to the HA

particles depends on the specific cell type. When tested, the efficiency of capture varied from

46 percent for E. coli to 99 percent for Yersinia enterocolitica (Mays, 2004).

7.5.3 Lectin and Carbohydrate Affinity

Another approach that could be used to capture microbial cells is to use lectins that target the

carbohydrate rich cell envelope polymers of microbes. The carbohydrate pieces are usually

fundamental structural elements of cell walls or proteins so are less likely to vary than protein

sequences that can mutate or are dependent on environmental conditions. Therefore, the use of

lectins is an attractive candidate for concentration methods. Lectin-based capture of several

eubacteria including E. coli and Salmonella spp. has been demonstrated. A microbial capture

approach analagous to using lectin affinity is to use the carbohydrate binding properties of the

microorganisms themselves. It is normally critical for pathogenic bacteria to adhere to the lining

of the gut in order to colonize. Well studied examples of carbohydrate binding in bacteria are

adhesions used by E. coli and S. flexneri. Also, necessary host cell recognition through

carbohydrates has been studied for certain viruses, such as rotavirus. It can be speculated that a

collection of lectins and/or carbohydrates could be chosen to bind organisms in a semiselective

manner to concentrate and purify them for detection.
U.S. EPA Office of Water Early Warning Systems

August 2005 104

Anticipated challenges to the use of hydroxyapatite and lectin/carbohydrate affinity include the

difficulty of immobilization of HA and lectins onto magnetic or polystyrene beads. Also, tests

would need to be performed to determine capture efficiency of the microbial contaminants of

interest, and tests would be needed to determine if these methods would co-concentrate inhibitors,

causing them to be of little use for detection (Mays, 2004).
U.S. EPA Office of Water Early Warning Systems

August 2005 105

8. Technologies that Detect Radiological Contaminants for Early Warning

Systems

Radiation is a possible contaminant in water and is associated with carcinogenic and noncarcinogenic adverse health effects. The Federal Water Pollution Control Act (Clean Water Act),

the Safe Drinking Water Act (SDWA), and the Maximum Contaminant Levels (MCLs) address

protection of water systems from radiation and other contaminants. Radiation MCLs are measured

at entry points, do not require routine monitoring, and currently exist for beta/photon emitters

(includes gamma radiation), alpha particles, combined radium 226/228, and uranium. These

regulations had been thought to be adequate in ensuring a long-term distribution of clean and safe

water. However, now that terrorism is a major security concern in the U.S., the importance of the

water sector’s preparedness for potential attacks and accidents has become increasingly important.

The Homeland Security Presidential Directives (HSPDs) and the Public Health Security and

Bioterrorism Preparedness and Response Act of 2002 (Bioterrorism Act) have obligated EPA to

focus on the water sectors’ strategies for emergency prevention and response.

In the case of intentional contamination, realtime monitoring of radiation is important for immediate

detection and response. Currently there is radiation measurement equipment that detects the total

amount of radiation, as well as equipment that detects specific types of radiation by the energy levels

emitted from a given source. SSS-33-5FT Drinking Water Rad-safety Monitor by Technical

Associates and 3710 RLS Sampler by Teledyne Isco, Inc. (Los Angeles, CA) (both mentioned 188

below) are examples of devices that analyze the aggregate radiation of alpha, beta, and gamma rays.

These instruments alert operators when the water has been radiated, but do not identify the specific

contaminant. Other instruments identify alpha, beta, and gamma radiations separately, and will be

discussed further in this section. The general information as well as many of the technology costs

presented in this section are available on EPA’s website, Water and Wastewater Security Product 189

Guide, which addresses radiation detection equipment for monitoring water assets. This website is

based on information culled from the Multi Agency Radiation Survey and Site Investigation Manual

(EPA, 2000), developed by EPA, DOE, DOD, and the U.S. Nuclear Regulatory Commission.

EPA does not endorse or recommend any of the following technologies. The summary

information below was obtained from company websites and promotional literature.

8.1 General Introduction to Methods of Detection

Gamma radiation emissions are long-range electromagnetic waves that penetrate many objects and

can be measured in the field with a sodium iodide (NaI) scintillation survey meter. On the other

hand, it is difficult to have in-field rapid detection technology for alpha and beta radiation in water

due to their physical properties. Alpha radiation emissions are positively charged particles that

cannot penetrate through objects while beta radiation emission are negatively charged particles that

have a moderate capacity to penetrate objects. Difficulties arise in measuring alpha and beta

emissions in water because these short range types of radiation are easily blocked (attenuated) by

water before they reach the detector.

Therefore, the instruments need to be placed close to the source without blocking the path of the

radiation to the detector. Furthermore, gas-flow proportional counters typically evaluate alpha and

beta radiation from smooth, solid surfaces. However, since water surfaces are not smooth, a large,
U.S. EPA Office of Water Early Warning Systems

August 2005 106

sensitive liquid scintillation counter in a laboratory is frequently required; thus, in-field

quantification of alpha and beta radiation in water is a rare practice. This chapter, however,

introduces certain devices that can detect and quantify radiation onsite.

The instruments and methods can be evaluated in terms of specificity and sensitivity. EPA defines

specificity as the ability of an instrument to quantify or evaluate the specific type of radiation or

radionuclide for which it is designed without false-positives, (e.g., without interference from other

radiation or radionuclides). Sensitivity is defined as the radiation level or quantity of radioactive

material that can be measured or detected with some estimated level of confidence, and is a function

of the instrumentation and the technique used. With regard to the specificity in measuring alpha and

beta radiations, liquid scintillation counters are generally extremely flexible and accurate when

properly calibrated and quenching effects are compensated (the full energy pulse may not reach the

photo-multiplier detector). The complex multi-energy spectra of beta radiation can be quantified

because its energy spectra are 10 to 100 times broader than the gamma spectra. With regard to

sensitivity, this scintillation survey meter is ideal for moderate to high energy beta and alpha

emitters because different radiation types can be easily distinguished by their pulse shape.

With regard to the specificity in measuring gamma radiation, some of these scintillation survey

meters make the preliminary identification of specific isotopes possible with their ability to analyze

selected ranges of gamma energies. The minimum sensitivity of these scintillation meters is 200 to

1000 counts per minute (cpm), and can be lower when switched to digital integrate mode. The cost

of the sodium iodide scintillation survey meter is approximately $2,000. Typically these in-line

gamma radiation detectors are used only at special facilities that handle radioactive materials.

Continuous online monitoring systems can monitor the water in real-time however, there are few

such units commercially available. These systems can be installed along with an alarm system that

would alert operators of unusual radiation measurements. There are units for measuring radiation

in wastewater but these would have to be adapted for drinking water. Grab sample units for drinking

water are much more common. Very few water districts have real-time radiation monitors in place

to protect water and the public.

8.2 Available Technology

The SSS-33-5FT by Technical Associates (Los Angeles, CA) is 190

a real-time, in-line, continuous flow-through scintillation detector of

alpha, beta, and gamma radiation in ground, surface, or waste water.

The detector can be applied to measure one type of radiation or all

radiations combined. This easily calibrated apparatus uses ion

exchange resin beads and charcoal filters, and does not require liquid

scintillant. The ion exchange resin collects ions from dissolved

metals, which are then measured for activity by gamma spectrum

detectors. The charcoal filter collects non-ionized stray radioactives.

Crushed anthracene scintillation crystals are the final detector of the

radiation. The instrument measures tritium up to 100 picoCurie/mL

and is equipped with a system that sends an alert if unusual readings

are made. All the data can be retrieved in a spreadsheet format.
U.S. EPA Office of Water Early Warning Systems

August 2005 107

This instrument is on the market for approximately $58,000. (Image reproduced with permission

from Technical Associates.)

MEDA-5T by Technical Associates is a continuous monitor of 191

intentional contamination or accidental spills of gamma radiation

into the water source. The instrument is equipped with pumps and

a scintillation detector. An automatic quick alarm will sound in the

event of a radioactive water contamination. The monitor is

available for approximately $25,000. (Image reproduced with

permission from Technical Associates.)

The 3710 RLS Sampler by 192

Teledyne Isco, Inc. (Los Angeles,

CA), detects radionuclides using

3M EmporeTM Rad Disks and a

known amount of flow-through. The sampler continuously

monitors in water for all types of radiation. (Image reproduced

with permission from Teledyne Isco Inc.)

The down-hole tritium in water detectors, SSS-33DHC and SSS33DHC-4 by Technical Associates, are used to continuously 193

monitor and detect underground plume or tritium leakage. These

detectors fit in bore holes, are not influenced by other nuclides, and

require no liquid scintillant. The monitors are sensitive below

EPA clean drinking water levels, have a sensitivity of 1

nanoCurie/ml in 100 seconds, and their lower limit of detection is

better than the FDA drinking water standard of 20,000 pCi/L

average over 24 hours. These monitors cost $72,000.

The SSS-33M8 monitor by Technical Associates is a real-time continuous monitor for tritium in 194

water. No liquid scintillant is required and it is sensitive to 0.1 nanoCurie/mL without being

influenced by other nuclides. It is useful in monitoring leaks in type reactors, tritium in

groundwater, and laboratory or plant liquid waste streams. This monitor costs $16,500.

8.3 Potentially Adaptable Technology

Canberra (Meriden, CT) has developed several devices that detect radiation in liquid pipes such as

those carrying waste streams, but these monitors are not intended for drinking water distribution

systems. All of Canberra’s devices can monitor liquid streams in realtime using the Radiological

Assessment Display and Control Software (RADACS), which allows online access to the monitors

from remote locations.

The LEMS600 Series Liquid Effluent Monitoring System (LEMS) by Canberra has the capacity 195

to continuously evaluate the gross gamma/beta radiation. The series consists of LEMS614,

LEMS615, and LEMS616. The detectors are equipped with alarms in case of high radiation or

failure conditions. The LEMS614 detects the combination of beta and gamma radiation, while

LEMS615 detects gamma radiation in liquid samples between 0 to 50° C. A similar gamma
U.S. EPA Office of Water Early Warning Systems

August 2005 108

detector, LEMS616, incorporates a cooling system for liquids with higher temperatures. The cost

of LEMS technologies is between $100,000 and $150,000.

The OLM100 Online Liquid Monitoring System by Canberra continuously monitors liquid and 196

gas gamma radioactivity in liquid and gaseous streams. It is available both as a clamp on model as

well as a clam shell model so as to fit various pipe sizes. The device uses a gain-stabilized

scintillation detector and has earned Class 1E Safety Qualifications. The instrument in an online

monitor that is attached to the exterior of pipes so as to not disrupt the flow rate within. Its

sensitivity/detection limit depends on a preprogrammed lower limit of detection and the normal

background. The cost of OLM-100 is between $35,000 and $70,000.

The ILM-100 by Canberra is similar to the OLM-100 but is installed within the pipe system. The 197

ILM-100 and OLM-100 cost between $35,000 and $70,000. The OLM system is typically cheaper

than the ILM system because it can be clamped onto an existing pipe, whereas the ILM system must

be fitted into the pipe. Both systems can be fitted into pipes of 1⁄2 inch to 16 inches, but the cost

increases with the pipe size because of the additional expense of ensuring that the detector is

properly installed in the pipes.

8.4 Emerging Technology

Clarion Sensing Systems, Inc. (Indianapolis, IN) has developed an in-pipe radiation detector that 198

the company plans to launch on the market in late 2005 (Martin Harmless, Clarion, personal

communication). The Gamma SharkTM sensor detects gamma radiation in water above background

levels. The device is able to expose more surface area for the radiation to contact by inserting the

scintillator tube in the water stream. The monitor logs fissions detected and converts the counts per

minute to normal units. The Gamma SharkTM compares the radiation levels in the water to

background and detects increases in radiation in the water. The company is in the process of third

party verification and the instruments are expected to be cost-effective compared to currently

available technology. Clarion’s radiation detectors will stand alone or interface with the company’s

SentinalTM unit (see Chapter 4) to provide website display results as they are obtained.

According to a DOE publication in 2000, Thermo Power Corporation (Waltham, MA) is 199

developing the Thermo Alpha Monitor (TAM) under the sponsorship of DOE. This instrument 200

is a near real-time monitor of alpha radiation, which was estimated to have a cycle time of

approximately 30 minutes for 1 ppb Uranium, and approximately 5 minutes for 10 ppm Uranium.

The concept was developed around the simultaneous in situ collection and quantification of

radioisotopes on a silicon detector using a solid-state semiconductor counter. The detector is similar

to those that use ionization chambers, but measures the lost energy caused by ionized radiation as

an electrical current.

The PNNL (Richland, WA) is in the process of developing a in-field radionuclide sensor to detect

technitium-99 (Tc-99) in groundwater. The technology will incorporate the use of chemically 201

selective beads to preconcentrate Tc-99 in the sensor in order to increase the sensitivity and

selectivity of the direct measurements. The laboratory strives to create a device that can demonstrate

reversible operation and the required sensitivity as well as the capability to operate the embedded

controls from remote locations.
U.S. EPA Office of Water Early Warning Systems

August 2005 109

In addition, an online real-time radiation detection instrument will be available for alpha radiation

in the near future. DOE tested this prototype, and further technological development has been

conducted under the Los Alamos National Laboratory since 2001. The detector is expected to be 202

used in monitoring radioactive liquid waste and groundwater using Long Range Alpha Detection

(LRAD) technology. The monitor is in real-time and is non-intrusive.203
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 111

9. Technical Evaluation of Early Warning Systems

This chapter provides a technical evaluation of the various components of an Early Warning System

(EWS) for drinking water, as characterized in Chapters 3 and 4. Such an evaluation is important to

allow utilities and drinking water quality officials to identify technologies appropriate to particular

situations and systems. Researchers and utilities need a better sense of what systems are becoming

fully developed and where there are research gaps. False-positives and false-negatives have

occurred with various devices and have caused great concern among first responders, emergency

agencies, and health and law enforcement officials. There are claims of performance that would

benefit from additional testing and evaluation. In addition, technology is rapidly evolving and at

various stages of development to detect chemical and biological contaminants. This report is

divided by the level of development of early warning. The level of development is set by three

categories, (1) available, (2) potentially adaptable, and (3) emerging. In Chapter 3, the desired

characteristics of an EWS (e.g., detects range of contaminants, sensitive) were presented. In this

chapter, an analysis is conducted on how close the existing EWS technologies meet these desired

characteristics.

9.1 Approach for Technical Evaluation

A scientific and technical evaluation of EWS technologies is based on expert review of qualitative,

semi-qualitative, and quantitative information sources as described below. It is important to note

that the evaluation did not involve actually testing equipment or assays. The information sources

include the following:

• verification studies

• degree of government involvement, support, and development for technology

• field experience and case studies

• other studies

• expert opinions

The sources are described in detail below.

9.1.1 Verification Studies

During the anthrax attacks of 2001, when hand-held assays proved unreliable, it became particularly

clear that the government has a responsibility for validating the performance of CBR detection

equipment (Emanuel et al., 2003). Verification, feasibility, and proof-of-concept studies of CBR

detectors, with a special focus for use in water, are underway at several government and private

facilities. Examples include the U.S. Army Edgewood Chemical Biological Center facility, the

DOD Chemical and Biological Defense Program Test and Evaluation Executive Agent Facility for

Water Monitor Test Methodology and Instrumentation Development, the EPA WATERS Facility,

and various contractor facilities. Specific efforts at evaluation include the following:

• EPA’s Environmental Technology Verification (ETV) program evaluates various

technologies, including sensors for chemical, microbial, and radiological contaminants.

• EPA’s Technology Testing and Evaluation Program (TTEP) tests the performance of

technologies related to homeland security applications.
U.S. EPA Office of Water Early Warning Systems

August 2005 112

• The National Technology Alliance, through the Chemical, Biological, and Radiological

Technology Alliance, examined and reported on state-of-the-art and emerging technologies

in water monitoring (Black & Veatch, 2004).

• Some local water utilities, including the Pittsburgh Water and Sewer Authority, have

conducted verification tests (States, 2004).

• AwwaRF has an extensive number of evaluation projects that deal with EWSs (see

Appendix D). However, most are on going, and were not available for this evaluation.

The challenge remains that only a limited number of facilities can test this equipment with real

chemical or biological agents. 

9.1.2 Degree of Government Involvement, Support, and Development for Technology

Government and industry have sponsored research into the development of various water monitoring

technologies, as well as the verification of their performance. Such research could be an indication

of the potential development of the technologies. Sponsoring agencies include DHS, EPA, U.S.

Army (ECBC), FDA, and CDC. For example, ECBC has an active program, including projects such

as “Development of Novel DNA Probes for Emerging BW Agents,” “PCR Assay Optimization for

BW Detection,” Validation of BW Detectors,” and “Development of Enzyme-based CW Sensors.”

FDA is investigating several technologies for identification of microbial contaminants, most of

which are food-related, but some have applicability to the water sector. For example, in September

2003, FDA awarded five research grants on; (1) development of the Waveguide Immunoassay for 204

Yersinia pestis; (2) a rapid immunoassay silver amplification test system; (3) uses of a novel,

compact microchip sensing system for rapid food screening; (4) development of PCR-based assays

on a microchip, and (5) use of thin layer chromatography and bioluminescence.

9.1.3 Field Experience and Case Studies

Some of the technologies have been widely used in source water or in the food industry that may

enable the technology to be applicable to finished drinking water. Some utilities are using these

technologies for grab samples from treated water, and a few utilities have online systems. The

limited field experiences and case studies that were examined during the development of this report

helped to provide insight into the technologies’ current uses. It is likely that further examination of

more detailed (and confidential) case studies would yield a wealth of valuable information for the

advancement of the EWS field.

9.1.4 Other Studies

There are several studies that provide evaluation information. These include the ASCE White

Papers and Interim Guidelines for Designing Online Contaminant Monitoring System (ASCE, 2004),

the CBRTA report Water Monitoring Equipment for Toxic Contaminants Technology Assessment

(Black and Veatch, 2004) and various AwwaRF research studies (see Appendix D; Roberson and

Morley, 2005).
U.S. EPA Office of Water Early Warning Systems

August 2005 113

9.1.5 Expert Opinions

Experts were contacted in various agencies and organizations, including DHS, USGS, EPA, DOD,

various national labs, water associations, utilities, and consultants contracted for this project.

Using the above sources, a technical evaluation was conducted on various operational features of

an EWS (e.g., data management, acquisition, security), on multi-parameter water quality monitors,

on chemical sensors, on microbial sensors, and on radiological sensors.

9.2 Evaluation of Various Operational Features of EWS

This section addresses the features of the EWS that are not related to sensors. These EWS features

include real-time data acquisition and analysis, contaminant flow predictive systems, sensor

placement, alert management, security enforcement, and communications, response, and decision

making.

9.2.1 Issues and Gaps

• Real-time Data Acquisition and Analysis

The SCADA interface is key to managing the data and identifying a contamination event. Most

utilities are familiar with SCADA systems. Remote data acquisition systems are commercially

available and used in many utilities for basic water quality control and monitoring. Adapting the

SCADA to track sensor data is not a large challenge. However, challenges include the ability to

handle the data load as well as to interpret the data that are collected. Analyzing large streams of

data requires special training. Various software exists, but many algorithms for data analysis are

not verified or demonstrated. Standardized methods for data analysis do not exist and may need to

be developed for such EWSs. Documentation of case studies could also further guide the proper use

of such data analysis techniques.

• Contaminant Flow Predictive Modeling Systems

There are some basic contaminant flow predictive systems, but their use by utilities for the purpose

of modeling the movement of contaminants is not widespread. Many utilities do use models for

tracking chlorine residuals and disinfection byproducts. However, as models undergo further

development by researchers, it is necessary to calibrate and verify the models and make the models

useful tools for sensor placement, for real-time contaminant flow prediction, and for identifying the

location of the contaminant source. Utilities would need to expand their current use of models to

include modeling for intentional contamination events. Also, utilities would either need to train

personnel to operate the expanded models, or hire contractors to run the predictive flow models.

• Sensor Placement

Sensor placement has implications for cost. Placement is often determined by logistic factors such

as location security and convenience, and access to a power source or data transmission rather than

risk minimization. Although current research on combining flow models and sensor technology is

a move in the right direction, such models must be verified before difficult and costly decisions are
U.S. EPA Office of Water Early Warning Systems

August 2005 114

made by the utilities. Simple guidance is needed for situations where the number of sensors is

limited.

• Alert Management

Managing the alert process will help determine when certain proper response actions are needed.

Proper alert levels will also minimize false-positives/false-negatives. It is not possible to eliminate

all false-positives and false-negatives at the same time. Therefore, it is preferable to optimize the

system to eliminate false-negatives and manage the inevitable false-positives in a way that

minimizes undesirable impacts on the utility and community. Currently, only some utilities have

experience with this as a part of their normal operations. The use of water quality parameters as a

first stage alert is a particular challenge for EWSs for terrorist attacks. Detailed baseline water

quality data are needed to set alerts with reasonable confidence that they do not result in too many

false-positives or false-negatives. More demonstration projects are needed to assure the

reasonability of certain approaches to alert management and further guide utilities to the proper use

of such alert management.

• Data Security

Current remote monitoring products are beginning to incorporate security precautions, including

encryption. However, demonstration projects are not frequent. Standardization from other data

security efforts could be applied to the water sector. Programs should be developed to link utility

security efforts surrounding SCADA generally with data security geared to EWSs.

• Communications, Response, and Decision Making 

The process linking the analysis of contamination data with the decision making and response is

outlined in EPA’s Response Protocol Toolbox. While this guidance provides a process, the

notification and communication equipment to effectively implement the process has not been

extensively developed for water utilities. Tools (e.g., Water Contaminant Information Tool) to assist

decision making and response are being developed.

9.2.2 Conclusions and Recommendations

Much of the data acquisition software and hardware already exist. The data acquisition systems do

not represent a major issue given currently recommended sampling times by EPA. Security of

SCADA systems for EWSs is a challenge but can probably be handled as the general security of

SCADA systems is addressed by utilities. Recommendations on the topics in the section include

the following:

• Standardized methods and guidance for data analysis and interpretation are needed. Some

of the efforts by ASCE will help to guide utilities in the use of such systems.

• Projects are needed to verify contaminant flow models and then adapt the models relatively

easily for use by various sized utilities.

• Simple guidance is needed, such as what to do if only a small number of sensors are

available.
U.S. EPA Office of Water Early Warning Systems

August 2005 115

• A demonstration project is needed to assure the reasonableness of certain approaches to alert

management. The USGS project is an example where multi-parameters sensors for water

quality are being used in conjunction with alert management. Additional projects should

examine alerts for other promising sensors such as mussel or bacteria monitors.

• Effective technologies should be developed to facilitate the rapid and efficient alert of

decision makers and response personnel with response information.

9.3 Evaluation of Multi-Parameter Water Quality Monitors

Traditional drinking water quality monitors have been bundled together and sold commercially.

They can now be monitored remotely, continuously, and in real-time. Several vendors have modular

systems, so that utility companies can choose which parameters they want to measure. These multiparameter monitors have proven valuable for maintaining daily water quality, and more recently

have been evaluated as a first-tier warning of the presence of an intentional contaminant. However,

combining monitors and sensors from different manufacturers is still problematic because these is

limited uniformity and interchangeability in hardware, signal generation and processing, and

connectivity. Several cities have used multi-parameter probes in their distribution systems both for

ensuring general water quality and for water security. Usually the probes were placed at convenient

sites with ready access.

An important part of developing a first stage EWS is to evaluate whether the normal operation of

water distribution systems can be documented in terms of sensor responses. One purpose of the test

at the WATERS Center was to determine if sensors can identify a baseline water quality or if sensor

drifting takes place. Thus, the basic performance characteristics of individual commercially

available sensors (in terms of use for early warning in water) were evaluated. The parameters

measured include pH, DO, turbidity, free chlorine, conductivity, ORP, TOC, and ion-selective

electrodes (Cl , NO and NH ). A basic conclusion was that specific-conductance, TOC, and free 3, 4

- +

chlorine monitors drift very little when properly calibrated and serviced; therefore, these sensors are

ideal for characterizing normal or safe conditions. However, it was also found that free chlorine

interferes with some of the above water parameters. Additionally, the test examined if the sensors

can qualitatively detect the contaminants. The contaminants injected into the system included

wastewater, potassium ferricyanide, malathion, and glyphosate. The test concluded that the sensors

can only provide a general indication of the contaminant class such as inorganic, organic, or a

reactive species producing chlorine demand (EPA, 2004).

The USGS and EPA have an Interagency study to implement and test an EWS at actual field sites.

The investigation team, composed of scientists and researchers from EPA, the USGS New Jersey

District, and a water utility are involved in the project whose purpose is to identify potential EWS

field sites, select sensors based on the previous EPA and USGS efforts, evaluate the distribution

system hydraulics and water quality, determine sensor locations, and collect sensor data. However,

no contaminants will be injected into the distribution system. The data will help determine how well

the sensors work, optimize the sensor location, and develop a baseline water quality profile of the

distribution system.

Another study from EPA’s WATERS test facility investigated the response of a combination of offthe-shelf sensors to detect changes caused by the injection of wastewater, groundwater, a chemical

cocktail, and individual chemicals, such as potassium ferricyanide, malathion, and glyphosate. The
U.S. EPA Office of Water Early Warning Systems

August 2005 116

feasibility of using the sensor information as an early warning of an attack was investigated. Initial

results show that water quality sensors responded to the injection of test materials. The parameters

monitored by the sensors include chloride, free chlorine, ORP, specific conductance, TOC, and

turbidity. These parameters exhibited a unique and consistent pattern of signal changes upon

injection of wastewater, potassium ferricyanide, malathion, glyphosate, and groundwater into a

drinking water distribution system simulator. The sensor system showed promise for providing

quick detection of water quality changes due to introduction of these test materials in the pipe loops.

Because of the unique physicochemical properties of these test materials, a specific sensor response

pattern was observed for each substance. This suggests that the sensor system may provide

information on the characteristics of unknown contaminants and facilitate the subsequent

identification with more sophisticated instruments. With further optimization, a system of sensors

may be used as an EWS (EPA, 2004). However, because the range of test materials was narrow,

additional types of contamination and scenarios should be examined to test this conclusion further.

Currently, EPA has several planned efforts to examine the use, development, and testing of multiparameter probes. EPA has an interagency agreement with the USGS and initiated CRADAs with

Hach Company, PureSense Environmental, Inc., and YSI, Inc. The goal of the partnerships is to

develop technologies for both detection devices (e.g., multi-parameter probes) and data analysis

software to facilitate the installation of early warning systems in the distribution networks of local

water utilities. The types of multi-parameter probes include pH, ORP, specific conductance, residual

chlorine, and temperature. 

Another series of tests currently being conducted at the EPA WATERS facility is verifying the

capability of multi-parameter water monitors for distribution systems. The testing is being

performed under the auspices of the EPA-ETV Program. The multi-parameter monitors for

distribution systems being used during these verification tests consist of instrument packages that

can be connected to or inserted into distribution system pipes for continuous monitoring. Also

included in this category are technologies that can be programmed to automatically sample and

analyze distribution system water at regular intervals, as well as hand-held technologies requiring

technicians to manually collect samples and perform the analysis. The monitors must be able to

measure free chlorine as well as at least one other water quality parameter (e.g., alkalinity, pH, DO,

ORP, temperature, turbidity, conductivity, ammonia, calcium, total carbon, chloramines).

The multi-parameter water monitors are being evaluated for the following parameters:

• Accuracy: Comparison to results from standard laboratory reference analyses.

• Response to individually injected contaminants: detection of changes in pipe loop water

chemistry. (Contaminants tested will include aldicarb, arsenic trioxide, and either E. coli

bacteria or nicotine.)

• Inter-unit reproducibility: comparison of results from two simultaneously operating

monitors.

• Ease of use: general operation, data acquisition, set up, demobilization, required

maintenance.

• Presence and identification of injected contaminants (if applicable): A total of 17 different

contaminants will be tested for identification by the appropriate monitoring system.
U.S. EPA Office of Water Early Warning Systems

August 2005 117

The monitors being verified during this series of tests include the following:

• Clarion Systems SentinalTM

• Emerson Model 1055 Solu Comp II Analyzer

• Man-Tech TitraSip SA (multi-parameter but not online)205

• Hach Event Monitor206

• Analytical Technology, Inc., Series C15 Water Quality Monitoring Module

Several manufacturers are exploring the signature monitoring approach. Using data from multiparameter continuous monitoring devices, one company tested a number of potential water

contaminants in an effort to establish signatures that could provide detection and a tentative

identification. A list of 60 contaminants (chemicals, toxins, biologicals) were analyzed for possible

detection. The sensors included pH, chlorine, conductivity, turbidity, and TOC. The sensors

showed response to the various contaminants, however, a few contaminants did not trigger a sensor

response at concentrations that are considered harmful. The manufacturer has developed a trigger

algorithm to set off an alarm when conditions in water depart from expected baseline parameter

values. Because utilities regularly experience changes in water quality, there are always concerns

in this type of system for false-positives (King, 2004).

It was announced in October 2004 that the Army and Hach Company have signed a CRADA to

complete testing of the Army’s new real-time water security detection and response technology by

the end of 2004. Under the agreement, ECBC, the Army Corps of Engineers, and Hach will conduct

live-agent testing using Hach monitoring equipment (GLI International panel, Cl-17, turbidmeter,

pH, and specific conductance, as well as Hach’s TOC monitor) to detect terrorist attacks on drinking

water distribution systems. The ECBC is one of the few sites in the U.S. where testing on actual

chemical and biological contaminants can take place. Pending verification tests, the technology is

scheduled for commercial production in 2005.

Exhibit 9-1 provides an evaluation of specific water quality parameter probes in the distribution

system. Exhibit 9-2 summarizes how the probes (both currently available or potentially adaptable)

compare with the desired characteristics of EWSs (as described in Chapter 3).

9.3.1 Issue and Gaps

The following discussion highlights various issues and gaps in using multi-parameter water quality

monitors in an EWS.

• Baseline Data are Needed 

Although research has demonstrated proof of concept for using water quality parameter fluctuations

as a signal that a contamination event has taken place, baseline data to calibrate the alarm triggers

may need to be gathered over months or years for each independent system. This will likely prove

to be sufficiently expensive that budgetary impacts would need to be addressed. Daily, seasonal,

and event- (i.e., storm-) related fluctuations will need to be identified and characterized, so they are

not confused with contamination events. Thus, systems with highly fluctuating source waters may

have considerable noise in the baseline.
U.S. EPA Office of Water Early Warning Systems

August 2005 118

Exhibit 9-1. Evaluation of Water Quality Parameter Monitors

Technology Manufacturer Evaluation

Single Parameter Sensors

Model A 15/B-2-1

– Free Chlorine

Analytical

Technology, Inc.

This is an online sensor that uses a polargraphic method to

monitor free chlorine. It showed less baseline stability and

sensitivity than Hach’s AquaTrend Panel, which also

monitors chlorine.

Hach TOC process

analyzer

Hach This is an online sensor that uses UV persulfate oxidation

to monitor total organic carbon. A good baseline and high

sensitivity was maintained when tested with all

contaminants. Cost is $30,000, higher than most of the

other devices tested in the study.

International

Model 5500

Dissolved Oxygen

GLI This is an online sensor that uses a membrane electrode to

monitor dissolved oxygen concentration.

Ion Selective

Electrodes

Various vendors No difference in chloride, nitrate, and ammonium analyzers.

Nitrate electrode not properly calibrated after exposure to

Cl. Chloride and ammonium sensor fail at a rate of 3-6

months. Recommend using 3 point calibration.

SpecificConductance

Various vendors No difference with vendors. Easy calibration, sensors last

years, care during cleaning of annular-ring carbon

electrodes

Dissolved Oxygen Various vendors Low flow technology no advantage over larger cell. DO

sensor based on plan sensor technology gave positive

deviation with sudden changes in Cl. Had failure rates for

chip higher than manufacturer anticipated.

OxidationReduction

Various vendors Similar performance of vendors, ORP robust, other sensors

(pH/electrodes) combined with ORP will fail before ORP

pH Various vendors Failure rates of 6 months in chlorinated water (planar sensor

failed at 1-2 months, and required at least weekly

calibration).

Temperature

sensor

Various vendors Rarely fail.

Turbidity

Monitors

Various vendors Very stable when properly cleaned (cleaning procedure is

more difficult but only required quarterly. Calibration

requires practices. Some false-positive readings when

vibrated or change pressure.

Free Chlorine Various vendors Colorimetric reliable when serviced properly. However,

sampling interval is 3 minutes. Polarographic technique

very reliable but must change membranes every 2 months

and need rigorous cleaning. Planar measurement failed

most frequently.

Total Organic

Carbon

One vendor Very stable but need experience to operate.
Exhibit 9-1. Evaluation of Water Quality Parameter Monitors

(continued)

U.S. EPA Office of Water Early Warning Systems

Technology Manufacturer Evaluation

August 2005 119

Multi-Parameter Sensors

Six-CenseTM

continuous

monitor

Dascore This online sensor monitors dissolved oxygen, free

chlorine, ORP, pH, specific conductance, and temperature.

It showed an unstable baseline when monitoring ORP,

specific conductance, and free chlorine.

AquaTrend panel Hach This online sensor monitors free chlorine, pH, specific

conductance, temperature, and turbidity. For free chlorine

detection, it showed the highest sensitivity and most stable

baseline compared to ATI’s and Dascore’s free chorine

sensors. It also had the most stable baseline for turbidity

monitoring. Overall, the AquaTrend showed consistent

responses, stable baselines, and high sensitivity in almost all

parameters measured in the study.

DataSonde 4a Hydrolab This online sensor monitors ammonia nitrogen, chloride,

dissolved oxygen, nitrate nitrogen, ORP, pH, specific

conductance, temperature, and turbidity. It performed well

compared to other sensors in measuring ORP.

In-Situ Model

Troll 9000

In-Situ This online sensor monitors dissolved oxygen, ORP, pH,

specific conductance, temperature, and turbidity. In

measuring ORP, it was noted that the In-Situ model had a

higher rate of failure than other sensors.

Signet Model 8710 Signet This online sensor monitors ORP and pH.

YSI Model 6000

continuous

monitor

YSI This online sensor monitors ammonia nitrogen, chloride,

dissolved oxygen, nitrate nitrogen, ORP, pH, specific

conductance, temperature, and turbidity. The YSI model

showed a more stable baseline for ammonia nitrogen and

nitrate nitrogen monitoring and a higher sensitivity for

chloride monitoring. Overall, the YSI model showed

consistent responses, stable baselines, and high sensitivity

in almost all parameters measured in the study.

Zero Angle

Photon

Spectrometer

MP-1

Oregon State

University

This online sensor uses optical measurement to monitor

bacterial fluorescence, humic fluorescence, nitrate nitrogen,

total fluorescence, transmission, and 245 nm UV

absorbance.

STIP-scan STIP Isco GmbH

(Germany)

UV/V is a spectroscopic sensor that is capable of

simultaneous measurement of nitrate, COD, TOC, spectral

absorption coefficient (SAC254), total solids, sludge

volume, sludge volume index, and turbidity

Sources: EPA, 2004a, 2004b.
U.S. EPA Office of Water Early Warning Systems

August 2005 120

Exhibit 9-2. Water Quality Monitors Comparison with Desired EWS Characteristics

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator Skill Analysis

Time

Currently

available?

Evaluation

Various SpecificConductance probes

single-parameter waterquality monitoring

conductance online $1,200 low < 5 min available EPA WATERS

Various DissolvedOxygen probes

single-parameter waterquality monitoring 

DO online $1,600 low < 5 min available EPA WATERS

Various Oxidationreduction probes single-parameter water quality monitoring ORP online $1,450 low < 5 min available EPA WATERSVarious pH probes single-parameter water

quality monitoring 

pH online $1,400 low < 5 min available EPA WATERS

Various Temperaturesensors

single-parameter waterquality monitoring 

temp online $1,100 low < 5 min available EPA WATERS

Various Turbiditymonitors

single-parameter waterquality monitoring 

turbidity online $1,100 medium < 5 min available EPA WATERS

Various Free Chlorinemonitors

single-parameter waterquality monitoring 

chlorine online $3,000 low < 5 min available EPA WATERS

Various Total OrganicCarbon monitors

single-parameter waterquality monitoring 

TOC online $25,000 medium 3-15 min available EPA WATERS

Hach TOC ProcessAnalyzer

single-parameter waterquality monitoring (totaloxygen concentration)

general toxicchemicals

online $30,000 low, automated 3-15 min available EPA WATERS

Hach Water DistributionMonitoring Panel

multi-parameter waterquality monitoring

general toxicchemicals

online $13,500 low, automated < 5 min available EPA WATERS

Diascore, Inc., SixCenseTM continuousmonitor

multi-parameter waterquality monitoring

general toxicchemicals

online $9,700 low, automated < 5 min available EPA WATERS

Emerson Model 1055Solu Comp II Analyzer

multi-parameter waterquality monitoring

general toxicchemicals

online not available

fromwebsite

low, automated < 5 min available none
Exhibit 9-2. Water Quality Monitors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator Skill Analysis

Time

Currently

available?

Evaluation

August 2005 121

Analytical Technology,Inc., Series C15 WaterQuality Monitoring

multi-parameter waterquality monitoring

general toxicchemicals

online not available

fromwebsite

low, automated < 5 min available none

Analytical TechnologyInc Model A 15/B-2-1

single-parameter waterquality monitoring (freechlorine)

general toxicchemicals

online $3,700 low, automated < 5 min available EPA WATERS

Clarion Systems’Sentinel

multi-parameter waterquality monitoring

general toxicchemicals

online not available

fromwebsite

low, automated < 5 min available none

GLI International Model5500

single-parameter waterquality monitoring(dissolved oxygen)

general toxicchemicals

online $3,700 low, automated < 5 min available EPA WATERS

Hydrolab DataSonde 4a multi-parameter water

quality monitoring

general toxicchemicals

online $15,000 low, automated < 5 min available EPA WATERS

Hach AquaTrend panel multi-parameter water

quality monitoring

general toxicchemicals

online $12,800 low, automated < 5 min available EPA WATERS

In-Situ Model Troll 9000 multi-parameter water

quality monitoring

general toxicchemicals

online $11,200 low, automated < 5 min available EPA WATERS

Signet Model 8710 multi-parameter water

quality monitoring

general toxicchemicals

online $830 low, automated < 5 min available EPA WATERS

YSI Model 6000continuous monitor

multi-parameter waterquality monitoring

general toxicchemicals

online $15,000 low, automated < 5 min available EPA WATERS

STIP-scan multi-parameter water

quality monitoring

general toxicchemicals

online not available

fromwebsite

low, automated < 5 min potentially

adaptable

none

Clarion Systems’Sentinel

multi-parameter waterquality monitoring

general toxicchemicals

online not available

fromwebsite

low, automated < 5 min available none
U.S. EPA Office of Water Early Warning Systems

August 2005 122

• Contaminant Specific Signatures are Needed 

Research has begun to develop contaminant specific signatures; however, the limited number of

contaminants examined lowers the confidence of the claim that the signature really is unique.

Classes of contaminants may be identifiable, but whether a wide range of specific contaminants can

be identified has not yet been determined. Regular changes in water quality can be a source of false

alarms (i.e., false-positives). Additionally, it is not known yet whether there are specific signatures

for biological contaminants.

• Data Storage and Manipulation are Needed 

For continuous real-time monitors, raw data can be generated on a scale that may be too large for

manual manipulation in a spreadsheet. Monitors that gather this volume of data would require

customized software (which vendors would usually supply) for data analysis. Utilities may choose

to archive summary data in a compressed form, to meet possible later needs. For many of the

techniques and devices reviewed in this report (see Chapters 5 to 8) the quantity of data generated

will not present a challenge. However, utilities should be mindful of what they may want their

system to handle if upgrades are planned. Approaches for storing and analyzing data are presented

in Chapter 4.

• System Can be Expensive

Not all vulnerable utility companies are able to afford the monitoring systems currently being

evaluated as EWSs. Reductions in price due to competition and technological advancements may

remedy this situation in the future, but in the interim, utilities with limited financial resources will

face a challenge in implementing online water quality monitoring.

• Cost Decisions

Current multi-parameter units cost approximately $10,000 without TOC. Although TOC appears

to be a valuable parameter to measure, it adds $18,000 to 29,000 per unit. Research needs to

determine the cost/benefit relationship of including this technology in an EWS. A basic system with

10 microprobe monitors (without TOC) linked to an existing SCADA system is estimated to cost

approximately $150,000, plus $60,000 per year in operational costs (DSRC Meeting, 2004).

Exhibit 9-3 provides a snapshot of capabilities, issues, and gaps for multi-parameter water quality

monitors.

9.3.2 Conclusion and Recommendations

Given the current developmental stage of multi-parameter technologies and based on preliminary

EPA tests, parameters that appear stable in monitoring a distribution system include chloride (ISE),

specific conductance (electrode), turbidity (nephelometric), free chlorine, and ORP. TOC also

appears to be extremely helpful, but it is expensive to monitor. Sensor probes and monitoring

systems are being developed by manufacturers. Such probes include free and total chlorine, pH,

temperature, specific conductance, chloride, nitrates, turbidity, and ORP. The cost per probe ranges

from a few hundred to several thousand dollars.
U.S. EPA Office of Water Early Warning Systems

August 2005 123

Exhibit 9-3. Water Quality Monitors as EWS

Capabilities Issues and Gaps

• Generally reliable and accurate for WQ

parameters

• Training and maintenance needs

considered reasonable by water utilities

• Have demonstrated the ability to identify

some chemical contaminants

• Wealth of multi-parameter monitors

available from a variety of companies

• A few utilities have experience in using in

distribution systems

• Significant testing of systems is ongoing

and will further evaluate use as an EWS

component

• Generally not prohibitively expensive

• Selection of parameters will determine

effectiveness

• Free chlorine sensor had the best response

for contaminants tested at EPA WATERS

laboratory

• Baseline data needed on regular water

quality fluctuations

• Contaminant specific signatures needed

• Large scale data storage and manipulation

needed

• Systems can be expensive to install and

operate depending on the parameters

chosen

• System not yet demonstrated for chemical

warfare agents, but future efforts planned

• Easy to place, but may present challenges

for placement based on risk evaluation

(space constraints, protection of the

equipment). Also, location may be

influenced by interferants created by

water source mixing and

routine/unexpected water quality

fluctuations.

Using the multi-parameter techniques, there is some preliminary evidence to suggest that such a

system appears to be able to detect an anomaly in the system. However, it is also reasonable to be

concerned about false-positives and whether the system can provide definitive indications of

contamination by a terrorist. Just gathering the baseline data may be prohibitively expensive.

Currently, these technologies need to demonstrate the ability to detect biological contaminants or

dangerous chemicals or develop a track record of field performance (e.g., how will it behave with

biofilms). Additional testing is needed, most likely in the field, before widespread use could be

recommended. For example, no tests have been performed on chloraminated systems. Full-scale

testing by the USGS New Jersey District, EPA, and a water utility during 2006 and 2007 may help

shed light on concern over false-positives and whether a system can function within the fluctuations

of normal water quality.

The signatures being developed by Hach and others to identify contaminants or classes are difficult

to evaluate independently or validate because their methods and algorithms are considered

proprietary and therefore are not available to the research community. As additional testing is

conducted using these methods and their performance is confirmed, there is less of a reason to be

cautious in proposing the use of these signature methods. Also, the examination of water quality

parameters for use in detecting and identifying contaminants is still being evaluated by EPA, USGS,

Army, and other organizations. Yet, no field scale tests of a full EWS with these multi-parameter

components have been implemented to date. This adds to the caution in currently recommending

use of these water quality parameter-based EWSs.
U.S. EPA Office of Water Early Warning Systems

August 2005 124

9.4 Evaluation of Chemical Sensors

Online continuous sensors and hand-held sensors for the detection of chemical/toxins in vapors or

air have been on the market and in use since before 9/11. The number of potential users of CBW

sensors greatly expanded after vulnerabilities to terrorist attacks were recognized. Researchers and

companies are rapidly developing technologies and products that will meet the needs of this

increased pool of end users.

• Microchip and microfluidics technology is advancing the sensor field by enabling

miniaturization of traditional methods (e.g., GC), as well as design of new methods.

• Portable and online gas chromatographs are available and in use by first responders. GC

can reliably identify a wide range of VOCs. Several portable GCs have been tested under

EPA’s ETV program. In one case, an online GC has been used in water distribution

systems.

• Kits that utilize bacteria to detect toxins have been developed for use with drinking water.

Several kits have been verified under the ETV program.

• Daphnia, mussels, algae, and fish have been incorporated into sensors for toxins in treated

waste effluent and source waters. However, only a mussel-based and a fish-based system

have been used to date with chlorinated drinking water.

• Portable infrared spectroscopy, ion mobility spectroscopy, surface acoustic waves, and

polymer composite chemoresistors technologies have been incorporated into portable

devices that can be used by first responders for the identification of numerous toxic

chemicals.

• Fiber optic cables are being coated with sensor materials to engineer continuous flexible

sensors for use in water and in air.

EPA’s ETV Program has investigated a number of the sensors that are sensitive to chemical

contaminants. A few utilities have experience using the biosensors for grab samples in distribution

systems. Another utility has experience using portable GC in the distribution system.

The following are evaluations of specific chemical detection devices starting with arsenic and

cyanide and then continuing with other specific detector systems. Exhibit 9-4 summarizes how the

chemical detectors (only those available now or potentially adaptable) compare favorably against

the desired characteristics of an EWS (as described in Chapter 3).

• Arsenic Sensor

There are two basic types of technologies that are used in commercially available tests, both of

which have been third party verified by EPA’s ETV Program. The first type involves a color

reaction kit (three manufactures evaluated) and the second employs anodic stripping voltammetry

(ASV; two manufacturers evaluated). The arsenic monitor manufactured by Industrial Test Systems,

Inc. (Rock Hill, SC) showed that low and high levels of interferents did not appear to affect the

detection of arsenic. A very low rate of false-positives was reported, but a variable rate of falsenegatives was reported. One source of error that ETV testers noted was that when samples contain

concentrations exceeding optimal detection, range accuracy and precision of the associated results

were reduced because of the difficulty in performing accurate dilutions in a field setting. The AS
U.S. EPA Office of Water Early Warning Systems

August 2005 125

Exhibit 9-4. Chemical Sensors Comparison with Desired EWS Characteristics

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

available?

Verification

Arsenic detectiondevices

color reaction oranodic strippingvoltammetry(ASV)

arsenic portable $100-$350

(colorreaction);$8,000 (ASV)

low (colorreaction); high(ASV)

15 min-1 hr < 10 ppb available EPA-ETV

Cyanide detectiondevices

colorimeter orion selectiveelectrodes

free cyanide portable $500- $1,500 low

(calorimeter);medium (ISE)

15-30 min < 0.1 mg/L available EPA-ETV

INFICONScentographCMS500

automated gaschromatograph

volatile organiccompounds

online not available

from website

low 30-60 min ppb available none

INFICONScentographCMS200

gaschromatograph

volatile organiccompounds

portable not available

from website

high 30-60 min ppb available none

INFICONHAPSITE®

gaschromatographmassspectrometer

volatile organiccompounds

portable $75-$5,000 high 30-60 min ppb available EPA-ETV,

AwwaRF

ConstellationTechnology CorpCT-1128

gaschromatographmassspectrometer

volatile organiccompounds

portable not available

from website

high not available

from website

ppb available none

Severn Trent FieldEnzyme Test

rapid enzymeinhibition

insecticides,nerve agents

portable not available

from website

low 5 min ppb available AwwaRF

Severn TrentEcloxTM

enzymeinhibition

chemicals andbiotoxins

portable $7,900 low 5 min detects ug/L to

mg/L ofcontaminant

available EPA-ETV,

AwwaRF

RandoxLaboratoriesAquanoxTM

enzymeinhibition

chemicals andbiotoxins

portable not available

from website

low not available

from website

not availablefrom website

available none
Exhibit 9-4. Chemical Sensors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

available?

Verification

August 2005 126

Lab_Bell inc.LuminoTox

Photosyntheticenzyme complexinhibition

chemicals andbiotoxins

portable not available

from website

medium < 15 min ppb available none

HarvardBioScience, Inc.MitoScan

submictochondrial particlesinhibition

chemicals andbiotoxins

portable not available

from website

medium 30 min not available

from website

available none

Check Light LTDToxScreen-IIRapid ToxicityTest

biomonitor(bacteria)

toxins - Aldicarb,Colchicine,Cyanide,Dicrotophos,Thallium sulfate,Botulinum,Ricin, Soman,VX

portable reagent kit -

$300; system -$2,895

low 30 min < ppm available EPA-ETV

Hidex Oy BioToxFlashTM

biomonitor(bacteria)

toxic substances portable reagent kit -

$128; system -$8,900

high 5-30 min not available

from website

available EPA-ETV

StrategicDiagnostics IncDeltaTox®

biomonitor(bacteria)

toxic substances portable reagent kit -

$370; system -$5,900

low 5-15 min 100 cfu/mL available EPA-ETV

StrategicDiagnostics IncMicroTox®

biomonitor(bacteria)

toxic substances not portable reagent kit -

$360; system -$17,895

low 15 min not available

from website

available EPA-ETV

none

Hach ToxTrakTMRapid ToxicityTesting System

biomonitor(bacteria)

toxic substances portable reagent kit -

$380; system -$3,950

low 45 min not available

from website

available EPA-ETV

InterLab SupplyPOLYTOXTM

biomonitor(bacteria)

toxic substances portable reagent kit -

$147; system -$1,600

low 20 min not available

from website

available EPA-ETV
Exhibit 9-4. Chemical Sensors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

available?

Verification

August 2005 127

SYSTEM Srl.microMAX-TOX

biomonitor(bacteria)

toxic substances online information not

available

information notavailable

informationnot available

information notavailable

available(expected 2005)

none

Delta ConsultMusselMonitor®

biomonitor(mussels)

toxic substances online $2,300 low 20 min see website for

26 contaminants

available none

BiologicalMonitoring Inc.Bio-Sensor®

biomonitor (fish) toxic substances online not available

from website

low < 1hr not available

from website

available none

Aqua Survey IQToxicity TestTM

biomonitor(daphnia)

toxic substances portable $2,400 (starter

kit) $400(maintenancekit)

medium 75 min not available

from website

potentiallyadaptable

EPA-ETV

bbe moldaenkeDaphnia Toximeter

biomonitor(daphnia)

toxic substances online not available

from website

low < 30 min not available

from website

potentiallyadaptable

none

bbe moldaenkeAlgae Toximeter

biomonitor(algae)

toxic substances online not available

from website

low not available

from website

potentiallyadaptable

none

bbe moldaenkeFish Toximeter

biomonitor(zebrafish)

toxic substances online not available

from website

low < 30 min not available

from website

potentiallyadaptable

none

US Army Centerfor EnvironmentalHealth Research

biomonitor(bluegill)

toxic substances online not available

from website

information notavailable

1 hr not available

from website

potentiallyadaptable

none

Lumintox GulfL.C. Lumintox

biomonitor(dinoflagellates)

toxic substances portable not available

from website

low 2-4 hrs not available

from website

potentiallyadaptable

none
Exhibit 9-4. Chemical Sensors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

available?

Verification

August 2005 128

SensIRTechnologiesHazMatIDTM

Fouriertransforminfraredattenuated totalreflectionspectroscopy

organicchemicals,biologicalcontaminants

portable not available

from website

low 10 min chemicals at

100 ppm

potentiallyadaptable

none

ITNX-Rayfluorescence

metals online not available

from website

information notavailable

not availablefrom website

not availablefrom website

potentiallyadaptable

none

Smiths DetectionSABRE 4000

ion mobilityspectroscopy(IMS)

explosives,chemicalswarfare agents,toxic chemicals

portable not available

from website

low < 1 min > 5-10 ppb potentially

adaptable

none

Cyranose® 320 polymer

compositechemiresistor

toxic chemicalsin vapor form

portable not available

from website

not availablefrom website

not availablefrom website

not availablefrom website

potentiallyadaptable

none

Cyrano SciencesNosechipTM

polymercompositechemiresistor

toxic chemicalsin vapor form

online not available

from website

not availablefrom website

not availablefrom website

not availablefrom website

potentiallyadaptable

none
U.S. EPA Office of Water Early Warning Systems

August 2005 129

 75 arsenic test kit manufactured by Peters Engineering (Austria) showed that low and high levels

of interferents did not appear to affect the detection of arsenic. A very low rate of false-positives

and negatives was reported. One problem ETV testers noted was that the reagent tablet took up to

1.5 hours to dissolve.

The As-Top Water test kit offered by Envitop, Ltd. (Oulu, Finland) indicated the presence of

interferents did not affect the arsenic test. The effect of operator skill level appears to be a

significant factor with the As-Top Water test kit. The non-technical operator rarely detected arsenic

in any samples, even those containing arsenic at over 90 ppb. The technical operator detected

arsenic more frequently, though rarely at the same concentration determined by the reference

method. One problem ETV testers noted was the color on the indicator did not correspond exactly

to colors on the comparison card.

Monitoring Technologies International Pty., Ltd. (Perth, Australia) offers the PDV 6000 portable

analyzer, which measures arsenic in water using anodic stripping voltammetry (ASV). ETV testers

noted that instructions in the operation manual for water analysis were difficult to follow, indicating

that the level of experience in the operation of the PDV 6000 analyzer and associated software is

likely to influence the reliability of results. Low and high levels of interferents (iron and/or sulfide)

adversely affected the detection of arsenic.

Another device that employs ASV technology is the Nano-BandTM Explorer made by TraceDetect

(Seattle, Washington). ETV testers noted the Nano-BandTM Explorer did not appear to be affected

by matrix interferences added to the samples. However, the data from the two operators were quite

different, with the non-technical operator reporting no detectable arsenic in any of the 16 samples.

Cyanide Sensor

There are two basic types of technologies (colorimetric and solid sensing element) that are used in

commercially available tests, both of which have been third party verified by EPA’s ETV Program.

Both types of technologies are used in portable devices designed for onsite rapid analysis of cyanide

in water. One problem common to all four portable colorimeters tested by the ETV was that

performing analyses under extremely cold conditions (sample water 4 to 6o C) negatively affected

the performance of the reagents. Also, for all four colormetrics, when a lethal amount of cyanide

was present, a drastic, rapid change in color was visible and no reading by the colorimeter was

necessary, making lethal amounts of cyanide in water quickly detectable. Using the VVR V-1000

multi-analyte photometer, there was a slight bias for a technical operator compared to a nontechnical operator. It takes approximately 17 minutes to obtain and analyze one sample. Using the

1919 SMART 2 Colorimeter, technical verses non-technical operator did not impact results. For the

Mini-Analyst Model 942-032 by Orbeco-Hellige (Farmingdale, NY), the manufacturer recommends

adjusting the pH of water samples to between 6.0 and 7.0. Since gaseous hydrogen cyanide can be

released at a pH less than 9.0, this adjustment is not desirable from a safety standpoint, especially

if lethal/near-lethal concentrations of cyanide are present. Although the model was easily

transported to the field and the sample preparation instructions were clear, the liquid pyridine

reagent had an offensive odor, and the granular reagent tablets were difficult to open. Also, the

operators stated that it was inconvenient to keep track of the mixing and waiting times during the

analysis. There was a slight bias for a technical operator. Using the AQUAfast® IV AQ4000
U.S. EPA Office of Water Early Warning Systems

August 2005 130

colorimeter by Thermo Orion (Beverly, MA), there was very little difference in results generated

by the non-technical operator compared with those of the technical operator.

Using the solid sensing element, the Thermo Orion Model 9606 Cyanide Electrode required

calibration and electrode polishing before every sample set. Operator bias was not tested. Also,

using the solid sensing element, the Cyanide Electrode CN 501 with the Reference Electrode R503D

and Ion Pocket Meter 340i (WTW ISE) by WTW Measurement Systems (Ft. Myers, FL) had a

difficult to understand instruction manual. A one-hour telephone consultation with WTW was

required before the WTW ISE was easy to operate. Operator bias was not evaluated.

MosselMonitor® by Delta Consult

MosselMonitor® detects toxins. One of the major problems for using the MosselMonitor® was the

low food content of the water to be monitored (fast running surface waters, groundwater). An

“Automated Food Device” (AFD) was developed to automatically and continuously feed algae to

the mussels using a flow-though system. Mussels are very sensitive to chlorine, and addition of

thiosulphate to the water minimizes the effects of free chlorine (Jan de Maat, Delta Consult, personal

communication). As a result of the adaptations, the Budapest Waterworks have now successfully

applied the MosselMonitor® in monitoring of chlorinated drinking water for 10 months.

EcloxTM by Severn Trent Services

EcloxTM detects chemicals and biotoxins. Sample analysis is simple and takes only five minutes.

Contaminant concentrations could be detected to a limit of μg/L to mg/L, but results were not

consistently reproducible. When compared to the similar detection device Microtox®, the actual

contaminant values generated by these devices may vary in different types of water, especially in

distilled water. It is necessary to establish site-specific baseline values (States, 2004). In another

study, clean chlorinated and chloraminated water samples produced very low inhibition of light,

indicating that the disinfection byproducts that may be present in drinking water do not interfere

with EcloxTM results. However, false-negative results were produced by lethal doses of soman and

Botulinum toxin. EcloxTM is easily transported and operated in the field, where similar results were

produced as in the lab (EPA-ETV, 2004).

MicroTox® and DeltaTox® by Strategic Diagnostics, Inc. 

MicroTox® and DeltaTox® detect chemicals and biotoxins. Sample analysis is moderately difficult

and takes 45 minutes. Copper was shown to be a potential interferent. Contaminant concentrations

could be detected to a limit of μg/L to mg/L, but results were not consistently reproducible. When

compared to the similar detection device EcloxTM, the actual contaminant values generated by these

devices may vary in different types of water, especially in distilled water. It is necessary to establish

baseline values for each site (States, 2004). In another study, MicroTox® had false-positive results

when testing clean chloraminated water, but not when testing clean chlorinated water. Half the

contaminants tested produced false-negatives when lethal doses were present. The operation of

MicroTox® was easy to understand for in-lab operation. This product is not field portable. For

DeltaTox®, false-positive results were produced when testing clean chloraminated water, but not

when testing clean chlorinated water. Over half the contaminants tested produced false-negatives
U.S. EPA Office of Water Early Warning Systems

August 2005 131

when lethal doses were present. DeltaTox® is straightforward to operate and easily transported to

the field (EPA-ETV, 2004).

Tox Screen II by Checklight, Ltd.

When using the pro-organic buffer, the low level of light production in water disinfected by

chlorination or chloramination may interfere with the ToxScreen II results, resulting in falsepositives. However, residual sodium thiosulfate from dechlorination may have caused these results.

When using the pro-metal buffer, as long as a similar reference sample is used, water disinfected

using either process is not likely to interfere with the ToxScreen II results. Operation of the

ToxScreen II was relatively straight forward and the instrument was easily transported to the field

when similar results as in the lab were produced (EPA-ETV, 2004).

ToxTrakTM by Hach Company 

Half of the samples from a water system using chlorination were analyzed in July and the other half

in September. In July, a significant amount of inhibition was noted, while in September, the same

sample was largely non-inhibitory. There seems to be a risk for false-positive results due to

interference of previously chlorinated water, though the reason for the difference in these results is

not clear. False-positives were also experienced due to iron in the water samples. False-negative

results were experienced when samples with lethal doses of contaminants were tested. The

ToxTrakTM was easy for testers to operate and is field portable, but the ToxTrakTM reagent must be

incubated over night at 35°C, which could be problematic for field deployment (EPA-ETV, 2004).

IQ Toxicity TestTM by Aqua Survey

Aluminum, copper, and iron are potential interferents because they adversely affected 90 percent

to 100 percent of the Daphnia organisms. In addition, all Daphnia organisms exposed to drinking

water from a system disinfected by chloramination were adversely affected, and therefore produced

false-positives. However, the water sample from a drinking water system that uses chlorination did

not adversely affect the daphnia. There were no false-negative results produced when using this test.

The IQ Toxicity testTM instruction manual is easy to understand and the test is field portable, though

a stock of Daphnia must be maintained to facilitate short-notice field testing (EPA-ETV, 2004).

BioTox FlashTM by Hidex Oy

Bacterial metabolic inhibition caused by copper and zinc may result in interference with BioToxTM

results. Slightly exaggerated inhibition may result when using chloraminated water, resulting in a

possible false-positive, while there is a risk for false-negatives when using chlorinated water

samples. The BioToxTM is field portable, but a flat, steady surface is needed to operate the

BioToxTM. ETV testers found it difficult to operate the BioToxTM without an instruction manual,

but once the correct procedure was determined, operation was easy (EPA-ETV, 2004).

POLYTOXTM by Interlab Supply, Ltd.

Without a baseline water sample of a matrix similar to the test water sample, there is a considerable

risk that an analysis of POLYTOXTM in clean chloraminated water would produce organism
U.S. EPA Office of Water Early Warning Systems

August 2005 132

respiratory inhibition great enough to yield a false-positive result. In clean chlorinated water

inhibition was low enough that false-positives were not produced. Over half of the contaminants

tested produced a false-negative when present at lethal doses. The POLYTOXTM is field portable

and ETV testers had no difficulty operating it (EPA-ETV, 2004).

Pesticide/Nerve Agent by Severn Trent Services

Pesticide/Nerve Agent is a rapid enzyme test that detects pesticides and nerve agents. Sample

analysis is performed in five minutes and is generally simple. This test is easily conducted using

concentrated or non-concentrated sample water (States, 2004).

HAPSITE® by INFICON Inc.

HAPSITE® is a field deployable gas chromatograph-mass spectrometer (GC-MS) that detects VOCs

found in toxic substances and chemical warfare agents. The recent addition of a “Situ Probe” purgeand-trap sampling device enables water samples to be analyzed. The GC portion of the device

detects volatile substances with a molecular weight between 45 and 300, and the MS portion of the

device identifies the compound from a library of 170,000 organic compounds (States, 2004).

Sample analysis takes 60 minutes but is very difficult to perform. This system has been deployed

in a distribution system and could serve as a case study.

9.4.1 Issues and Gaps

This section highlights various issues and gaps in using chemical detectors for early warning for

finished drinking water. 

• Cost for Some Available Technology is High

Online and portable devices such as GC-MS are expensive, ranging from $75,000 to $95,000.

• Field Kits are Not Optimal

The bacterial monitoring kits tested by EPA’s ETV have high false-positive and false-negative rates.

A common drawback for kits is the stability of reagents. Often reagents require reconstitution (if

they are lyophilized) or careful measurement of reaction components to constitute a fresh reaction

mixture. Kits can be subject to variability due to different users because it is difficult for users to

mix and pipette in a consistent manner. They require trained personnel and have set up

requirements, such as culturing log phase growth bacteria. The results do not provide specific

identification of a toxin. Although these kits may be suitable for confirming the presence of a toxin,

further methods would need to be utilized for specific identification.

• Some Detection Methods Face Challenges from the Chlorine Residual

Organism-based biomonitors are sensitive to the chlorine residuals in drinking water. Although the

fish-based Bio-Sensor® and MosselMonitor® remove chlorine, broadly applicable methods for

chlorine removal have not yet been developed. Although one company, Checklight, is developing
U.S. EPA Office of Water Early Warning Systems

August 2005 133

a system for removal of chlorine, the effect of chlorine removal on other biosensors has not been

demonstrated.

• Many Technologies Have Not Been Adapted for Water

Portable infrared spectroscopy, ion mobility spectroscopy, surface acoustic waves, and polymer

composite chemoresistors technologies are being aggressively pursued for air and vapor

applications, but have not been developed specifically for drinking water monitoring. These

techniques could be adapted for water if companies’ market research indicates there is a potential

market.

Exhibit 9-5 provides a snapshot of capabilities, issues, and gaps for chemical sensor technologies

and techniques.

9.4.2 Conclusion and Recommendations

Portable technology (e.g., GC) is available for conducting analysis of many possible chemical

contaminants. This area will continue to improve as high technology equipment is based on

microchip technology (e.g., nose chip). Certain biomonitors are portable and can be used for site

assessments. Chlorine would have to be removed for such analyses. The technology that is readily

available and reliable are specific probes like arsenic and cyanide probes that could be effective

against a narrow selection of contaminants. Online technologies are not cost effective and are not

reasonably available. GC and ion mobility have cost and technical challenges. The current

experience of using high-tech GC in a utility’s distribution system has not been determined to be

cost-effective to cover the distribution system.

Certain biomonitors may be promising if the issue of chlorine and chloramine residual interference

can be resolved. For example, the mussel monitor has been recently demonstrated in finished water

in Europe and there are various efforts to make other monitors (MicroTox® and ToxScreen)

adaptable to finished water. The mussel monitor could be a good candidate for an EPA-ETV

Program verification and perhaps used for a laboratory and/or field study on finished water or with

CBR surrogates or agents. In the next three years, the field should show further development in

terms of cost effective and reliable devices. A few new technologies (such as microchips) could

revolutionize the chemical detection field for drinking water.
U.S. EPA Office of Water Early Warning Systems

August 2005 134

Exhibit 9-5. Chemical Sensor Technologies and Techniques

Method Capabilities Issues and Gaps

Arsenic and

cyanide probes

• established monitors for arsenic/cyanide

• reliable

• ETV reports available

• limited to one parameter identified at a

time

• various issues (reliability) with certain

methods

GC • range of VOCs detected

• online for drinking water

• expensive

• not widely used for drinking water

Enzyme

Inhibition

• detects chemicals (phenols, amines, heavy

metals)

• detects substances toxic to cholinesterase

(nerve agents and pesticides

• portable (kit)

• requires mixing and pipetting

• chlorine residual interferes (false-positive

source)

Bacterial

biomonitors

• detects substances toxic to bacteria

• portable (kit)

• ETV reports available

• online for surface water

• requires mixing and pipetting

• false-positive/false-negative rate high

(ETV reports)

• chlorine residual interferes

Daphnia, fish,

algae biomonitors

• detects substances toxic to daphnia, fish

or algae

• online for source and treated waste water

monitoring

• chlorine residual adversely affects the

living organisms

Mussel and fish

biomonitors

• detects substances toxic to mussels or fish

• online systems exist

• in use in a few distribution systems

• not proven for drinking water

• no third party verification

Eukaryotic cell

and tissue

biomonitors

• can potentially detect substances toxic to

human cells

• emerging technology, commercial

products not available

Fiber optic cablebased sensors• detects toxic chemicals

• being designed to be on line for water

distribution systems

• can cover long continuous areas

• emerging technology

• most advanced products are for air

Infrared • identifies wide range of substances

• portable (suitcase)

• water matrix interference requires use of

extraction method

• unidentified substance must be

concentrated

Ion mobility • detects wide range of compounds

(explosives, chemical warfare agents,

toxic industrial chemicals or narcotic

substances)

• portable (hand-held)

• expensive

• developed for vapor sensing, would

require accessory equipment for water

SAW-based

sensors

• detects VOCs, explosives, illicit drugs,

and chemical warfare agents

• online for groundwater monitoring

• MEMS-SAW is emerging technology

• water applications will lag behind air

applications

Microchip

chemoresistors

• detects wide range of volatile compounds

• portable (hand-held)

• developed for vapor sensing, would

require accessory equipment for water
U.S. EPA Office of Water Early Warning Systems

August 2005 135

9.5 Evaluation of Microbial Sensors

Rapid microbial detection technologies are not as advanced as chemical detection technologies.

However, advances in the last few decades in molecular biology, genomics, and microfluidics, have

stimulated the imagination of researchers and resulted in the appearance of the first generation of

detection devices for microbes. There are many technological approaches with laboratory

prototypes and the beginning of commercial product development.

• Immunoassays are available in several formats including: test strips, columns, linked to fiber

optics, attached to microspheres and quantum dots, and incorporated into a wide array of

microchip technologies. Specific contaminants can be identified with antibody-based

technologies.

• ATP is a general indicator for the presence of live cells. There are numerous small portable

kits for detecting ATP that are used in the food industry. There are also portable kits for

testing grab samples in water. 

• Portable and rapid (30 minutes or less) PCR is a reality, with four systems currently on the

market.

• Light scattering technologies have a long history of use for measuring turbidity and are now

being adapted for detecting microbial cells in drinking water.

• Technologies that utilize microchips/microarrays are being aggressively pursued. The

proliferation of approaches should yield some viable options for drinking water applications

in the long-term.

ECBC conducts research applicable to biological and chemical defense sensors and integrated

detection systems. It has conducted many studies, including some that can detect contaminants in

water. In March 2002, ECBC issued the Bio-Detector Assessment (ECBC, 2002). The report

evaluated several biological detection devices including immunoassay-based or nucleic acid-based

technologies. The devices include Bio-HAZTM, FACSCount, Luminex 100, ANALYTE 2000,

BioDetector, Hand-Held Assays, ORIGEN Analyzer, Tetracore Tickets, Cepheid Smart Cycler®,

and Rapid System. The ANALYTE 2000 technology has been replaced by the company’s newer

technology, RAPTORTM. ORIGEN Analyzer technology is now being further developed by

BioVeris. The evaluation used criteria including portability, reliability, time to analyze, classes

detected, viability, sensitivity to bacteria, toxins, viruses, ease of use, rate of processing samples,

portability, and price for consumables. The methods were evaluated using a quantitative scale and

input from experts. Hand-Held Assays, Tetracore, and New Horizon (referred to as SmartTM Tickets

elsewhere in this report) received the highest score of all immunoassay-based devices. PCR was

credited with being specific and sensitive and not prone to false-positives. Specifically, RAPID

from Idaho Technologies received high scores. Freeze-dried PCR assays are already available, and

the system can operated from a battery and connected via Internet to transmit data to remote sites

to assist in response. ECBC also has a program (Early Sentinal Biomonitoring System Program)

to screen and examine, and verify the performance of up to 28 technologies for rapid detection for

drinking water (Stanley States, Pittsburgh Water and Sewer Authority, personal communication).

Evaluations of specific microbial detection devices are provided below. Exhibit 9-6 summarizes

how the microbial detectors (those available now or potentially adaptable) compare with the desired

characteristics of an EWS (as described in Chapter 3).
U.S. EPA Office of Water Early Warning Systems

August 2005 136

Exhibit 9-6. Microbial Sensors Comparison with Desired EWS Characteristics

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

Available?

Verification

Tetracore BioThreat Alert (BTA)

antibody lateral flowassay

biological agentsincluding anthrax,botulinum toxin,ricin

portable $625 (25 strip

kit) $4,000(strip reader)

low 15 min anthrax - 106

spores/mL;bot.- .02mg/L; ricin -.0075 mg/Llow

available AwwaRF,

ETV, ECBC

New HorizonsDiagnosticsSMARTTM Tickets

antibody lateral flowassay

biological agentsincluding anthrax,botulinum toxin,ricin

portable $15-20 per

strip

low 15 min bacteria 105

cfu/mL;biotoxin 50ppb

available AwwaRF

EAI CorporationBio-HAZTM (withSMARTTM tickets)

antibody lateral flowassay

biological agentsincluding anthrax,botulinum toxin,ricin

portable $20,000 low < 30 min see above available ECBC

ResearchInternationalRAPTORTM

antibodyfluorometric assay

biological agents,toxins, chemcontaminants

portable $50,000 medium 7-12 min anthrax

detected at< 1.0 ng/mL

potentiallyadaptable

none

ResponseBiomedical CorpTest Cartridges

antibody lateral flowassay

biological agents(anthrax, botulinumtoxin, ricin)

portable $10,000 (25

cartridges &reader)

low 15 min anthrax - 107

spores/mL,bot. - 2 mg/L;ricin - 1 mg/L

available EPA-ETV

ADVNT BADD Test Strips

antibody lateral flowassay

biological agents(anthrax, botulinumtoxin, ricin)

portable $250 (10

strips)

low 15 min anthrax - 107

spores/mL;bot. > 5 mg/L;ricin -20 mg/L

available EPA-ETV

LLNL AutonomousPathogen DetectionSystem usingLuminexCorporation’sxMAP®

microspheres withbiological capturemolecule

biologicalcontaminants

in lab; online information

not available

high information

not available

informationnot available

potentiallyadaptable

none
Exhibit 9-6. Microbial Sensors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

Available?

Verification

August 2005 137

BioDetect Microcyte Aqua®

flow cytometer cells portable not available

on website

informationnot available

not availableon website

not availableon website

available none

BrightwellTechnologiesMicro-FlowImaging

digital imagingparticle counter

particles and cells online not available

on website

informationnot available

1 min particles

> 2 μm in size

available none

AMSALiteTMAntimicrobialSpecialists andAssociates

luminescence ATP portable $2,000 low < 10 min not available

on website

available none

WaterGieneTMCharm Sciences, Inc

luminescence ATP portable not available

on website

low < 10 min 100 cfu/mL available none

Continuous FlowATP DetectorBioTraceInternational

luminescence ATP online $50,000 not available

on website

1 min not available

on website

available none

Celsis-LumacLandgraaf, theNetherlands

luminescence ATP portable not available

on website

not availableon website

< 10 min not available

on website

potentiallyadaptable

none

ProfileTM -1 (usingFiltravetteTM)New HorizonsDiagnostic Corp

luminescence ATP portable not available

on website

not availableon website

< 5 min not available

on website

available none

LXT/JMARBioSentry

light scattering biological

contaminants

online not available

on website

low 1 min low available 2005 none

Rustek Ltd light scattering -

MALS

biologicalcontaminants

online not available

on website

not availableon website

not availableon website

not availableon website

potentiallyadaptable

none
Exhibit 9-6. Microbial Sensors Comparison with Desired EWS Characteristics

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Description Range of

Contaminants

Online/

Portable?

Cost Operator

Skill

Analysis

Time

Sensitivity Currently

Available?

Verification

August 2005 138

Idaho TechnologyRAPID

PCR biological

contaminants

portable $55,000 medium 30 min-3 hrs 1,000 cfu/mL potentially

adaptable

AwwaRF,ECBC

Smiths DetectionBio-SeeqTM

PCR biological

contaminants

portable $25,000 medium 30 min 1 cfu/sample

volume(28 μL)

potentiallyadaptable

none

InvitrogenPathAlertTM

PCR biological

contaminants

mobile lab not available

on website

high 30 min 10 cfu/mL potentially 4

adaptable

ETV DoD

Cepheid Hand-HeldNucleic AcidAnalyzer (HANAA)

PCR biological

contaminants

portable not available

on website

informationnot available

< 10 min information

not available

potentiallyadaptable

none

Cepheid SmartCycler® XC

PCR biological

contaminants

portable $46,000 medium 30 min-3 hrs < 30 anthrax

spores

potentiallyadaptable

ECBC

Ibis Pharmaceuticalsand SAICT.I.G.E.R.

PCR biological

contaminants

portable not available

on website

not availableon website

few hrs not available

on website

potentiallyadaptable

none

Nomadics®SpreetaTMEvaluation Module

surface plasmonresonance (SPR)

biological andchemical

portable $695-$9,995 not available

on website

not availableon website

not availableon website

potentiallyadaptable

none

Georgia TechBOSS

fiberopticevanescent wavespectroscopy

biological andchemical

portable,online

informationnot available

informationnot available

minutes information

not available

potentiallyadaptable

none

InnovativeBioSensors Inc.BioFlashTM

cell-based biosensor biological

contaminants

portable not available

on website

medium 5 min not available

on website

potentiallyadaptable

none

BioVerisM1M

ECL biological mobile lab not available

on website

high 1 min not available

on website

potentiallyadaptable

none
U.S. EPA Office of Water Early Warning Systems

August 2005 139

BTA Test Strips by Tetracore (Gaithersburg, MD)

BTA Strips detect pathogens by rapid immunoassay. In one evaluation study, the detection limit

was found to be 10 cfu/mL for pathogenic bacteria. They are useful for screening acute hazards, 5

but poor sensitivity limits their usefulness in detecting low levels of contaminants in water. Analysis

is simple and takes 15 minutes (States, 2004). EPA conducted a second evaluation test for anthrax,

botulinum, and ricin. The anthrax test strips generated one false-positive when testing each Florida

and New York drinking water sample. False-negatives were generated in water due to Ca and Mg

ion presence, and in concentrated drinking water from California and New York. The strips were

not able to detect spores at the vendor indicated concentration limit of 10 , only at levels 100 to 5

1,000 times greater. For Botulinum toxin test strips, false-positives resulted due to the presence of

humic acid, fulvic acid, and lipopolysaccharides in water. There were no false-negatives. Both

toxin types were detected near the vendor-indicated limit of 0.1 mg/L. For ricin, false-positives

occurred in Florida drinking water while false-negatives occurred in New York drinking water. Test

strips can detect to concentrations of 0.035 mg/L, as stated by vendor. All types of BTA test strips

had consistency near 100 percent. A 25 test strip kit costs $625 and the Alexeter strip reader costs

$4,000 (EPA-ETV, 2004).

In a third evaluation study, BTA Tetracore Tickets identified four of eight contaminants. Many

BTA reagents are available commercially or through the government and are not likely to produce

false-positives or negatives. Furthermore, there was low opportunity for error due to ease of use and

it takes less than 30 minutes to set up the device and analyze one sample. It is a hand-held device

and costs $4,500. Tetracore scored one of the highest of all immunoassay-based devices in this

evaluation (ECBC, 2002).

SMARTTM Tickets by New Horizons Diagnostics (Columbia, MD)

SMARTTM Tickets detect biotoxins by rapid immunoassay with a detection limit of 2 to 50 ug/L.

Analysis is simple and takes 15 minutes; however, poor sensitivity limits their usefulness in

detecting low levels of contaminants in water (States, 2004). SMARTTM Tickets have been

incorporated into Bio-HAZTM. In a study of Bio-HAZTM with New Horizon SMARTTM Tickets, it

was able to identify all four of the bioagent classes (sporulated bacteria, vegetative bacteria, toxins,

and viruses), and identified four of eight traditional bioagents identified by DOD. Some SMARTTM

Tickets reagents are available commercially or through the government and the method is not likely

to produce false-positives or negatives. There is also low opportunity for error due to ease of use

and it takes less than 30 minutes to set up and analyze one sample. It is field portable and costs

$20,000. Bio-HAZTM scored one of the highest of all immunoassay-based devices (ECBC, 2002).

R.A.P.I.D. (Ruggedized Advanced Pathogen Identification Device) by Idaho Technology 

R.A.P.I.D. uses PCR to detect pathogens and biotoxins to a limit of 10 cfu/mL. This device is used 3

extensively by the military, but the detection capabilities suggest potential application for water

utility personnel or contaminated drinking water investigators. The sample preparation is

standardized, the kit includes positive and negative DNA controls, and initial data interpretation is

automated. The effectiveness of this test is limited by its sensitivity. Analysis is moderately

difficult and takes 90 minutes (States, 2004). In another evaluation study, the Rapid System

identified four of eight contaminants with half of reagents being available commercially or through
U.S. EPA Office of Water Early Warning Systems

August 2005 140

the government. It was not likely to produce false-positives or negatives, but had a high opportunity

for error due to difficulty of use. The Rapid System takes approximately three hours to set up the

device and analyze one sample. It is field portable and costs $55,000 (ECBC, 2002).

EcloxTM by Severn Trent Services

EcloxTM detects chemicals and biotoxins. Sample analysis is simple and takes only five minutes.

Contaminant concentrations could be detected to a limit of μg/L to mg/L, but results were not

consistently reproducible. When compared to the similar detection device MicroTox®, the actual

contaminant values generated by these devices may vary in different types of water, especially in

distilled water. It is necessary to establish baseline values for each site (States, 2004). In another

study, clean, chlorinated, and chloraminated water samples produced very low inhibition of light,

indicating that byproducts of either disinfection process that may be present in drinking water do

not interfere with EcloxTM results. However, false-negative results were produced by lethal doses

of soman and butulinum toxin. EcloxTM is easily transported and operated in the field, where similar

results were produced as in the lab (EPA-ETV, 2004).

HandHeld Assays from the Department of Defense

HandHeld Assays can identify seven of the eight traditional bioagents identified by DOD. Reagents

are mostly available commercially or through the government with the assays being found to be less

unlikely to produce false-positives or negatives. They have a low opportunity for error due to ease

of use and take less than 30 minutes to set up and analyze one sample. HandHeld Assays scored

high in the ECBC study (ECBC, 2002). In another study, HandHeld Assays were determined to

have limits of detection that are many times the infectious dose. There can be false-positives

because of environmental contamination and they are sometimes not used properly. The DOD

determined that the HandHeld Assays are effective if used in concert with other confirmatory

detectors (Emanuel et al., 2003). In another report generated by scientific experts from 14 federal

agencies, HandHheld Assays had either high false-positive rates (ranging from 3 percent to 207

83 percent) or sensitivity problems. Thus, none of the assays could be considered reliable for field

detection.

Smart Cycler® from Cepheid

Smart Cycler® identified four of eight traditional bio agents identified by DOD, but the reagents are

not currently available commercially or through the government. It is less likely to produce falsepositives or negatives, has high opportunity for error due to difficulty of use, and takes

approximately three hours to set up the device and analyze one sample. It is field portable and costs

$35,000 (ECBC, 2002).

Light-Scatter

The identification rate of Cryptosporidium parvum oocysts varied from 11 percent to 45 percent,

and false-positive rates varied from 0.3 percent to 3 percent. The MALS system may be tuned by

the user, who must understand that a higher identification rate will be accompanied by a higher

false-positive rate. MALS was also able to differentiate between different physical states of

Cryptosporidium oocysts, including oocysts treated with ozone, heat treated, or excysted from live
U.S. EPA Office of Water Early Warning Systems

August 2005 141

untreated oocysts. The limit of detection was such that MALS could be used as an early warning

tool for water contamination outbreaks. For purified water, the estimated limit of detection (ELOD)

was found to be 7, 0.7, and 0.1 oocysts/mL in 1, 10, and 60 minutes respectively. For finished

drinking water samples, the ELOD was 75, 7.5, and 1 oocysts/mL in 1, 10, and 60 minutes

respectively. The researchers concluded that MALS technology has suitable applications to water

distribution system monitoring (Quist et al., 2004, AwwaRF Project #2720, see Appendix D).

RAMP Anthrax Assay by Response Biomedical Corporation (Vancouver, Canada)

RAMP uses a cartridge that is a lateral flow immunoassay device with a test and control line. The

detector is an antigen-specific antibody attached to a fluorescent bead. The RAMP instrument

detects the presence of fluorescent beads that attach to the capture assay line. In the test study, three

non-pathogenic strains of Bacillus anthracis and three non-anthracis Bacillus strains were tested.

The detection limit of the three Bacillus anthracis strains ranged from 1,000 to 2,000 spores. The

non-anthracis Bacilli did not cross-react and no false-positives were produced in the presence of

interferents. The RAMP Anthrax Assay has not been tested for use in water systems (Heroux and

Anderson). In another verification test conducted by EPA, three types of test cartridges were

available for anthrax, botulinum toxin, and ricin. The anthrax cartridges produced no false-positives

or negatives due to interferants, though were not able to detect anthrax spores at the vendor indicated

concentration of 4x10 spores/mL (only at levels 100 to 1,000 times greater). The botulinum toxin 5

cartridges had no false-positives, but were not able to detect Type B. They detected Type A to a

concentration of 2 mg/L, though the vendor indicated detection limit was 0.5 mg/L. No falsepositives or negatives resulted when testing the ricin cartridges, which could detect to a

concentration of 5 mg/L, thought the vendor indicated limit was 1 mg/L. Results from all types of

cartridges were very consistent. Sample throughput was four samples per hour. The cartridges were

portable and easy to use with minor direction from a trained operator. Cost is $10,000 for 25

cartridges, a reader, carrier, and printer (EPA-ETV, 2004).

BADD Test Strips by ADVNT

Three types of test strips are available that detect either anthrax, botulinum toxin, or ricin. The

anthrax strip had no false-positives, but there was one false-negative in concentrated New York

drinking water. Consistency was 90 percent. Sensitivity was 4 × 10 to 8 × 10 spores/mL. The 7 7

botulinum toxin strips had no false-positives or negatives due to interferents. However, the strips

were not able to reproducibly detect Type B toxin, and only detected Type A at a concentration of

5 mg/L. However, the vendor stated that the limit was 0.4 mg/L for either type. Consistency was

84 percent. The ricin strips produced no false-positives, but produced false-negatives due to

interferents in drinking water. Consistency was 100 percent. Sensitivity was 20 mg/L, higher than

the 0.4 mg/L detection level indicated by the vendor. Cost is $250 for a box of 10 strips. Strips are

portable and easy to use; although the indicator line color was very faint sometimes, increasing the

risk for false-negatives. It takes 15 minutes for an indicator line to appear. Sample throughput was

20 to 30 samples per hour (EPA-ETV, 2004).

ELISA by Tetracore

Anthrax ELISA produced false-positives due to water with humic and fulvic acid in it and no falsenegatives were produced. However, the ELISA was not able to detect anthrax at the vendor-
U.S. EPA Office of Water Early Warning Systems

August 2005 142

indicated level of 2x10 , only at concentrations 100 times greater. Botulinum toxin ELISA had no 4

false-positives, but false-negatives were produced when humic and fulvic acid were present in the

water sample. The lowest detectable concentration for Type A was 0.02 mg/L, but it was not clear

for Type B. The ricin ELISA showed no false-positives or negatives and could detect ricin to a

concentration of 0.0075 mg/L, slightly higher than vendor indicated level. ELISA was easily

portable, but not easily operated by an untrained user. The cost for one Tetracore ELISA (96 well

plate) is $400 (EPA-ETV, 2004).

9.5.1 Issues and Gaps

The following section highlights various issues and gaps in using microbial detectors for early

warning for finished drinking water. 

• Contaminants Need to be Concentrated to be Detected 

Many microbial pathogens are a risk to human health at low concentrations. Detecting low

concentrations is difficult for the binding assays that most capture-target technologies utilize. Thus,

it may be necessary to concentrate large volumes of water samples to gather enough contaminant

to detect. Two AwwaRF research papers expected in 2005 (Extraction Methods for Early/RealTime Warning Systems for Biological Agents - Project A and B) may help with this issue (see

Appendix D).

• Concentration Techniques can also Concentrate Interference Compounds

Techniques that concentrate the target contaminant will very often also concentrate other non-target

contaminants and interferants that will interfere with the biosensor assay. For example, to

successfully perform PCR analysis of environmental waters, it is necessary to remove analytical

interferences such as humic and fulvic acids.

• Antibodies Cross-React and are Subject to Binding Kinetics

Antibodies may bind with known or unknown affinity to non-target antigens. The sensitivity of

antibodies needs to be calibrated for each batch, even for monoclonals. Cross-reactivity is a problem

if different target molecules have overlapping epitopes. Antibodies designed against specific unique

epitopes would have less cross reactivity. Even the best antibody will only have detectable binding

if the target antigen is sufficiently concentrated; therefore, it is necessary to concentrate drinking

water samples before testing.

• Emerging and Bioengineered Microbes Could Escape Detection 

Even with a broad selection of capture molecules, microbes will evolve such that they may lose

target epitopes or DNA, and therefore escape detection. Bioengineered pathogens could be designed

to evade detectors, if detailed information on capture molecules was obtained. The only technology

that minimizes this problem is Triangulation Identification Genetic Evaluation of Risks (TIGER),

developed by Isis Pharmaceuticals, Inc., because it integrates a variety of approaches (DNA base

composition and PCR) into one analysis.
U.S. EPA Office of Water Early Warning Systems

August 2005 143

• Reagents May Not be Stable in Field Environmental Conditions

Reagents containing biological molecules usually degrade or become inactive within hours of being

subjected to room temperature conditions. Even if partial activity is maintained, quality control is

jeopardized. This problem can partially be addressed with freeze-dried reagents, but reagent-grade

water at the field site is required to reconstitute the reaction solutions. Molecular stability of

biomolecules on biochips is even more difficult.

• Most Microbial Detector Technologies are for Grab Samples, Not Online

With the exception of Micro-Flow Imaging, there are no commercial online technologies for

detecting microbes. Two light scattering technologies (BioSentry and MALLS) are online and are

undergoing beta testing, but are not yet on the market.

Exhibit 9-7 provides a snapshot of capabilities, issues, and gaps for microbial sensor technologies

and techniques.

9.5.2 Conclusion and Recommendations

Development of an online microbial technique appears years away. Light scattering methods show

some promise, but most methods are not suited for continuous online monitoring or differentiating

among microbes. However, there are several potentially adaptable methods, including

immunoassay, PCR, and ATP, that could be used for confirmation testing of grab samples. For

drinking water, the challenge that remains with most methods is the issue of concentrating the

sample. A few methods of concentration show promise including the hollow fiber, the micropump,

and the PNNL BEADS technology. Generally, this does not seem like an insurmountable obstacle

for some methods. However, for PCR, current technology and concentration methods still do not

have the adequate level of detection. Overall, none of the methods met all requirements for rapid

detection technology. Therefore, the recommended approach was to screen a sample with a generic

detector (e.g., multi-parameter probe or perhaps light scatter), then use an immunoassay device in

tandem with another method for identification. Detectors based on ATP are promising, but have not

been verified for water (one is online for water). An ETV Program testing ATP products is

recommended. In the future, microchips have great potential in online measurement, but presently

the field is not sufficiently mature.
U.S. EPA Office of Water Early Warning Systems

August 2005 144

Exhibit 9-7. Microbial Sensor Technologies and Techniques

Method Capabilities Issues and Gaps

Strip tests

(immunoassay)

• detects 1-4 antigens in one test

• portable

• seconds to complete test

• EPA conducting research on use

for finished water

• sample concentration needed

• lack of necessary sensitivity

Fiber optic-based

biosensor

• can detect specific antigens

• portable

• high potential to be online

• emerging for water

Microspheres • can detect specific antigens • emerging for water

• not in portable format

Flow cytometry and

micro-flow imaging

• potentially identify specific

microbes

• can quantify

• portable

• sample concentration may be

needed

ATP • detects cellular components

• portable (kits)

• chlorine residual is not an issue

• not independently validated for

water

• cannot provide microbe specific

information

PCR • detects specific DNA sequences

• portable (suitcase and hand-held)

• not designed for water

• sample concentration required

• current level of technology has

limits of detection that are still not

adequate

Light scattering • detects cells, oocysts, spores,

possibly species specific

• potential for online

• does not require concentration

techniques

• not widely used for pathogen

detection

• not independently validated for

water

• may be prone to false-positives

• cannot detect viruses

Microchips and

microarrays

• potential to identify many

specific pathogens

• small size is good for minaturized

devices

• portable versions are emerging

technology

• sample concentration probably

required

9.6 Evaluation of Radiological Sensors

With the possibility of accidental radioactive spills and emerging terrorist threats, it is important that

water systems have the capability to detect a surge in radioactivity as soon as it occurs.

Furthermore, identifying the type of radiation and its source will greatly contribute to a rapid

response and recovery effort. Continuous, online monitoring in real-time will allow for rapid

detection of intentional or accidental contamination of the water system. The use of an alarm system

will help alert the appropriate operators. For intentional contamination of distribution systems,

radionuclides that have a high specific activity (Curies/gram), deliver a relatively high gamma and
U.S. EPA Office of Water Early Warning Systems

August 2005 145

maybe alpha/beta dose, and can be obtained and solubilized in high concentrations are the most

likely contaminants of concern.

The devices described below are the instruments used for measuring alpha, beta, and gamma

radiation in liquid or water. New technology that allows detection of radiation at lower levels has

been emerging. In-field, gamma radiation detectors are more common than detectors for alpha and

beta radiation, which have properties that make them difficult to detect. There were very few

verification studies of radiation detectors for use in drinking water. They are provided below.

Exhibit 9-8 summarizes how the radiological detectors (those available now or potentially adaptable)

match up against the desired characteristics of radiation sensors for use in an EWS.

Isco 3710 RLS Samplers

A study by Westinghouse Savannah River Company, using Isco 3710 RLS samplers, showed that

“Data collected over a four-month field test period compares very favorably with concurrent

laboratory-based analyses and historical data, at a reduction in cost and significant time savings.”208

Thermo Alpha Monitor

Oak Ridge National Laboratory has tested this instrument and demonstrated its capabilities on water

under 1 picocurie/L, and has analyzed isotopic U levels of 10 ppt natural U (15 femtocuries/L), as

well as 20 ppb natural U (30 pCi/L) in under 30 minutes. This detector is still under development

and requires further testing of durability and accuracy as well as peer reviews and EPA approval.

9.6.1 Issues and Gaps

The following section highlights various issues and gaps in using radiation detectors for early

warning for finished drinking water.

• Devices and Results Show Variability

The appropriate devices and methods will vary according to local conditions such as temperature

and humidity, or the properties of the radionuclide at the source of the radiation.

• Require Special Expertise

All of the devices mentioned in this chapter usually require specialized expertise for installation,

setup, and routine calibration, even if they are labeled maintenance-free.

• Costly for Online Monitoring

Although online analyzers are efficient in monitoring water quality, they are expensive and limited

in number. Many facilities may find grab samplers to be more appropriate. Manufacturers are in

the process of developing and refining other applications of small-scale flow-through scintillation

technology. Utilities will need to collaborate with manufacturers to customize the monitors for

small-scale needs.
U.S. EPA Office of Water Early Warning Systems

August 2005 146

Exhibit 9-8. Radiological Sensors Comparison with Desired EWS Characteristics

Product Description Range of Contaminants Online/ Portable? Cost Operator Skill Analysis Time Sensitivity Currently Available? Verification

TechnicalAssociates SSS33-5FT

continuous flowthroughscintillationdetector

alpha, beta,gamma rays

online $58,000 medium to

high

< 5 min detects tritium

up to 100pCurie/mL

available none

TechnicalAssociatesMEDA 5T

scintillationdetector

gamma online $25,000 medium to

high

< 5 min not available on

website

available none

TechnicalAssociates SSS33DHC and SSS33DHC -4

no scintillationdetector

monitors tritiumand plume

online $72,000 medium to

high

< 5min 1 nano

Curie/mL

available none

TechnicalAssociates SSS33M8

no scintillationdetector

monitors tritium online $16,500 medium to

high

< 5 min 0.1 nano

Curie/mL

available none

Teledyne Isco,Inc 3710 RLSSampler

filter all online $35,000-

$75,000

medium tohigh

< 5min not available on

website

available none

GammaSharkTM details not yet

available

gamma online not yet

available

informationnot available

< 5 min not available on

website

available 2005 planned

CanberraLEMS600 SeriesLiquid EffluentMonitoring

monitors radiationin liquid fromoutside of pipe

beta and gammarays

online $100,000-

$150,000

medium tohigh

< 5 min not available on

website

potentiallyadaptable

none

CanberraOLM100 OnlineLiquidMonitoring

monitors radiationin liquid fromoutside of pipe

gamma rays online $35,000-

$75,000

medium tohigh

< 5 min not available on

website

potentiallyadaptable

none

Canberra ILM

100

monitors radiationin liquid fromwithin pipe

gamma rays online $35,000-

$75,000

medium tohigh

< 5min not available on

website

potentiallyadaptable

none
U.S. EPA Office of Water Early Warning Systems

August 2005 147

• Few Detectors are Available or Verified

There are only a few detectors that are designed to monitor for alpha and beta radioactivity. There

are also only a few detectors that are designed for online monitoring of gamma radioactivity.

Verification studies have not been extensively performed on radiological detectors for finished

drinking water.

• Not Geared to Distribution Systems

Some of these monitors are intended for waste streams rather than distribution systems due to the

more stringent requirements for drinking water monitors. Waste stream monitors would be geared

more towards the detection of accidental spills rather than intentional contamination.

Exhibit 9-9 provides a snapshot of capabilities, issues, and gaps for radiation sensor technologies.

Exhibit 9-9. Radiation Sensor Technologies

Radiation Detected Capabilities Issues and Gaps

Alpha • none • difficult to detect in water

Beta • continuous and real-time

measurements

• difficult to detect in water

• typically designed for wastewater

and groundwater

• not verified for drinking water

Gamma (liquid scintillation) • continuous and real-time

measurements

• has required sensitivity in

water

• typically developed for wastewater,

not drinking water

• not verified for drinking water

• requires special expertise for setup,

operation and maintenance

• costly for online monitoring

9.6.2 Conclusions and Recommendations

There are demonstrated technologies for examining radiation in wastewater, but the transfer or

adaptation to drinking water has not taken place. Only a few products claim applicability to water,

some on a grab-sample basis. More products are being developed by a few vendors, but it is still

unclear whether the threat merits use of these expensive products on a real-time basis. The few

items that are commercially available should be verified either by EPA or by a national laboratory

that specializes in radiation. Grab sampling can be performed by a number of products, but it is

unclear if there is any generic monitor that can trigger this more detailed analysis. Thus, early

warning for radiation detection is not currently available, and the market forces for such

development may not be strong.
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 149

10. Conclusions and Recommendations

The following are conclusions and recommendations from this state-of-the-art review of

technologies and techniques for EWSs. General conclusions and recommendations are provided

first. These are followed by specific conclusions and recommendations organized by features of the

EWS: data acquisition and analysis; flow modeling; sensor placement; alarm management; decision

making and response; multi-parameter water quality technologies; and detection of chemical,

microbial, and radiological contaminants. The recommendations include a list of near- and longterm knowledge and research gaps.

10.1 General Conclusions and Recommendations

Viable integrated EWSs that meet the desired characteristics and can be routinely used are several

years away. Some individual components are available currently, however, others need further

development. Designs of EWSs for water distribution systems are largely theoretical or in

preliminary stages. Much of the required data acquisition software and hardware already exists, but

software for security of EWS SCADA systems is still under development and needs verification.

Distribution system modeling in general, and contaminant flow predictive systems in particular, are

developing rapidly with the incorporation of graphic software; however, most utilities have not

implemented software for modeling intentional contamination events. Most sensor and EWS

components have not been tested or verified, and the types of contaminants and levels of exposure

have not been well defined to support selection of sensor technologies. Several companies are

working on alert management methods but are in preliminary stages of research, with often

proprietary trigger algorithms. Linking contamination data analysis with decision making and alert

response has been outlined; however, the equipment to effectively implement the process has not

been extensively developed for water utilities. Research on approaches and technologies to detect

engineered microbes is needed. Also, all of these technologies should be verified and affordable,

and should operate consistently in the field.

Short-Term Research Needs

• An in-depth review of EWS architecture and implementation should be conducted.

Because a detailed examination of the basic design and features of an EWS architecture is

beyond the scope of this study, follow-up studies to prioritize certain features and provide

comprehensive guidance to implement the selection, linking, and testing of various EWS

components are recommended. Any guidance on design should include considerations for small

and large systems, public health surveillance, and consumer complaint monitoring. Also, the

research should provide guidance on EWS performance, alarm, and response criteria.

• Methods for vulnerability assessments should be adapted to focus on contamination scenarios.

There are various vulnerability assessment methods that utilities have used. To develop an

EWS, vulnerability to contamination has to be examined. It is unclear whether utilities have

specifically examined their vulnerabilities for contamination or whether the existing

methodologies can adequately assess contamination vulnerabilities. This is an area of further

research to see how adequately utilities have examined contamination vulnerability and how

such information can be incorporated into EWS architecture.
U.S. EPA Office of Water Early Warning Systems

August 2005 150

• Research on international efforts on EWS is needed.

EPA may find it useful to continue to engage the international research and development

community to gain access to innovations and advancements being made in other countries.

• Grab-sampling protocols and analysis technologies should be developed quickly.

Online detectors, as part of an integrated EWS, may be years away. However, near real-time

monitoring can be approached by establishing periodic grab samples that can be analyzed as

appropriate by field or laboratory instruments.

Long-Term Research Needs

• Survey case study and analysis should be performed on monitors/sensors/detectors used by

utilities.

Some water utilities have installed or tested EWS component technology, such as monitors,

sensors, or detectors, in the field but the experiences are not extensive or shared. Experience

gained from using these technologies in a distribution system, even if they are not part of a fully

integrated EWS, as defined by this report, should be captured. A survey of such case studies can

provide great insights into the validated use and capabilities/disadvantages of certain

technologies. Further research efforts should be undertaken to more fully document and

evaluate the case study experience of utilities using EWS components in the field.

• EWS technologies and techniques need to undergo verification testing.

The ETV or TTEP program should test various sensor technologies, including for example, ATP

products, mussel biodetectors, and radiological online detectors.

• Potential contaminants list should be reviewed on an ongoing basis.

The types of contaminants of concern for public health are important to evaluating EWS

adequacy. Determining the specific contaminants is an area of ongoing work that is not publicly

available and is generally under classified review. There will be further such classified efforts.

There is a research need to continue to determine the types of contaminants that are harmful and

that need to be detected by EWSs.

• Concentrations that must be detected by a sensor should be reviewed on an ongoing basis.

Another recognized area of research is to determine the concentration of contaminants that need

to be detected by EWSs. The concentration depends on the properties of the contaminant, the

routes and magnitude of exposure, and the susceptibility of the exposed population to particular

contaminants. Without a determination of these concentrations, the adequacy of any specific

instrument or set of instruments in reducing public health risk is difficult to determine.

Continued research is recommended to fully determine concentrations that must be detected.

Related to concentrations, research should also be conducted to determine the anticipated

exposures and doses based on specific concentrations that impact human health, as well as to

determine if decontamination efforts were sufficient to protect human health.

• The fate and transport (including exposure levels, doses, and detectible concentrations) of

contaminants, especially toxic byproducts, should be examined.

As research occurs on the contaminants of concern, additional research should be conducted to

determine the toxic byproducts of certain contaminants and to model the fate and transport of

these contaminants in real world water distribution systems. The persistence, stability,
U.S. EPA Office of Water Early Warning Systems

August 2005 151

resistance to chlorine, and ease of dispersion of a contaminant in an aqueous environment are

important fate and transport factors. This research area will assist with the evaluation and

selection of EWS technologies.

• Results from laboratory research by various agencies on EWSs should be replicated and the

conclusions of EWS studies should be shared among government agencies and water utility

stakeholders.

There are various laboratory research efforts on EWSs in distribution systems that are sponsored

or conducted by the EPA WATERS Center, U.S. Army ECBC facility, USGS facilities, and

specific utilities. These efforts should be replicated when possible to verify results. The

information from these efforts and other EWS studies should be shared among government

agencies and water utility stakeholders.

10.2 Specific Conclusions and Recommendations

10.2.1 Data Acquisition and Analysis

Data collection by Supervisory Control and Data Acquisition (SCADA) or other automated systems

is essential to handle the large volume of data from online sensors in an EWS. Existing data

acquisition systems do not present a major issue given currently recommended sampling times by

EPA (between 2 and 10 minutes, depending on the SCADA system setup and bandwidth, the sensor

location, and the water flow rate). Because of the large amount of data generated, automated data

validation processes are indispensable to ensure accurate results from data analysis. Data

transmission to a central database, through hardwired or wireless systems, requires a simple yet

effective protocol to ensure accuracy and completeness, and can be done by comparing data received

from monitoring sites with data stored at the sensor locations. Much of the data acquisition software

and hardware already exists. Software for security of SCADA systems for EWSs is still under

development and needs verification, but can probably be addressed by utilities simultaneously with

general security issues (e.g., encryption).

Short-Term Research Need

• Standardized methods and guidance for data analysis and interpretation are needed.

Specifically, further research and development in mining software to identify outlier detection

is needed. Verification programs are needed to substantiate the data analysis algorithms. Some

of the efforts by ASCE will help to guide utilities in the use of such systems (ASCE, 2004).

Long-Term Research Needs

• Large-scale data storage and manipulation techniques and technologies are needed.

For continuous real-time monitors, data are generated on a large scale. SCADA is the likely

vehicle to collect the data. New ways of storing and manipulating the information for immediate

and long-term uses are needed.

• SCADA data security programs should be developed to link existing utility efforts with security

characteristics inherent in EWS.

Current remote monitoring products are beginning to incorporate security precautions including

encryption. However, demonstration projects are not frequently undertaken. Standardization
U.S. EPA Office of Water Early Warning Systems

August 2005 152

from other data security efforts could be applied to the water sector. Programs should be

developed to link utility security efforts surrounding SCADA with data security geared to EWSs.

10.2.2 Flow Modeling

Predicting the movement and flow of contaminants in a water distribution system EWS is important

not only to prepare for a potential contamination event, but also to improve the effectiveness of the

monitoring system. Distribution system modeling in general, and contaminant flow predictive

systems in particular, are developing rapidly. Current contaminant flow models can also integrate

data from geographic information systems and display results using computer-aided drafting (CAD)

software. PipelineNet, an integration of EPANET and ArcView GIS, and commercial integration

packages such as WaterGEMS and InfoWater provide direct capabilities to assess impacts of

contamination events. Calibration using optimization methods or tracer studies has been

increasingly used in distribution systems. Utilities are not generally using models specifically for

the purpose of modeling intentional contamination events. Consumption-of-water models are also

being occasionally incorporated. Utility efforts to validate and develop predictive flow models

would meet the dual purposes of general planning (expansion, upgrades, repairs, maintenance) and

testing intentional contamination scenarios. There are currently few established calibration criteria

in the U.S., although a committee of the AWWA did propose a set of possible calibration guidelines

in 1999 and the EPA is preparing a distribution system handbook which will include a section on

hydraulic model calibration and validation. These possible calibration guidelines should serve as

a catalyst or starting point to move forward on developing accepted calibration guidelines or

standards. Incident Commanders Water Modeling Tool (ICWater) extends the capability of a

previously developed RiverSpill modeling tool to allow an incident commander to analyze and react

quickly to chemical and/or biological contaminants introduced into surface water sources. EPA’s

TEVA program incorporates a probabilistic framework for a large range of contamination attacks

in assessing vulnerabilities and estimating the most appropriate sensor placements.

Short-Term Research Need

• Improved contaminant flow models are needed.

Research is recommended to develop improved models and methods for validating the models

in specific applications. The models should be improved to better include the effect of chemical

fate and byproducts.

Long-Term Research Need

• Flow models need to be verified and then used to improve EWS design.

Projects are needed to verify contaminant flow models and to make the tools useful for sensor

placement, real-time contaminant flow prediction, and identifying the likely location of the

contaminant source. These models need adaptation for ease of use by various sized utilities.

There are no established calibration criteria for contaminant flow models in the U.S., although

a committee of the AWWA did propose a set of possible calibration guidelines (ECAC, 1999).

However these guidelines have not been officially accepted and there is no active process

underway to adopt them. Using these possible calibration guidelines as a catalyst or starting

point, it would be recommended to move forward on developing accepted calibration guidelines

or standards.
U.S. EPA Office of Water Early Warning Systems

August 2005 153

10.2.3 Sensor Placement

Because of both budgetary and technical constraints, utilities can make only a modest initial

investment in sensors within their distribution system, and therefore the utilities want to determine

the most appropriate locations. Without resorting to the sophisticated experimental optimization

techniques, a two-stage procedure is typically followed. In the first stage, likely sites for sensors

are determined based on technological (e.g., available power source, access to communications) and

physical (e.g., access) constraints. In the second stage, sensors are placed throughout the system on

larger pipes that serve the most customers. Current research combining flow models and sensor

technology is beginning to be developed, but such models must be verified before difficult and

costly decisions are made by the utilities.

Short-Term Research Need

• Hardware and materials to protect remote sensors are needed.

Online sensors are typically installed using special sample taps that require interruption of water

flow through pipes. New installation techniques are being developed to enable installation

without interrupting the water flow or major excavation. Sensors also need to be able to

withstand the harsh environment of different locations. New development in construction of

materials and protective hardware is necessary to enable sensor systems to be installed in areas

open to the environment (AwwaRF, 2002).

Long-Term Research Need

• Research into sensor placement parameters is recommended.

Simple guidance, such as what to do with a limited number of specific sensors, is needed. Also,

validation of sensor placement strategies should be investigated by perhaps comparing results

of several models that determine sensor placement and optimization.

10.2.4 Alert Management

Alert management systems typically consist of two general areas: (1) establishing parameters for

alert triggers and (2) reducing false alarms. Any anomalies in the comparison of sensor data to the

baseline trigger alerts to the operator. Establishing reliable baseline data is key, especially when

water quality fluctuates. Alert management systems usually rely on strict data validation protocols

or specialized software to reduce false alarms. Several companies are working on alert management,

but are in preliminary stages of research, with often proprietary trigger algorithms.

Long-Term Research Need

• Alert management approaches/technologies should be examined and sensitivity to false-positives

and false-negatives should be quantified.

A demonstration project is needed to ensure the reasonableness of certain approaches to alert

management. The relationship between alert sensitivity and the potential for adverse

consequences (false-positives and false-negatives) should be quantified. Additional projects

should examine alerts for other promising sensors such as mussel or bacteria monitors.
U.S. EPA Office of Water Early Warning Systems

August 2005 154

10.2.5 Decision Making and Response

The process linking the analysis of contamination data with the decision making and response is

outlined in EPA’s Response Protocol Toolbox; however, additional tools to effectively implement

the process are needed for water utilities.

Long-Term Research Need

• Technology to support and implement decision making and response are needed.

Tools to assist decision making and response, such as the Water Contaminant Information Tool,

are being developed and will help fill a current void.

10.2.6 Multi-Parameter Water Quality Technologies

There is an active research program in the use of the multi-parameter water quality monitors as part

of an EWS for distribution systems. Preliminary evidence suggests that such monitors can detect

an anomaly in the distribution system and provide an initial red flag warning. However, it is also

reasonable to be concerned about false-positives and whether the system can provide definitive

indications of intentional contamination. Gathering baseline data may also be prohibitively

expensive. Currently, these technologies need to be demonstrated to detect biological contaminants

or dangerous chemicals or develop a track record of field performance. The technology has not been

sufficiently evaluated to recommend widespread use; for example, no tests have been performed on

chloraminated systems. However, full-scale testing by USGS, EPA, and a water utility during 2006

and 2007 may help shed light on concern over false-positives and whether a system can work with

the fluctuations of normal water quality.

Given the current developmental stage of multi-parameter technologies, parameters that appear from

EPA’s preliminary tests to be useful to monitor in distribution systems include chloride (ISE),

specific conductance (electrode), turbidity (nephelometric), free chlorine, and ORP. TOC is

extremely helpful, but may be too expensive to be widely used. Probes are being developed by

manufacturers to include free and total chlorine, pH, temperature, specific conductance, chloride,

nitrates, turbidity, and ORP. Not all utility companies are able to afford the monitoring systems

currently being evaluated as EWSs. Reductions in price due to competition and technological

advancements may remedy this situation in the future, but in the interim, utilities with limited

financial resources will face a challenge in implementing online (e.g., continuous) water quality

monitoring.

The signatures being developed by Hach Company and others to identify contaminants or classes

are difficult to independently validate or be understood because their methods and algorithms have

not been made public. Also, the examination of water quality parameters in detecting and

identifying contaminants is still being evaluated by EPA, USGS, the Army, and other organizations.

There has yet to be a field-scale test of an EWS with these water quality parameter components.

These are reasons for caution in recommending the use of water quality parameter-based EWSs.

Short-Term Research Needs

• Verified baseline data to calibrate EWS alarm triggers are needed.

Although research has demonstrated proof-of-concept for using water quality parameter

fluctuations as a signal that a contamination event has taken place, baseline data to calibrate the
U.S. EPA Office of Water Early Warning Systems

August 2005 155

alarm triggers may need to be gathered over months or years for each distribution system.

Because this is very expensive, research demonstration projects such as the USGS project are

needed to advance the understanding of how baseline water quality data might influence the

performance of EWSs in the field.

• Contaminant specific signatures are needed.

Research has begun to develop contaminant specific signatures; however, the limited number

of contaminants examined to date lowers the confidence of the claim that the signature really is

unique. Classes of contaminants may be identifiable, but whether a comfortable range of

specific contaminants can be identified has not yet been determined. Additionally, it is not

known yet whether monitors can detect biological contaminants and dangerous chemicals.

Further research is needed to develop specific signatures for a wider range of contaminants and

concentrations, including actual agents.

• Validation of event detection algorithms is needed.

It is important that the algorithms used to determine when alarm conditions are encountered are

validated for a variety of real world operational conditions.

Long-Term Research Need

• Costs and benefits (e.g., ability to detect contaminants with multi-parameter water quality

monitors) of using TOC sensors should be determined and more affordable and reliable TOC

sensors should be developed.

Current multi-parameter units cost approximately $10,000 without TOC. Although TOC

appears to be a valuable parameter to measure, it adds $18,000 to 29,000 per unit. Research

needs to determine the cost/benefit relationship of including this technology in an EWS. A basic

system with 10 microprobe monitors (without TOC) linked to an existing SCADA system is

estimated to cost approximately $150,000, plus $60,000 per year in operational costs. Also, a

research/development need is to have cheaper and reliable online TOC monitors. A TOC

monitor for an EWS would not need to be capable of compliance monitoring but would only

need to detect gross changes in TOC levels that warrant further investigation.

10.2.7 Detection of Chemical Contaminants

Portable field technology is available for conducting analyses of grab samples on site for many

possible chemical contaminants. This area will continue to improve as high technology equipment

evolves based on microchip technology (e.g., taste-chip). The technology that is readily available

and reliable uses specific probes, such as arsenic and cyanide, that could be effective against a

narrow selection of contaminants. Certain biomonitors are portable and can be used for site

assessments. Chlorine in the water would have to be removed for many such analyses. In contrast

to portable field technology, online chemical detection technologies are not reasonably available or

are not cost-effective. GC and ion mobility have cost and technical challenges. Certain biomonitors

may be promising, if the interference issue of chlorine and chloramine residual can be resolved. In

one case, the mussel monitor has been recently demonstrated in finished water in Europe. There are

various efforts in the U.S. to make other monitors (MicroTox® and ToxScreen) adaptable to finished

water. The MosselMonitor® or Bio-Sensor® could be a good candidates for an EPA-ETV Program

study and perhaps used for a laboratory and/or field study on finished water or with CBR surrogates

or contaminants. In the next three years, the field should show further development in terms of cost-
U.S. EPA Office of Water Early Warning Systems

August 2005 156

effective and reliable devices. A few new technologies (such as microchips) could revolutionize the

chemical detection field for drinking water.

Short-Term Research Need

• The impact and removal of chlorine and other residues on accuracy of detection should be

examined.

Organism-based biomonitors are sensitive to the chlorine residuals in drinking water. Although

the fish-based Bio-Sensor® and MosselMonitor® remove chlorine, broadly applicable methods

for chlorine removal have not yet been developed. Although one company, Checklight, is

developing a system for removal of chlorine, the effect of chlorine removal on other biosensors

has not been demonstrated. 

Long-Term Research Needs

• Reliable field kits should be developed.

The bacterial monitoring kits tested by EPA’s ETV Program have high false-positive and falsenegative rates. A common drawback for such kits is the stability of reagents. Often reagents

require reconstitution (if they are lyophilized) or careful measurement of reaction components

to constitute a fresh reaction mixture. Kits can be subject to variability due to different users

because it is difficult for users to mix and pipette in a consistent manner. They require trained

personnel and have set-up requirements, such as culturing log phase growth bacteria. The results

do not provide specific identification of a toxin. Although these kits may be suitable for

confirming the presence of a toxin, further methods would need to be utilized for specific

identification.

• Existing state-of-the-art detection technologies should be adapted for use in EWSs.

Portable infrared spectroscopy, ion mobility spectroscopy, surface acoustic waves, and polymer

composite chemoresistors technologies are being aggressively pursued for air and vapor

applications, but have not been developed specifically for drinking water monitoring. Research

could examine whether these techniques could be adapted for water with further research if there

is a potential market.

10.2.8 Detection of Microbial Contaminants

Development of an online microbial technology appears years away. An exception to this may be

the light-scattering methodology, which shows some promise. Most methods are not suited for

continuous online monitoring or for differentiating among microbes. However, to confirm a

contaminant using a portable field unit with grab samples, there are several potentially adaptable

methods from which to choose, including immunoassay, PCR, and ATP. These methods have not

yet been exploited to their full potential, so will likely continue to be incorporated into new

monitoring devices and systems. Grab sampling could include sampling at scheduled intervals or

taking composite samples (e.g., collecting small volumes of sample continuously over time). In any

sampling, the microbial integrity must be ensured. For drinking water, the challenge for most

methods is the need to concentrate the sample. A few methods of concentration show promise

including the hollow fiber, the micropump, and related efforts by Pacific Northwest National

Laboratory. Generally, this does not seem like an insurmountable obstacle for some methods.

However, for PCR, current online technologies and concentration methods are not sufficiently

advanced to detect microbes at levels that threaten public health. Overall, none of the methods by
U.S. EPA Office of Water Early Warning Systems

August 2005 157

themselves provide sufficiently rapid detection. Therefore, one recommended approach is to screen

a sample with a generic detector (e.g., multi-parameter probe or perhaps light scatter), then use an

immunoassay device in tandem with another method for identification. Detectors based on ATP are

promising, but have not been verified for water (one is online for water). ATP detection products

should be third party evaluated for EWS application. In the future, microchips have great potential

in online measurement, but presently the field is not sufficiently mature.

Short-Term Research Needs

• Extraction and concentration technologies need improvement.

Many microbial pathogens are a risk to human health at low concentrations. The concentration

of pathogens that needs to be detected to adequately protect public health is a policy issue.

However, it is widely acknowledged that current detection methods for online or near continuous

use are not sensitive enough to detect the lowest microbial concentrations that may be a concern

for human health. Therefore, microbial contaminants need to be sufficiently concentrated to be

detected. Detecting low concentrations is difficult for the binding assays that most capturetarget technologies utilize. Thus, it may be necessary to concentrate large volumes of water

samples to gather enough contaminant to detect. Two AwwaRF research papers expected in

2005 (Extraction Methods for Early/Real-Time Warning Systems for Biological Agents - Project

A and B) and research at Idaho National Laboratory in Idaho Falls, ID may help with this issue.

• Methods to distinguish concentrated interferants from target compounds are needed.

Concentration techniques could also concentrate interference compounds. Techniques that

concentrate the target contaminant will very often also concentrate other non-target

contaminants that will interfere with the biosensor assay. For example, to successfully perform

PCR analysis of environmental waters it is necessary to remove analytical interferences such as

humic and fulvic acids. 

• The development of field-stable reagents is needed.

Reagents may not be stable in field environmental conditions. Reagents containing biological

molecules usually degrade or become inactive within hours of being subjected to room

temperature conditions. Even if partial activity is maintained, quality control is jeopardized.

This problem can be partially addressed with freeze-dried reagents, but reagent-grade water at

the field site is required to reconstitute the reaction solutions. Molecular stability of

biomolecules on biochips is even more difficult. 

Long-Term Research Needs

• Antibodies for unique epitopes that would show less cross-reactivity should be developed.

Antibodies cross-react and are subject to binding kinetics. Antibodies may bind with known or

unknown affinity to non-target antigens. The sensitivity of antibodies needs to be calibrated for

each batch, even for monoclonals. Cross-reactivity is a problem if different target molecules

have overlapping epitopes. Antibodies designed against specific unique epitopes would have

less cross-reactivity.

• Research on additional approaches and technologies that can detect emerging, evolving, and

engineered microbes is needed.
U.S. EPA Office of Water Early Warning Systems

August 2005 158

Emerging and bioengineered microbes could escape detection. Even with a broad selection of

capture molecules, microbes will evolve such that they may lose target epitopes or DNA, and

therefore escape detection. Bioengineered pathogens could be designed to evade detectors, if

detailed information on capture molecules was obtained. The only existing technology that

minimizes this problem is Triangulation Identification Genetic Evaluation of Risks (TIGER),

developed by Isis Pharmaceuticals, Inc., because it integrates a variety of approaches (DNA base

composition and PCR) into one analysis.

10.2.9 Detection of Radiological Contaminants

There are demonstrated technologies for examining radiation in wastewater, but the transfer or

adaptation to drinking water has not yet taken place. Only a few products claim applicability to

water, some on a grab-sample basis. Also, the appropriate devices and methods will vary according

to local conditions, such as temperature and humidity, or the properties of the radionuclide at the

source of the radiation. More products are being developed by a few vendors, but it is still unclear

whether the threat merits use of these expensive products on a real-time basis. The few items that

are commercially available should be verified either by EPA or by a national laboratory that

specializes in radiation. Grab sampling can be performed by a number of products, but it is unclear

if there is any generic monitor that can trigger this more detailed analysis. In addition, all of the

radiological monitoring devices mentioned in this study usually require specialized expertise for

installation, set-up, and routine calibration, even if they are labeled maintenance-free. Thus, early

warning for radiation detection is not currently available, and the market forces for such

development may not be strong.

Short-Term Research Need

• Beta and gamma radioactivity detectors should be developed and verified for drinking water

monitoring applications.

There are only a few detectors that are designed to monitor for alpha and beta radioactivity.

There are also only a few detectors that are designed for online monitoring of gamma.

Verification studies do not seem to have been performed on detectors that are geared to radiation

terrorist attacks on drinking water.

Long-Term Research Needs

• Low-cost, online, radioactivity monitors are needed.

Although online analyzers are efficient in monitoring the water quality, they are expensive and

limited in number. Many facilities may therefore find grab samplers to be more appropriate.

Manufacturers are in the process of developing and refining other applications of small scale

flow-through scintillation technology. Utilities will need to collaborate with these manufacturers

to research and customize the monitors for small scale needs.

• Monitors should be developed that are specifically intended for water distribution systems.

Some of these monitors are intended for waste streams rather than distribution systems due to

the more stringent requirements for drinking water monitors. Waste stream monitors would be

geared more towards the detection of accidental spills rather than intentional contamination.
U.S. EPA Office of Water Early Warning Systems

August 2005 159

REFERENCES

ACS (2002) American Chemical Society. “PNNL Research: Biodetection Enabling Analyte

Delivery System.” Chemical and Engineering News. 80(20):32-36.

ASCE (2004) Interim Guidelines for Designing an Online Contamination Monitoring System,

American Society of Civil Engineers.

Alberts, B; Bray, D; Lewis, J; Raff, M; Roberts, K; Watson, JD. (1994) Molecular Biology of the

Cell. Third Edition Garland Publishing Inc. NewYork.

AWWA Workshop (2004) Contamination Monitoring Technologies sponsored by the American

Water Works Association, Richmond, VA; May 2004.

AwwaRF (2002) Online Monitoring for Drinking Water Utilities (Project #2545) Order number

90829. Report prepared by: E. Hargesheimer, O. Conio, and J. Popovicova.

Bahadur, R; Samuels, W; Pickus, J. (2003a) Case Study for a Distribution System Emergency

Response Tool. AwwaRF, Denver, CO.

Bahadur, R; Samuels, W; Grayman, W; Amstutz, D; Pickus; J. (2003b) PipelineNet: A Model for

Monitoring Introduced Contaminants in a Distribution System. World Water & Environmental

Resources Congress, Environmental & Water Resources Institute - ASCE.

Baxter, CW; Lence, BJ. (2003) A Framework for Risk Analysis in Potable Water Supply. World

Water & Environmental Resources Congress, Environmental & Water Resources Institute - ASCE.

Berry, ED; Siragusa, GR. (1999) Integration of hydroxyapatite concentration of bacteria and seminested PCR to enhance detection of Salmonella typhimurium from ground beef and bovine carcass

sponge samples. J. Rapid Methods Automation Microbiol. 7:7-23.

Berry, J; Hart, W; Phillips, C; Uber, J. (2004) A General Integer-Programming-Based Framework

for Sensor Placement in Municipal Water Networks. World Water & Environmental Resources

Congress, Environmental & Water Resources Institute - ASCE.

Black & Veatch (2004) “Water Monitoring Equipment for Toxic Contaminants Technology

Assessment” General Dynamics, and Calspan/University of Buffalo Research Center, October 2004.

Bodurow, CC; Campbell, DP; Gottfried, DS; Xu, J; Cobb-Sullivan, JM; Caravati, KC. (2005) A

low-cost, real-time optical sensor for environmental monitoring and homeland security. EPA

Science Forum 2005. http://www.epa.gov/sciforum/2005/pdfs/oeiposter/bodurow_catherine.pdf

Bravata, DM; Sundaram, V; McDonald, KM; Smith, WM; Szeto, H; Schleinitz, MD; Owens, DK.

(2004) Evaluating detection and diagnostic decision support systems for bioterrorism response.

Emerging Infectious Diseases.10(1):100-108.

Bunk, S. (2002) Sensing Evil. The Scientist. 16(15):13.
U.S. EPA Office of Water Early Warning Systems

August 2005 160

Carlson, K; Byer, D; Frazey, J. (2004): Section 5.2 - Candidate Instruments and Observables.

Section 5.3. - Models. May, 2004 Draft of Methodology and Characteristics of Water System

Infrastructure Security.

Cross, H. (1936) Analysis of Flow in Networks of Conduits or Conductors. Univ. of Illinois Eng.

Experiment Station Bulletin. Page 286.

DARPA (2004) Chemical and Biological Sensor Standards Study. LTC John Carrano, Study Chair.

Daviss, B. (2004) A Springboard to Easier Bioassays. The Scientist. 18(4):40. March 1, 2004.

Deininger, R; Lee, JY. (2001) Rapid determination of bacteria in drinking water using an ATP

assay. Analytical Chemistry and Technology. 5(4):185-189.

DSRC Meeting (2004) Distribution System Research Consortium Draft Summary Report.

Distribution System Research Consortium Meeting, presentations by Vowinkle, Uber, and

McKenna: August 25-26, 2004, Cincinnati, Ohio USEPA.

ECBC (2002)Bio-detector Assessment. ECBC-TR-171, March 2002, Walther, Emanuel and Goode.

Edgewood Chemical Biological Center.

Emanuel, P; Chue, C; Kerr, L; Cullin, D. (2003) Validating the Performance of Biological Detection

Equipment: the Role of the Federal Government, BioSecurity and Bioterrorism: Biodefense

Strategy, Practice and Science.

ECAC (1999) Engineering Computer Applications Committee Calibration Guidelines for Water

Distribution System Modeling. Proc. AWWA ImTech Conference, 1999.

EPA (2000) Multi Agency Radiation Survey and Site Investigation Manual. (EPA 402-R-97-016),

August, 2000.

EPA (2003) A Review of Emerging Sensor Technologies for Facilitating Long-Term Ground Water

Monitoring of Volatile Organic Compounds. (EPA 542-R-03-007.)

http://www.epa.gov/tio/download/char/542r03007.pdf

EPA-ETV (2004) U.S. Environmental Protection Agency, Environmental Verification Program

http://www.epa.gov/etv/

EPA (2003/2004) Response Protocol Toolbox: Planning for and Responding to Drinking Water

Contamination Threats and Incidents. Modules 1-6. 2003/2004.

EPA (2004) Office of Research and Development, Shaw Environmental, Draft Report Evaluation

of Water Quality Sensors in Distribution Systems; May 2004 and EPA, Office of Research and

Development, Shaw Environmental, Draft Report: Water Quality Sensor Responses to Chemical and

Biological Warfare Agent Simulants in Water Distribution Systems July 2004.

EPA (2005) Distribution System Water Quality Report: A Guide to the Assessment and
U.S. EPA Office of Water Early Warning Systems

August 2005 161

Management of Drinking Water Quality in Distribution Systems. ORD NRMRL Water Supply and

Water Resources Division. June 2005 Draft.

Fitzgerald, DA. (2002) Microarrayers on the spot. The Scientist. 16(4):42.

Fontenot, E; Ingeduld, P; Wood, D. (2003) Real-time Analysis of Water Supply and Water

Distribution Systems, World Water & Environmental Resources Congress, Environmental & Water

Resources Institute - ASCE.

Goodey, AP; McDevitt, JT. (2003) Multishell Microspheres with Integrated Chromatographic and

Detection Layers for Use in Array Sensors. J. Am. Chem. Soc. 125(10):2870-2871.

Gorman, J. (2003) NanoLights! Camera! Action! Tiny semiconductor crystals reveal cellular

activity like never before. Science News. 163(7):107. 

Grayman, W; Roberson, A; States, S. (2003) AWWA Contamination Monitoring Technologies

Seminar; Richmond, VA. May 2003.

Grayman, W; Deininger, R; Males; Gullick, R. (2004a) Source water early warning systems.

Chapter in Water Supply Systems Security. Edited by Larry Mays, McGraw-Hill and Companies,

New York, NY.

Grayman, WM; Clark, RM; Harding, BL; Maslia, M; Aramini, J. (2004b) Reconstructing Historical

Contamination Events. Chapter in Water Supply Systems Security. Edited by Larry Mays,

McGraw-Hill and Companies, New York, NY.

Grayman, W; Rossman, L; Deininger, R; Smith, AC; Smith, J. (2004c) Mixing and aging of water

in distribution system storage facilities. J. AWWA. 96(9).

Grow, AE; Deal, MS; Thompson, PA; Wood, LL. (2003) Evaluation of the Doodlebug: a biochip

for detecting waterborne pathogens. Water Intelligence Online IWA (WERF).

Hasan, J; States, S; Deininger, R. (2004) Safeguarding the security of public water supplies using

early warning systems: A Brief Review. J. of Contemporary Water Research and Education.

129:27-33.

Haupt, K. (2002) Creating a good impression. Nature Biotechnology. 20:884-885.

Heroux, K. and Anderson, P. (No date) “Evaluation of a Rapid Immunoassay System for the

Detection of Bacillus anthracis Spores.” U.S. Army Edgewood Chemical Biological Center,

Aberdeen Proving Ground, MD. http://www.responsebio.com/pdf/EdgewoodEvaluation.pdf

Hindson, BJ; Brown, SB; Marshall GD; McBride, MT; Makarewicz, AJ; Gutierrez DM; Wolcott

DK; Metz, TR; Madabhushi, RS; Dzenitis, JM; Colston, BW Jr. (2004) Development of an

automated sample preparation module for environmental monitoring of biowarfare agents.

Analytical Chemistry. 76(13):3492-3497.
U.S. EPA Office of Water Early Warning Systems

August 2005 162

Hrudey, SE; Rizak, S. (2004) Discussion of rapid analytical techniques for drinking water security

investigations. J. AWWA. 96(9):110-113.

Kessler, A; Ostfeld A; Sinai, G. (1998) Detecting accidental contaminations in municipal water

networks. J. of Water Resources Planning and Management. 124(4):192-198.

King, KL. (2004) Presentation by K.L. King, Event Monitor for Water Plant or Distribution System

Monitoring; Hach Homeland Security Technologies; AWWA Water Security Congress; April 25-27,

2004.

ILSI (1999) Early Warning Monitoring to Detect Hazardous Events in Water Supplies. International

Life Sciences Institute-Risk Science Institute. http://rsi.ilsi.org/file/EWM.pdf

Jentgen, L; Conrad, S; Riddle, R; Von Sacken, EW; Stone, K; Grayman, WM; Ranade, S. (2003)

Implementing a Prototype Energy and Water Quality Management System. AwwaRF/AWWA.

Kirby, R; Cho, EJ; Gehrke, B; Bayer, T; Park, YS; Neikirk, DP; McDevitt, JT; Ellington, AD.

(2004) Aptamer-based sensor arrays for the detection and quantitation of proteins. Analytical

Chemistry. 76(14):4066-4075.

Koblizek, M; Maly, J; Masojidek, J; Komenda, J; Kucera,T; Giardi, MT; Mattoo, AK; Pilloton,

R. (2002) A biosensor for the detection of triazine and phenylurea herbicides designed using

photosystem ii coupled to a screen-printed electrode. Biotechnology and Bioengineering.

78(1):110-116.

Kretzmann, H; Van Zyl, J. (2004) Stochastic Analysis Of Water Distribution Systems. World Water

& Environmental Resources Congress, Environmental & Water Resources Institute - ASCE.

Kuhn, R; Oshima, K. (2002) Hollow-fiber Ultrafiltration of Cryptosporidium parvum oocysts from

a wide variety of 10-L surface water samples. Canadian J. of Microbiology, 48(6):542-549.

Lee, B; Deininger, R; Clark, R. (1991) Locating monitoring stations in water distribution systems.

J. AWWA. 83(7):60-66.

Li, Z; Buchberger, S; Tzatchkov. (2005) Importance of Dispersion in Network Water Quality

Modeling. Proc. World Water & Environmental Resources Congress, Environmental & Water

Resources Institute - ASCE. 2005.

Li, Z; Buchberger, S. (2004) Effect of Time Scale on PRP Random Flows in Pipe Network. World

Water & Environmental Resources Congress, Environmental & Water Resources Institute - ASCE.

Mays, LW. (2004) Water Supply Systems Security. New York: McGraw-Hill.

McCleskey, SC; Griffin, MJ; Schneider, SE; McDevitt, JT, Anslyn, EV. (2003) Differential

receptors create patterns diagnostic for ATP and GTP. J. Am. Chem. Soc. 125(5):1114-1115. 
U.S. EPA Office of Water Early Warning Systems

August 2005 163

Murray, R; Janke, R; Uber, J. (2004) The Threat Ensemble Vulnerability Assessment Program for

Drinking Water Distribution System Security, Proceedings of the World Water and Environmental

Resources Congress, Salt Lake City, June 2004.

Ostfeld, A. (2004) Optimal Monitoring Stations Allocations for Water Distribution System Security.

Chapter in Water Supply Systems Security. Edited by L. Mays, McGraw-Hill.

Ostfeld, A; Salomons, E. (2004) Optimal layout of early warning detection stations for water

distribution systems security. J.WRPM, ASCE. 130(5):377-385.

Perkel, JM. (2003) Microbiology vigil: probing what’s out there. The Scientist. 17(9):40.

Pesavento, M; D’Agostino, G; Alberti, G. (2004) Molecular Imprinted Polymers as Sensing

Membrane for Direct Electrochemical Detection of Pollutants, IAEAC: The 6th Workshop on

Biosensors and BioAnalytical μ-Techniques in Environmental and Clinical Analysis

ENEA - University of Rome “La Sapienza”: October 8-12, 2004 - Rome, Italy.

Powell, J; Clement, J; Brandt, M; Casey, R; Holt, D; Grayman, W; LeChevallier, M. (2004)

Predictive Models for Water Quality in Distribution Systems. AwwaRF-AWWA, Denver, CO.

Pyle, BH; Broadway, SC; McFeters, G. (1999) Sensitive detection of Escherichia coli O157:H7 in

food and water by immunomagnetic separation and solid-phase laser cytometry. Applied and

Environmental Microbiology. 65:1966-1972.

Quist, GM; DeLeon, R; Felkner, IC. (2004) Evaluation of a Real-time Online Continuous

Monitoring Method for Cryptosporidium. AwwaRF Project #2720.

Rider, TH; Petrovick, MS; Nargi, FE; Harper, JD; Schwoebel, ED; Mathews, RH; Blanchard, DJ;

Bortolin, LT; Young, AM; Chen, J; Hollis, MA. (2003) A B cell-based sensor for rapid

identification of pathogens. Science. 301:213-215.

Rife, JC; Miller, MM; Sheehan, PE, Tamanaha, CR; Tondra, M; Whitman, LJ. (2003) Design and

performance of GMR sensors for the detection of magentic microbeads in biosensors. Sensors and

Actuators A. 107:209-218.

Roberson, JA; Morley KM. (2005) Contamination Warning Systems for Water: An Approach for

Providing Actionable Information to Decision-makers. American Water Works Association.

http://www.awwa.org/Advocacy/pressroom/pr/index.cfm?ArticleID=424

Rosen, JS; Miller, DM; Stevens, KB; Ergul, A; Sobrinho, JAH; Frey, MM; Pinkstaff, L. (2003)

Application of Knowledge Management to Utilities. AWWA Research Foundation. ISBN

1-P-4.5C-90895-2/03-CM.

Rossman, L. (2000) EPANET Version 2 User’s Manual. USEPA.

Ruan, C.; Zeng, K; Varghese, OK; Grimes, CA. (2004a) A staphylococcal enterotoxin B

magnetoelastic immunosensor. Biosensors and Bioelectronics. 20:585-591.
U.S. EPA Office of Water Early Warning Systems

August 2005 164

Ruan, C; Varghese, OK; Grimes, CA; Zeng, K; Yang, X; Mukherjee, N; Ong, KG. (2004b) A

magnetoelastic ricin immunosensor. Sensor Letters. 2:1-7.

Ruan, C; Zeng, K; Varghese, OK; Grimes, CA. (2003) Magentoelastic immunosensors: amplified

mass immunosorbent assay for the detection of Escherichia coli O157:H7. Analytical Chemistry.

75:6494-6498.

Shaffer, KM; Gray, SA; Fertig, SJ; Selinger, JV. (2003) Neuronal Network Biosensor for

Environmental Threat Detection. Internet abstract found at:

http://www.nrl.navy.mil/content.php?P=04REVIEW118.

States, S. (2004) Rapid Screening, How Good Is it for Security Investigations? AWWA Jan 2004.

Tamanaha, CR; Whitman, LJ; Colton, RJ. (2002) Hybrind macro-micro fluidics system for a chipbased sensor. J. of Micromechanics and Microengineering. 12:N7-N17.

Tuck, K; Powers, M.; Millward, H; Chen, Y; Zharkikh, L; Wall, M; Li, W; Gundry, C; Pavlov, I;

Ditty, S; Hadfield, T; Karaszkiewicz, J; Nielsen, D; Teng, DH-F. (2005) Joint Biological Agent

Identification and Diagnostic System (JBAIDS): Stability and Sensitivity of Freeze-Dried Real-Time

PCR Assays. American Society of Microbiology 2005. Abstract 089/Y-018.

Uber, J; Janke, R; Murray, R; Meyer, P. (2004a) Greedy Heuristic Methods for Locating Water

Quality Sensors in Distribution Systems. Proc. World Water & Environmental Resources Congress,

Environmental & Water Resources Institute - ASCE, 2004.

Uber, J; Shang, F; Rossman, L. (2004b) Extensions to EPANET for Fate and Transport of Multiple

Interacting Chemical or Biological Components. World Water & Environmental Resources

Congress, Environmental & Water Resources Institute - ASCE.

van Bloemen Waanders, BG; Bartlett, R; Biegler, L; Laird, C (2003) Nonlinear Programming

Strategies for Source Detection of Municipal Water Networks. World Water & Environmental

Resources Congress, Environmental & Water Resources Institute - ASCE.

Walski, TM; Chase, DV; Savic, DA; Grayman, W; Beckwith, W; Koelle, E. (2003) Advanced

Water Distribution Modeling and Management, Haestad Methods. Waterbury CT: Haestad Press.

Watson, J; Greenberg, HJ; Hart, WE. (2004) A Multiple-Objective Analysis of Sensor Placement

Optimization in Water Networks. World Water & Environmental Resources Congress,

Environmental & Water Resources Institute - ASCE. 

Whelan, RJ; Wohland, T; Neumann, L; Huang, B; Kobilka, BK; Zare, RN. (2002) Analysis of

biomolecular interactions using a miniaturized surface plasmon resonance sensor. Analytical

Chemistry. 74:4570-4576.

Whelan, RJ; Zare R.N. (2003) Surface plasmon resonance detection for capillary electrophoresis

separations. Analytical Chemistry. 75:1542-1547.
U.S. EPA Office of Water Early Warning Systems

August 2005 165

Whitman, LJ; Sheehan, PE; Colton, RJ; Miller, RL; Edelstein, RL; Tamanaha, CR. (2001) Naval

Research Laboratory Review/Chemical/Biochemical Research.

WHO (2004) Public Health Response to Biological and Chemical Weapons: World Health

Organization Guidance. http://www.who.int/csr/delibepidemics/biochemguide/en/index.html
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 A-1

APPENDIX A

WaterSentinel Overview

Promoting the security of the nation’s water infrastructure is one of the most significant

undertakings and responsibilities of the U.S. Environmental Protection Agency (EPA) in a

post-September 11 world. An attack, or even a credible threat of an attack, on water infrastructure

could seriously jeopardize the public health, infrastructure, and economic vitality of a community.

Although historical evidence suggests that the probability of intentional contamination of the

drinking water supply is relatively low, experts agree that it is possible to contaminate a portion of

a drinking water system, resulting in adverse public health consequences. Furthermore, the

probability of a contamination threat (the mere indication that contamination of the drinking water

supply may have occurred) is relatively high. Given that it is possible to contaminate drinking water

at levels of public health concern, and the probable occurrence of contamination threats in the water

sector, there is a need to evaluate the credibility of any contamination threat and identify appropriate

response actions in a very short period of time.

In recognition of this threat and in response to Homeland Security Presidential Directive 9, EPA

developed the proposed WaterSentinel initiative. HSPD-9 directs EPA to:

• “develop robust, comprehensive, and fully coordinated surveillance and monitoring systems .

. . for . . . water quality that provide early detection and awareness of disease, pest, or poisonous

agents”; and

• “develop nationwide laboratory networks for . . . water quality that integrate existing Federal and

State laboratory resources, are interconnected, and utilize standardized diagnostic protocols and

procedures.”

The proposed WaterSentinel initiative will build on existing EPA efforts to design and deploy a

contamination warning system (CWS). A CWS is an evolution of the “early warning system”

concept and involves the active deployment and use of monitoring technologies/strategies and

enhanced surveillance activities to collect, integrate, analyze, and communicate information to

provide a timely warning of potential water contamination incidents and initiate response actions

to minimize public health and economic impacts.

The key to an effective and timely response to a water contamination threat is to minimize the time

between indication of a contamination incident or change in water quality and implementation of

effective response measures through early detection of threat warnings of potential contamination.

Identification of a contamination threat leads to response actions designed to determine whether or

not a threat is credible and to protect public health in the case of a credible threat. Early detection

can be achieved through the implementation of a CWS. A CWS is not merely a collection of

monitors and equipment placed throughout a water system to alert of intrusion. Fundamentally, it

is an exercise in information management. Different information streams must be managed,

analyzed, and interpreted in a timely manner to recognize potential contamination incidents in time

to respond effectively.

Figure 1 presents an overview of the components of the proposed concept of operations for the

WaterSentinel contamination warning system (WS-CWS). Although an effective CWS should be

designed to maximize the detection of contamination incidents, accidental or intentional, it is
U.S. EPA Office of Water Early Warning Systems

August 2005 A-2

Figure 1 Overview of the WS-CWS Concept of Operations

important to demonstrate the effectiveness of the design and integration of CWS components

through a systematic process that can be expanded and adapted over time to ensure sustainability.

In the design of the WS-CWS, EPA will partner with drinking water utilities, key water sector

stakeholders, technical experts, representatives from public health, law enforcement, and other

federal agencies to focus on first-generation CWS components that initially address a representative

subset of priority contaminants to improve a utility’s ability to respond to any contamination threat

or incident. In addition, the WS-CWS will yield operational benefits for non-security related water

quality issues and enhance collaboration/integration of water utilities and local health departments.

Through working with these partners, EPA will use the results of the WaterSentinel initiative

demonstration project to develop a sustainable model for a CWS that can be implemented by utilities

throughout the nation.

Major Components of the WS Initiative

The major components of the WS initiative include the following:

• System architecture and program design

• Selection of baseline contaminants

• Laboratory support and the Water Laboratory Alliance

• Event detection and credibility determination
U.S. EPA Office of Water Early Warning Systems

August 2005 A-3

• Consequence management

• Data management

System Architecture and Program Design

The WS system architecture will define the

conceptual approach for the WS-CWS and

document the most effective combination of

CWS components to yield a sustainable

program that can be adopted and implemented

by drinking water utilities. The key

components of a CWS are shown in Figure 2

and are described as follows:

• Water quality monitoring. Multiple

approaches are available for monitoring

water quality as part of a CWS. The

WS-CWS will focus primarily on two

options as described below.

Online monitoring for changes in

water quality parameters. Online

monitors for water quality parameters, such as chlorine residual, pH, conductivity, turbidity,

etc., can potentially detect an identifiable change from an established water quality baseline

and serve as an indicator of potential contamination in the WS-CWS.

Routine sampling for select contaminants. Water samples can be collected at a

predetermined frequency or in response to a trigger and analyzed for specific, targeted

contaminants. It may also be possible to detect some non-target analytes if the analytical

techniques used in the routine monitoring program are sufficiently robust and if the analysts

are trained and encouraged to investigate tentatively identified contaminants.

• Consumer complaint surveillance. Consumer complaints regarding unusual taste, odor, or

appearance of the water are often reported to and recorded by water utilities, which

conventionally use them to identify and address water quality problems. Using an appropriate

methodology, WS could track and analyze these complaints to look for unusual trends that may

be indicative of a contamination incident.

• Public health surveillance. Syndromic surveillance by the public health sector as well as

reports from 911 call centers and poison control hotlines might serve as a warning of a potential

drinking water contamination incident if there is a reliable link between the public health and

drinking water utilities.

• Enhanced security monitoring. Security breaches, witness accounts, and notifications by the

perpetrator, news media, or law enforcement can be monitored through enhanced security

practices.

Figure 2
U.S. EPA Office of Water Early Warning Systems

August 2005 A-4

Factors for consideration in the development of the WS system architecture for a given utility

include the following:

• Sustainability and dual use: The ability of utilities to operate and maintain the WS-CWS to

benefit water security as well as routine operations and water quality concerns.

• Cost-benefit of implementation: The ability to demonstrate that the cost of implementing,

operating and maintaining the WS-CWS is justified by the benefits. This factor is directly

related to the previous consideration of sustainability and dual use.

• Universal application: The ability to adapt and implement the WS-CWS design, in some

manner, at any drinking water utility regardless of size, treatment type, location, or complexity.

Under the proposed initiative, EPA would work with utilities to determine sensor placement and

sampling locations, develop and enhance communication and coordination between the utility and

public health community, identify approaches for enhancement and integration of consumer

complaint and public health surveillance, and define dual use benefits of implementation of the

WS-CWS.

Selection of Baseline Contaminants

Many potential monitoring and surveillance components that could be integrated into a CWS, and

evaluated during WS demonstration project, have not been thoroughly demonstrated in a CWS

application. Thus, it is critical that the WS demonstration project be limited to contaminants for

which technologies/strategies are well understood or characterized through other water monitoring

application. For example, there is substantial experience with technologies used to monitor basic

water quality parameters, such as chlorine residual, pH, and conductivity. Use of such established

technologies during the WS demonstration project will allow for the focus on the performance of

the contamination warning system, without introducing additional uncertainty associated with

research techniques. Once the concept of a CWS has been demonstrated, novel detection

technologies could be evaluated in the context of this proven system.

The WS initiative is intended to increase protection against those contaminants that could cause

serious harm to public health or economic well-being if introduced into a drinking water system.

Thus, selection of candidate contaminants for the WS initiative should consider the threat posed by

potential contaminants. Therefore, the first step in the development of the WS initiative is to

identify those baseline contaminants that will be included in the demonstration project.

The objectives of the WS contaminant selection process are to:

• Select a reasonable number of baseline contaminants that provide coverage for all categories of

priority contaminants using a combination of different monitoring and surveillance

technologies/strategies.

• Identify research priorities related to sampling and analysis methods that can be initiated in the

near term for evaluation in the WS demonstration project.

• Identify long-term research priorities related to sampling and analysis to ensure future coverage

of all priority contaminants.
U.S. EPA Office of Water Early Warning Systems

August 2005 A-5

Laboratory Support and the Water Laboratory Alliance

To provide necessary analytical support for both routine monitoring and response actions, the Water

Laboratory Alliance (WLA) is intended to establish capability and capacity at drinking water utility

laboratories for routine monitoring of baseline contaminants. The WLA is a network of laboratories

with extensive capability for the analysis of water samples for a wide range of potential

contaminants. It is proposed that the WLA integrate existing water quality labs with the existing

Laboratory Response Network (LRN), established by the U.S. Center for Disease Control and

Prevention (CDC) to support analysis of potential biothreat agents.

Required confirmatory and response analysis capabilities and capacities should be established to

support the WS initiative. Since many CWS components may provide non-specific indicators of

potential contamination, laboratories that are part of the WLA should be proficient in the screening

and analysis of unknown samples for chemicals, pathogens, and radionuclides. In addition to the

development of laboratory capabilities to support the WS-CWS, the development of standardized

analytical methods that can be utilized for screening, presumptive, and confirmatory analysis will

be a key focus of research activities.

Event Detection and Credibility Determination

While the WS initiative is designed to gather and integrate information from a number of sources

that might be indicative of a contamination threat, the information is only useful in the context of

a CWS if it can be quickly and effectively used to make appropriate response decisions. Thus, there

is a need for decision support tools.

In the WS-CWS model, event detection is defined as a signal from the CWS that is indicative of a

possible contamination incident. This signal could be a pattern of unusual water quality, a cluster

of unusual consumer complaints, or unusual symptoms picked up by a public health surveillance

program. Although public health surveillance systems have their own event detection algorithms,

these do not exist, or are not widely deployed, for water quality and consumer complaints. Thus,

there is a need to develop event detection software (EDS). The most important function of the EDS

is to filter out the anomalies that normally occur, or which have known causes, and signal only those

events that are likely to be possible contamination incidents. In short, the purpose of the EDS is to

reduce the false-positive rate without missing potential events.

Although the EDS can indicate a possible contamination threat, it cannot indicate a credible threat

that requires response actions to protect public health. Furthermore, the human element cannot be

removed from the credibility determination step. However, it is possible to develop a tool to support

officials in decision making by guiding them through the evaluation process and aiding in the

synthesis of information necessary to make timely and appropriate response decisions. Ultimately,

the decision will always rely on human judgment and evaluation of incomplete information.

However, this decision tool can be a great aid in the process, and might substantially reduce the time

to make critical response decisions.
U.S. EPA Office of Water Early Warning Systems

August 2005 A-6

Consequence Management

Early detection of a contamination incident is only beneficial in minimizing public health or

economic impacts if effective response decisions also can be made in a timely manner. A

consequence management protocol will provide a decisionmaking framework that governs when,

how, what, and who will be involved in making decisions in response to contamination threat

warnings to minimize the response timeline and implement operational or public health response

actions appropriately. Availability of a robust and tested consequence management protocol will

be a key factor in initiation of monitoring and surveillance activities.

The systematic approach for assessing credibility in response to contamination threat warnings

ensures that all available information is analyzed in a timely and efficient manner to minimize both

false alarms and over-response to a trigger that has not been determined to be credible. While the

system architecture will identify an integrated set of contamination threat warnings that provide

input for consequence management decisions, the consequence management protocol will be

independent and able to inform response decisions and containment strategies for existing triggers

and contamination threat warnings in the absence of a formal CWS.

Data Management

A CWS is not merely a collection of monitors and equipment placed throughout a water system to

alert of intrusion. Fundamentally, it is an exercise in information management. Different

information streams must be managed, analyzed, and interpreted in a timely manner to recognize

potential contamination incidents in time to respond effectively. 

The elements of the WS-CWS present a rich topography of information needs to be collected,

integrated, and analyzed to make response decisions. For each CWS component, EPA and partners

in the WS initiative would identify the requirements of the technology employed to analyze data and

distinguish a potential incident from the established baseline.

Based on CWS components identified through WS system architecture and program design, data

may need to be extracted from a combination of SCADA systems, laboratory information

management systems (LIMS), consumer complaint surveillance systems, security monitoring

systems, and public health surveillance systems in a manner that allows for timely decision making

and response.

Next Steps

WaterSentinel has been proposed as a demonstration project to commence in Fiscal Year 2006. EPA

will launch this project by building on existing efforts. Throughout Fiscal Year 2005, EPA will

continue to work with the water sector on activities that could lay the groundwork for WaterSentinel.

Such activities could include the design of a model contamination warning system, analysis of

contaminants that could be effectively monitored for a timely response, the development of

consequence management protocols for response to a potential incident, and research into

technologies that could be candidates for deployment.
U.S. EPA Office of Water Early Warning Systems

August 2005 B-1

APPENDIX B

Agencies Involved in Early Warning Systems

The following are brief descriptions of agencies involved in research, evaluation, or development

of early warning systems.

Federal Agencies (Research and Programs)

The U.S. Environmental Protection Agency

EPA plays a lead role in protecting the water sector. In National Strategy for Homeland Security

(July 2002), EPA is designated as responsible for protecting our national water supply. Also, under

the Homeland Security Presidential Directive-9 (January 2004), EPA is one of the Federal Agencies

responsible for agriculture, food, and water security to “develop robust, comprehensive, and fully

coordinated surveillance and monitoring systems, ... that provide early detection and awareness of

disease, pest, or poisonous agents.”

To spearhead the research efforts on water security, EPA formed the National Homeland Security

Research Center (NHSRC) in the Office of Research and Development (ORD). EPA has initiated

many efforts related to early warning systems, including the following:

• Drafting the Water Security Research and Technical Support Action Plan (Action Plan), which

provides the basis for this project.

• Initiation of an NHSRC’s Water Awareness Technology Evaluation Research Security

(WATERS) Center to conduct research projects including an evaluation of various sensor

technologies and data acquisition systems.

• Use of EPA’s Environmental Technology Verification (ETV) Program to provide credible

performance data for commercial-ready environmental technologies including homeland security

technologies (e.g., early warning systems).

• Sponsoring efforts by the American Society of Civil Engineers to develop Guidance for

Designing Online Contamination Monitoring System.

• Forming the Distribution System Research Consortium (DSRC) in June 2003 to provide a forum

for information exchange on a diverse water distribution system security topics including early

warning systems research (e.g., sensor, field studies, sensor placement).

• Forming the Threat Ensemble Vulnerability Assessment (TEVA) Research Program for

Drinking Water Distribution System Security. One of the products is the help in designing early

warning systems and for evaluating strategies for locating sensors in the distribution system.

• Developing various guidance on emergencies and early warning systems.

Department of Homeland Security

The Department of Homeland Security was established in 2002 in order to protect the nation from

terrorist attacks. As part of this mission, DHS has the responsibility to protect the nation’s 209

drinking water. DHS has established the Ready Campaign for the purpose of educating the public

on a continuous basis so that communities will be ready in case of an emergency scenario. The 210

2004 Homeland Security Presidential Directive/HSPD-9 also requires DHS to protect the agriculture

and food systems from attacks, disasters, and other emergencies. Part of this directive’s 211
U.S. EPA Office of Water Early Warning Systems

August 2005 B-2

Awareness and Warning section is to enhance intelligence operations in securing water assets, such

as implementing effective monitoring and detecting capabilities. The directive also orders further

research and development of detection, prevention, characterization, response, and recovery

countermeasures. Furthermore, DHS, in conjunction with EPA and other agencies, is involved

reviewing the available information on technology performance. DHS has also provided grants 212

to projects involved with the research and development of technologies that could be used for early

warning systems in water, such as the SCADA systems.213

Department of Defense

The danger of nuclear, biological, and chemical arms has been a concern of the Department of

Defense (DOD) even before the 9-11 terrorist attacks. Programs such as the Joint Service Agent

Water Monitor Program and other detector and sensor programs were formed since the late 1990s.214

Now, under E2.1.20. Food and Water Security of the Antiterrorism Program from Directive number

2000.12 of 2003, the Department of Defense is obligated to protect food and water sources from

disruption and contamination or other terrorist attacks. DOD must fulfill this requirement by taking

action to detect, prevent, and mitigate the effects from intentional contaminations of food and water

sources. DOD is thus continuously supportive of the research and development of more advanced 215

water contamination detective devices such as detectors that are faster, lighter, and smaller and can

be used in-field. DOD strives to achieve this by funding organizations, such as SNL, that are 216

developing EWS technology. Finally, DOD contributes to the development of EWS through its

research and development programs, such as the Defense Advanced Research Projects Agency

(DARPA), further described below. A list of other DOD-funded R&D organizations is available

at http://www.dtic.mil/ird/websites/orgsites.html.

Defense Advanced Research Projects Agency

DARPA is the main research and development organization under DOD and strives for superior

military technology. For water security measures, DAPRA is looking for fast, highly sensitive, 217

and highly specific biosensor systems. The four thrust areas of the Biosensors Technologies 218

Program are, (1) Mass-Based Identification Technologies, (2) Surface-Based Identification

Technologies, (3) Nucleic Acid-Based Identification Technologies, and (4) Breath Analysis-Based

Identification Technologies. The Biosensors Technologies Program is conducted in collaboration 219

with 20 universities and laboratories. As mentioned in this report, the DARPA Chemical and

Biological Sensors Standards Study presents methods for evaluating sensors by capturing the

performance trade-offs between sensitivity, probability of correct detection, false-positive rate, and

response time.

Naval Research Laboratory

The Naval Research Laboratory (NRL) is the corporate research laboratory for the Navy and Marine

Corps. The focus of this laboratory encompasses scientific and technology research and

development particularly for maritime applications as well as atmospheric and space sciences and

technologies. NRL has been researching and developing methods to detect contaminants in the 220

environment. In collaboration with GeoCenters, Inc., these efforts have resulted in the development

of a method to detect radioactive material such as uranium on a microchip. Under the sponsorship 221

of the Office of Naval Research, NRL also developed a field test method in potable water for
U.S. EPA Office of Water Early Warning Systems

August 2005 B-3

cyanide that did not require laboratory testing. NRL also developed a microchip for detecting 222

cyanide in vapor and drinking water, in a collaborative effort with GeoCenters, Inc., the New 223

Mexico State University, and the University of California. NRL is currently developing a highsensitivity biosensor for monitoring airborne and water-borne contaminants in the environment. The

force amplified biological sensor can detect the force between DNA and antigen molecules. Other 224

advancements include the development of RAPTORTM and the Bead ARray Counter (BARC) chip,

as discussed in this report. RAPTORTM is a portable, rapid, automatic fluorometric assay system

for monitoring biological agents, toxins, explosives, and chemical contaminants. The BARC chip

consists of an array of DNA spots immobilized on a surface, detecting hybridized sample DNA 225

using magnetic beads. The development of BARC was sponsored by DARPA and ONR. 226 227

Edgewood Army Proving Grounds

Although Edgewood Army Proving Grounds was originally founded as a chemical weapons

research, development, and testing facility, Edgewood now focuses on chemical weapon defensive

measures, and responds to the Army Chemical and Biological Defense Command, which oversees

the Army’s nonmedical chemical and biological defense activities. Army Edgewood Joint Service 228

Agent Water Monitor Program is actively looking at sensors for distribution using the following

proven classes of detection technologies: conventional, optical techniques, polymers/materials,

assays, and sentinel species. Additionally, it is examining new areas of MEMS (Micro-ElectroMechanical Systems) and MOEMS (Micro Optical Electro Mechanical Systems), which rely on a

concept proven in one of the other classes. Edgewood is collaborating with EPA in order to

heighten homeland security efforts.229

U.S. Geological Survey

Water quality has been a large focus for the U.S. Geological Survey. USGS has evaluated many

different real-time continuous water quality monitoring stations. In addition, USGS was part of 230

workshops such as the ILSI monitored Early Warning Monitoring to Detect Hazardous Events in

Water Supplied in 1999, as well as the 2004 National Monitoring Conference, “Building and 231

Sustaining Successful Monitoring Programs” by the National Water Quality Monitoring Council.232

USGS has also supported EWS projects such as the development of the Efficient Hydrologic Tracertest Design Program, which provides scenario simulations of a release event so that water systems

can test their preparedness.233

National Laboratories

Sandia National Laboratories

Since well before 2001, Sandia National Laboratories’ (SNL) Chem/Bio Program has been involved

in the development of advanced sensor technologies for rapid detection of chemical and biological

warfare agents. Most of these technologies are pre-commercial and in various stages of 234

prototyping, including the μChemLab and Micromachined Acoustic Chemical Sensor. However,

SNL believes that once mature, its technologies should offer cost-effective monitoring alternatives.

SNL’s specific water sensor development activities include (Wayne Einfield, SNL, personal

communication) the following:
U.S. EPA Office of Water Early Warning Systems

August 2005 B-4

1) Adaptation of gas-phase μChemLab for detection of trihalomethanes and hydrolysis products

of chemical agents in water. Researchers are building a “front-end” for an existing chip-based

gas chromatograph. The system is initially being developed for analysis of trihalomethanes in

water as well as hydrolysis products of chemical agents. They anticipate the completion of a

field-ready prototype in 2005. 

2) Use of liquid-phase μChemLab for the continuous online detection of biotoxins in water. This

is probably the most mature of the SNL portfolio of technologies. A proteomics-based analysis

scheme utilizes microfluidics-based capillary-zone and capillary-gel analyses for biotoxin

separation coupled with laser induced fluorescence detection, all in a hand-held, field portable

package. SNL is in final discussions with two major cooperative research and development

agreement (CRADA) partners and a successful agreement will launch an aggressive project to

optimize and test this system for use as a real-time device for water distribution system

monitoring.

3) Preconcentration of bacterial species in water using insulative dielectrophoresis and

microfabricated fixtures. This project is aimed at the development of a preconcentrator for

biological species in water that offers promise to separate various types of bacteria based on

their mobility in an electric field. Researchers have demonstrated the ability to differentiate

between live and dead E. coli cells as well as the ability to differentiate between bacteria and

inert particles in the water matrix. 

4) Microfabricated electroanalysis system for the detection of inorganics in water. This project

is aimed at the detection of various electroactive species in water (e.g., lead, cadmium, arsenic)

and utilizes a microfabricated multi-electrode array to measure various species by anodic

stripping voltametry. SNL researchers have a table-top prototype that is being optimized for

lead analysis, however, they anticipate that the functionality of this instrument could be

expanded as one of a suite of early warning sensors.

5) SNL, CH2M Hill (Colorado), and Tenix Investments (Australia) have signed an agreement that

calls for an online water monitoring prototype, based on μChemLab, to be developed and testing

to begin by June 2005. The first phase of testing will focus on detecting ricin and botulinum 235

toxin. The development team eventually also hopes to address viruses, bacteria, and parasites.

Lawrence Livermore National Laboratory

Lawrence Livermore National Laboratory (LLNL) is a national laboratory operated by the

University of California for U.S. Department of Energy. Although LLNL was founded as a nuclear

weapons design laboratory, it has broadened its field of work to include energy, biomedicine, and

the environment. LLNL has been developing a wide range of technologies for sensors. As 236 237

discussed in this report, LLNL utilized Luminex® technology to develop an Autonomous Pathogen

Detection System (APDS). The system has an automated sample preparation module based on

sequential injection analysis (SIA). Also discussed in this report is the “hand-held nucleic acid

analyzer”(HANAA) based on real-time PCR (TaqMan) developed by LLNL.
U.S. EPA Office of Water Early Warning Systems

August 2005 B-5

Oak Ridge National Laboratory

The Oak Ridge National Laboratory (ORNL) is a multiprogram science and technology laboratory

managed by UT-Battelle, LLC for the DOE. ORNL conducts research and development in the 238

areas of energy, environment, and national security. In addition, the laboratory produces isotopes,

manages information and technical programs, and provides research and technical assistance to other

organizations. ORNL is one of the leading laboratories in developing biosensors and 239

bioreporters. With regard to EWS in water, ORNL has developed the Large-Scale Water Supply 240

Sentinel, a device that analyzes the characteristics of algae photosynthesis, in response to concerns

for military and municipal water safety. ORNL also licensed the VeriScanTM 3000 System, 241

produced by Protiveris. In addition, ORNL is associated with organizations such as the Center 242

for Advanced Biomedical Photonics, and the Advanced Biomedical Sciences and Technology

Group. ORNL researchers are collaborating with Gary Sayler, University of Tennessee on 243

biosensor and nanotechnology projects (Gary Sayler, U. of Tennessee, personal communication).

Pacific Northwest National Laboratory

The Pacific Northwest National Laboratory (PNNL) is a national laboratory operated by Batelle for

DOE. PNNL conducts research and development and supports education in the areas of

environment, energy, health and national security, and economics. Homeland security has been 244

a focus of PNNL even before 9/11. In the area of chemical, nuclear, and biological weapon

detection, PNNL has contributed to the development of sensor and measurement technology,

electronic (including controls) and system integration application requirements. The Sensors and 245

Electronics branch of PNNL is developing its electronics and systems in the areas of biological

sensors, chemical sensors, physical property sensors, nuclear radiation sensors, and macro property

measurement. In order to supplement the rapid detection of biological threats, PNNL has 246

developed the Biodetection Enabling Analyte Delivery System (BEADS). BEADS automated

technology that isolates bacteria, spores, viruses, and their DNA from water, air, or dirt samples

without requiring any manual preparations of samples.247

Idaho National Laboratory

On February 1, 2005, the Idaho National Engineering and Environmental Laboratory and Argonne

National Laboratory-West became the Idaho National Laboratory (INL ). EPA-NHSRC and INL 248

have an interagency agreement to develop and produce a next generation prototype of the

Ultrafiltration Concentration (UC) device previously developed by NHSRC and other stakeholders.

The UC bench top device concentrates microbial pathogens within a 100 L municipal drinking water

sample into a 250-mL volume in approximately a 2-hour time frame (400-fold concentration). INL

hopes to use the bench top UC system, which has been tested at the NHSRC in Cincinnati, to

redesign/repackage and automate the components such that the new device can be operated in the

field as a near-commercial, or field prototype system
U.S. EPA Office of Water Early Warning Systems

August 2005 B-6

Other Agencies/Organizations

Pittsburgh Water & Sewer Authority

The Pittsburgh Water & Sewer Authority is one of the organizations that the Water Environment

Research Foundation and EPA are funding in order to identify, screen, and treat contaminants to

ensure water security. For example, the Authority has conducted verification tests on many of the

newer technologies for rapid detection in drinking water. It is also determining the risks and toxicity

associated with biological, chemical, and radiological agents introduced to sewers, analyzing the fate

and transport as well as treatment methods in the wastewater treatment facility, and developing

emergency operating/containment procedures.249

National Academy of Sciences: Water Science and Technology Board

The Water Science and Technology Board (WSTB) was organized in 1982 by the National Research

Council to provide a focal point for studies related to water quality and water resources. Projects 250

administered by the WSTB related to EWS include “Public Water Supply Distribution Systems:

Assessing and Reducing Risks”, and the “Review of EPA Homeland Security Efforts: Panel on 251

Water System Security Research.”252

American Water Works Association Research Foundation

The American Water Works Association Research Foundation (AwwaRF) is an international

nonprofit organization that sponsors research efforts for its subscribing member organizations to

provide safe and affordable drinking water. AwwaRF has been sponsoring many water security 253

projects with the support of governmental agencies such as CDC and EPA, national and international

research foundations, city and state water departments, and universities. These projects cover a wide

range of water security topics including assessment of technologies, online monitoring and early

warning systems, communication, assessing microbial contamination, and disaster response.

AwwaRF projects relevant to early warning systems for drinking water have focused on the early

detection of pathogens, chemicals, radioactivity, and biotoxins so that utilities can appropriately

respond in case of an intentional contamination of the water system. As terrorist concerns heighten,

the ability to quickly detect and identify contaminants is vital. One of the major focuses of the

AwwaRF projects is to develop a portable hand-held water monitor capable of real-time detection

of all harmful agents and implement Supervisory Control and Data Acquisition (SCADA) systems

to facilitate and advance monitoring and communication. Projects are developing and advancing

methods to correctly identify E. coli and the different stages of Cryptosporidium parvum using

technology such as the Multi-Angle Light Scattering (MALS). Other projects are focusing on

strategy planning, from preventing intrusions into the drinking water systems, selecting water

sampling locations and methods, and protecting utility SCADA equipment, to emergency

management planning. Finally, some projects are focused beyond water treatment and distribution

systems. For example, point-of-use drinking water devices may be useful as a short-term emergency

response option. AwwaRF Project Summaries are presented in Appendix D.
U.S. EPA Office of Water Early Warning Systems

August 2005 B-7

Water Environment Research Foundation

The Water and Environment Research Foundation (WERF), created in 1989, funds wastewater and

water quality research. The subscribers of the Foundation are utilities, municipalities, 254

corporations and industrial organizations, all with a common interest in promoting research and

development in water quality science and technology. The vast majority of WERF's research

embraces a broad spectrum of scientific and technical disciplines (e.g., microbiology, wastewater

ecology, toxicology, biological sciences, environmental engineering, and instrumentation) as well

social/behavioral sciences (e.g., communications and public perception).

Prior to 9/11, WERF has undertaken studies on sensors with a view to study influent toxicity

monitoring and process control. Since 9/11, WERF, under the aegis of a security grant from EPA,

has been carrying out projects in the areas of (i) chemical, biological, and radioactive contamination

events (accidental or purposeful), (ii) design of expert support systems for tracking anomalies in

wastewater characteristics, (iii) GIS-based modeling of contaminants travel in piped conveyance

systems, (iv) design of intelligent sensors for online, real-time upset early warning devices (UEWD)

for tracking chemical and biological contaminants, and (iv) cyber security related to process control

systems at water/wastewater utilities. WERF undertook a review of UEWDs in Yr 2000 that

recommended that fundamental studies would be needed to articulate the links between how an

influent event (the source) leads to an intermediate biochemical/physiochemical response (the cause)

that results in an observable disruption in the treatment process (the effect). In Yr 2004, WERF

sponsored sensor technology studies for water quality monitoring using fiber-optic biosensors (for

rapid pathogen detection), bioluminescent biosensors (for toxicity-screening) and x-ray fluorescence

spectroscopy (for waterborne metals). WERF also organized a sensor workshop (August 30-31,

2005) to prioritize research and development needs for rapid online contaminant monitoring.

American Society of Civil Engineers - Water Infrastructure Security Enhancements (WISE) -

Standards Committee

EPA has contracted WISE to produce a guidance document to assist water utility companies to

design and implement online contamination monitoring systems to detect intentional contamination

events.

Rutgers University

With the support of EPA, Rutgers University has been involved in the research on EWSs. For

example, they recently sponsored an annual Workshop on Advanced Technologies in Real-Time

Monitoring and Modeling for Drinking Water Safety and Security.255
[this page intentionally left blank]
U.S. EPA Office of Water Early Warning Systems

August 2005 C-1

APPENDIX C

List and Criteria for Selecting Products and Technologies

The goal of this EWS document is to report on the state-of-the-art techniques for detecting

contaminants, specifically chemical/microbial/radiological agents in drinking water distribution

systems. To focus on the most promising products/technologies in this relatively new area, the

following criteria were developed for including technologies/products in this document. The list of

technologies is included at the end of this appendix. 

The following three categories of technology development were designated:

• Available now (being used or could be used by water utilities)

• Potentially adaptable technology used (but needs additional steps to address specific challenges

for use with water distribution system)

• Emerging technologies that may be applicable

The overriding criterion for categories is the focus on field portable (carried into field) and online

technologies (not benchtop). Also, because an analysis of market viability was beyond the scope

of the document, technologies/products are presented regardless of whether they would be at some

point cost effective for the water utility industry. However, some costly technologies/products may

not be considered because the manufacturers already determined that their products are too

expensive for the water utilities market and thus have not actively developed or adapted their

products for water detection.

Category 1. Available now:

Criteria:

• used/available now for water

• may be validated for water, perhaps for distribution conditions

Elaboration on Criteria:

• Portable and online products that are on the market and are specifically marketed for drinking

water distribution systems. This includes basic water quality online monitors, since they may

be adapted to provide early warning for CBW agents. This also includes toxicity kits that are

marketed to water utilities. This will cover the online technologies listed in the ASCE Guidance

and include additional portable kits and devices.

Category 2. Potentially adaptable technology used, but needs additional steps to address specific

challenges for use with water distribution system:

Criteria:

• demonstrated bench top version for water with ongoing work on field portable version (carried

into the field)

• portable products for water, but have some hurdles (sample concentration, chlorine removal)
U.S. EPA Office of Water Early Warning Systems

August 2005 C-2

• available for detecting CBW agents (in use for other media such as food or air ) and can be

adapted to water (accessory equipment)

• technology used in similar application (source water)

Elaboration on Criteria:

Several technologies that are in use for applications other than drinking water testing could be used

for drinking water if additional sample preparation steps are taken.

• Systems that would require removal of chlorine residuals - Cell- and organism-based

biomonitors, are presented. Their adaptation for drinking water relies on the development of

methods for removing chlorine residuals. These methods are in the research stage, but are highly

desired, so should be forthcoming. 

• Concentration of sample volume - Some technologies, such as portable PCR systems, could

be used with drinking water samples if used in conjunction with methods for concentrating large

sample volumes into reaction-size volumes. These products are presented with the expectation

that sample concentration techniques are forthcoming.

• Vaporization/Volatilization - Some of the portable and online vapor phase detectors that are

on the market for detecting CBW agents and are used by first responders can read water samples

if used with accessory equipment. There are existing methods/equipment for vaporization and

volatilization. This technology would not be suggested for microbial detection. Specific vapor

phase sampling products will be presented with the note that they have not been validated for

use with water samples. Companies are interested in adapting existing products for use with

water.

Category 3. Emerging technologies

Criteria:

• considered technologies defined as promising, given funding/grants from organization working

directly on EWS technologies (AwwaRF, EPA, DHS, DOD)

• appears in literature numerous times (could be various researchers) at recognized Detection

Conferences. Efforts from company, university, national laboratory, or government, and/or are

now being licensed to company for development/testing of prototype or product

• proof-of-concept has been demonstrated and the technology is still being aggressively pursued

• could be utilized for drinking water sampling with further development

Elaboration on Criteria:

The following conference abstracts were examined to determine which technologies are current hot

topics:

• 2004 Biodetection Technologies, Washington DC, June 2004256

• Detection Technologies, Arlington, VA, December 2003257

• Research, Technologies and Applications in Biodefense, Washington, DC, August 2003258

• 2003 Biodetection Technologies, Arlington, VA, June 2003259
U.S. EPA Office of Water Early Warning Systems

August 2005 C-3

• Biosensing Research and Development, World Technology Evaluation Center, Inc. National

Institutes of Health, December 2002260

• Detection Technologies, Arlington, Va, December 2002261

• Workshops on Advanced Technologies in Real-Time Monitoring and Modeling for Drinking

Water Safety and Security, Rutgers CIMIC, Newark, NJ, June and December 2002262

• BioMEMS & Biomedical NANOtech World 2002, Columbus, Ohio, September 2002263

• Biodetection Technologies, Alexandria, VA, May 2002264

Additionally, Army Edgewood Joint Service Agent Water Monitor Program is actively looking at

sensors for distribution systems using the following proven classes of detection technologies:

conventional, optical techniques, polymers/materials, assays, and sentinel species. It is also

examining new areas of MEMS (Micro-Electro-Mechanical Systems) and MOEMS (Micro Optical

Electro Mechanical Systems), which rely on a concept proven in one of the other classes.

What was not covered:

• Benchtop products for drinking water analysis.

• Portable products designed specifically for clinical samples.

• Sporadic research papers that have not gained wide attention.

• Technologies/products that were either only conceptual or were not currently envisioned to

apply to water.

In the report, technologies are classified based on the categories above (e.g., available, potentially

adaptable, emerging) and details are provided on the level of verification, proof of concept,

pilot/field tested, or round robin, if the information was available. Note that for most products,

except where noted, manufacture’s claims have not been evaluated by independent sources and

products mentioned are not endorsed by EPA. The following is a list of technology products by

the type of contaminant detected (e.g., chemical, microbial, or radiological), the status of the

technology development (e.g., available now, potentially adaptable, or emerging), and the chapter

that it appears in the document; the assay type, and the primary contaminant monitored.

The tables presented in Chapter 9 that compare detectors to desired EWS characteristics (Exhibits

9-2, 9-4, 9-6, and 9-8) are based on information obtained from references cited in the main text in

Chapters 5-8 where the technologies are discussed. In some cases information is incomplete because

the information was not available on the public part of the company website. In cases where there

is no vendor website or the product has not yet been released, information was also not available.
U.S. EPA Office of Water Early Warning Systems

August 2005 C-4

List of Technologies and Techniques

Product Company or Developer Technology Status Chapter

GENERAL WATER QUALITY

Series C15 Water Quality

Monitoring

Analytical Technology Inc. Available 5 & 9

SentinalTM Clarion Systems Available 5 & 9

Six-CenseTM Dascore Available 5 & 9

Model 1055 Solu Comp II

Analyzer

Emerson Available 5 & 9

AquaTrend panel Hach Available 5 & 9

TOC Process Analyzer Hach Available 9

Model A 15/B-2-1 Analytical Technology Inc Available 9

Model 5500 GLI International Available 9

DataSonde 4a Hydrolab Available 9

Model Troll 9000 In-Situ Available 9

Signet Model 8710 Signet Available 9

Model 6000 continuous monitor YSI Available 9

STIP-Scan STIP Isco GmbH Potentially Adaptable 5

CHEMICAL

QuickTM tests Industrial Test Systems, Inc Available 6.2.1 & 9

AS 75 arsenic test kit Peters Engineering (Austria) Available 6.2.1 &9

As-Top Water test kit Envitop Ltd. (Oulu, Finland) Available 6.2.1 & 9

PDV 6000 portable analyzer Monitoring Technologies

International Pty. Ltd. (Perth,

Western Australia)

Available 6.2.1 & 9

Nano-BandTM Explorer TraceDetect (Seattle,

Washington)

Available 6.2.1 & 9

CHEMetrics VVR CHEMetrics Available 6.2.2 & 9

1919 SMART 2 Colorimeter LaMotte Company (Chesterton,

MD)

Available 6.2.2 & 9

Mini-Analyst Model 942-032 Orbeco-Hellige (Farmingdale,

NY)

Available 6.2.2 & 9

AQUAfast® IV AQ4000 Thermo Orion (Beverly, MA) Available 6.2.2 & 9

Thermo Orion Model 9606

Cyanide Electrode

Thermo Orion (Beverly, MA) Available 6.2.2 & 9

Cyanide Electrode CN 501 with

the Reference Electrode R503D

and Ion Pocket Meter 340i

WTW Measurement Systems (Ft.

Myers, FL)

Available 6.2.2 & 9

ScentographTM CMS500 Inficon Available 6.2.3 & 9

ScentographTM CMS200 Inficon Available 6.2.3 & 9
List of Technologies and Techniques

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Company or Developer Technology Status Chapter

August 2005 C-5

CT-1128 Constellation Technology

Corporation with Agilent's

(5973N MSD)

Available 6.2.3 & 9

HAPSITE® Inficon Available 6.2.3 & 9

Field Enzyme Test Severn Trent 6.2.4 & 9

AquanoxTM Randox Laboratories Available 6.2.4 & 9

EcloxTM Severn Trent Available 6.2.4 & 9

Tox Screen Check Light, Ltd Available 6.2.5 & 9

Tox Screen II Check Light, Ltd Available 6.2.5 & 9

ToxTrakTM Hach Company Available 6.2.5 & 9

Bio ToxTM Flash Hidex Oy Available 6.2.5 & 9

PolytoxTM Interlab Supply, Ltd Available 6.2.5 & 9

Microtox® Strategic Diagnostics Inc. Available 6.2.5 & 9

DeltaTox® Strategic Diagnostics Inc. Available 6.2.5 & 9

microMAX-TOX Screen SYSTEM Srl. (Italy) Available 6.2.5 & 9

MosselMonitor® Delta Consult Available 6.2.5 & 9

Bio-Sensor® Biological Monitoring Inc. Available 6.2.5

LuminoTox Lab_Bell inc. Potentially Adaptable 6.3.1

MitoScan Harvard BioScience, Inc Potentially Adaptable 6.3.1

IQ-Toxicity TestTM Aqua Survey Potentially Adaptable 6.3.2 & 9

Daphina Toximeter bbe moldaenke, Germany Potentially Adaptable 6.3.2 & 9

Algae Toximeter bbe moldaenke, Germany Potentially Adaptable 6.3.2 & 9

Fish Toximeter bbe moldaenke, Germany Potentially Adaptable 6.3.2 & 9

Fish and Daphnia Toximeter bbe moldaenke, Germany Potentially Adaptable 6.3.2 & 9

Lumitox® Lumitox Gulf L.C. Potentially Adaptable 6.3.2 & 9

HazMatIDTM SensIR Potentially Adaptable 6.3.3 & 9

X-ray fluorescence ITN Potentially Adaptable 6.3.4

SABRE 4000 Smiths Detection Potentially Adaptable 6.3.5 & 9

HAZMATCADTM Microsensor Systems Inc.

(Bowling Green, KY)

Potentially Adaptable 6.3.7 & 9

Cyranose 320® CyranoTM-Smiths Detection Potentially Adaptable 6.3.8 & 9

NosechipTM CyranoTM-Smiths Detection Potentially Adaptable 6.3.8 & 9

Clam Biomonitoring U. North Texas-EPA Emerging 6.4.1

Transgenic zebrafish Great Lakes WATER Inst. Emerging 6.4.1

Fish Biomonitoring System US Army Center for

Environmental Health Research

Emerging 6.4.1
List of Technologies and Techniques

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Company or Developer Technology Status Chapter

August 2005 C-6

SOS Cytosensor Adlyfe Inc. Emerging 6.4.2

Portable Cell-Based Biosensor Gregory Kovacs at Stanford

University

Emerging 6.4.2

Portable Neuronal

Microelectrode Array

U.S. Naval Research Laboratory Emerging 6.4.2

Dicast® Optical Security Sensing (Optech

Ventures LLC)

Emerging 6.4.3

Fiber optic Great Lakes WATER Inst. Emerging 6.4.3

MicroDMxTM Sionex Emerging 6.4.4

SAW based sensor PNNL Emerging 6.4.5

Micromachined Acoustic

Chemical Sensor

SNL Emerging 6.4.5

Micro-ChemLab CBTM SNL Emerging 6.4.5

S-CAD Science Applications

International Corporation

Emerging 6.4.5

Surface enhanced raman Real-Time Analyzers Emerging 6.4.6

MICROBIAL

Bio-HAZTM EAI Corporation Available 7.2.1 & 9

SMARTTM Tickets New Horizons Diagnostics Available 7.2.1 & 9

Bio Threat Alert (BTA) Tetracore Available 7.2.1 & 9

BADD ADVNT Available 7.2.1 & 9

RAMP Response Biomedical

Corporation

Available 7.2.1 & 9

AMSALiteTM Antimicrobial Specialists and

Associates Inc.

Available 7.2.2 & 9

Continuous Flow ATP Detector BioTrace International Available 7.2.2 & 9

WaterGieneTM Charm Sciences Inc. Available 7.2.2 & 9

ProfileTM -1 (using FiltravetteTM) New Horizons Diagnostic Corp. Available 7.2.2 & 9

Microcyte Aqua® and Microcyte

Field®

BioDetect Available 7.2.3

Micro-Flow Imaging Brightwell Technologies Available 7.2.3

BioSentry LXT/JMAR Potentially Adaptable 7.2.4 & 9

Light scattering technology Rustek Inc. Potentially Adaptable 7.2.4 & 9

RAPTORTM Research International (Naval

RL)

Potentially Adaptable 7.3.1 & 9

xMAP® / Automated Pathogen

Detection System (APDS)

Luminex and LLNL Potentially Adaptable 7.3.2 & 9
List of Technologies and Techniques

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Company or Developer Technology Status Chapter

August 2005 C-7

RapiScreenTM Celsis-Lumac Potentially Adaptable 7.3.3 & 9

BioFlashTM Innovative Biosensors Potentially Adaptable 7.3.4

Smart Cycler® XC System Cepheid Potentially Adaptable 7.3.5 & 9

HANAA Cepheid Potentially Adaptable 7.3.5 & 9

TIGER Ibis Potentially Adaptable 7.3.5 & 9

RAZOR Idaho Technologies Potentially Adaptable 7.3.5 & 9

Ruggedized Advanced Pathogen

Identification Device (RAPID)

Idaho Technologies Potentially Adaptable 7.3.5 & 9

Bio-SeeqTM Smiths Detection Potentially Adaptable 7.3.5 & 9

PathAlertTM Invitrogen Potentially Adaptable 7.3.5

BOSS Georgia Tech Potentially Adaptable 7.3.6

SpreetaTM Nomadics Potentially Adaptable 7.3.7 & 9

M1M BioVeris Potentially Adaptable 7.3.8

Meso Scale cartridge reader Meso Scale Defense Emerging 7.3.8

Quantitative lateral flow assay

(QLFA)

NASA Emerging 7.4.1

QdotTM Quantum Dot Co. /EPA research

project

Emerging 7.4.2

Upconverting Phosphor

TechnologyTM

SRI International-OraSure

Technologies

Emerging 7.4.2

DynaBeads® Dynal Emerging 7.4.3

BEADS PNNL Emerging 7.4.4

Doodlebug Biopraxis Emerging 7.4.5

Sen-Z CombiMatrix Emerging 7.4.6

MAGIChip Argonne/DARPA Emerging 7.4.7

Bead Array Counter BARC Naval Research Lab Emerging 7.4.8

GeneChip Affymetrix Emerging 7.4.9

VeriScanTM 3000 Protiveris Emerging 7.4.10

Bio-AlloyTM IatroQuest Corporation Emerging 7.4.11

“electronic taste chip” University of Austin John T.

McDevitt)

Emerging 7.4.12

Molecularly Imprinted Polymers Emerging 7.4.13

Magnetoelastic Sensors Grimes Group Emerging 7.4.14

RADIOLOGICAL

SSS-33-5FT Technical Associates Available 8.2 & 9

SSS-33DHC Technical Associates Available 8.2 & 9
List of Technologies and Techniques

(continued)

U.S. EPA Office of Water Early Warning Systems

Product Company or Developer Technology Status Chapter

August 2005 C-8

SSS-33DHC-4 Technical Associates Available 8.2 & 9

SSS-33M8 Technical Associates Available 8.2 & 9

MEDA-5T Technical Associates Available 8.2 & 9

3710 RLS Sampler Teldyne Isco Available 8.2 & 9

LEMS-600 Canberra Potentially Adaptable 8.3 & 9

OLM-100 Online Liquid

Monitoring System

Canberra Potentially Adaptable 8.3 & 9

ILM-100 Canberra Potentially Adaptable 8.3 & 9

GammaSharkTM Clarion Systems Emerging 8.4

Online real-time alpha radiation

detection instrument

DOE, now Los Alamos National

Laboratory

Emerging 8.4

Groundwater radiation detector PNNL Emerging 8.4

Thermo Alpha Monitor Thermo Power Corp. Emerging 8.4
U.S. EPA Office of Water Early Warning Systems

August 2005 D-1

APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

Applications of OnlineMonitoring #2516

Will document successful online monitoringoperations as well as problems encountered toidentify operational, maintenance, and calibrationrequirements. Will focus on existing problems whichincludes:• Poor design of sample-handling systems (plugging

of sample lines)

• Uncertainty in results and poorly implemented

quality assurance

• Inappropriate application of the instruments,

resulting in misleading information.

McGuireEnvironmentalConsultants, Inc.Project Manager: RyanUlrich

9 participatingorganizations; seewebsite

8/15/2001To be published in late2004

Design of EarlyWarning andPredictive SourceWater MonitoringSystems #2527

Developed early warning and source watermonitoring systems for real-time contaminantmonitoring. These systems will allow operators topredict water quality events that may tax subsequenttreatment processes. This study showed that anintegrated approach that considers all parts of thewater delivery system should be adopted in designingand operating an early warning system. A generalpurpose, one-dimensional spill model for use in riversthat was developed and applied to the Ohio Rivercould be easily adapted for use in a wide range ofrivers. Additionally, a systematic method fordesigning and operating early warning systems thatconsiders the highly variable, probabilistic nature ofmany aspects of the system was developed anddemonstrated.

Walter GraymanConsulting Engineerand University ofMichiganProject Manager:Albert Ilges

Partner: EPA and 5other participatingorganizations;see website

1/1/2002Published in 2001
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-2

Online Monitoring forDrinking WaterUtilities #2545

AwwwaRF and the Italian research organizationCRS-PROAQUA recognized the drinking waterindustry’s need for a comprehensive resourcecovering online monitoring technology and initiatedthis project to develop such a publication. Providesstate-of-the-science practical, and referenceinformation about physical, inorganic, organic, andprocess online instruments. Also includesinformation on data handling, case studies, andemerging online technologies. Many of the analyticalmethods upon which the identified technologies arebased are included in Standard Methods for theExamination of Water and Wastewater (1998).

Awwa ResearchFoundation and CRSPROAQUA (Italy)

Participants:Azienda MediterraneaGas e Acqua Spa

Published in 2002

Development ofEvent-Based PathogenMonitoring Strategiesfor Watersheds #2671

Will develop and validate a strategy for selection of

sampling locations, frequencies, and methods toaccurately depict pathogen occurrence and variabilityin relation to various sources within watershedsduring and after weather, hydrologic, or land-useevents.

University ofMassachusetts atAmherstProject Manager:Linda Reekie

Partner: EPA andMetropolitan DistrictCommission

38716
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-3

Evaluation of RealTime OnlineMonitoring Method forCryptosporidium#2720

This project was looking to develop a more utilityfriendly real-time continuous online monitoringmethod. The multi-angle light scattering (MALS)technique was found to be useful as an early warningtool for the rapid detection of large scale watercontamination outbreaks since it enabled theestimation of the Cryptosporidium oocyst detection

limit. MALS can also discriminate between differentphysical states of oocysts, including oocysts that weretreated with ozone, heat treated, or excysted from liveuntreated oocysts. The technology tested in thisproject has the potential to provide an impact on thedrinking water industry through distribution systemmonitoring, treatment optimization, end-userprotection and monitoring, and influent monitoringand source water selection.

PointSourceTechnologies, Inc.,AndMetropolitan WaterDistrict of SoutherCalifornia (LA)Project Manager:Misha Hasan

— 12/1/2004

To be published in2004
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-4

Conventional andUnconventionalApproaches to WaterService Provision#2761

While some unconventional options have beenexamined in connection with specific contaminantsand regulations, future regulatory scenarios have notbeen taken into account. Unconventional approachesmay turn out to be more cost effective and feasible inmeeting new stringent standards. This project willcompare conventional and unconventional watertreatment and distribution providing quality water tocustomers, including POU and point-of-entry (POE)devices, small neighborhood systems, and bottledwater. Will include capital costs, operational andmaintenance costs, ability to meet health standards,and aesthetic quality goals. Will also consider risk

associated with the options, long-term reliability ofthe options, and practical engineering considerations.Will assume plausible stringent future regulatoryscenarios and consumer demands for high quality andaesthetically pleasing drinking water. See alsoProject #2924,

Stratus Consulting Inc.Project Manager: IndiaWilliams

Participants:California UrbanWater Agencies

3/15/2004To be published in2005
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-5

Water Utility SelfAssessment for the

Management ofAesthetic Issues #2777

The lack of regulation for aesthetic qualities may bethe reason many utilities are not proactive inroutinely analyzing the taste-and-odor (T&O) of thewater. Although AwwaRF has produced numerousreports on T&O control, much of the knowledgecontained in them has not yet be widely applied, nordoes it provide guidance on communication duringthese events. Self-assessment programs already existin AWWA’s QualServ and the Partnership for SafeWater; however, these programs address only thetreatment component of the utility business. Theseprograms could serve as models for the developmentof a self-assessment program on aesthetic issues.Provides guidance for utility self-assessment in threeareas: identification of potential and real T&Oproblems, management of T&O problems when theyoccur, and communication during T&O events withinthe utility and with the public.

McGuireEnvironmentalConsultants, Inc.Project Manager:Albert Ilges

— 7/31/2003

Includes a CD-ROM.Published in 2004

Innovative Systems forEarly Warning WaterMonitoring #2779

Will develop and evaluate new and innovative

systems to rapidly detect chemicals (individual orclasses), radioactivity, pathogens, or biotoxins inwater in order to help make these systems moreviable for use by the drinking water community.

Kiwa N.V.Project Manager: RyanUlrich

Partner: Kiwa N. V. 9/1/2004

Will be published byKiwa
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-6

Rapid Detection ofBioterrorism Agents inWater Supplies #2852

Will develop and evaluate new and innovativesystems to rapidly detect chemicals (individual orclasses), radioactivity, pathogens, or biotoxins inwater in order to help make these systems moreviable for use by the drinking water community.

University ofCincinnatiProject Manager: RyanUlrich

Partner: EPAParticipants:University ofCincinnati, EPA,Cincinnati WaterWorks

To be completed in2005

Application of DNAMicroarrayTechnology toSimultaneously Detectand Genotype Isolatesof Pathogens in Water#2896

Some of the difficulties in developing a universalmethod include the physical differences betweenpathogen groups, the need to concentrate largevolume water samples to detect low targetconcentrations of certain pathogen groups, the needto remove co-concentrated inhibitors from thesample, and the problem of standardizing a cultureindependent endpoint detection method. This projectwill design a DNA microarray as the endpointdetector that simultaneously targets several wellcharacterized virulence genes such as E. coliO157:H7 and Cryptosporidium parvum.

Battelle PacificNorthwestLaboratoriesProject Manager:Misha Hasan

— To be completed in

2005

Molecular Methods forMicrosporidiaDetection (MMMD)#2901

Will assess the suitability of an automated extractionmethod and real-time PCR assay for the detection ofMicrosporidia in source water. Source waterspecimens will be seeded with Microsporidia spores

to provide test samples with which to characterizeassay performance. The assay will be optimized toprovide the lowest possible detection limit,efficiency, and reproducibility.

Southern ArizonaVeteransAdministration HealthCareandUniversity of ArizonaProject Manager:Alice Fulmer

Participants:SAVAHCS/BRFSAUniversity of ArizonaCH Diagnostics &Consulting ServicesInc.

To be completed in2005
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-7

Extraction Methods forEarly/Real-TimeWarning Systems forBiological Agents A#2908

Will screen three to five different water extractionmethods for biological agent surrogates. This projectwill develop a portable water monitor, preferablyhand-held, that is capable of real-time detection of allharmful substances, while providing no falsepositives.

New Mexico StateUniversityProject Manager:Misha Hasan

Partner: DODParticipants: U.S.Bureau of Reclamation(d5510)

To be completed in2005

Results From theWater UtilityVulnerabilityAssessment LessonsLearned Study #2909

Captures lessons learned and provides a forum forinformation exchange on vulnerability assessment

conducted by large drinking water utilities.

Sandia NationalLaboratoriesProject Manager:Frank Blaha

— 12/1/2003

Report Available

Case Study for aDistribution SystemEmergency ResponseTool #2922

Evaluates the feasibility and applicability of the

PipelineNet, a distribution system modeling toolavailable to water utilities free of charge through

EPA, in different water utility settings for monitoringof distribution systems.

Science ApplicationsInternationalCorporationProject Manager:Frank Blaha

Partners:EPA

5/31/2003Published in 2003;

available only in PDFformat

Security Implicationsof Innovative andUnconventional WaterProvision Options#2924

Provide utilities with a security-oriented evaluation of

water service provision options that they may beconsidering now or in the future. Also helps utilitiesevaluate and plan short-term emergency responseoptions using bottled water, POU, and otherapproaches (see also Project #2761).

Stratus Consulting Inc.Project Manager: IndiaWilliams

4 Participatingorganizations;see website

Completed in 2003Report available
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-8

Disaster Response,Recovery, andBusiness ContinuityPlanning for WaterUtilities #2929

Emergency management planning consists of fourprincipal functions: planning, crisis management,consequence management, and mitigation. Betterpreparation will minimize damage and financial

losses, reduce recovery time, and improve publiccredibility. The ability to respond and recover isgreatly enhanced if a water utility has developed inconjunction with stakeholders a disaster response,recovery, and business continuity plan and conductedroutine training.

Stratus Consulting Inc.Project Manager: IndiaWilliams

Partner: EPAand 21 otherparticipants:see website.

To be completed in2006

Vulnerable Points inWater DistributionSystems #2931

Identifies the vulnerable points in a typicaldistribution system by determining likely points ofintrusion. Also creates reasonable scenarios outliningthe consequences of purposeful contamination to thedrinking water system. Develops recommendationsto reduce the vulnerability of critical elements andsub-elements of the distribution system.

Economic andEngineering Services,Inc.Project Manager:Frank Blaha

Partner: USEPAand 9 otherparticipatingorganizations;see website.

Completion 2005Report available
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-9

Cyber-Security forSCADA Systems#2969

Supervisory control and data acquisition (SCADA)systems are increasingly susceptible to hackerintrusions. The Gas Technology Institute (GTI)recommended in 1999 that the gas industry adopt theDigital Encryption Standard (DES), the Rivest,Shamir, Adelman (RSA) public key algorithm, andthe Diffie-Hillman number generating algorithm as a

suite of algorithms. This cyber-attack protectionincludes preventing assailants from studying thesystem by listening to the communications, fromaltering authorized commands to lead to unauthorizedoperations, and to originate unauthorized commands.It is also possible to prevent a single insider fromperforming an unauthorized operation.

Gas TechnologyInstituteProject Manager:Frank Blaha

Partner: GasTechnology InstituteParticipants:TSWGEPRIGas TechnologyInstituteChicago Departmentof Water Management

To be completed in2005

Extraction Methods forEarly/Real-timeWarning Systems forBiological AgentsB#2985

Will develop a large-volume extraction method for

biological agents that is rapid (< 3 hours) andefficient (60 percent to70 percent recovery) byshortening the extraction step. This project will buildupon research being done by the DOD on the JointService Agent Water Monitor (JSAWM).

Battelle MemorialInstituteProject Manager:Misha Hasan

Partner: CDC-Divisionof Parasitic Diseases

To be completed in2006
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-10

Point-of-Use DrinkingWater Devices forAssessing Extent ofMicrobialContamination inDistribution Systems#2986

This project will determine the feasibility of usingPOU drinking water devices in the event of abioterrorism attack to help identify the contaminant,contaminant dissemination, and the public healthimpacts. POU devices exist that removecontaminants and have their performance certified bycredible testing regimes administered by independentorganizations, but have not been tested and certifiedfor their effectiveness in reducing chemical orbiological sabotage agents. Several studies haveresearched extraction of bacteria from granularactivated carbon cores, and will constitute a starting

point for this project. Some standard methods utilizefiber filters as a means to concentrate microorganisms(e.g., Cryptosporidium) when large water volumes

have to be sampled. The intent of this study is tobetter understand possible patterns of delivery of thecontaminant in the distribution system.

New Mexico StateUniversityProject Manager:Misha Hasan

Partner: CDC/DPD To be completed in

2006

Assessing andImproving WaterQuality SamplingPrograms in DrinkingWater DistributionSystems #3017

The data collected from sampling and monitoringnetworks in distribution systems are often of limiteduse for detecting and diagnosing important changes in

water quality. This project will develop methods and

tools to help utilities scientifically evaluate existingsampling plans and improve them. This project willalso include the development of procedures andalgorithms to address multiple purposes and benefits.

Malcolm Pirnie Inc.Project Manager: MyLinh Nguyen

Partner: EPA To be completed in

2007
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-11

Data Processing andAnalysis for OnlineDistribution SystemMonitoring #3035

Research is needed to explore data-processingmethods that can distinguish normal variability indistribution system conditions from patterns relatedto unacceptable water quality trends or events. This

project will develop a general data processingapproach to assist water quality managers and watersystem operators detect abnormal patterns in onlinemonitoring data.

CSIRO(CommonwealthScientific andIndustrial ResearchOrganisation)Project Manager:My-Linh Nguyen

— To be completed in

2007

Model for Quality ofWater in DistributionSystems #3038

Will develop a system of integrated, hierarchical

models that not only describe the fundamentalprocesses that determine water quality in pipesystems, but also simulate the temporal and spatialbehavior of water quality in the complete network.

UKWIR and UKEngineering andPhysical SciencesResearch Council.Project Manager: JianZhang

— To be completed in

2007
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-12

Security Measures forComputerized andAutomated Systems at(Water) andWastewater Facilities#3045

Will identify, organize, prioritize, and describe the

most probable electronic security threats; risksassociated with the various security weaknesses; theavailable technology that can prevent unauthorizedand willful attacks; secure and stable infrastructureoptions for data communication; the best practices forimplementing each of the available security and datacommunication options; and critical areas ofuncertainty. Will document proven implementations

of the listed technologies at water and wastewaterfacilities. Will also document existingimplementations of data communication and securityoptions, studies demonstrating the feasibility ofoptions not currently in use, and the effectiveness ofeach solution to eliminate the security weaknessesdiscovered.

EMA, Inc.Project Manager: IndiaWilliams

Partner: WaterEnvironment ResearchFoundation (WERF)

To be completed in2006

EmergencyCommunications WithLocal Government andCommunities #3046

Will develop and provide written and oral message

statements that can be used by public agencies (waterand wastewater utilities) and elected officials tocommunicate with the public following disasters, aswell as during disaster warning alerts. Will also

include an action plan for working with the public toincrease public awareness of potential public healthrisks, and appropriate responses.

To be determinedProject Manager:Frank Blaha

Partner: WaterEnvironment ResearchFoudnation

To be completed in2007
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-13

Decision SupportSystem for WaterDistribution SystemSecurity #3086

Will provide a broad and substantial knowledge basefor utilities about the impact of a toxicological attackon a distribution network, and cost-effectiveapproaches for detecting and mitigating such attacks.

Charleston (S.C)Commission of PublicWorksProject Manager:Frank Blaha

Participants:Colorado StateUniversityAdvanced DataMining

To be completed in2007; need specialprotocol for release

Integrated Program forEarly-Warning-SystemSensors forSafeguarding WaterSupply Systems #3093

Will integrate research on sensors and early warningsystems to enhance benefits and cost-effectiveness ofthe research. Will consist initially of nine subordinatestudies:• Online Monitoring Using a UV-Probe• Organic Contaminant Detection Using an Online

HPLC and GC Analysis

• Combined Daphnia and Zebrafish Monitor• Detection of Cholinesterase-Inhibiting

Contaminants

• Feasibility Study on the Use of Chemical-Optical

Sensors for the Detection of OrganicMicro-Pollutants

• Annual Reporting on Developments in the Fields

of Sensors and Detection Techniques DataHandling for Detection Systems Containing Singleor Multiple Sensors, and Procedures for Follow-up

on Alarms

• Strategies for Network Clean-up After

Contamination

• Exploring the Opportunities for Co-funding and

Collaboration in Sensor Development andImplementation

Project manager:Frank Blaha

Partner: KIWA NV -Water Research

To be determined
APPENDIX D

Summary of Early Warning System and Other Applicable Research Projects

Sponsored by American Water Works Association Research Foundation

(continued)

U.S. EPA Office of Water Early Warning Systems

Title Project Description Contractor and

Project Manager

Investigator Date of

Completion

August 2005 D-14

Pilot Study on theIntegration ofCustomer ComplaintData With OnlineWater Quality Data Asan Early WarningSystem #3140 

Will undertake a joint pilot-study project that willintegrate customer complaint and online water qualitydata into an early warning system. Will include 8-10large and medium-sized utilities, covering bothgeographical distribution and source water (surfacewater and groundwater).

Virginia PolytechnicInstitute & StateUniversityProject Manger: IndiaWilliams

Partner: AmericanWater WorksAssociation

To be determined
U.S. EPA Office of Water Early Warning Systems

August 2005 E-1

http://cfpub.epa.gov/safewater/watersecurity/home.cfm?program_id=9 1

http://www.epa.gov/safewater/watersecurity/pubs/action_plan_final.pdf

http://www.whitehouse.gov/news/releases/2004/02/20040203-2.html 2

http://www.whitehouse.gov/homeland/book/ 3

http://www.whitehouse.gov/news/releases/2004/02/20040203-2.html 4

http://www.epa.gov/ordnhsrc/index.htm 5

http://www.epa.gov/etv/ 6

http://www.epa.gov/ordnhsrc/news/news031005.htm 7

http://www.ewrinstitute.org/wisesc.html 8

http://www.epa.gov/safewater/security/index.html 9

http://cfpub.epa.gov/safewater/watersecurity/home.cfm?program_id=8#response_toolbox

http://cfpub.epa.gov/safewater/watersecurity/home.cfm?program_id=9 10

http://www.epa.gov/safewater/watersecurity/pubs/action_plan_final.pdf

http://www.epa.gov/ordnhsrc/pubs/fsTTEP031005.pdf 11

http://www.awwa.org/conferences/congress/ 12

http://www.awwa.org/education/seminars/index.cfm?SemID=47 13

http://www.ewrinstitute.org/wisesc.html 14

http://www.infocastinc.com/tech/rapid.html 15

http://www.who.int/csr/delibepidemics/en/chapter3.pdf 16

http://www.who.int/csr/delibepidemics/biochemguide/en/index.html

http://www.verdeit.com/VPages/SpiralDev.htm 17

http://www.aoac.org 18

http://www.stowa-nn.ihe.nl/Summary.pdf 19

http://www.epa.gov/ORD/NRMRL/wswrd/distrib.htm#Table%202.0%20Proposed%20DSS 20

http://www.hydrarms.com/brochurepdf.pdf 21

http://www.waterindustry.org/Water-Fact/Hach-1.htm 22

http://www.tswg.gov/tswg/news/2004TSWGReviewBookHTML/ip_p18.htm 23

ENDNOTES (including website references)
U.S. EPA Office of Water Early Warning Systems

August 2005 E-2

http://www.nsf.gov/eng/general/sensors/vanbrie.ppt 24

http://www.epa.gov/NHSRC/pubs/fsPureSenseCrada060204.pdf 25

http://www.7t.dk/company/default.asp 26

www.waterisac.org 27

http://www.hach.com 29

http://www.hach.com/hc/search.product.details.invoker/PackagingCode=6950000/NewLinkLabel= 30

Hach+Event+Monitor+Trigger+System/PREVIOUS_BREADCRUMB_ID=HC_SEARCH_

KEYWORD/SESSIONID|Bmd5TURZME56SW1aM1ZsYzNSUFZVOUNWREV4TVE9PUNEazV

Oag==|

http://www.instrument.org/Newsletter%20Articles/Summer%202003/Innovative%20Monitoring.pdf 31

http://www.swig.org.uk/Nick%20Sutherland.pdf

http://www.emersonprocess.com/raihome/liquid/articles/06-14B-2004.asp 32

http://www.emersonprocess.com/raihome/documents/Liq_Brochure_91-6030_200408.pdf

http://www.emersonprocess.com/raihome/liquid/products/Model_1055.asp

http://www.afcintl.com/water3.htm 33

http://www.clarionsensing.com/howitworks.shtml 34

http://www.elscolab.be/e/Stipscan%20iem%202003%20july1.pdf 35

http://www.elscolab.be/e/stipscan.pdf

http://www.stateoftheart.it/STIP-Buoy-SCAN.htm

http://www.baumpub.com/publications/arc/cep_04may/avensys.htm

http://www.epa.gov/watersecurity/guide/chemicalsensortotalorganiccarbonanalyzer.html

EPA Press Release May 19, 2004. 36

http://yosemite.epa.gov/opa/admpress.nsf/b1ab9f485b098972852562e7004dc686/754a0739ba5bc9c9

85256e99005a9f60!OpenDocument

http://www.epa.gov/ORD/NRMRL/wswrd/distrib.htm#Table%202.0%20Proposed%20DSS 37

Phone conversation with Dr. Ryan James, Battelle Laboratory Advance Monitoring Systems, Center 38

Verification Test Coordinator, 19 August 2004; Interviewer - Stanley States

Presentation by K.L. King, Event Monitor for Water Plant or Distribution System Monitoring; Hach 39

Homeland Security Technologies; AWWA Water Security Congress; April 25-27, 2004

http://www.inficonvocmonitoring.com/downloads/pdf/haps-smart.pdf 40

http://www.inficonvocmonitoring.com/downloads/pdf/situprobe.pdf

http://www.inficonvocmonitoring.com/downloads/pdf/Scentograph%20CMS200%20Brochure%20-

%20Screen.pdf

http://www.contech.com/Chemical_Detection_Products.htm 41

http://www.awwa.org/education/seminars/index.cfm?SemID=47 42
U.S. EPA Office of Water Early Warning Systems

August 2005 E-3

http://www.epa.gov/etv/pdfs/vrvs/01_vr_eclox.pdf 43

http://www.quotec.ch/services/qeclox.htm

http://www.wateronline.com/content/Downloads/SoftwareDesc.asp?DocID={13C2390F-C9B1-4362-

A1F0-4C3BDDD04B97}

http://www.randox.com/products.asp 44

http://www.epa.gov/etv/verifications/vcenter1-27.html 45

http://www.checklight.co.il/pdf/manuals/ToxScreen-II%20manual.pdf 46

http://www.epa.gov/etv/pdfs/vrvs/01_vr_toxscreen.pdf 47

http://www.hidex.com/index.php?a=4&b=12&c=12 48

http://www.epa.gov/etv/pdfs/vrvs/01_vr_biotox.pdf 49

http://www.azurenv.com/dtox.htm 50

http://www.epa.gov/etvprgrm/pdfs/vrvs/01_vr_deltatox.pdf 51

http://www.epa.gov/etv/pdfs/vrvs/01_vr_microtox.pdf

http://www.epa.gov/etv/pdfs/vrvs/01_vr_toxtrak.pdf 52

http://polyseed.com/html/polytox.htm 53

http://www.epa.gov/etv/pdfs/vrvs/01_vr_polytox.pdf 54

http://www.mosselmonitor.nl/ 55

http://www.biomon.com/biosenso.html 56

http://www.sparksdesigns.co.uk/biopapers04/papers/bs171.pdf 57

http://abstracts.co.allenpress.com/pweb/pwc2004/document/?ID=42895

http://www.alga.cz/mk/papers/bios_02.pdf

http://www.lab-bell.com/main.jsp?c=/content/gestiondeseaux_en.html&g=left_produits_en.html&l=en

http://www.lab-bell.com/main.jsp?c=/news/new.jsp&n_id=30&l=en

http://www.alga.cz/mk/papers/bios_02.pdf 58

http://www.mitoscan.com/Applications.htm 59

http://www.mitoscan.com/technol.htm

http://www.detect-water-terrorism.com/ 60

http://www.epa.gov/etv/pdfs/vrvs/01_vr_aqua_survey.pdf 61

http://www.bbe-moldaenke.de/ 62

http://www.bbe-moldaenke.de/ 63

http://www.bbe-moldaenke.de/ 64
U.S. EPA Office of Water Early Warning Systems

August 2005 E-4

http://www.lumitox.com/bioassay.html 65

http://www.dewailly.com/LUMITOX/lumitox.html

http://www.bioinfo.com/dinoflag.html

http://www.smithsdetection.com/PressRelease.asp?autonum=25&bhcp=1 66

http://www.sensir.com/newsensir/Brochure/ExtractIR%20Product%20Note.pdf 67

http://www.hazmatid.com/ 68

http://www.itnes.com/ 69

http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/7477/report/0 70

http://www.etgrisorse.com/pubblicazioni/contamination.PDF 71

http://pms.aesaeion.com/ionpro/Products/theory

http://www.chemistry.org/portal/a/c/s/1/feature_ent.html?id=7635201a690a11d7f2a16ed9fe800100 72

http://www.emedicine.com/emerg/topic924.htm#section~ion_mobility_spectroscopy 73

http://www.smithsdetection.com/prodcat.asp?prodarea=Life+sciences&bhcp=1 74

http://www.healthtech.com/2003/mfl/index.asp 75

http://www.memsnet.org/mems/what-is.html 76

http://www.memsnet.org/mems/beginner/ 77

http://www.biochipnet.com/EntranceFrameset.htm 78

http://www.nano.gov/index.html 79

http://www3.sympatico.ca/colin.kydd.campbell/ 80

http://www.sensorsmag.com/articles/1000/68/main.shtml

http://www.microsensorsystems.com/index.html 81

http://www.army-technology.com/contractors/nbc/microsensor_systems/

http://media.msanet.com/NA/USA/PortableInstruments/ToxicGasandOxygenIndicators/Hazmatcad

AndPlus/HazmatcadProductAnnounce.pdf

http://www.raeco.com/products/toxicagents/hazmatcad.pdf#search='HAZMATCAD'

http://hld.sbccom.army.mil/downloads/reports/hazmatcad_detectors_addl_info.pdf 82

http://www.smithsdetection.com/PressRelease.asp?autonum=12&bhcp=1 83

http://www.ias.unt.edu/~jallen/littlemiami/Clam_Page.html 84

http://www.ias.unt.edu/~jallen/clampage.html

http://www.uwm.edu/Dept/GLWI/cws/projects/carvan.html 85

http://usacehr.detrick.army.mil/aeam/Methods/Fish_Bio/ 86
U.S. EPA Office of Water Early Warning Systems

August 2005 E-5

http://www.adlyfe.com/adlyfe/home.html 87

http://www.nrl.navy.mil/content.php?P=04REVIEW118 88

http://www.uwm.edu/Dept/GLWI/cws/ 89

http://www.optech-ventures.com/products.htm 90

http://www.intopsys.com/markets_brochures/Continuous-CableFOCSensor.pdf

http://www.sionex.com/technology/index.htm 91

http://www.saic.com/products/security/pdf/S-CAD.pdf 92

http://www.saic.com/products/security/s-cad/

http://www.sandia.gov/media/acoustic.htm 93

http://www.isa.org/Content/ContentGroups/InTech2/Features/20012/2001_October/Surface_

acoustic_waves_to_the_mission_control/Dangerous_chemicals_in_acoustic_wave_sensorsandNum82

17;_future.htm

http://www.sandia.gov/mstc/technologies/microsensors/flexural.html 94

http://www.sensorsmag.com/articles/1000/68/index.htm 95

http://www.mdl.sandia.gov/mstc/documents/uchembrochure.pdf 96

http://www.ca.sandia.gov/chembio/factsheets/chemlab_chemdetector.pdf

http://www.sandia.gov/water/projects/ChemLab.htm

http://www.sandia.gov/water/FactSheets/WIFS_SensorDevNew.pdf

http://www.ca.sandia.gov/chembio/tech_projects/detection/chemlab_gas.html

http://www.ca.sandia.gov/chembio/tech_projects/detection/chemlab_liquid.html

http://www.mdl.sandia.gov/mstc/technologies/microsensors/chem.html

http://www.oit.doe.gov/sens_cont/pdfs/annual_0602/robinson.pdf

http://www.ca.sandia.gov/chembio/tech_projects/detection/factsheets/chemlab-bio-detector2.pdf

http://www.ca.sandia.gov/chembio/microfluidics/index.html

http://www.ca.sandia.gov/news/2003-news/031110news.html

http://www.ca.sandia.gov/chembio/tech_projects/detection/factsheets/famebrochure.pdf

http://www.nanodetex.com/index.html 97

http://www.ca.sandia.gov/news/2004_news/120704Mercury.html 98

99 http://www.technet.pnl.gov/sensors/chemical/projects/es4cwsen.stm

http://www.technet.pnl.gov/sensors/chemical/projects/es4selct.stm

http://www.technet.pnl.gov/sensors/chemical/projects/ES4SurfWvSnsr.stm

http://availabletechnologies.pnl.gov/chemmaterials/chem.stm

http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/7487/report/0 100

http://www.medical-test.com/product119/product_info.html 101

http://www.pall.com/OEM_4154.asp 102
U.S. EPA Office of Water Early Warning Systems

August 2005 E-6

http://www.idmscorp.com/pregnancytest.html 103

http://www.qdots.com/live/upload_documents/wQDVOct03_pg8-9.pdf

http://www.tetracore.com/products/domestic.html 104

http://www.nhdiag.com/index.htm 105

http://www.eaicorp.com/products_sca_bh.htm 106

http://www.baddbox.com/ 107

http://www.osborn-scientific.com/PDF/Positive_test_for_terror_toxins_in_Iraq.htm 108

http://www.responsebio.com/pdf/summaryanthrax_aug02.pdf 109

http://user.fundy.net/pjwhalen/adenosinetriphosphate.html 110

Biosensors & Food Safety Diagnostics (Paul S. Satoh Neogen Corporation March 1, 2004)

http://www.celsis.com/products/pdfs/cels0150.pdf 111

http://www.amsainc.com/atp.asp 112

http://www.amsainc.com/atp-numbers.asp 113

http://www.charm.com/pdf/400-6505-503-300-01_WaterG.pdf 114

http://www.biotrace.com/content.php?hID=2&nhID=16&pID=16 115

http://www.geneq.com/catalog/en/profile-1.htm 116

http://www.bio.umass.edu/micro/immunology/facs542/facsprin.htm 117

http://pcfcij.dbs.aber.ac.uk/aberinst/mcytmain.html 118

http://www.biodetect.biz/products/mc.shtml

http://www.biodetect.biz/products/MC.pdf

http://www.biodetect.biz/applications/app303.pdf

http://www.brightwelltech.com/pdf_files/Micro-Flow_Imaging.pdf 119

http://www.brightwelltech.com/applications/app_notes/wtp.php

“JMAR Technologies, Inc. Plans Launch of Laser-Based Early-Warning System to Detect 120

Microorganisms in Water Supplies” JMAR Technologies, Inc. Press Release.

http://biz.yahoo.com/bw/040621/215346_1.html;

ETV Technology Profile: On-Line Turbidimeters 121 http://www.epa.gov/etv/pdfs/techprofile/01_turbid.pdf

AwwaRF #2720: Continuous Monitoring Method for Crytpotsporidium (abstract from website) 122

http://www.awwarf.com/research/TopicsAndProjects/projectSnapshot.aspx?pn=2720

http://www.connect.org/members/april.htm 123

http://www.awa.asn.au/news&info/news/26jan03.asp
U.S. EPA Office of Water Early Warning Systems

August 2005 E-7

“JMAR Technologies, Inc. Plans Launch of Laser-Based Early Warning System to Detect 124

Microorganisms in Water Supplies” JMAR Technologies, Inc. Press Release.

http://www.shu.ac.uk/scis/artificial_intelligence/IntelMALLS.html 125

http://www.shu.ac.uk/scis/artificial_intelligence/biospeckle.html 126

http://www.nrl.navy.mil/pressRelease.php?Y=2004&R=26-04r 127

http://www.resrchintl.com/pdf/spie_wqm.pdf

http://www.resrchintl.com/product_bibliography_source.htm

http://www.resrchintl.com/raptor.html

http://www.resrchintl.com/pdf/raptor_2%20.pdf

http://www.luminexcorp.com/01_xMAPTechnology/08_Tutorials/How_xmap_works 128

http://www.luminexcorp.com/01_xMAPTechnology/02_Applications/01_index.html

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_ 129

uids=15228315

http://www.celsis.com/products/pdfs/cels0158.pdf 130

http://www.celsis.com/products/products_dairy.php

http://www.vectech.com/newsletters/2003/November_Newsletter.pdf 131

http://www.innovativebiosensors.com/overview.htm 132

http://www.innovativebiosensors.com/tech.htm

http://www.idahotec.com/rapid/index.html 133

http://www.idahotech.com/pdfs/RAPID_pdfs/ETV%20Report-RAPID-short-release.pdf 134

http://www.idahotech.com/pdfs/RAPID_pdfs/SocietyScopeV6.3.pdf 135

http://www.defenseindustrydaily.com/2005/05/jbaids-a-step-forward-for-bioweapon-detection/index.php 136

http://www.idahotec.com/razor/index.html 137

http://stm2.nrl.navy.mil/~lwhitman/pdfs/nrlrev2001_BARC.pdf

http://www.smithsdetection.com/product.asp?product=Bio%2DSeeq&prodgroup=Bio%2DSeeq& 138

prodcat=Biological+Agent+Detection&prodarea=Trace+detection&division=Detection

http://www.the-scientist.com/asp/Registration/login.asp?redir=http://www.the-scientist.com/yr2003/ 139

may/lcprofile_030505.html

http://www.wrenwray.com/images/pdf/CEPHEIDA.PDF 140

http://news.moneycentral.msn.com/ticker/sigdev.asp?Symbol=CPHD&PageNum=1 141

http://www.chem.agilent.com/Scripts/PCol.asp?lPage=50 142

http://www.securitypronews.com/news/securitynews/spn-45-20050407InvitrogenandAgilent

TechnologiesToCoMarketPathAlertDetectionSystem.html
U.S. EPA Office of Water Early Warning Systems

August 2005 E-8

http://www.ibisrna.com/ 143

http://www.robodesign.com/tiger2.shtml

http://www.micro.uiuc.edu/boss/bossframes.htm 144

http://www.darpa.mil/mto/optocenters/presentations/cheng.pdf#search='Georgia%20Tech%20BOSS

%20sensor%20system'

http://asl.chemistry.gatech.edu/research_ir-sensors-frame.html 145

http://gtresearchnews.gatech.edu/newsrelease/ESMART.html

http://asl.chemistry.gatech.edu/pdf-files/conference%20abstracts/Mizaikoff_SIcon_031301.pdf#

search='evanescent%20field%20sensor'

http://www.cpac.washington.edu/~campbell/projects/spr.html 146

http://www.photonics.com/spectra/features/XQ/ASP/artabid.745/QX/read.htm

http://www.ee.washington.edu/research/denise/www/Lab/files/mike_spr_final.ppt 147

http://www.bitc.unh.edu/annual.reports/2004BITCfactsheet.pdf 148

http://www.aigproducts.com/surface_plasmon_resonance/spr_considering.htm 149

http://www.aigproducts.com/surface_plasmon_resonance/spr_evaluation_module.htm

http://www.nomadics.com/products/spr3/

http://www.aigproducts.com/surface_plasmon_resonance/spr.htm 150

http://www.stanford.edu/~bohuang/Research/Anal%20Chem%202002.pdf 151

http://www.bioveris.com/technology.htm 152

http://www.mesoscaledefense.com/technology/ecl/diagram.htm

http://www.mesoscaledefense.com/technology/ecl/walkthrough.htm

http://www.sbs-archi.org/02pres/Umek.pdf

http://www.bioveris.com/products_services/life_sciences/instrumentation/m1manalyzer.htm 153

http://www.biospace.com/news_story.cfm?StoryID=17104620&full=1 154

http://us.diagnostics.roche.com/press_room/2003/072403.htm

http://www.mesoscaledefense.com/coming_soon.htm 155

http://spaceresearch.nasa.gov/general_info/homeplanet.html 156

http://www.qdots.com/live/upload_documents/wQDVOct03_pg8-9.pdf 157

http://www.qdots.com/live/render/content.asp?id=47 158

http://www.qdots.com/live/render/content.asp?id=87 159

http://www.bio-itworld.com/archive/021804/horizons_dot.html
U.S. EPA Office of Water Early Warning Systems

August 2005 E-9

http://www.sciencenews.org/articles/20030215/bob10.asp 160

http://www.sciencedaily.com/releases/2002/11/021127071742.htm

http://www.eurekalert.org/pub_releases/2004-06/uosc-qds061404.php

http://www.smalltimes.com/document_display.cfm?document_id=3811

http://www.llnl.gov/str/Lee.html

http://www.epa.gov/OGWDW/methods/current.html 161

http://www.bravurafilms.com/projects/projectrep/phosphors.html 162

http://www.orasure.com/products/default.asp?cid=10&subx=4&sec=3

http://www.sri.com/news/releases/02-17-98.html

http://www.sri.com/rd/chembio.html

http://www.orasure.com/products/prodsubarea.asp?cid=1&pid=126&sec=3&subsec=4 163

http://www.sri.com/rd/chembio.html 164

http://www.nanobioconvergence.org/speakers.aspx?ID=33 165

http://www.orasure.com/products/prodsubarea.asp?cid=2&pid=126&sec=3&subsec=4

http://www.dynal.net/ 166

http://www.technet.pnl.gov/sensors/biological/projects/ES4BEADS-Sys.stm 167

http://www.pnl.gov/breakthroughs/win-spr02/special3.html#biothreat

http://www.chem.vt.edu/chem-ed/spec/vib/raman.html 168

http://en.wikipedia.org/wiki/Raman_spectroscopy

http://www.iwaponline.com/wio/2003/04/wio200304WF00HHE8UR.htm 169

http://www.deltanu.com/companyinfo.htm 170

http://www.chemimage.com/products/

http://www.combimatrix.com/news_NBCKing5Aug04.htm 171

http://www.combimatrix.com/products_biothreat.htm

http://www.promega.com/geneticidproc/ussymp11proc/content/llewellyn.pdf 172

http://www.eurekalert.org/features/doe/2003-11/dnl-lft031804.php

http://www.foresight.org/conferences/MNT8/Abstracts/Colton/ 173

http://stm2.nrl.navy.mil/~lwhitman/pdfs/nrlrev2001_BARC.pdf

http://stm2.nrl.navy.mil/~lwhitman/pdfs/Rife_Sensors_Actuators_A_published.pdf 174

http://www.gwu.edu/~physics/colloq/miller.htm 175

http://www.affymetrix.com/technology/manufacturing/index.affx 176

http://www.dsls.usra.edu/meetings/bio2003/pdf/Biosensors/2149Stahl.pdf 177

http://www.sciencemag.org/feature/e-market/benchtop/biochips3_10_18_02.shl 178
U.S. EPA Office of Water Early Warning Systems

August 2005 E-10

http://www.protiveris.com/new/products_folder/veriscansystem.html 179

http://www.buscom.com/nanobio2003/session3c.html

http://pharmalicensing.com/news/headlines/1070473459_3fce20f35628c 180

http://www.memsnet.org/mems/what-is.html 181

http://www.iatroquest.com/En.htm 182

http://www.iatroquest.net/Linked%20Docs/IatroQuest%20Corporation%20Fact%20Sheet%2004

0217-1334.pdf

http://www.cm.utexas.edu/mcdevitt/ET_Broch.pdf 183

http://www.cm.utexas.edu/mcdevitt/tastechip.htm

http://www.silsoe.cranfield.ac.uk/staff/apturner.htm 184

http://www.cranfield.ac.uk/ibst/ccst/mips/sensors.htm

http://www.scs.uiuc.edu/suslick/pdf/pressclippings/naturebiotech.0902-884.pdf 185

http://www.tekes.fi/ohjelmat/diagnostiikka/diag_esitykset/turner.pdf 186

http://www.ee.psu.edu/grimes/sensors/ 187

http://www.isco.com/WebProductFiles/Product_Literature/201/Specialty_Samplers?3710RLS_ 188

Radionuclide_Sampler.PDF

http://www.epa.gov/watersecurity/guide/radiationdetectionequipmentformonitoringwaterassets.html 189

U.S. EPA, Radiation Detection Equipment for Monitoring Water Assets, Water and Wastewater Security

Product Guide

http://www.tech-associates.com/dept/sales/product-info/sss-33-5ft.html 190

Drinking Water Rad-Safety Monitor Model #SSS-33-5FT. Updated 1/31/2002.

http://www.tech-associates.com/dept/sales/product-info/meda-5t.html 191

Updated in 2002.

http://www.isco.com/WebProductFiles/Product_Literature/201/Specialty_Samplers?3710RLS_ 192

Radionuclide_Sampler.PDF

http://www.tech-associates.com/dept/sales/product-info/sss-33dhc.html 193

http://www.tech-associates.com/dept/sales/product-info/sss-33m8.html 194

http://www.canberra.com/products/802.asp 195

http://www.canberra.com/products/803.asp 196

http://www.canberra.com/products/801.asp 197

http://www.clarionsensing.com/home.shtml 198

http://apps.em.doe.gov/ost/pubs/itsrs/itsr312.pdf 199
U.S. EPA Office of Water Early Warning Systems

August 2005 E-11

http://www.cpeo.org/techtree/ttdescript/alpharad.htm Last updated 10/2002. 200

http://www.technet.pnl.gov/sensors/nuclear/projects/ES4Tc-99.stm 201

http://www.epa.gov/watersecurity/guide/radiationdetectionequipmentformonitoringwaterassets.html 202

http://www-emtd.lanl.gov/TD/WasteCharacterization/LiquidAlphaMonitor.html 203

http://www.cfsan.fda.gov/~dms/fssupd72.html#grants 204

205 http://www.johnmorris.com.au/html/Mantech/titrasip.htm

http://www.hach.com/hc/search.product.details.invoker/PackagingCode=6950000/NewLinkLabel= 206

Hach+Event+Monitor+Trigger+System/PREVIOUS_BREADCRUMB_ID=HC_SEARCH_

KEYWORD/SESSIONID|B3hNRFkwTlRRNE56RTROekVtWjNWbGMzUk5Sdz09QWxKYVZ6RQ==|

FBI/CDC June 2002 Evaluation of Hand-Held Immunoassays for Bacillus anthracis and Yersinia pestis 207

http://www.isco.com/WebProductFiles/Product_Literature/201/Specialty_Samplers/3710RLS_Radio 208

nuclide_Sampler.PDF

http://www.dhs.gov/dhspublic/theme_home1.jsp 209

http://www.dhs.gov/dhspublic/display?theme=36 210

http://www.globalsecurity.org/security/library/policy/national/hspd-9.htm 211

http://www.epa.gov/etv/homeland/ 212

http://www.dhs.gov/dhspublic/display?theme=38&content=4014&print=true 213

http://www.fcw.com/fcw/articles/2004/0419/web-scada-04-19-04.asp

http://www.dhs.gov/dhspublic/interapp/editorial/editorial_0359.xml

http://www.fas.org/man/dod-101/army/docs/astmp98/sec3k.htm 214

http://www.dtic.mil/whs/directives/corres/pdf2/d200012p.pdf 215

http://www.defenselink.mil/news/Sep2004/n09032004_2004090304.html 216

http://www.darpa.mil/index.html 217

http://www.darpa.mil/dso/thrust/biosci/biostech.htm 218

http://www.darpa.mil/dso/thrust/biosci/biosensor/enabtech.html 219

http://www.darpa.mil/mto/People/PMs/carrano_dtec.html

http://www.darpa.mil/dso/thrust/biosci/biostech.htm

http://www.darpa.mil/dso/thrust/biosci/biosensor/enabtech.html

http://www.darpa.mil/dso/thrust/biosci/biosensor/auburn_d.html

http://www.darpa.mil/dso/thrust/biosci/biosensor/auburn_i.html

http://www.darpa.mil/dso/thrust/biosci/biosensor/sandia.html

http://www.darpa.mil/dso/thrust/biosci/biosensor/rush_med.html

http://www.darpa.mil/dso/thrust/biosci/biosensor/argonne.html
U.S. EPA Office of Water Early Warning Systems

August 2005 E-12

http://www.darpa.mil/body/procurements/old_procurements/jan2000/mtojan00.html

220 http://www.nrl.navy.mil/content.php?P=ABOUTNRL

http://pubs.rsc.org/ej/CC/2000/b003185m.pdf 221

http://www.nrl.navy.mil/content.php?P=04REVIEW115 222

http://www3.interscience.wiley.com/cgi-bin/abstract/107061018/ABSTRACT 223

http://www.nrl.navy.mil/pao/pressRelease.php?Y=1996&R=26-96r 224

http://www.foresight.org/conferences/MNT8/Abstracts/Colton/ 225

http://stm2.nrl.navy.mil/~lwhitman/pdfs/nrlrev2001_BARC.pdf

http://stm2.nrl.navy.mil/~lwhitman/pdfs/Rife_Sensors_Actuators_A_published.pdf 226

http://stm2.nrl.navy.mil/~lwhitman/pdfs/nrlrev2001_BARC.pdf 227

http://www.globalsecurity.org/wmd/facility/edgewood.htm 228

229 http://www.epa.gov/ordnhsrc/

http://water.usgs.gov/wicp/acwi/monitoring/conference/2004/conference_agenda_links/power_points 230

_etc/06_ConcurrentSessionD/90_Rm15_Vowinkel.pdf

http://www.ilsi.org/publications/pubslist.cfm?pubentityid=13&publicationid=268 231

http://water.usgs.gov/wicp/acwi/monitoring/conference/2004/conference_web_agenda.html 232

http://water.usgs.gov/ogw/karst/kig2002/msf_development.html 233

http://www.mdl.sandia.gov/mstc/technologies/microsensors/techinfo.html 234

http://www.sandia.gov/sensor/noframes.htm

http://www.ca.sandia.gov/chembio/news_center/ST2002v4no3.pdf

http://www.ca.sandia.gov/news/2004_news/120704Mercury.html 235

http://www.llnl.gov/llnl/001index/02about-index.html 236

http://www.llnl.gov/sensor_technology/SensorTech_contents.html 237

http://www.ornl.gov/ornlhome/about.shtml 238

http://www.ornl.gov/ornlhome/about.shtml 239

http://www.ornl.gov/info/ornlreview/rev29_3/text/biosens.htm 240

http://www.o rnl.gov/sci/engineering_science_technology/sms/Hardy%20Fact%20Sheets/ 241

Countermeasures.pdf

http://pharmalicensing.com/news/headlines/1070473459_3fce20f35628c 242
U.S. EPA Office of Water Early Warning Systems

August 2005 E-13

http://www.ornl.gov/sci/biosensors/ 243

http://www.ornl.gov/adm/tted/LifeSciencesTechnologies/LifeSciencesTechnologyList.htm

http://www.pnl.gov/main/welcome/ 244

http://www.pnl.gov/main/sectors/nsd/%20homeland.pdf 245

http://www.technet.pnl.gov/sensors/ 246

http://www.pnl.gov/main/sectors/nsd/%20homeland.pdf 247

http://www.inl.gov/index.shtml 248

http://www.amsa-cleanwater.org/meetings/04winter/ppt/ppt/30%20--%20FRI%20-%20Reinhardt, 249

%20Glen/AMSA%20-%20Security%20Panel%20Discussion%20-%20GR.pps

http://www7.nationalacademies.org/wstb/index.html 250

http://www4.nationalacademies.org/webcr.nsf/CommitteeDisplay/WSTB-U-04-06-A?OpenDocument 251

http://www4.nas.edu/webcr.nsf/5c50571a75df494485256a95007a091e/5d3beab7fa3bb8bc85256d0b 252

00705acf?OpenDocument

http://www.awwarf.org/theFoundation/ 253

WERF's website: 254 www.werf.org

http://cimic.rutgers.edu/epa-workshop.html 255

http://www.knowledgepress.com/ 256

http://www.knowledgepress.com/events/7011409_p.pdf 257

http://www.healthtech.com/2003/btr/ 258

http://www.knowledgepress.com/events/12111105_p.pdf 259

http://www.wtec.org/biosensing/proceedings/ 260

http://www.knowledgepress.com/events/7191716_p.pdf 261

http://cimic.rutgers.edu/epa-workshop.html 262

http://cimic.rutgers.edu/workshop2.html

http://www.healthtech.com/2002/bms/abstracts/symposium3.htm 263

http://www.knowledgepress.com/events/11071420_p.pdf 264
United States

Environmental Protection

Agency

Office of Research and Development

National Homeland Security Research Center

Cincinnati, OH 45268

Official Business

Penalty for Private Use

$300

EPA/600/R-05/156

December 2005

PRESORTED STANDARD

POSTAGE & FEES PAID

EPA

PERMIT NO. G-35