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WASTEWATER AUTOMATION – THE DEVELOPMENT OF A

LOW COST DISTRIBUTED AUTOMATION SYSTEM

A Dissertation

Presented to

The Engineering Institute of Technology

by

Tom Davies

In Partial Fulfillment

of the Requirements for the Degree

Master of Engineering in

INDUSTRIAL AUTOMATION

APRIL 2017

COPYRIGHT © 2017 BY TOM DAVIES

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TABLE OF CONTENTS

List of Tables ................................................................................................................. 7

List of Figures ................................................................................................................ 8

Abstract ........................................................................................................................ 10

Chapter 1. Introduction ................................................................................................ 17

1.1 The Problem Statement ................................................................................... 17

Chapter 2. Background ................................................................................................ 19

2.1 Moora Waste Water Scheme Overview .......................................................... 19

2.1.1 Catchment Areas ...................................................................................... 22

2.1.2 Pump Stations .......................................................................................... 22

2.1.3 Pump Station Components ....................................................................... 24

2.1.3.1 Switchboard ................................................................................ 24

2.1.3.2 Programmable Logic Controller ................................................. 25

2.1.3.3 Alarm Dialler .............................................................................. 25

2.1.4 Wastewater Treatment Plant (WWTP) .................................................... 26

2.2 Scheme Geography ......................................................................................... 26

2.2.1 Topology .................................................................................................. 27

2.2.2 Topography .............................................................................................. 31

Chapter 3. TheProblem ................................................................................................ 35

3.1 The Existing Problem ..................................................................................... 35

3.2 Problem Frequency and Cost .......................................................................... 36

3.2.1 Pump Station 3 Data ................................................................................ 37

3.3 Legislation....................................................................................................... 39

3.3.1 Regulatory Bodies .................................................................................... 39

3.3.1.1 Economic Regulation Authority (ERA) ..................................... 39

3.3.1.2 Department of Water (DoW) ...................................................... 39

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3.3.1.3 Department of Health (DoH) ...................................................... 39

3.3.1.4 Department of Environmental Regulations (DER) ..................... 39

3.3.2 Prosecutions & Penalties.......................................................................... 40

3.3.3 Sewage Incidents ..................................................................................... 41

Chapter 4. Method ...................................................................................................... 42

4.1 Relevant Scholarship ...................................................................................... 43

4.2 Requirements .................................................................................................. 43

4.2.1 Alarms Proposed ...................................................................................... 43

4.2.2 Parameters ................................................................................................ 44

4.2.3 Pump current ............................................................................................ 44

4.2.4 Constraints / Factors ................................................................................ 44

4.2.5 In-house Installation Considerations........................................................ 44

4.3 Objectives ....................................................................................................... 45

4.3.1 Benefit to public ....................................................................................... 45

4.3.2 Cost savings ............................................................................................. 45

4.3.3 Staff Knowledge ...................................................................................... 45

4.4 Comparison of Possible Solutions .................................................................. 45

4.4.1 Possible Vendors / Suppliers ................................................................... 46

4.4.1.1 External Engineering Contractors ............................................... 46

4.4.1.2 Internet of Things........................................................................ 47

4.4.1.3 ZigBee Mesh Network ................................................................ 48

4.4.1.4 Schneider .................................................................................... 49

4.4.1.5 Automation IT Oleumtech .......................................................... 50

4.4.1.6 Automation IT – ZigBee + 3G Modems ..................................... 51

4.4.1.7 Automation IT – ZigBee RTUs .................................................. 52

4.4.1.8 Auto Control Systems – Burkert ................................................. 52

4.4.1.9 NHP – Ewon ............................................................................... 53

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4.4.2 Quantitative Comparison ......................................................................... 54

4.4.3 Outcome of Comparison .......................................................................... 58

Chapter 5. ZigBee- Critical Analysis ........................................................................... 59

5.1 The ZigBee Standard ...................................................................................... 59

5.1.1 ZigBee Wireless Network ........................................................................ 60

5.1.1.1 Power Consumption & Data Rate ............................................... 63

5.1.1.2 Factors Degrading RSSI ............................................................. 64

5.1.2 Fresnel Zone............................................................................................. 64

5.1.3 Preliminary ZigBee Security Risk Assessment ....................................... 65

5.1.3.1 Wastewater Security ................................................................... 67

5.1.3.2 Network Security Risk Analysis ................................................. 68

5.1.3.3 Attack Types ............................................................................... 70

5.1.3.4 Results ......................................................................................... 72

5.1.3.5 Conclusion .................................................................................. 74

5.2 Site Surveys .................................................................................................... 75

5.2.1 Signal Strength ........................................................................................ 75

5.2.1.1 Signal Strength Survey Configuration ........................................ 75

5.2.1.2 Site Survey Results ..................................................................... 77

5.2.1.3 Site Survey Conclusion ............................................................... 78

5.2.2 Security Survey ........................................................................................ 78

5.3 Component Configuration .............................................................................. 80

5.3.1 Component List ........................................................................................ 81

5.3.1.1 Central Station Components ....................................................... 81

5.3.1.2 Pump Station Component List .................................................... 81

5.3.2 Component Descriptions .......................................................................... 82

5.3.2.1 Network Controller ..................................................................... 82

5.3.2.2 Modbus Gateway ........................................................................ 83

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5.3.2.3 Remote End Units ...................................................................... 83

5.3.2.4 Antennas ..................................................................................... 83

5.3.2.5 Current Transformers .................................................................. 84

5.3.2.6 Ultrasonic Level Transducers ..................................................... 84

Chapter 6. Results ........................................................................................................ 85

6.1 Results Analysis Approach ............................................................................. 85

6.2 Summarised Results ........................................................................................ 85

6.3 Quantitative Results ........................................................................................ 90

6.3.1 Communications ...................................................................................... 90

6.3.3.1 Initial setup – low profile switchboard antennas ........................ 90

6.3.3.2 Antenna Modifications ............................................................... 91

6.3.2 Uptime...................................................................................................... 92

6.3.2.1 Weather ....................................................................................... 92

6.3.2.2 Power Loss .................................................................................. 92

6.3.3 User interaction ........................................................................................ 93

6.3.3.1 Device Configuration .................................................................. 93

6.3.3.2 Wiring & Cabling ....................................................................... 93

6.3.4 GUI Setup ................................................................................................ 94

6.3.5 Calibration................................................................................................ 94

6.3.6 Cost .......................................................................................................... 94

6.3.6.1 Network Components ................................................................. 95

6.3.6.2 Transducers ................................................................................. 95

6.3.6.3 Antennas ..................................................................................... 96

6.3.6.4 Extras .......................................................................................... 96

6.3.6.5 Subscription ................................................................................ 96

6.3.7 Effectiveness ............................................................................................ 96

6.3.7.1 Monitoring .................................................................................. 97

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6.3.7.2 Pump Operation .......................................................................... 99

6.3.7.3 Impact on Response .................................................................. 100

6.3.7.4 Callout Savings ......................................................................... 101

6.3.7.5 Event Mitigation ....................................................................... 102

6.3.7.6 Alarms ....................................................................................... 102

Chapter 7. Further Work ............................................................................................ 103

7.1 Network Expansion ....................................................................................... 103

7.2 Scripting ........................................................................................................ 104

7.2.1 Gradients and flow rate .......................................................................... 104

7.2.2 Pump Current Data ................................................................................ 105

7.3 Other ............................................................................................................. 106

Chapter 8. Conclusion ................................................................................................ 107

Acknowledgments...................................................................................................... 109

References ......................................................................................................... 110

List of Appendices ..................................................................................................... 114

Appendix A. Water Corporation and Shire data 2012-2014 ................................. 115

Appendix B. Customer Complaints and Blockages - Shire of Moora Sewerage

Scheme ...................................................................................................... 116

Appendix C. Sewage Spills and Incidents ............................................................. 117

Appendix D. ZigSense Reference Projects ............................................................ 120

Appendix E. Topographical data between network nodes .................................... 120

Appendix F. Pump Station 1-7 Summary Statistics from archive data ................. 122

Appendix G. Sample archive data Pump Stations 1, 3 & 4 – Water level, pump

current & pump duty (in colour) ............................................................... 123

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LIST OF TABLES

Table 1 Catchment Area and Pump Station ................................................................. 21

Table 2 Distances between Central Station (C) and each Pump Station ..................... 27

Table 3 ‘Closer’ paths using a mesh network topology ............................................... 29

Table 4 Optimum distances between nodes ................................................................. 31

Table 5 Optimum distances between nodes and corresponding topographical

figure .................................................................................................................... 32

Table 6 Coordinates and Elevation in Pump Stations and the Central Station ............ 33

Table 7 Pump Station 3 alarm log for year 2014–2015 ............................................... 38

Table 8 Quantitative comparison of researched solutions ........................................... 54

Table 9 Meaning of factor scale 1–10 .......................................................................... 55

Table 10 IEEE 802.15.4 characteristics ....................................................................... 62

Table 11 Determining risk severity.............................................................................. 69

Table 12 Summary of Preliminary Security Analysis ................................................. 72

Table 13 Interpretation of Range Tester output ........................................................... 76

Table 14 Site RF Survey results - Range Tester output ............................................... 76

Table 15 Pump Station 7 to 4 & 2 RF Survey results - Range Tester output .............. 78

Table 16 Results Analysis Criteria. ............................................................................. 86

Table 17 Communications reliability to Central Station with low profile antennas.... 91

Table 18 Extract of archived log data with notes excluding alarms ............................ 98

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LIST OF FIGURES

Figure 1 Shire of Moora Aerial .................................................................................... 19

Figure 2 Scheme Process ............................................................................................. 20

Figure 3 Catchment Areas ........................................................................................... 22

Figure 4 Basic Pump Station Schematic ...................................................................... 23

Figure 5 Pump Station ................................................................................................. 23

Figure 6 Switchboard Electrical Components and PLC .............................................. 25

Figure 7 WWTP Aerial & Sample Locations .............................................................. 26

Figure 8 Positions of each Pump Station and the Central Station ............................... 28

Figure 9 Possible paths using a mesh network topology ............................................. 29

Figure 10 Optimum paths between nodes .................................................................... 30

Figure 11 Elevation Profile between PS1 and PS3 ...................................................... 33

Figure 12 System Configuration .................................................................................. 59

Figure 13 ZigBee Mesh Network and device types ..................................................... 60

Figure 14 Mesh network as applies to Moora Pump Stations ..................................... 61

Figure 15 ZigBee Device Construction ....................................................................... 62

Figure 16 Power consumption and data rate comparison between different wireless

technologies ......................................................................................................... 63

Figure 17 Fresnel Zone calculation using excel spreadsheet ....................................... 65

Figure 18 How ZigBee integrates security with IEEE 802.15.4.................................. 67

Figure 19 Range testing results .................................................................................... 77

Figure 20 Wireshark program displaying ZigBee network data packets ..................... 79

Figure 21 Wireshark data output.................................................................................. 79

Figure 22 Vendor recommended network configuration ............................................. 81

Figure 23 Network controller & cloud application GUI .............................................. 82

Figure 24 Gateway Controller and software interface ................................................. 83

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Figure 25 GUI with labels for Pump Station 3 ZigSense monitoring system ............. 97

Figure 26 Typical life cycle costs for pumps in a municipal environment ................ 100

Figure 27 The detection of a ragged pump at Pump Station 3 ................................... 101

Figure 28 Example of observed current and water level data in the ZigSense

desktop GUI ....................................................................................................... 106

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ABSTRACT

Wastewater treatment is essential infrastructure. In order to ensure public

health is not compromised by means of human contact with sewage-borne pathogens,

this is a licensed and regulated industry within Australia. The governing bodies have

and do prosecute for breaches in the required standards. Wastewater treatment can

vary from large, complex systems servicing the needs of large conurbations to small

regional installations with the associated differences in budgets. A regional

wastewater treatment system was analysed and though functional, there was scope for

improvement. For example, though alarms triggered, the source of the problem was

not identifiable. Rather than solve individual problems an alternative, cost effective

upgrade was identified to be the optimum solution. Without any restrictions a wide

range of different solutions were analysis and evaluated. Factors considered included:

cost, security, ease of use etc. A ZigBee based system ranked the highest in addition

to which the data rates and functionality of this standard were deemed best suited to

simple, low-volume data transmissions. Furthermore the data packets are encrypted

thereby providing some cyber-security. The system was installed and tested and either

met or exceeded all requirements. In effect, it proved to be a simple, cost effective

solution ideally suited to small, regional installations.

The work in this thesis has been published through the process of full paper,

blind peer review as follows: Modern Applied Science; Vol. 11, No. 6; 2017, Pages

29 to 34, Wastewater Automation – The Development of a Low Cost, Distributed

Automation System. Authors: Tom Davies, Stanislaw Paul Maj.

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Keywords: regional, wastewater, sewerage, automation, shire, local

government

I would like to express my gratitude to the Shire of Moora for the financial

backing of the project and training, EIT (Engineering Institute of Technology) for

creating a very positive, supportive and professional academic environment, and

especially to Associate Professor Dr S. P. Maj (Paul) for giving help and support

exactly where and when it was needed.

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CHAPTER 1. INTRODUCTION

Water Corporation handed over management of the Moora town site

wastewater scheme to the Shire of Moora. The Shire hired staff, organised training,

allocated a budget and took over managing the treatment lagoons, sewerage piping,

pump stations, customer service, legislative reporting and automation systems.

1.1 The Problem Statement

The Shire of Moora took control of the Moora town site wastewater scheme

from the Water Corporation at the end of 2013. The handover from Water

Corporation to the Shire was relatively brief and due to security and/or privacy

policies not all information and software was received by the Shire.

In particular, SCADA software was not received leaving the Shire with

outdated dialling alarms that could only be reprogrammed to Shire staff phone

numbers. If an alarm went off, no status information was conveyed to the staff, only

where the call was coming from.

This system did not meet the needs of successfully managing and operating a

wastewater scheme. An alternative, cost effective solution is sought - ideally one that

utilizes the staff involved rather than external engineering contractors. We propose to

search for a solution that is both suitable and cost effective.

As the need for automated monitoring and control increases and the income

from small municipal wastewater remain limited, there exists a need for an

automation system that is reliable, robust, customizable and cost effective.

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This study looks at the viability of such a system and continues toward

implementation and successful commissioning. A description of the scheme follows

to better outline the problem. The problem is detailed in Section 3. The Problem.

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CHAPTER 2. BACKGROUND

2.1 Moora Waste Water Scheme Overview

To understand the importance and context of the problem the scope of the

wastewater scheme must be briefly looked at in figure 1. Figure 1 shows the

Wastewater Treatment Plant and Reuse Scheme in white, The Pump Stations (1-7) in

green and the sewerage gravity fed network (sewer piping) in red.

Figure 1 Shire of Moora Aerial.

The Shire of Moora maintains a wastewater scheme having:

537 connected services – 105 of which are classified as commercial /

industrial

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Serves a population of approximately 1500

100,000m3 inflow wastewater per year to the Wastewater Treatment Plant

(WWTP)

Recycles 40,000m3 per year to town site parks and gardens (Reuse Scheme)

Figure 2 Scheme Process.

Figure 2 shows the overall sewerage scheme flow process. The wastewater is

collected in the catchment areas via piping. It then flows to the catchment areas

respective pump station, shown in table 1. From there it flows to the WWTP through

four lagoons, to a Reuse Scheme with one lagoon where it is disinfected, then finally

it waters parks and ovals.

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Table 1 Catchment Area and Pump Station.

Catchment Area Pump Station

A 1

B 2

C 3

D 4

E 5

F 6

G 7

The Scheme consists of:

17km of piping with cut-ins for each connection

216 access chambers

7 Catchment areas

7 Pump Stations

WWTP (4 lagoons)

Reuse scheme (1 lagoon, chlorine disinfection system)

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2.1.1 Catchment Areas

Figure 3 Catchment Areas.

Figure 3 illustrates how the catchment areas are related and in what order they

flow. The piping in red belongs to a particular Catchment Area and therefore flows to

a particular Pump Station as described in table 1. The pump station pumps the water

through the network as above and finally from Catchment Area A (Pump Station 1) to

the WWTP (Waste Water Treatment Plant).

2.1.2 Pump Stations

Pump stations are 5-7m deep. The wet well (Figure 4 & 5 Left) contains two

pumps (alternating duty and standby), four floats and other various items. The

switchboard (Figure 4 & 5 right) contains electrical components, a PLC and an alarm

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dialler. There is one phone connection for each pump station (7 phone lines) that

connects directly to the alarm dialler. The Pump Stations raise the water to the

required level for the next process. Moora is very flat, hence the need for seven pump

stations. The Pump Stations are identical for the purposes of this study.

Figure 4 Basic Pump Station Schematic.

Figure 5 Pump Station (left: wet well inside, right: surface surrounds).

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2.1.3 Pump Station Components

The system being looked at is control of water levels and pump function at the

pump station wet wells. Each Pump Station has one wet well approximately 3m

diameter and 6m deep. Two pumps are located around 10 -15 cm from the well

bottom and are lowered and raised via rails. In the old system, mercury switch floats

provide the PLC and alarm dialler with water level heights. These have been budgeted

to be upgraded to ultrasonic transducers. The PLC operates the automated functioning

of the pumps. The alarm dialler connects to a phone line and makes a call when the

alarm inputs are triggered. Each pump station has a near identical configuration

conforming to the Water Corporation standards when they were installed. This

includes components within the switchboard and wet well e.g. seven PLCs are all the

same model.

The main components are (also in figure 4):

Switchboard & electrical components

Floats (low, medium, high, extra high) & pumps – in wet well

PLC controlling 2 pumps (PLC in switchboard, pumps in wet well)

Dialler with 3 Digital Inputs (alarms that were previously interpreted by Water

Corporation software)

2.1.3.1 Switchboard

The switchboard contains electrical components, alarm dialler and PLC.

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Figure 6 Switchboard Electrical Components and PLC.

The plan has components inserted that make up the manual and automated

control of the pumps (figure 6). All seven Pump Stations have the same configuration

as in figure 6. They transport waste water from the catchment Areas to the WWTP

lagoons.

Refer to table 1 to see which Catchment Area feeds to which Pump Station.

Refer to figure 3 to see where each Pump Station pumps.

Refer to figure 1 to see the location of each Pump Station.

2.1.3.2 Programmable Logic Controller

The model is a Koyo Direct Logic 205 with software making viewing, editing

and backing up of the ladder logic program possible.

2.1.3.3 Alarm Dialler

Each of these units has its own dedicated phone line. This hardware is

outdated (pre 2000) has 3 inputs: Extra high water level, power loss and pump fail.

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Before the Shire took control of the Scheme, Water Corporation (located offsite in

Geraldton) received a readout showing which alarms were triggered with their Citect

software. This software was not provided to the Shire during the handover.

2.1.4 Wastewater Treatment Plant (WWTP)

The water runs through four lagoons in series. Figure 7 shows the sampling

points for each lagoon. The primary is seen top right in figure 7 (sample 1), then the

Secondary (sample 2), third and fourth. Various treatment processes are in play,

though the lagoons can be categorized as ‘Facultative’ lagoons – allowing both

anaerobic and aerobic processes to occur. Sampling is carried out to comply with

legislative requirements. Automation is proposed for the pump stations only, not the

WWTP systems.

Figure 7 WWTP Aerial & Sample Locations.

2.2 Scheme Geography

The layout between Pump Stations and the Central Station was studied in

order to determine if there were any major obstacles that would impact the project,

and what types of technologies could possibly be employed. This section relates to

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distances, elevations, obstacles in the wireless network context. If mobile carriers,

landlines or cabled internet were to be used, no physical constraints prevent these

from being employed (except for costs).

2.2.1 Topology

A preliminary study shows the positions of the Pump Stations and Central

Station with relation to each other. ‘Topology’ has been used to term the ‘network’

relationship, ‘topography’ more terrain and elevation.

Table 2 Distances between Central Station (C) and each Pump Station.

Path Distance (m)

C-PS1 585

C-PS2 571

C-PS3 214

C-PS4 375

C-PS5 337

C-PS6 650

C-PS7 852

The distances between the Central Station and each Pump Station are shown

in table 2. In table 2, green indicates a distance that is already the shortest possible

path (in a mesh network scenario).

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Figure 8 Positions of each Pump Station and the Central Station.

When using a mesh network, the REUs can use each other as a relay to pass

the signal on. Taking this into account, the distances not highlighted in Table 2 can be

reduced by relaying off another Pump Station between it and the Central Station. All

possible paths are illustrated in figure 9. The path distances are listed in table 4.

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Figure 9 Possible paths using a mesh network topology.

Table 3 ‘Closer’ paths using a mesh network topology.

Closer Paths Distance (m)

PS1-PS2 525

PS1-PS3 414

PS2-PS4 334

PS6-PS3 558

PS7-PS4 482

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Figure 10 Optimum paths between nodes.

Figure 10 shows the closest or optimum distances between Pump Stations and

the Central Station. The Pump Stations will contain Remote End Units and the

Central Station will contain the Gateway and Cloud Controllers. Therefore, each

Pump Station must communicate with the Central Station.

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Table 4 Optimum distances between nodes.

Best Paths Distance (m) Rank

PS1-PS3 414 5

PS2-PS4 334 2

PS3-C 214 1

PS4-C 375 4

PS5-C 337 3

PS6-PS3 558 7

PS7-PS4 482 6

The optimum paths using a mesh network topology shown in figure 11 has

distances tabulated in table 4. The greatest distance is between PS6 and PS3 (558m).

Not using a mesh network the greatest distance would have been between PS7 and

Central (852m) – table 2.

2.2.2 Topography

Topographical features are of concern for radio communications and are

factored into Fresnel Zone calculations when trying to establish required antenna

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characteristics and mast heights. Moora town site is particularly flat with a node

elevation range of about 5m. Figures 12 and Appendix E show the elevation profile

for each of the optimum paths between Pump Stations and the Central Station. These

paths are listed in tables 4 & 5.

Table 5 Optimum distances between nodes and corresponding topographical

figure.

Best Paths Distance (m) Figure

PS1-PS3 414 9

PS2-PS4 334 Appendix E

PS3-C 214 Appendix E





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Figure 11 Elevation Profile between PS1 and PS3.

A preliminary study shows the distances and elevations between the Central

Station and the Seven Pump Stations. The Coordinates and elevations are given in

table 6. AHD stands for Australian Height Datum.

Table 6 Coordinates and Elevation in Pump Stations and the Central Station.

Latitude Longitude

Elevation

AHD

Central 30°38'29.85"S 116° 0'27.26"E 209

PS1 30°38'40.23"S 116° 0'9.48"E 206

PS2 30°38'23.42"S 116° 0'7.23"E 210

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PS3 30°38'36.31"S 116° 0'24.42"E 209

PS4 30°38'19.94"S 116° 0'19.21"E 209

PS5 30°38'23.59"S 116° 0'37.64"E 211

PS6 30°38'46.90"S 116° 0'41.55"E 210

PS7 30°38'8.30"S 116° 0'7.38"E 208

Figure 9 shows the positions on a satellite image of each Pump Station relative

to the Central Station. Further elevation profiles between nodes are compiled in

Appendix E. Due to the flatness and lack of notable topographical features around the

whole town site; it is assumed that distance will be the greatest factor when

determining signal strength and communication ability.

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CHAPTER 3. THE PROBLEM

The problem, its cost and relevant legislation are covered in this section.

3.1 The Existing Problem

The hardware was reprogrammed to call Shire mobile numbers when an alarm

was triggered. No information was sent – only the origin phone number – making the

alarm impossible to prioritize.

The Shire purchased Honeywell numerical key panels but that only served to

program the alarm dialler. The alarm dialler is an Ademco Advantage Series built in

the 1990s and was designed to send different analogue tone patterns for each alarm

triggered. These ‘obsolete’ analogue protocols are not interpreted by the Shire. The

Shire has gone as far as to reprogram the Sewerage Staff mobile numbers into the

alarm diallers – this allows notification of ‘an’ alarm from a specific Pump Station

location (the Pump Station ID could be programmed into a mobile phone as a caller

ID). However, when the call is received, only a garbled analogue tone is received –

similar to that of a fax machine or phone modem. Therefore, no further information

about which alarm was triggered is provided.

In the previous system three possible states could trigger the alarm:

Power Loss,

Extra High Float,

Pump Fault

If one of the above were triggered, a call was made to a staff member’s mobile

phone. The staff would see the call came from, for example, Pump Station 3 but no

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further information was available. A staff member then had to go out on-site and to

determine which of the alarms had gone off. After either resolving the problem or

determining that there was no problem, the issue had to be recorded and logged. The

reason for this situation was the fact that the Shire inherited equipment (but no

software) from the Water Corporation during the handover of the Sewerage Scheme

in the end of 2013.

The problems:

no information is sent– it is not known what triggered the alarm - no

immediate planning possible. This has cost implications as staff are sent on

call outs possibly unnecessarily.

no trending is possible – no information means no trending is possible apart

from number of alarms - level height and pump current is needed. The lack of

trending prevents proper asset management of pump system occurring, also

having cost implications.

Seven phone lines are being utilised (approx. $350 / month) – this could

potentially be improved. In fact, the only trending possible is that manually collected

by a technician on a bi-weekly basis (level height and pump current). Although

effective and useful, this also has manpower cost. Additionally, the system does not

allow for pumps running dry (if the low float fails). The pump could run dry for days

without setting an alarm.

3.2 Problem Frequency and Cost

The existing problem is the limited functionality of the installed SCADA

system – primarily being the lack of information available during an alarm

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notification. This lack of information doesn’t allow for adequate interpretation,

assessment and prioritization of the alarm event. This in itself leads to a non-optimal

use of staff budget as callouts occur when they are not necessary.

In the financial year 2014 – 2015, at all seven pump stations,110 alarm events

occurred; only 34 had to be acted upon, of these, only 5 had to be acted immediately.

This equates to 110 alarms being potential breaches of governmental

requirements. If correct information was presented, only 5 had to be responded to. In

monetary terms, a savings of callout wages in the order of $3675 could have been

saved (105 events X $35/hr).

3.2.1 Pump Station 3 Data

For 2014-2015, Pump Station 3 had 31 alarms which are itemised in table 7.

Information from table 7 combined with dates of each alarm constitutes the extent of

the monitoring and logging available with the old system.

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Table 7 Pump Station 3 alarm log for year 2014-2015.

Alarm Status shown on panel

Times called

Reason recorded after callout

Power Loss 19 6 X POWER LOSS - were due to loss of power – Electric Utility works

13 X were due to fluctuations (faults, electrical storms etc.)

Extra High Float

4 2 X required attention

2 X were due to incorrect float heights

Pump Fault 8 5 X required a pump to be pulled up and de-ragged

3 X Actual fault not found

Total 31 Staff received 31 identical alarms

Out of the 31 alarms shown coloured in table 7;

2 had to be responded to within 10 hours (red)

5 had to be responded to within 4 days (orange)

8 had to be monitored (yellow)

16 required no action or monitoring (green)

A potential improvement of reducing the number callouts to 23% (7 callouts /

31 alarms) will also have a potential corresponding financial benefit.

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3.3 Legislation

3.3.1 Regulatory Bodies

Within Australia, Wastewater is regulated by state governmental bodies and

guidelines are issued nationally.

Aspects of the scheme must be reported to the state authorizing bodies:

3.3.1.1 Economic Regulation Authority (ERA)

Asset Management System and Policies audit. They will place fines of up to

$100,000 if it appears that the assets are not being managed properly according to 3rd

party audit. They also monitor customer complaints and number of blockages.

3.3.1.2 Department of Water (DoW)

oversees all matters water related. A license is required from the DoW to

operate as a Sewerage Scheme Operator.

3.3.1.3 Department of Health (DoH)

health issues especially pathogens coming into contact with public. The DoH

monitors the recycled water pathogen level on a monthly basis. Any deviation results

in the scheme being closed. They can conduct investigations of issues that are health

related and can shut down the scheme or faulty parts thereof if considered unsafe for

the public. A license is required from the DoH to operate the Reuse Scheme.

3.3.1.4 Department of Environmental Regulations (DER)

Cover spills, overflows and odours affecting the environment. They can also

conduct an audit, investigation of incident and can hand out penalties and fines. A

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license is required from the DER to operate the WWTP. They can limit quantities and

types of waste water accepted by the scheme. The DER monitors spills and the

quarterly wastewater quality sampling. Breaches can result in license suspension /

loss.

Breach of any of these authority’s regulations will have a significant financial

impact on any Shire. The audits are expensive and costs are born by the Shire. The

system in place steers Local Government management toward a proactive, not

reactive, approach to Wastewater Scheme management. The most thorough authority

would be the ERA. They will conduct an audit, create to list of items to be completed,

follow up, and clear the items or issues fines and penalties.

The DER and DoH can simply close the scheme leaving the Shire to dispose

of its wastewater to a WWTP belonging to another Shire. The logistics and costs

simply rule this option out – disposal of one truck in another WWTP costs approx.

$500 and over 50 trucks would be needed each day. The only sensible solution is

compliance.

3.3.2 Prosecutions & Penalties

The DER has a Summary of Prosecutions found at [15] listing offences and

penalties charged over the last several years. The ERA has a listing of Wastewater

license holders and the status of each license and whether penalties have been charged

[16]. The DoW has an information page on Compliance and Enforcement for license

holders [17]. Worksafe WA are the responsible body for regulating onsite safety

conditions, tickets and permits. Summaries of successful prosecutions can be found at

[18]. The Health Department maintain an online ‘convictions register’ [19]

publicising offenders details and business premises.

36

3.3.3 Sewage Incidents

According to [14], ‘Sewage spills can have extreme consequences releasing

pathogens into natural water bodies, swimming areas and sometimes even

contaminating drinking water’. Sewage spills receive a lot of public attention and

invite heavy criticism for the parties’ responsible and authorising bodies.

Some illnesses caused by sewage spills may include [14]:

gastroenteritis (diarrhoea, vomiting)

viral infections such as hepatitis

infections of the skin or eyes.

Sewage incidents can happen for various reasons, but the risk of occurrences

can be minimised by good asset management practises and monitoring systems.

Therefore, the need for an effective automation system customised for the particular

plant must be realistically cost effective and obtainable for smaller regional

communities. The results can range from closure of public areas to multiple deaths

and destruction of communities. Appendix C contains a summarised list of sewage

related incidents.

37

CHAPTER 4. METHOD

In this section, a literature search is covered. Requirements and objectives

along with the primary problem contain the content which will make up the

assessment criteria when results are analysed in section 6. A quantitative vendor

comparison is carried out.

4.1 Relevant Scholarship

The proposal is to search for a cost effective and reliable solution based on

research of existing solutions and custom made possibilities. Studies have been made

on the implementation of automation in wastewater schemes [1], [5]. Also, some

accepted solutions have been developed for urban WWTPs [1], [4], [6], [7] and

smaller scale plants [3]. These studies looked at well-known automation brands and

the implementation of a more expensive installation by engineering staff. They also

dealt mostly with automation within a WWTP.

The implementation of customized low-cost yet reliable automation in a

municipal wastewater scheme managed and installed by specialised staff hasn’t been

so thoroughly documented. The literature search did not reveal a wastewater scheme

implementing:

1. a low-cost reliable, non-specialist installation and

2. the usage of a wireless radio based network in a rural wastewater environment.

In this way, the study has some originality. It is also a situation applicable to

many regional Local Government Shires. The historical data used for the study is

from the Shire of Moora (2013 – present) and Water Corporation alarms and costings

38

(2012-2013) – Appendix A. Various standards and communications have been

considered such as the Ethernet, Modbus protocols, ZigBee radio and internet of

things (IoT) [8], [9], [10], [11] and [12]. It is even possible to keep the current phone

lines in place – but due to running costs and other communication methods (e.g.

ZigBEE [11]), it doesn’t seem likely as a cost effective solution.

UnityWater have procured the services of IT Automation Pty. Ltd. [13] using

Schneider components to implement a similar project. IT Automation Pty. Ltd. are

familiar with working with Government installations but are relatively expensive - the Shire

will look toward carrying out its own installation to keep costs minimal.

4.2 Requirements

The goal of successfully installing and implementing a reliable solution that

meets the needs of the scheme at a reasonable cost is primary. Preferably, an in-house

installation will be carried out to further minimise costs and increase staff

participation and integration.

The following needs have been identified:

4.2.1 Alarms Proposed

Pump fail (existing)

Pump 1 fault

Pump 2 fault

Extra High Water level (existing)

Abnormal current

Power loss (existing)

39

4.2.2 Parameters

The following parameters are to be monitored:

Extra High Water level

4.2.3 Pump current

System operational / non-operational

Trending both pump current and water level would be beneficial

4.2.4 Constraints / Factors

Only a low bit rate is necessary

It is not time critical

Cost is a major factor

Friendly setup and GUI suitable for non-specialised staff

Modular installation and commission – so thorough testing one by one is

possible

4.2.5 In-house Installation Considerations

Project management plan including budgeting

Individual Pump Station requirements

Configuration of remote units

Network configuration

Testing and commissioning

Drawings and documentation

40

4.3 Objectives

Objectives include:

4.3.1 Benefit to public

decreasing the number of related incidents and events before and during the

study

faster response to catchment area blockages due to monitoring of pump

operating hours

4.3.2 Cost savings

calculating the cost benefit of being proactive thanks to the trending data

pump stoppages minimized by monitoring pump current and performance

overtime saved on prioritizing and monitoring the alarms remotely

alarms can immediately be prioritized and planned for

studying the savings of not having to manually collect data

4.3.3 Staff Knowledge

Increased understanding of the scheme – due to information being available

continuously rather than only from inspection, a better understanding of

scheme characteristics will follow.

4.4 Comparison of Possible Solutions

The following is a comparison between different vendors and their solutions.

This section is not just a comparison between competing vendors offering similar

41

products. Diversity is important to remain open to different solution designs as the

best solution to fit the task is being sought, not necessarily the most usual or expected.

The vendors were approached by contacting the most local ones first (Perth,

WA) then proceeding to the vendors based in the other States in Australia. It is a

policy of local government to attempt to use local available business when possible.

No international companies were contacted though some of the local vendors were

agents for products.

4.4.1 Possible Vendors / Suppliers

Nine products are examined with the headings; description, cost, advantages

and disadvantages

4.4.1.1 External Engineering Contractors (Kapp Engineering Pty Ltd) [20]

Description

Modbus system to connect to existing PLC and radio modems at each station,

connected to a central station with SCADA software.

Cost

$50,000+ similarly quoted by KAPP Engineering and other Perth Engineering

companies specializing in this work. The cost of travel for Engineering staff keep the

project cost quite high.

Advantages

Professionally certified work

Sophisticated, secure and many features

42

Disadvantages

Customization can be costly

Ongoing service and maintenance expensive

Expensive

4.4.1.2 Internet of Things Kit (Texas Instruments) [21], [22]

Description

Kit solution configured to match the needs of the scheme. Seven units

deployed at each pump station with appropriate transducers.

Cost

$15,000.

Advantages

Cheap

Information and components readily available

Customizable

Once installed modular and replaceable

Website available – cloud monitoring

Disadvantages

Requires a ‘kit professional’ to successfully install and configure

43

Items are not reliable for wastewater purpose – not fit for purpose

Requires onsite internet connections

Limited trending

This installation may show negligence in a government context – not fit for

purpose

4.4.1.3 ZigBee Mesh Network [23], [24]

Description

Customized ZigBee wireless mesh network

Cost

$19,000.

Advantages

Full in-house installation possible

Inputs are customisable suited to the schemes process and operability

Reliable and fit for this purpose

Communication antennas and other features can be tweaked until staff are

satisfied

Most repairs done in-house

Cheap

44


Customizable

Once installed modular and replaceable

Mesh network requires smaller, cheaper antennas than other topologies

Disadvantages

Security, sophistication – not required as control not necessary – only

monitoring

4.4.1.4 Schneider [40]

Description

ScadaPack RTUs, Trio radio units and central HMI unit

Cost

$29,505.

Advantages

Not designed for in-house install


Possibly the most reliable and fit for this purpose


Customizable

45

Company with the most comprehensive track record

Disadvantages

Price

External install adds on $36,000

4.4.1.5 Automation IT Oleumtech [40]

Description

Oleumtech RTUs, radio units and central HMI unit – cheaper alternative to

Schneider

Cost

$15,744

Advantages

Price

Not designed for in-house install


Quite reliable and fit for this purpose


Customizable

46

Disadvantages

Price


4.4.1.6 Automation IT – ZigBee + 3G Modems [40]

Description

Zigbee RTUs, 3G modems when necessary to assist communications

Cost

$11,950 + $2,000/yr

Advantages

In-house install possible



Customizable

Disadvantages

Ongoing costs

No track record


47

4.4.1.7 Automation IT – ZigBee RTUs [40]

Description

Chinese imported ZigBee RTUs plus central unit

Cost

Cheaper than 4.4.1.6

Advantages

Price?

Unknown product – no track record


Not known whether it is reliable and fit for this purpose

Disadvantages

Unknown product – no track record

Not known whether it is reliable and fit for this purpose


4.4.1.8 Auto Control Systems – Burkert [41]

Description

Burkert MXConnect and uMesh

48

Cost

$16,950

Advantages




Customizable

Price reasonable

Disadvantages

No track record with wastewater

4.4.1.9 NHP – Ewon [42]

Description

Ewon Flexy Routers and modems

Cost

$10,500 + $2,000/yr

Advantages



49


Customizable

Disadvantages

Ongoing costs

No track record

GUI

4.4.2 Quantitative Comparison

Table 8 shows a comparison of possible solutions. The measures chosen were

eight factors that were deemed important by the Shire. The scale is 1 -10 giving a

minimum score of 8 and a maximum of 90. The factors and their scale rationale are

explained in table 9.

Table 8 Quantitative comparison of researched solutions.

Score out of 90

Per

th

Eng.

com

pan

y

(Kap

p

Engin

eeri

ng)

Inte

rnet

of

Thin

gs

(Tex

as

Inst

rum

ents

)

Zig

Bee

Zig

Sen

se

Dig

imes

h

net

work

Sch

nei

der

Sca

daP

ack

&

Tri

o

Auto

mat

ion I

T

Ole

um

tech

A

uto

mat

ion I

T

Zig

Bee

+ 3

G

Auto

mat

ion I

T

Zig

Bee

RT

U

Auto

Contr

ol

Syst

ems

Burk

et

NH

P

Fle

xy

Reliable & reputable

10 4 8 10 8 8 5 8 6

Cost 3 10 10 2 7 8 9 8 7

Staff setup difficulty

5 7 9 6 6 6 6 8 7

Local supplier

10 10 10 10 9 9 5 8 8

GUI suitability

10 6 9 10 7 6 6 6 6

Features 10 6 8 10 8 7 5 6 6

Support 10 8 10 10 7 6 4 6 5

50

Security 9 4 6 10 8 6 4 6 6

Operating & servicing costs

3 7 8 4 7 5 8 8 6

Total 70 62 78 72 67 61 52 64 57

Rank 3 6 1 2 4 7 9 5 8

Table 9 Meaning of factor scale 1–10.

Factors Scale 1-10 Meaning

Reliable & reputable 10 great track record and reputation.

5 Average track record and reputation

1 no known information.

Cost - 10 within budget for the complete product e.g.

$25,000

5 Over budget 50%

1 completely inappropriate price range e.g.

$100,000

Staff setup difficulty 10 external engineer / specialized contractor

required

51

5 Complex installation

1 simple setup by untrained staff

Local supplier 10 WA based company / agent

5 Australian / NZ company / agent

1 Overseas company / agent

GUI suitability 10 Clear GUI displaying desired trends with

history and logging

5 Basic symbols

1 Just numbers / raw data

Features 10 Many features to select from

5 Some features

1 No extra features

Support 10 Easy, free information and help

5 Cumbersome, paid support

52

1 No support

Security 10 Many high quality security features

5 Option of some security features

1 Limited or no security

Operating & servicing

costs

10 Cost free connectivity and minimal servicing

5 Some paid components

1 Paid connection at every site and expensive

servicing

The factors selected for the comparison were those deemed to be significantly

valuable to the Shire.

Reliable & reputable: local government does not typically take business risks

with unknown entities.

Cost: everything is decided upon with budget in mind.

Setup: The ability to setup gives enhanced understanding, training and cost

effectiveness to the project.

Local: There is an obligation to use local vendors whenever possible.

GUI: Must be for layman.

53

Features: Can be useful for clarity and future development.

Support: Support is required as a means of keeping the system online must be

maintained.

Security: It is a public utility and therefore could become a target.

Operating costs: A cheap product with high running costs is not viable long

term.

4.4.3 Outcome of Comparison

According to the comparison outlined in table 8, the optimal choice is the

ZigBee based network. ZigSense is the vendor - some of their projects using this

product can be found in Appendix D. It scored 8-10 for all factors except security

(where it scored a 6). Security is a significant issue for public utilities and must be

addressed. Therefore, a preliminary risk assessment has been carried out in Section

5.1.3 ZigBee Security Risk Assessment.

The most reputable and well known vendors supply a product solution not

economically suitable for the Shire – they ranked second and third with cost factors of

two and three respectively. Therefore, the most well priced, reliable, robust solution is

the ZigBee based network. The cloud based GUI is sufficient for Shire needs and does

not require training to be used.

54

CHAPTER 5. ZIGBEE – CRITICAL ANALYSIS

The proposed system was installed in a modular fashion, one by one. The

system is comprised of two Remote End Units, one Antenna, one Current transformer

and one Level Transducer at each Pump Station, and the Central Station has a

network controller, gateway and antenna.

The system is configured as in figure 12.

Figure 12 System Configuration.

5.1 The ZigBee Standard

In 2003 the IEEE 802.15.4 standard was ratified [12]. According to the author

[12], this standard represented a significant break from the “bigger and faster”

55

standards that the IEEE 802 organization continues to develop [12]: “instead of higher

data rates and more functionality, this standard was to address the simple, low-data

volume universe of control and sensor networks, which existed without global

standardization through a miasma of proprietary methods and protocols.” [12]. The

lack of a standard approach was a major impediment to mass manufacturing of

inexpensive silicon radios that could drive down the cost of these devices [12].

5.1.1 ZigBee Wireless Network

Peer-to-peer networking allows each device to communicate directly with

each other. A mesh network may be used if configured by the higher layer entity.

ZigBee networking is natively mesh-based.

Figure 13 indicates routes that requires other radios to “relay” the information

[12].

Figure 13 ZigBee Mesh Network and Device Types [12].

56

The IEEE 802.15.4 standard defines device types as in figure 13.

Figure 14 Mesh network as applies to Moora Pump Stations.

Each ZigBee mesh network node can relay data for the neighbouring nodes

within their transmit range as well providing a self-healing function by re-routing

with other contacted nodes [43]. This also serves to improve energy efficiency.

Figure 14 shows the depiction of a mesh network for the Shire of Moora

Central Stations and Pump Stations. The modulation mode used by 802.15.4 is phase-

shift-key based. It was selected due to its ability to be restored even in low signal to

interference environments [12]. The ZigBee standard employs several frequencies and

they have been designed for minimal interference with other well-known networks

such as WIFI. Three frequencies that are provided by the vendor are shown in table

10.

57

Table 10 IEEE 802.15.4 characteristics [32].

Frequency Range urban

Range outdoors

Tx power Data rate Rx Sensitivity

2.4GHz 100m 2km 63mW 256Kbps – 102dBm

900MHz 600m 14km 250mW 10K / 200Kbps

– 101dBm / – 110dBm

868MHz 600m 14km 250mW 10K / 200Kbps

– 101dBm / – 110dBm

This application will use the 900MHz as longer distances are required with a

low data rate (table 10). The range is sufficient as are the data rate and power

requirements. The relationship between 802.15.4 ZigBee products and the OSI

network model layer is shown in figure 15.

Figure 15 ZigBee Device Construction [12].

58

The emergence of ZigBee as a standard for accepted low-power, low

maintenance, smart devices are summarised in the following extract [44]: “The

wireless technologies are becoming an important asset in the smart grid, particularly

the ZigBee devices. These smart devices are gaining increased acceptance, not only

for building and home automation, but also for energy management, efficiency

optimization and metering services, being able to operate for long periods of time

without maintenance needs. “

5.1.1.1 Power Consumption & Data Rate

ZigBee is a technology that is often employed for its low power consumption

making it suitable for remote sites [47]. Figure 16 shows the power consumption and

data rate comparison between different wireless technologies.

Figure 16 Power consumption and data rate comparison between different

wireless technologies [47].

59

5.1.1.2 Factors Degrading RSSI

Factors that degrade and impact the Received Signal Strength Indicator (RSSI)

values in ZigBee wireless networks [48]:

Reflections on metallic objects

Superposition of electro-magnetic fields

Diffraction at edges

Refraction by media with different propagation velocity

Polarisation of electro-magnetic fields

Unadapted MAC protocols

The Shire of Moora has a mobile cellular network tower located at the centre

of town – which is somewhat central to the Pump Stations. There are also a number of

five metre high tin workshops.

5.1.2 Fresnel Zone

A Fresnel zone calculation from [36] was carried out using mast heights of 6m

(Central Station) and 2.4m (Switchboard height). This simulates the communication

path between the Central Station and a Pump Station. The frequency used was 900

MHz and link to link distance was 500m. The results are shown in figure 17.

60

Figure 17 Fresnel Zone calculation using excel spreadsheet from [36].

The closer obstacles are to the line of sight between two antennas, the more

interference will be experienced due to reflections of the original signal out of its

phase angle. In figure 17, it can be seen that there may be some phase shifting of

signals at the set parameters. It is not yet clear whether this makes this antenna

configuration viable or not. It is not a perfect Fresnel zone, that is, clear, and obstacles

such as buildings have not been taken into account. It is a useful tool for determining

how close an obstacle can occur to a link – The 6m antenna can shoot over close

obstacles 1 or 2m high. It is a preliminary study that is followed by a signal strength

survey (Section 5.2.1) conducted at the appropriate frequency on-site.

5.1.3 Preliminary ZigBee Security Risk Assessment

As discussed, a security assessment looking at ZigBee’s vulnerabilities has

been carried to determine overall suitability for public utilities. Examples of industrial

control systems being vulnerable and victims of cyber-attacks as extracted from [45]:

61

March 2007, Idaho National Laboratory conducted an experiment in which

physical damage was caused to a diesel generator through the exploitation of a

security flaw in its control system.

During the Russian- Georgian war in 2008, cyber-attacks brought down the

Georgian electric grid during the Russian army’s advance through the country.

In April 2009, the Wall Street Journal reported that cyber spies had penetrated

the U.S. electrical grid and left behind software programs that could be used to disrupt

the system.

In 2010, Stuxnet, a large complex piece of malware with many different

components and functionalities, targeted Siemens industrial control systems and

exploited four zero-day vulnerabilities running Windows operating systems. As a

result, 60 percent of Iranian nuclear infrastructure was targeted.

These example were based around electrical supply grids, however the

importance of other utilities such as water and wastewater also make them a potential

target for widespread public disruption and attention.

62

Figure 18 How ZigBee integrates security with IEEE 802.15.4 [49].

ZigBee has its own security features such as 128-bit Advanced Encryption

Standard cryptography and trust centred authentication layered on top of the IEEE

802.15.4 standard having physical and media access control layers as shown in figure

18 [49].

5.1.3.1 Wastewater Security

Industrial network security is a major issue as productivity and profitability

can be compromised. Classified information and compliance can also become

expensive issues when ‘secure’ operations are infiltrated. For the Shire’s application,

security is not as a critical issue as it could be if control was used. Only monitoring is

used and the outputs on the Network Controller and the Remote Units are not

connected. Each of the Pump Stations exist within the Moora town site and this is

63

where the majority of employees also reside. Therefore, after diagnosing a problem

online, a staff member can be sent on site to make a change.

The other issue was that functions such as emergency pump downs are used. If

communication was somehow lost after initiating an emergency pump down online, it

would pump out all of the water and continue to run, heating up the pumps which can

cause damage.

The 802.15.4 does have encryption inbuilt [11] According to the 802.15.4

standard (7.2), “A device may optionally implement security” [11]. This is done by

setting the attribute macSecurityEnabled. Further research must be done to determine

what setting has been implemented. To this end, the Shire has purchased a wireless

interface that can read all transmission sent via 802.15.4. It is called Open Sniffer [31]

and works with the well-known network sniffing software ‘Wireshark’ [33].

5.1.3.2 Network Security Risk Analysis

The risk of an intruder having an impact on the wastewater services is looked

at. In particular, the effect of the introduction of a wireless ZigBee network to monitor

the scheme is analysed. The main defence against all wireless attacks or disturbances

in this situation is the fact that the network is used only for monitor and alarm

purposes, not for control. Therefore, security is much less an issue than it would be if

control (e.g. switching on/off of pumps) was employed.

In one security based study [37], the author looks at techniques for launching a

variety of security attacks on an 802.15.4/ZigBee wireless network [37]. Specifically,

the link layer was attacked using jamming techniques to intercept and corrupt traffic.

64

The following extract illustrates the type of damage that insecure utilities can sustain

when control is executed remotely [38]:

“During March and April 2000, Vitek Boden made 46 attempts using wireless

connections to hack into Maroochy Shire Council's computerised waste management

system. He had lost his job in developing the wireless network that controlled the

sewage and drinking water system. During the attack his laptop identified itself as

Pumping Station 4 and sent commands leading to the release of millions of litres of

raw sewage into rivers and parks, with considerable environmental costs. In October

2001, Boden was found guilty on various charges involving computer hacking, theft

and causing environmental damage, and sentenced to two years imprisonment. On

appeal, convictions on two of the charges were set aside but the sentence was left

unchanged: R v Boden [2002] QCA 164 (10 May 2002). A subsequent special leave

application to the High Court of Australia was dismissed on 25 June 2003.”

A preliminary security risk analysis of the ‘read-only’ wireless 802.15.4

network has been conducted using the factors shown in table 9.

Table 11 Determining risk severity [39].

65

5.1.3.3 Attack Types

The author analysed typical attacks and looked at possible attacks in the Shires

‘read only’ system:

A. Falsifying a network address – hacking in and pretending to be node in the

network.

1) Creating false alarms

False alarms could potentially be created from any node address. This

would be costly as staff would have to go onsite to verify situation. It

would require an individual with the correct transmission equipment and

an understanding of how ZigBee Packets are structured. It would also

require knowledge of what registers belong to what alarms – this would be

more difficult to acquire.

Likelihood: Low

Impact: High

Risk Severity: MEDIUM

2) Corrupting data

Changing packet data would require an understanding of dissecting

ZigBee packets. In many cases the data would be rejected.

Likelihood: Low

Impact: Medium

Risk Severity: LOW

66

3) Giving false readings

Creation of false readings would require an understanding of packet

structure plus the meaning of data in each register. The impact would be

limited by alarm event triggering.

Likelihood: Low

Impact: Medium

Risk Severity: LOW

4) Masking real alarms

Masking real alarms would require an understanding of packet structure

plus the meaning of data in each register.

Likelihood: Low

Impact: High


B. Recording and storing data for other purposes – industrial espionage

1) Creating a profile for future attacks

This translates into future events so is difficult to assess. Nevertheless, this

type of vulnerability should be minimised.

Likelihood: Low

Impact: Med

Risk Severity: LOW

2) Attempting exploitation by use of gathered data

The information transmitted has limited use to any third party. Also, there

is only basic operating data – nothing that could be exploited.

Likelihood: Low

Impact: Low

67

Risk Severity: LOW

C. Jamming the airwaves by transmitting on the same frequency.

1) Jamming all monitoring and alarms

A basic understanding of what frequency the network operates on and a

transmitter is all that is required. Continuous jamming would be relatively

easy to locate.

Likelihood: Medium

Impact: Low

Risk Severity: LOW

D. Selective jamming of the airwaves by transmitting on the same frequency at

specific times

1) Jamming all monitoring and alarms at key times

This could be more of a disturbance as it would be difficult to physically

trace. The disturbance would have a cost.

Likelihood: Medium

Impact: Medium


5.1.3.4 Results

Table 12 Summary of Preliminary Security Analysis.

Attack Likelihood Impact Severity

A i Low High MEDIUM

68

A summary of the preliminary security analysis is shown in table 12. The

outcome is that the most likely attack (D i) to do damage is a selective jamming attack

which requires motive and only some technical knowledge. Encrypting data will not

treat this problem as it would others. The consequence is a block of information

which could potentially mask an alarm. The jamming action would be observable by

the monitoring system – once the jamming characteristics are measured, an alarm can

be configured to be triggered when jamming occurs. In this way, the impact will be

minimised. A change of frequency (which may prove difficult) or an effort to

apprehend the offender by use of frequency monitors and loggers may be a possible

treatment.

A ii Low Medium LOW

A iii Low Medium LOW

A iv Low High MEDIUM

B i Low Medium LOW

B ii Low Low LOW

C i Medium Low LOW

D i Medium Medium MEDIUM

69

The other two attacks (A i and A iv) require motive and technical expertise –

and considerable research / inside information. This attack may be motivated by a

disgruntled employee. The consequence could be false alarms requiring staff callouts

or an attempt of completely masking an alarm which could, in the worst case

scenario, result in a sewage overflow. This mitigated by having staff physically do

inspections at least twice per week. As it would take about 4-5 days for the system to

go from alarm state (extra high level) to an overflow, it would require a combination

of staff negligence and effective hacking for this to occur. Even in this scenario,

stopped sewerage services prior to an overflow would undoubtedly result in

customers phoning in and complaining that their drains aren’t flowing.

As stated earlier, encryption can be enabled in the ZigBee protocol by

checking a security flag. Once hacking is suspected, security measures can be put into

place such as encryption and changing of node IDs and resetting register address

locations. This means that the hacker would have to start their research all over again.

The regime of changing addresses may be a good security practise to adopt akin to

changing passwords.

5.1.3.5 Conclusion

According to the Preliminary Security Analysis in Section 5.1.3, it has been

found that ZigBee security issues are within acceptable risk limits relevant to the

application. If control was being used, that is if the system was ‘read / write’, then the

risk assessment would have much different results. As a follow up to the Preliminary

ZigBee Security Analysis, which was essentially a desktop exercise, a field network

ZigBee security analysis will be carried out to validate and verify the desktop

findings. This assessment is found in Section 5.2.2 Security Survey.

70

5.2 Site Surveys

Equipment was purchased; a 900MHz range tester and a 900MHz packet

sniffer to assess the viability of communications ability and quality of security

implemented in the wireless network.

5.2.1 Signal Strength

5.2.1.1 Signal Strength Survey Configuration

A signal strength survey was carried out using a ZigSense Range Tester. The

device was designed to help conduct an RF site survey in order to optimise wireless

communications paths of identify problem locations. The test was carried out using

900MHz frequency and at 250mW transmission power. Two units communicate with

each other across a site a give a signal strength output. The outputs are interpreted by

the manufacturer as shown in table 12.

71

Table 13 Interpretation of Range Tester output adapted from [34].

Range Tester output Manufactures Interpretation

-53 dBm Hi

-54 dBm Very good

-62 dBm Good

-69 dBm Somewhat good

-73 dBm OK – Acceptable strength

-82 dBm Slightly weak

-85 dBm Weak

-90 dBm Low

-95 dBm Too Low – refrain from using at this strength

One unit was based at the Shire of Moora office (Central Station), where the

gateway & network controllers will be based and the other unit was transported

around the town site where readings were taken. The test was done using the units at

1.7m height which is less than the 2.4m switchboard height – minimum height of

proposed antennas. Key results are shown in table 14. An estimate radius from results

has been constructed in figure 19.

Table 14 Site RF Survey results - Range Tester output.

Between Central Station and:

Reading Interpretation

Pump Station 1 -82 dBm Slightly weak


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Pump Station 3 -62 dBm Good

Pump Station 4 -73 dBm OK

Pump Station 5 -85 dBm Weak

Pump Station 6 -85 dBm Weak

Pump Station 7 -95 dBm Too Low

Figure 19 Range testing results.

5.2.1.2 Site Survey Results

The one signal path that is clearly too low is from Central Station to Pump

Station 7. Refer to table 5 and figure 10 – the preliminary site study illustrates the fact

that Pump Station 7 will use Pump Station 4 as a relay in a mesh network. Failing

that, Pump Station 7 may then use Pump Station 2. The results are shown in table 15.

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Table 15 Pump Station 7 to PS 4 & PS 7 to PS 2 RF Survey results - Range

Tester output.

Between Pump Station 7 and:

Reading Interpretation


Pump Station 4 -73 dBm OK

5.2.1.3 Site Survey Conclusion

Although some results are slightly weak, it must be noted that the antennas

used were the original ZigSense module antennas. Larger, higher gain antennas will

therefore be purchased that are designed for outdoor conditions and are vandal proof.

The Dome Antenna from Rojone Pty Ltd [35] looks to be a product with these

characteristics. The low profile antenna mounts directly onto the top of the

switchboard with 4 fixings making it secure against vandalism. It operates at 800-900

MHz and has transmission power of 50W [35].

5.2.2 Security Survey

OpenSniffer is a device that can read the 802.15.4 wireless network data

packets. Use of Wireshark software, relevant protocol plugins (ZEP and ZigBee)

combined with the OpenSniffer hardware confirmed that the packets were indeed

encrypted. A concept diagram is shown in figure 20. The output displays the

encryption status of each packet confirming whether encryption has been enabled or

not. It also gives details on the authentication process.

74

Figure 20 Wireshark program displaying ZigBee network data packets.

Wireshark [33] and the OpenSniffer [31] hardware produces output verifying

that the authentication process is indeed encrypted.

Figure 21 Wireshark data output.

75

Figure 21 gives some of the data output of this particular network. The bottom

right of the diagram (….T…8…E. etc) indicates that the data packets are

encapsulated and encrypted. The protocols observed were UDP (User Datagram

Protocol), ZEP (ZigBee Encapsulation Protocol), ZigBee (IEEE 802.15.4) sent over

Ethernet II.

5.3 Component Configuration

The ZigBee network requires remote units to pick up analogue and digital

information at each Pump Station. They communicate to a Modbus Gateway and

Cloud Controller facilitating the cloud applications. An over view is given in figure

22.

Figure 22 Vendor recommended network configuration [28].

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5.3.1 Component List

The components will have the following quantities

5.3.1.1 Central Station Components

The Central Station can be linked to an existing computer, the internet, and

will have the highest antenna mast. The items include:

1 X Network Controller

1 X Modbus Gateway

1 X Antenna

5.3.1.2 Pump Station Component List

This is the item list for all seven Pump Stations:

14 X Remote End Units

7 X Antennas

7 X Current transformers

7 X Ultrasonic level meters

77

5.3.2 Component Descriptions

5.3.2.1 Network Controller

Figure 23 Network controller & cloud application GUI.

The Cloud Controller (Figure 23 left) provides information for the cloud

application and is physically located at the Central Station. A Modbus cable connects

it to the Gateway Controller. The connection uses the ModBus protocol. An Ethernet

cable connects the Cloud Controller to the internet via TCP/IP protocol where

connection to the cloud application server can take place. The Cloud Application

requires a paid registration ($40/month) and each device must be added. Alarms and

unit calibration takes place using access via a web page. An example of the web

application is shown in figure 23 (right).

78

5.3.2.2 Modbus Gateway

Figure 24 Gateway Controller and software interface.

The ModBus Gateway in figure 24 (left) wirelessly connects via ZigBee

protocol to the remote units and is physically located at the Central Station. It also

connects via USB cable to PC running the ZigSoft software shown in figure 22

(right). The ModBus Gateway holds all register data for all connected devices. This

register data is passed to the Cloud Controller where it will be interpreted and

displayed.

5.3.2.3 Remote End Units

The Remote Units will collect the analogue and digital data from the outputs

and transducers in the Pump Stations. The type used has two digital inputs and two

analogue inputs.

5.3.2.4 Antennas

Antennas were selected after testing. The most important factor is

communication ability. Other factors include form factor, durability and cost.

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5.3.2.5 Current Transformers

A current transformer measures pump current (0-20 Amps) and delivers it as

4-20mA to the analogue input of the Remote End Unit. One at each pump station

reads the current drawn and combined with the Digital Input ‘PumpDuty1 or

PumpDuty 2’, it can be determined which pump is running and what current is being

drawn.

5.3.2.6 Ultrasonic Level Transducers

The ultrasonic level meter outputs 4-20mA for reading water level at each

pump station. This output connects to the analogue input of the ZigBee Remote End

Unit. The ultrasonic sensor hangs approximately 0.5 metre from the top of the wet

well and bounces an audible signal of the surface of the water.

80

CHAPTER 6. RESULTS

6.1 Results Analysis Approach

The results are compared to the objectives previously covered in this project.

These problems, requirements and objectives will make up the criteria of the

effectiveness of the given solution. They have been drawn from different sections

(listed below) and are tabulated in section 6.2.

The main problems were outlined in section 3:

No alarm information is sent

No trending is possible

Requirements were outlined in section 4.2 which covered the following main

components:

Alarms to be set

Parameters to be monitored

Factors to be considered

In-house installation factors

Objectives were outlined in section 4.3:

Benefit to public (effectiveness of scheme)

Cost Savings

Staff Knowledge

6.2 Summarised Results

From section 6.1, criteria were determined that form the basis of the results

evaluation. This, and the outcomes (Items 1-5), have been tabulated in table 16. There

are 33 items which are derived from the following:

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Items 1-5 Section 3 Problem – Primary

Items 6-15 Section 4.2 Problem – Requirements

Items 16-22 Section 4.3 Problem – Objectives

This links the problem directly to the results and additional supporting items

were added (Items 22-33).

Table 16 Results Analysis Criteria.

Item

# Section Item

1

Never

0%

2

Seldom

<50%

3

Often

>50%

4

Mostly

>70%

5

Always

1 3

Is the alarm status

accurately sent?

2 3

Alarms triggered

reliably?

3 3

Alarms communicated

effectively?

4 3 Is trending functioning?

5 3 Is archiving possible?

6 4.2.1 Alarm pump fail

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working?

7 4.2.1

Alarm extra high water

level?

8 4.2.1

Alarm pump current

deviation?

9 4.2.1 Alarm power loss?

10 4.2.2 Water level trending?

11 4.2.2 Pump current trending?

12 4.2.2 System status trending?

13 4.2.3

Within budget

expectations?

14 4.2.3

Friendly GUI and

suitable for untrained

staff?

15 4.2.3

Modular and easy

installation?

83

16 4.3.1

Can mitigate events?

E.g. overflow

17 4.3.1 Improves response?

18 4.3.1

Improves asset

management?

19 4.3.2

Results in more cost

efficient scheme?

20 4.3.2

Reduces callouts and

overtime?

21 4.3.2

Replaces manual data

collection?

22 4.3.3

Increases knowledge of

pump station

characteristics?

23 General

Communications

functioning?

24 General Wiring simple?

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25 General Antennas adequate?

26 General Uptime continuous?

27 General

Reliability during

weather events?

28 General

Reliability during

power loss events?

29 General

Ease of user

interaction?

30 General

Device configuration

simple?

31 General

GUI configuration

simple?

32 General

Parameter calibration

simple?

33 General

Ongoing costs as

expected?

85

According to the criteria in table 16, the ZigBee solution fulfilled the

requirements. The antennas did not always meet up to expectations and some had to

be replaced with more powerful designs that had a negligible adverse effect on start-

up costs as antennas are a relatively inexpensive component of the system. Such

issues and other details of the results are elaborated further in section 6.3

6.3 Quantitative Results

6.3.1 Communications

Communications in this context refers to the successful two way exchange of

data between Pump Station nodes and Central Station node.

6.3.3.1 Initial setup – low profile switchboard antennas

The units were deployed at all pump stations with a small, low profile antenna.

After installation it was found that this antenna was not sufficient for the outlying

stations. The low profile antenna was selected as it was the most physically robust and

was difficult to damage / vandalise. Results of communications reliability to Central

Station with low profile antenna mounted on switchboard is shown in table 17.

Two conclusions can be drawn. Firstly, the signal survey gave positive results

for all Pump Stations except number Seven. Therefore, the survey was not accurate

for the low profile antenna type. Secondly, the low profile antenna type has a

maximum practical range of about 500m (PS1 is 585m from the Central Station.

Signal quality may be affected by a mobile phone transmitter in the town site which

operates at a similar frequency. Certain directions may have more interference. The

units at Pump Stations 1, 2, 3, 4 were configured to act as routers to facilitate the

86

mesh network topology. With the low profile antennas, this did not seem to improve

signal quality.

6.3.3.2 Antenna Modifications

The Central Station was replaced with a higher gain omni-directional antenna.

Pump Stations 2, 5, 6, 7 had Higher gain (14dBi) Yagi direction antennas installed.

These changes enabled communications to take place from all Pump Stations to the

Central Station. There was little difference in the price of each antenna type.

Table 17 Communications reliability to Central Station with low profile

antennas.

Pump Station Signal reliability After

modifications

1 YES YES

2 NO YES

3 YES YES

4 YES YES

5 NO YES

6 NO YES

7 NO YES

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6.3.2 Uptime

Since the first week of setting up the system at the first Pump Station, the

communication has stayed online for three full months. The antennas were set up as

suggested, Central Station 4m high, Pump Station 3 2.4m high. It was found that a

small antenna inside a closed switchboard will not be able to communicate; the

antenna must be mounted outside of the switchboard. Connection can ‘break’ quite

often but the local unit stores the data and sends on next available signal. This was

sufficient to capture all necessary data for this application. Therefore, it can be stated

that the uptime for a 3 month period was 100%.

6.3.2.1 Weather

Once effective communications had been established, there was no significant

down time. During weather events (high winds – late February, 2017). Some stations

would drop out occasionally (up to 30% of the time during these events) as detected

by direct connection to the Gateway Controller. However, the sampling continued

(and saved locally) at the Pump Station and when communications was re-established,

the online cloud application database was populated. There was no significant

disturbance to data collection due to weather conditions.

6.3.2.2 Power Loss

It was observed that when power loss was experienced (e.g. 2nd

March, 2017),

the ZigBee module operated on its backup battery. An alarm was configured to notify

lost power. However, the ultrasonic level transducer that is used to measure the pump

station water level was offline. Although not completely essential, knowing the water

levels during a widespread blackout could be useful.

88

Two ways of achieving this would be to:

install a UPS type backup for the transducer

install a non-powered mercury switch float connected directly to a digital

input of the ZigBee module sending an alarm when a certain water level was

reached.

Seven UPS’s would have some cost involved but would continue to provide

online monitoring. The float switches would be cheaper but only alert at a set height.

Given the low frequency of blackouts and a stockroom full of float switches, the Shire

of Moora is considering installing these to mitigate such an event. Another scheme

may consider the battery backup as a better solution, for example in the case of more

extended blackouts, more Pump Stations to monitor, less staff resources etc.

6.3.3 User Interaction

User refers to the person not only using the system but also installing the

hardware and configuring the equipment.

6.3.3.1 Device Configuration

The connectivity of network devices was assisted by instruction manuals and

guidebooks but wasn’t completely without issue. In particular the link between the

network controller and the gateway controller was not clear. The process is simple

enough – the support is not yet fully established in Australia. Having done it once, the

process is straightforward.

6.3.3.2 Wiring & Cabling

The ZigBee modules were connected to

89

DC power supply

A powered current transformer (analogue input)

An ultrasonic level transducer (analogue input)

Antenna (sma coax)

Data cable from PLC – 3 wires (2 digital inputs)

6.3.4 GUI Setup

The device configuration was intuitive. Some addressing concepts were

needed, Modbus was used but understanding of the protocol was not necessary.

Alarm setting was also simple.

Each parameter could be displayed in a limited set of display methods such as

graphs, bar charts, gauges etc. The data could easily be exported in excel format (as

well as other formats).

Scripting is possible in the PAWN language and will be looked at to further

quantify some information such as Pump Station Operating Hours, or accumulated

time that current is above a specified threshold.

6.3.5 Calibration

Calibration was carried out by two people comparing actual amps and levels

to the raw data. A formula can be determined (these cases were linear y=ax+b) and

then adjusted until the online output matches the actual local data.

6.3.6 Cost

The total cost amounted to $11,355 with an optional extra of $14,350 for

ultrasonic transducers.

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The ongoing subscription amounted to $432 / year.

6.3.6.1 Network Components

Item Price (circa) Quantity Total

Network Controller $910 1 $910

Gateway Controller $900 1 $900

ZigBee modules $795 7 $5565

Sum $7375

6.3.6.2 Transducers

Ultrasonic Transducer

These were purchased previously and are outside the scope of the project.

Existing float switches / alternative level transducers could be used.


Ultrasonic

Transducer

$2050 7 $14,350

Current Transformers

Not necessary if the pump system has an analogue output for current drawn. In

most cases these would be required.

91


Current Transformer $340 7 $2,380

6.3.6.3 Antennas


Antenna $150 8 $1,200

6.3.6.4 Extras & Modifications

Data cabling and fixings were about $400. Antennas had to be changed twice

for outer Pump Stations (PS 2, 6 & 7).

An interesting bonus and significant cost reduction was the fact that one

ZigSense module was used at each Pump Station instead of the proposed two. This

saved $5565 and it was found that one unit would provide all necessary operational

parameters.

6.3.6.5 Subscription

The online subscription giving access to data, GUI and trending amounted to

$432 / year.

6.3.7 Effectiveness

This section covers the critical items such as monitoring parameters, savings

realised, alarm reliability and possible event mitigation.

92

6.3.7.1 Monitoring

Some variables that had not previously been monitored continuously were

now available. This gave the staff an opportunity to get to know the patterns and

characteristic behaviour of pump currents, pump run times and water level shifts.

Examples of the parameters monitored are shown in figure 25. The first unit

monitored was Pump Station 3 which was installed on 3rd

November, 2016. The

remaining units were installed in January, 2017.

See Appendix F for summarised Pump Station 1-7 data and Appendix G for

raw data.

Figure 25 GUI with labels for Pump Station 3 ZigSense monitoring.

It can be seen in figure 25 when water levels are rising and falling and a more

rapid increase when an upstream pump station is pumping (first rise in water level in

figure 25). Also, the pump current and operating duration can be noted.

93

Table 18 Extract of archived log data with notes excluding alarms.

Time

PS3

LEVEL

(metres) Note

PS3

Pump

Current

(Amps) Note

PS3

Duty

Select Note

PS3

Fault

Code Note

2/12/2016

11:06 1.1 MID 0 Pump off 2

Pump 1

selected 15 No fault

2/12/2016

11:07 1.1 4.5

Operating

normally 2

Pump 1


2/12/2016

11:16 1 4.5

Operating

normally 2

Pump 1


2/12/2016

11:24 0.9 4.4

Operating

normally 2

Pump 1


2/12/2016

11:29 0.8 4.4

Operating

normally 2

Pump 1


2/12/2016

11:30 0.7 4.4

Operating

normally 2

Pump 1


2/12/2016 0.6 LOW 0 Pump off 1

Pump 2 15 No fault

94

11:31 selected

Table 18 shows extracts of an archive log data file that can be extracted from

the cloud based online system. Two months of data takes up about five megabytes of

disk storage. In table 18, Pump unit 1 pumps the water level down from 1.1m to 0.6m

respectively from MID level to LOW level as designed. The ability to log so much

information makes dealing with audits and compliance easier and more transparent.

Alarm states have been omitted as no alarms were triggered in this period.

6.3.7.2 Pump Operation

Previously, the current was checked weekly, if a deviation was observed it

was acted upon that day. This means if the pump did not completely fail it could run

with a high current drawn for 1-6 days. We can say 4 days on average as weekends

come into play. Using the ‘old’ system, it was impossible to determine exactly when

the problem began.

With the new system, over a period of two months, 7 observations of high

currents were observed and were acted on the same day (3 times), the next day (3

times) and once two days later due a weekend. This averages out to a 1 day response

from detection to treatment. This saves about 3 days for each event, equivalent to 126

days of high current pumping which can be assumed is damaging to the pumps. How

damaging each event is, is difficult to measure as each situation is different

Making the assumption that a pump running out of its normal current range for

6 months will develop a major problem, it can be calculated that the new system saves

95

one pump every one and a half years. For the Shire of Moora, the average cost of the

pumps are around $7500. This equates to a savings of approximately $5,000 per year.

Figure 26 Typical life cycle costs for pumps in a municipal environment [46].

According to [46] as shown in figure 26, electrical energy costs make up the

largest cost portion in a pumps life cycle. When pumping current is monitored (and

responded to) effectively, this improves the pumps overall efficiency reducing

electrical costs.

6.3.7.3 Impact on Response

Once the characteristic behaviour of the pumps and water levels had been

determined (as in figure 27), meaningful deviations were recognised. An example of

this occurring is shown in figure 27 when the pump current deviated outside normal

96

ranges. Staff decided to pull the pump immediately and it was ragged. From such

occurrences an accurate understanding of the system is obtained and limits can be set

to provide staff with warnings. The history can be viewed as far back as 2 months so

behaviour over a previous period can be studied. During working hours, problems can

be identified and treated within an hour. Without monitoring, these situations can

linger for weeks putting unnecessary strain on the pumps and their power

consumption. In figure 27, the deviation can be seen on the first half of the curve, the

bumpy region at about 07:59am.

Figure 27 The detection of a ragged pump at Pump Station 3.

6.3.7.4 Callout Savings

36 alarms would have been triggered under the ‘old’ system over the two

month period as opposed to 7 callouts (none critical) with the ‘new’ system. This has

97

saved 29 callouts over 2 months, at 1 hour per callout ($40 / hour) equated to $1160

over the two month period or $6960 per year.

6.3.7.5 Event Mitigation

The online water level monitoring was useful during a high rainfall week in

February – all monitoring was possible online rather than onsite leaving time for other

tasks.

6.3.7.6 Alarms

The previous’ systems alarms (outlined in section 3) were replaced with

configurable SMS alarms that texted specific alarm parameters. Once the alarm had

been received, the staff member could then log on remotely and read all measured

parameters. The history could also be viewed (as in figure 25). This allowed for an

accurate and rapid diagnosis of the problems without moving location (via mobile

device). An example of an alarm that was avoided is given in figure 27. Setting alarm

parameters will be different for each pump and each Pump Station – each having their

own particular behaviour. Unusually long pump running times can now be alarmed

which wasn’t previously possible. Also, low water levels (under pump inlet) are now

alarmed.

98

CHAPTER 7. FURTHER WORK

7.1 Network Expansion

Extension of the network into other services is possible and expands the size

and therefore usability of the network. A recycled water scheme will have one of

these units installed as will the town swimming pool. The recycled water quality and

chlorine levels will be monitored. From the swimming pool, chlorine gas leaks will be

monitored and alarms set. Other future station may include natural water way levels

and meteorological stations.

Once the network is established, it is relatively simple and cost effective to

add nodes. Most of the problems have been ironed out, there are no extra ongoing

costs, just the hardware cost and installation. Additional nodes configured to act as

routers should increase the stability of the network.

A study has been conducted by [50] that couples ZigBee radio modules with

external power amplifiers and low noise amplifiers. It was shown that with an

external power amplifier and a low-noise amplifier the outdoor radio range can reach

up to 1600 m with a negligible packet error rate [50]. This indicates that the extension

of the mesh network is physically possible. However, care should be taken to comply

with legislation changes found at [51]. Currently the restrictions of this band (in

Australia) are no longer in force [51]. Cellular networks in Australia operate in this

frequency range.

99

7.2 Scripting

Scripting using the PAWN language in the online GUI allows parameters to

be included as variables into functions. These functions can also be allocated

acceptable ranges of operation and alarmed accordingly.

Small data - optimum processing.

Using a minimal number sensors, data is carefully chosen to extract the

maximum amount of operational information. Rather than continual expansion and

collection of more and more data and then figuring out how to handle it, an alternative

approach could be to use a minimal number of sensors and from that, infer maximal

information. Figuring out more ways to extract information from a minimal data set

keeps costs and maintenance low. The handling of this data does not add extra

running costs to the system once the scripting is established. If the correct sensors are

in place then scripts can be written – the result is cost effective optimisation of the

system.

7.2.1 Gradients and flow rate

Once enough data has been analysed, pump characteristics can be determined

for each pump station. Some pump stations have a relatively uniform inflow from the

local catchment area, some have a combination of inflows from catchment area and

one or two adjacent pump stations flowing in. Therefore, the characteristics, although

individual for each pump station, are able to be analysed in terms of when a particular

pump station is pumping and possibly even which pump unit is running from the

incoming station.

An example of the total inflow to say Pump Station 2 would be:

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The catchment area inflow rate + inflow from PS4 (pump unit 1 or 2) + inflow

from PS7 (pump unit 1 or 2)

Or PS2 = Catchment B + PS4 + PS7

Once the inflow rates have been determined for each of the 4 pump units from

PS 4 & 7 including multiple pump units running simultaneously (one from PS4 and

one from PS7 – 4 combinations). The catchment area inflow is added on as a

‘tolerance’ as these flows are relatively low and more variable. The scripting could

additionally link the operation of each pump (PS4 & 7) unit to the PS2 inflow. When

this has been established and acceptable limits have been determined, exceedances

can be used to trigger warnings. In particular:

No local catchment area flow – local blockage

Low flow rate from a pump station – PS problem or pressure main pipe

obstruction

Low flow from a pump unit – pump problem (blockage, bearings, rags…)

7.2.2 Pump Current Data

The pump current can be analysed. Refer to Appendix F for summary statistics

including accumulated pump current which can be used for overall power

consumption over a given period of time. Deviation from the set range can be caused

by a blockage in the impellor. Moving increase in range of data could be an

accumulated blockage, bearings or seals deteriorating. Decrease of data could be a

burst line or pumps not delivering water effectively. Current deviation can be directly

related to poor pump operating conditions and maintenance requirements:

Gradual rise of current – accumulated ragging of pump, bearings

Rapid rise – foreign object in impellor, blockage

101

Erratic current – objects around impellor

Low current – water not being moved (burst line)

Long pumping times – low pump performance – damaged impellor,

obstruction

Figure 28 Example of observed current and water level data in the ZigSense

desktop GUI.

7.3 Other

An uninterruptable power supply (UPS) may be installed to keep the water

level data coming in during a power loss. Eight units would be required; seven for the

pump station level transducers and one for the Central Station gateway controller.

102

CHAPTER 8. CONCLUSION

The implementation of ZigBee technology to the Shire of Moora’s town site

wastewater has proven to be successful. The cost effectiveness, reliability and

relatively easy install have made it possible for Local Municipalities to adopt such a

system. The ZigBee solution certainly seems to meet the requirements for low cost. It

has the benefit of having a standardized platform, reliability and well developed

products. The cases are thick, strong moulded plastic and are easy to open and work

on when necessary.

The ZigSense cloud based applications are easy to configure (though some

connection issues were experienced early on) and the graphs and gauges are simple to

set up. It is missing some on / off graphical; buttons for DI states and at this stage no

graphics are available with the mobile version. Using a desktop browser on the

mobile device is one work-around but not a very friendly one. Scripting is an option

that will be pursued to further customize the cloud app and to calculate and log further

diagnostic data such as total pump operating hours. Currently, logs are downloaded

(up to one months’ worth) and calculations are made on the excel file. This operation

should be automated at the cloud level as well as more streamlined and relevant data

monitoring, logging and alarm settings. All staff members (not specifically trained for

using this system) were satisfied with the GUI and the skills required to monitor

relevant parameter was acquired within a few hours.

One unexpected outcome is that members of staff have determined is that after

getting to know the system, only one remote end unit is required. The analogue

parameters must be measured as well as which pump is running, but the other fault

103

codes can be inferred directly from the analogue parameters exceeding normal

operating ranges. For example, nearly all problems have an impact on water level, so

if water level goes beyond its limits and is alarmed then other fault codes are not

necessary. Likewise, if pump current and duration are monitored and deviations are

alarmed, then the additional pump fault code is not needed. The removal of one unit

greatly simplifies installation and reduces cost. This significant cost reduction equates

to $900 times 7 units which is a total savings of $6300.

The greatest underestimation was the range of the ZigBee modules. A

literature study revealed potential ranges as did specific advertising material.

However, the distance with the selected antennas seemed to be around 350-450m and

nodes beyond this required individual consideration. It is an important note that a

node requiring 850m communication distance may require a physically large antenna

(say, one meter in length). This may not be viable and should be considered in early

planning phases. Selecting the best antenna was the task that proved to be most

difficult as desktop studies did not equate to actual local conditions perfectly.

A benefit of the low cost mesh network is that it can be expanded to other

utility types. An expansion of the network results in more routable paths that

communication can take place in, increasing the overall effectiveness of the network.

The network is being expanded to cover the online chlorine analyser at the Shire of

Moora’s recycled wastewater scheme. The data will be incorporated into the current

system at the cost of just the extra hardware and installation.

104

ACKNOWLEDGMENTS

Acknowledgement and thanks to the Shire of Moora and EIT for support of

the project.

105

REFERENCES

[1] Haimi. H., Mulas. M., Vahala, R. Process Automation in Wastewater

Treatment Plants: the Finnish Experience. (2010). E-Water.

[2] Symphony Plus: The Total Automation Solution for Water and Wastewater.

(2012). ABB

[3] Automation Within Reach Even for Small Water, Wastewater Facilities.

(2011). General Electric.

[4] How Automated Real-Time Controls Can Provide More Consistency in

Wastewater Treatment Operations. (2015). HACH.

[5] Olsson, G., Rosen, C. Automation in Wastewater Treatment. (2011). Lund

University, Lund, Sweden..

[6] Solutions for the Water & Wastewater Industry. (2011).NHP Electrical

Engineering Products Pty Ltd.

[7] Wastewater treatment plant: automation of floc filtration. (2009). FESTO.

[8] The Internet of Things: Opportunities & Challenges. (2015). Texas

Instruments.

[9] Wireless connectivity for the Internet of Things (IoT) with MSP430™

microcontrollers (MCUs). (2014). Texas Instruments.

[10] IEEE 802.15.4 - 2003

[11] IEEE 802.15.4 – 2011 IEEE Standard 802.15.4 for local and metropolitan area

networks— Part 15.4: Low-Rate Wireless Personal Area Networks (LR-

WPANs) LAN/MAN Standards Committee of the IEEE Computer Society

IEEE-SA Standards Board, 2011.

http://www.zigsense.com.au/


106

[12] Adams, J. T. An Introduction to IEEE STD 802.15.4. (2006) Freescale

Semiconductor. Inc.

[13] Munday, P. Automation IT awarded contract to upgrade SCADA system for

Unitywater Sewage Pump Stations. (2015). Automation IT Pty. Ltd.

[14] http://healthywa.wa.gov.au/Articles/S_T/Sewage-spills

[15] https://www.der.wa.gov.au/our-work/enforcement/summary-of-prosecutions

[16] https://www.erawa.com.au/water1/water-licensing/licence-holders

[17] http://www.water.wa.gov.au/licensing/water-licensing/compliance-and-

enforcement

[18] http://prosecutions.commerce.wa.gov.au/

[19] http://ww2.health.wa.gov.au/Articles/F_I/Food-offenders/Publication-of-

names-of-offenders-list

[20] http://www.kapp.com.au/

[21] The Evolution of the Internet of Things. Texas Instruments, 2013.

[22] The Internet of Things: Opportunities & Challenges. Texas Instruments, 2013.

[23] http://www.zigsense.com.au/

[24] http://www.zigbee.org/

[25] Your solution for water and wastewater pumping stations. Schneider Electric,

2007.

[26] Water Wastewater Solutions Guide. Schneider Electric, 2009.

[27] www.der.wa.gov.au

[28] https://www.erawa.com.au

[29] http://www.water.wa.gov.au

[30] Ww2.health.wa.gov.au

[31] www.sewio.net

https://www.der.wa.gov.au/our-work/enforcement/summary-of-prosecutions

https://www.erawa.com.au/water1/water-licensing/licence-holders

http://prosecutions.commerce.wa.gov.au/

http://www.kapp.com.au/


http://www.zigbee.org/

http://www.der.wa.gov.au/

https://www.erawa.com.au/

http://www.water.wa.gov.au/

http://www.sewio.net/

107

[32] ZigSense brochure, 2013. www.zigsense.com

[33] www.wireshark.org

[34] ZigBee (TM) RANGE TESTER. User Manual. Revision E. ZigSense, 2010.

[35] Rojone A-490-18F 838 MHz Next G Antenna. Rojone Pty Ltd. 2009.

[36] www.extronics.com extronics rf calculator.

[37] Melgares, R. A. 802.15.4 / ZigBee Analysis and Security: Tools for Practical

Exploration of the Attack Surface. Dartmouth College, 2011.

[38] http://www.aic.gov.au/publications/current%20series/tandi/321-

340/tandi329.html

[39] https://www.owasp.org/index.php/OWASP_Risk_Rating_Methodology

[40] Offer Document. Automation IT. 2016.

[41] www.burkert.com.au

[42] www.ewon.biz

[43] Jin Zhu and Recayi Pecen. Paper #086, IT 303 A Novel Automatic Utility

Data Collection System using IEEE 802.15.4- Compliant Wireless Mesh

Networks. Department of Industrial Technology University of Northern Iowa,

2008.

[44] N.C. Batista, R. Melício, J.C.O. Matias, J.P.S. Catalão. Photovoltaic and wind

energy systems monitoring and building/home energy management using

ZigBee devices within a smart grid. Universtiy of Beira Interior, University of

Evora, Technical Universtiy of Lisbon, 2012.

[45] Elias Bou-Harb, Claude Fachkha, Makan Pourzandi, Mourad Debbabi, and

Chadi Assi, Communication Security for Smart Grid Distribution Networks.

IEEE Communications Magazine • January 2013.

http://www.zigsense.com/

http://www.wireshark.org/

http://www.extronics.com/

http://www.aic.gov.au/publications/current%20series/tandi/321-340/tandi329.html

http://www.aic.gov.au/publications/current%20series/tandi/321-340/tandi329.html

https://www.owasp.org/index.php/OWASP_Risk_Rating_Methodology

http://www.burkert.com.au/

http://www.ewon.biz/

108

[46] T. Augustyn. ENERGY EFFICIENCY AND SAVINGS IN PUMPING

SYSTEMS – THE HOLISTIC APPROACH. Southern African Energy

Efficiency Convention, 2012.

[47] Mohamed Samra, Shiemaa Sidahmed, Stephen Greedy, Armando Mndez.

Feasibility Analysis of Wireless Technologies for Railway Signalling

Systems. Birmingham Center for Railway Research and Education, University

of Birmingham, UK, 2016.

[48] R, Mardeni. Othman, Shaifull Nizam. Node Positioning in ZigBee Network

Using Trilateration Method Based on the Received Signal Strength Indicator

(RSSI). European Journal of Scientific Research ISSN 1450-216X Vol.46

No.1 (2010).

[49] David Geer. Users Make a Beeline for ZigBee Sensor Technology, 2005.

[50] Allan HUYNH, Jingcheng ZHANG, Qin-Zhong YE and Shaofang GONG.

ZigBee Radio with External Power Amplifier and Low-Noise Amplifier.

Sensors & Transducers, 2010.

[51] https://www.legislation.gov.au/Details/F2005B01395

https://www.legislation.gov.au/Details/F2005B01395

109

LIST OF APPENDICES

Appendix A Water Corporation data 2012 / 2013

Table A1. Water Corporation costs 2012-13

Table A2. Shire of Moora costs 2013-14

Appendix B Customer Performance History

Table B2. Customer Complaints & Blockages History

Appendix C Sewage Spills & Incidents

Appendix D ZigSense Reference Projects

Table D1. ZigSense past projects [23]

Appendix E Elevation profiles between nodes

Figure E1. Elevation Profile between PS2 and PS4.

Figure E2. Elevation Profile between PS3 and Central Station.



Figure E5. Elevation Profile between PS6 and PS3.

Figure E6. Elevation Profile between PS7 and PS4

Appendix F Pump Station 1-7 Summary Statistics from archive data

Table F1 – Average water height and accumulated pump current from PS 1-7.

Appendix G – Sample archive data Pump Stations 1,3 & 4 – Water level, pump current

& pump duty (in colour)

Table G1 – Sample Archive data PS1, 3 & 4 – Water height and pump

current.

61

61

61

62

62

63

64

64

65

65

65

65

65

66

66

66

66

67

67

110

Appendix A Water Corporation and Shire data 2012-2014

Water Corporation data 2012 / 2013

Table A1 Water Corporation costs 2012–13.

Reactive Maintenance - Immediately Dispatched $ 16,696.06

Reactive Maintenance - Not Immediately Dispatched $ 32,805.78

Planned Maintenance $ 25,024.63

Water Corporation annual management fee $ 150,000.00

Total $ 224,526.47

Blockages for this year and the preceding 10 ranged from 9-24. The most

suitable KPI to be minimised is reactive maintenance $49,501.84.

Shire of Moora data 2013 / 2014

Table A2 Shire of Moora costs 2013–14.

Reactive Maintenance - Immediately Dispatched $ 5,000

Reactive Maintenance - Not Immediately Dispatched $ 2,000

Planned Maintenance & upgrades $

111

81,000

Total $

224,526.47

Appendix B Customer Complaints and Blockages - Shire of Moora Sewerage

Scheme

Another commonly accepted KPI is the number of blockages / customer

complaints experience in a year. According to the ERA, compliance was based on 40

events / 100km of piping as being acceptable. Therefore, the Shire of Moora can have

up to 6 (but not 7) events per year and still be compliant.

Table B1 Customer Complaints & Blockages History.

Customer Performance History

Note: fewer than 40 blockages per 100km per year

Year

Allowed per

year Actual Compliant?

2009-10 6.64 24 No

2010-11 6.64 9 No

112

2011-12 6.64 11 No

2012-13 6.64 15 No

2013-14 6.64 3 Yes

2014 6.64 2 Yes

2015 6.64 1 Yes

2016 6.64 2 Yes

With this KPI having already dropped to quite a low level, it may not be the

most suitable as an indicator for this study but nevertheless cannot be ignored.

Appendix C Sewage Spills and Incidents

Sewage Spills & Incidents

Location: Australia, Perth, Swan River, Caversham

Size: 400,000 L

Date: Oct 2004

Impact: Water sports, swimming, fishing stopped

Source: http://www.abc.net.au/news/2004-10-17/health-warning-after-swan-river-sewage-spill/569762

Location: Australia, Bendigo

Size: 600,000 L

Date: Nov 2009

Impact: Required full cleanup

http://www.abc.net.au/news/2004-10-17/health-warning-after-swan-river-sewage-spill/569762

http://www.abc.net.au/news/2004-10-17/health-warning-after-swan-river-sewage-spill/569762

113

Source: http://www.abc.net.au/news/2009-11-30/sewage-spill-raises-health-concerns/1162544

Location: New Zealand, Palmerston

Size: North Ambulatory Unit ‘soaked’ in sewage

Date: May 2008

Impact: Disturbance of patients

Source: http://www.stuff.co.nz/manawatu-standard/news/409667/Sewage-spill-a-massive-disaster

Location: South Africa Johannesburg

Size: heavy contamination of Hartbeespoort Dam

Date: Nov 2016

Impact: Required full clean up

Source: http://ewn.co.za/2016/11/07/sewage-spill-hits-hartbeespoort-dam

Location: USA, Long Beach

Size: 2.4M Gallons

Date: July 2016

Impact: Polluted waterway

Source: http://www.surfermag.com/features/two-and-a-half-million-gallons-of-sewage-spills-into-los-angeles-river/#A0BWb5S2Pseic3h1.97

Location: Hawaii, Waikiki

Size: 48 million Gallons

Date: 2006

Impact: beaches closed

Source: http://www.mnn.com/green-tech/research-innovations/stories/when-waste-attacks-5-big-sewage-disasters

http://ewn.co.za/2016/11/07/sewage-spill-hits-hartbeespoort-dam

http://www.mnn.com/green-tech/research-innovations/stories/when-waste-attacks-5-big-sewage-disasters


114

Location: Gaza

Size: sewage basin collapse

Date: 2007

Impact: 4 dead 20 injured, village flooded


Location: Scotland , Edinburgh

Size: Treatment Plant failure

Date: 2007

Impact: 100 million litres into waterway


Location: San Isidro, Mexico

Size: 6000 cubic metres per second flooding into a residential area

Date: 2011

Impact: 200 homes flooded








115

Appendix D ZigSense Reference Projects

Table D1 ZigSense past projects [23].

Appendix E Topographical data between network nodes

Elevation profiles between nodes

Figure E1 Elevation Profile between PS2 and PS4.

116

Figure E2 Elevation Profile between PS3 and Central Station.



117



Appendix F Pump Station 1-7 Summary Statistics from archive data

Table F1 Average water height and accumulated pump current from PS 1-7.

PS1 PS2 PS3 PS4 PS5 PS6 PS7

Average water height 1.65 1.34 1.02 1.07 1.83 1.02 1.32

Sum of pump current 2089 1854 1676 655 1937 702 754

118

The length of data collection was 44.2 days. The sample rate was 30 seconds.

The water height is distance from the bottom of the wet well. The sum of

current is indicative of the total power used by each pump station.

Appendix G Sample archive data Pump Stations 1, 3 & 4 – Water level, pump

current & pump duty (in colour)

Table G1 Sample Archive data PS1, 3 & 4 – Water height and pump current.

Time PS1_

LEV

EL

(Met

res)

PS1_AM

PS

(Amps)

PS3_LE

VEL

(metres)

PS3_AM

PS

(Amps)

PS4_L

EVEL

(Metr

es)

PS4_AM

PS

(Amps)

Pump unit 1

Pump unit 2

24/02/2017 3:53 1.96 0 1.13 0 0.59 0

24/02/2017 3:53 2.07 0 1.13 0 0.6 0

24/02/2017 3:54 2.15 0 1.13 0 0.6 0

24/02/2017 3:54 2.22 7 1.13 0 0.6 0

24/02/2017 3:55 2.17 9 1.13 0 0.6 0

24/02/2017 3:55 2.04 9 1.13 0 0.61 0

119

24/02/2017 3:56 1.92 9 1.13 0 0.61 0

24/02/2017 3:56 1.8 9 1.13 0 0.62 0

24/02/2017 3:57 1.67 9 1.13 0 0.62 0

24/02/2017 3:57 1.53 9 1.13 0 0.62 0

24/02/2017 3:58 1.39 9 1.13 0 0.63 0

24/02/2017 3:58 1.27 1 1.13 0 0.63 0

24/02/2017 3:59 1.26 0 1.13 0 0.63 0

24/02/2017 3:59 1.27 0 1.13 0 0.64 0

24/02/2017 5:00 2.23 0 0.76 0 0.7 0

24/02/2017 5:01 2.24 0 0.76 0 0.7 0

24/02/2017 5:01 2.23 3 0.76 0 0.71 0

24/02/2017 5:02 2.15 9 0.76 0 0.72 0

24/02/2017 5:02 2.06 9 0.76 0 0.72 0

120

24/02/2017 5:03 1.83 9 0.76 0 0.72 0

24/02/2017 5:03 1.66 9 0.77 0 0.73 0

24/02/2017 5:04 1.52 9 0.77 0 0.74 0

24/02/2017 5:04 1.34 7 0.77 0 0.74 0

24/02/2017 5:05 1.26 0 0.77 0 0.74 0

24/02/2017 5:05 1.26 0 0.77 0 0.75 0

24/02/2017 5:32 2.11 0 0.85 0 0.59 0

24/02/2017 5:32 2.19 0 0.85 0 0.59 0

24/02/2017 5:33 2.21 9 0.85 0 0.6 0

24/02/2017 5:33 2.11 9 0.85 0 0.6 0

24/02/2017 5:34 2 9 0.85 0 0.61 0

24/02/2017 5:34 1.87 9 0.85 0 0.61 0

24/02/2017 5:35 1.73 9 0.86 0 0.62 0

121

24/02/2017 5:35 1.6 9 0.86 0 0.62 0

24/02/2017 5:36 1.45 9 0.86 0 0.63 0

24/02/2017 5:36 1.32 5 0.86 0 0.64 0

24/02/2017 5:37 1.26 0 0.86 0 0.64 0

24/02/2017 5:37 1.26 0 0.86 0 0.65 0

24/02/2017 6:49 1.42 0 1.13 0 0.57 0

24/02/2017 6:49 1.43 0 1.14 0 0.58 0

24/02/2017 6:50 1.43 0 1.14 1.3 0.58 0

24/02/2017 6:50 1.44 0 1.16 3.7 0.58 0

24/02/2017 6:51 1.45 0 1.18 3.7 0.59 0

24/02/2017 6:51 1.46 0 1.19 3.6 0.59 0

24/02/2017 6:52 1.46 0 1.21 3.6 0.61 0

24/02/2017 6:52 1.47 0 1.22 3.6 0.63 0

122

24/02/2017 6:53 1.47 0 1.23 3.6 0.65 0

24/02/2017 6:53 1.48 0 1.25 3.6 0.66 0

24/02/2017 6:54 1.49 0 1.26 3.6 0.67 0

24/02/2017 6:54 1.49 0 1.27 3.7 0.69 0

24/02/2017 6:55 1.5 0 1.29 3.7 0.7 0

24/02/2017 6:55 1.51 0 1.3 3.6 0.72 0

24/02/2017 6:56 1.51 0 1.31 3.7 0.73 0

24/02/2017 6:56 1.51 0 1.32 3.7 0.73 0

24/02/2017 6:57 1.54 0 1.33 3.7 0.75 0

24/02/2017 6:57 1.57 0 1.34 3.7 0.76 0

24/02/2017 6:58 1.57 0 1.35 3.7 0.77 0

24/02/2017 6:58 1.57 0 1.36 3.6 0.78 0

24/02/2017 6:59 1.77 0 1.37 3.6 0.78 0

123

24/02/2017 6:59 1.95 0 1.39 3.7 0.79 0

24/02/2017 7:00 1.97 0 1.4 3.7 0.8 0

24/02/2017 7:00 2.1 1 1.41 3.7 0.81 0

24/02/2017 7:01 2.21 9 1.42 3.6 0.81 0

24/02/2017 7:01 2.14 9 1.43 3.6 0.82 0

24/02/2017 7:02 2.13 9 1.44 3.7 0.83 0

24/02/2017 7:02 2.01 10 1.45 3.7 0.83 0

24/02/2017 7:03 1.9 10 1.45 3.7 0.84 0

24/02/2017 7:03 1.8 10 1.46 3.6 0.84 0

24/02/2017 7:04 1.68 10 1.47 3.6 0.85 0

24/02/2017 7:04 1.59 10 1.48 3.7 0.86 0.72

24/02/2017 7:05 1.57 10 1.49 3.7 0.84 5.13

24/02/2017 7:05 1.34 8 1.5 3.6 0.77 5.16

124

24/02/2017 7:06 1.28 0 1.5 3.7 0.7 5.15

24/02/2017 7:06 1.32 0 1.51 3.6 0.63 5.11

24/02/2017 7:07 1.35 0 1.52 3.6 0.56 5.15

24/02/2017 7:07 1.39 0 1.53 3.6 0.51 0.43

24/02/2017 7:08 1.46 0 1.53 3.6 0.5 0

24/02/2017 7:08 1.49 0 1.54 3.6 0.51 0

24/02/2017 7:09 1.5 0 1.55 3.7 0.52 0

24/02/2017 7:09 1.5 0 1.55 3.6 0.52 0

24/02/2017 7:10 1.51 0 1.55 3.6 0.52 0

24/02/2017 7:10 1.66 0 1.55 3.6 0.53 0

24/02/2017 7:11 1.69 0 1.54 3.6 0.54 0

24/02/2017 7:11 1.75 0 1.54 3.6 0.54 0

24/02/2017 7:12 1.77 0 1.53 3.6 0.54 0

125

24/02/2017 7:12 1.79 0 1.53 3.6 0.55 0

24/02/2017 7:13 1.89 0 1.52 3.6 0.55 0

24/02/2017 7:13 1.92 0 1.52 3.6 0.56 0

24/02/2017 7:14 1.94 0 1.51 3.6 0.56 0

24/02/2017 7:14 1.94 0 1.51 3.6 0.57 0

24/02/2017 7:15 2.05 0 1.5 3.7 0.57 0

24/02/2017 7:15 2.09 0 1.5 3.7 0.57 0

24/02/2017 7:16 2.13 0 1.49 3.7 0.58 0

24/02/2017 7:16 2.17 0 1.49 3.7 0.58 0

24/02/2017 7:17 2.21 0 1.48 3.7 0.59 0

24/02/2017 7:17 2.2 4 1.48 3.6 0.6 0

24/02/2017 7:18 2.11 10 1.47 3.6 0.61 0

24/02/2017 7:18 1.97 9 1.47 3.6 0.61 0

126

24/02/2017 7:19 1.86 9 1.46 3.6 0.62 0

24/02/2017 7:19 1.78 10 1.46 3.7 0.63 0

24/02/2017 7:20 1.66 10 1.45 3.7 0.64 0

24/02/2017 7:20 1.48 9 1.45 3.7 0.65 0

24/02/2017 7:21 1.36 9 1.45 3.6 0.65 0

24/02/2017 7:21 1.28 2 1.44 3.6 0.67 0

24/02/2017 7:22 1.29 0 1.43 3.6 0.68 0

24/02/2017 7:22 1.33 0 1.43 3.7 0.68 0

24/02/2017 7:23 1.37 0 1.43 3.7 0.69 0

24/02/2017 7:23 1.39 0 1.42 3.7 0.7 0

24/02/2017 7:24 1.46 0 1.41 3.7 0.71 0

24/02/2017 7:24 1.51 0 1.41 3.7 0.71 0

24/02/2017 7:25 1.6 0 1.4 3.7 0.72 0

127

24/02/2017 7:25 1.68 0 1.4 3.7 0.72 0

24/02/2017 7:26 1.76 0 1.39 3.7 0.73 0

24/02/2017 7:26 1.93 0 1.39 3.7 0.73 0

24/02/2017 7:27 2.01 0 1.38 3.7 0.74 0

24/02/2017 7:27 2.14 1 1.38 3.6 0.75 0

24/02/2017 7:28 2.21 9 1.37 3.6 0.75 0

24/02/2017 7:28 2.15 10 1.36 3.6 0.76 0

24/02/2017 7:29 2.11 10 1.36 3.6 0.77 0

24/02/2017 7:29 2.03 9 1.35 3.6 0.79 0

24/02/2017 7:30 1.95 9 1.35 3.6 0.8 0

24/02/2017 7:30 1.81 9 1.35 3.7 0.8 0

24/02/2017 7:31 1.76 9 1.34 3.6 0.81 0

24/02/2017 7:31 1.58 9 1.33 3.6 0.82 0

128

24/02/2017 7:32 1.42 9 1.33 3.6 0.83 0

24/02/2017 7:32 1.32 4 1.32 3.6 0.84 0

24/02/2017 7:33 1.28 0 1.32 3.6 0.85 0

24/02/2017 7:33 1.33 0 1.31 3.6 0.85 0.49

24/02/2017 7:34 1.34 0 1.31 3.6 0.85 3.87

24/02/2017 7:34 1.41 0 1.3 3.6 0.82 3.88

24/02/2017 7:35 1.46 0 1.29 3.6 0.8 3.93

24/02/2017 7:35 1.5 0 1.29 3.6 0.78 3.93

24/02/2017 7:36 1.56 0 1.28 3.6 0.75 3.92

24/02/2017 7:36 1.6 0 1.27 3.6 0.72 3.94

24/02/2017 7:37 1.62 0 1.27 3.7 0.71 3.95

24/02/2017 7:37 1.69 0 1.27 3.6 0.67 3.91

24/02/2017 7:38 1.73 0 1.26 3.6 0.64 3.92

129

24/02/2017 7:38 1.76 0 1.25 3.7 0.62 3.94

24/02/2017 7:39 1.78 0 1.25 3.6 0.6 3.96

24/02/2017 7:39 1.83 0 1.24 3.6 0.57 3.89

24/02/2017 7:40 1.89 0 1.23 3.6 0.55 3.9

24/02/2017 7:40 1.91 0 1.23 3.7 0.53 0.24

24/02/2017 7:41 1.98 0 1.22 3.7 0.53 0

24/02/2017 7:41 2.01 0 1.22 3.6 0.54 0

24/02/2017 7:42 2.05 0 1.21 3.6 0.55 0

24/02/2017 7:42 2.1 0 1.2 3.6 0.56 0

24/02/2017 7:43 2.15 0 1.2 3.6 0.57 0

24/02/2017 7:43 2.17 0 1.19 3.6 0.58 0

24/02/2017 7:44 2.18 0 1.18 3.5 0.6 0

24/02/2017 7:44 2.18 0 1.18 3.6 0.61 0

130

24/02/2017 7:45 2.12 8 1.17 3.6 0.62 0

24/02/2017 7:45 2.04 9 1.16 3.7 0.63 0

24/02/2017 7:46 1.93 10 1.15 3.7 0.64 0

24/02/2017 7:46 1.83 9 1.14 3.7 0.66 0

24/02/2017 7:47 1.7 9 1.14 3.7 0.68 0

24/02/2017 7:47 1.56 9 1.13 3.7 0.69 0

24/02/2017 7:48 1.4 9 1.12 3.7 0.7 0

24/02/2017 7:48 1.34 8 1.1 3.7 0.72 0

24/02/2017 7:49 1.31 0 1.09 3.7 0.73 0

24/02/2017 7:49 1.33 0 1.08 3.7 0.75 0

24/02/2017 7:50 1.5 0 1.06 3.7 0.76 0

24/02/2017 7:50 1.62 0 1.04 3.7 0.77 0

24/02/2017 7:51 1.7 0 1.02 3.7 0.78 0

131

24/02/2017 7:51 1.7 0 1 3.6 0.79 0

24/02/2017 7:52 1.7 0 0.99 3.7 0.81 0

24/02/2017 7:52 1.97 0 0.97 3.6 0.81 0

24/02/2017 7:53 2.22 6 0.95 3.7 0.82 0

24/02/2017 7:53 2.21 8 0.93 3.7 0.82 0

24/02/2017 7:54 2.16 9 0.91 3.7 0.84 0

24/02/2017 7:54 2.12 9 0.91 3.6 0.85 0

24/02/2017 7:55 2.07 9 0.93 3.6 0.85 3.06

24/02/2017 7:55 1.96 9 0.96 3.7 0.8 5.21

24/02/2017 7:56 1.86 9 0.99 3.7 0.73 5.24

24/02/2017 7:56 1.78 9 1.02 3.7 0.67 5.23

24/02/2017 7:57 1.7 9 1.05 3.7 0.6 5.19

24/02/2017 7:57 1.61 9 1.09 3.7 0.54 3.51

132

24/02/2017 7:58 1.45 9 1.12 3.7 0.51 0

24/02/2017 7:58 1.37 9 1.14 3.7 0.51 0

24/02/2017 7:59 1.3 2 1.16 3.7 0.52 0

24/02/2017 7:59 1.3 0 1.18 3.7 0.52 0

24/02/2017 8:00 1.36 0 1.19 3.7 0.53 0

24/02/2017 8:00 1.4 0 1.2 3.7 0.53 0

24/02/2017 8:01 1.44 0 1.21 3.7 0.54 0

24/02/2017 8:01 1.48 0 1.22 3.8 0.54 0

24/02/2017 8:02 1.51 0 1.23 3.7 0.55 0

24/02/2017 8:02 1.56 0 1.24 3.7 0.55 0

24/02/2017 8:03 1.59 0 1.25 3.7 0.56 0

24/02/2017 8:03 1.62 0 1.26 3.7 0.56 0

24/02/2017 8:04 1.65 0 1.27 3.7 0.57 0

133

24/02/2017 8:04 1.65 0 1.27 3.7 0.58 0

24/02/2017 8:05 1.72 0 1.28 3.7 0.58 0

24/02/2017 8:05 1.77 0 1.29 3.7 0.58 0

24/02/2017 8:06 1.84 0 1.3 3.7 0.59 0

24/02/2017 8:06 1.84 0 1.31 3.7 0.6 0

24/02/2017 8:07 1.84 0 1.32 3.7 0.6 0

24/02/2017 8:07 1.84 0 1.32 3.7 0.6 0

24/02/2017 8:08 1.84 0 1.33 3.7 0.61 0

24/02/2017 8:08 1.84 0 1.34 3.7 0.62 0

24/02/2017 8:09 1.84 0 1.35 3.7 0.62 0

24/02/2017 8:09 1.95 0 1.35 3.7 0.62 0

24/02/2017 8:10 2.13 0 1.36 3.7 0.64 0

24/02/2017 8:10 2.19 0 1.37 3.7 0.67 0

134

24/02/2017 8:11 2.19 0 1.38 3.7 0.69 0

24/02/2017 8:11 2.19 0 1.38 3.6 0.71 0

24/02/2017 8:12 2.15 5 1.39 3.6 0.73 0

24/02/2017 8:12 2.11 10 1.4 3.6 0.73 0

24/02/2017 8:13 2.11 10 1.41 3.6 0.73 0

24/02/2017 8:13 2.11 10 1.41 3.6 0.75 0

24/02/2017 8:14 2.11 10 1.42 3.6 0.77 0

24/02/2017 8:14 2.11 10 1.43 3.6 0.77 0

24/02/2017 8:15 1.96 10 1.43 3.6 0.79 0

24/02/2017 8:15 1.72 9 1.44 3.6 0.8 0

24/02/2017 8:16 1.72 9 1.45 3.6 0.81 0

24/02/2017 8:16 1.72 9 1.45 3.6 0.82 0

24/02/2017 8:17 1.72 9 1.46 3.6 0.83 0

135

24/02/2017 8:17 1.48 3 1.46 3.6 0.84 0

24/02/2017 8:18 1.3 0 1.47 3.6 0.84 0

24/02/2017 8:18 1.3 0 1.48 3.6 0.85 0

24/02/2017 8:19 1.4 0 1.48 3.6 0.86 0.66

24/02/2017 8:19 1.4 0 1.48 3.6 0.83 3.78

24/02/2017 8:20 1.4 0 1.47 3.6 0.8 3.83

24/02/2017 8:20 1.4 0 1.47 3.6 0.78 3.81

24/02/2017 8:21 1.58 0 1.46 3.6 0.76 3.79

24/02/2017 8:21 1.62 0 1.46 3.6 0.73 3.79

24/02/2017 8:22 1.65 0 1.46 3.6 0.7 3.82

24/02/2017 8:22 1.69 0 1.45 3.6 0.68 3.8

24/02/2017 8:23 1.69 0 1.45 3.6 0.67 3.8

24/02/2017 8:23 1.69 0 1.44 3.6 0.62 3.81

136

24/02/2017 8:24 1.69 0 1.44 3.6 0.6 3.8

24/02/2017 8:24 1.83 0 1.43 3.6 0.57 3.77

24/02/2017 8:25 1.88 0 1.43 3.6 0.55 3.76

24/02/2017 8:25 1.9 0 1.42 3.6 0.54 3.76

24/02/2017 8:26 1.97 0 1.42 3.6 0.53 1.54

24/02/2017 8:26 1.99 0 1.41 3.6 0.54 0

24/02/2017 8:27 2.04 0 1.41 3.6 0.55 0

24/02/2017 8:27 2.07 0 1.4 3.6 0.55 0

24/02/2017 8:28 2.11 0 1.39 3.6 0.57 0

24/02/2017 8:28 2.15 0 1.39 3.6 0.58 0

24/02/2017 8:28 2.16 0 1.38 3.6 0.59 0

24/02/2017 8:29 2.2 0 1.38 3.6 0.6 0

24/02/2017 8:29 2.2 4 1.37 3.6 0.61 0

137

24/02/2017 8:30 2.2 9 1.37 3.6 0.62 0

24/02/2017 8:30 2.2 9 1.36 3.7 0.63 0

24/02/2017 8:31 2.03 9 1.36 3.7 0.64 0

24/02/2017 8:31 1.75 9 1.35 3.7 0.65 0

24/02/2017 8:32 1.68 9 1.34 3.8 0.66 0

24/02/2017 8:32 1.54 9 1.34 3.7 0.66 0

24/02/2017 8:33 1.44 9 1.33 3.7 0.68 0

24/02/2017 8:33 1.39 9 1.33 3.7 0.69 0

24/02/2017 8:34 1.38 9 1.32 3.7 0.7 0

24/02/2017 8:34 1.31 1 1.32 3.8 0.71 0

24/02/2017 8:35 1.37 0 1.31 3.8 0.72 0

24/02/2017 8:35 1.49 0 1.31 3.7 0.73 0

24/02/2017 8:36 1.6 0 1.3 3.7 0.74 0

138

24/02/2017 8:36 1.71 0 1.3 3.7 0.75 0

24/02/2017 8:37 1.81 0 1.29 3.7 0.75 0

24/02/2017 8:37 1.81 0 1.28 3.7 0.76 0

24/02/2017 8:38 2.06 0 1.28 3.7 0.77 0

24/02/2017 8:38 2.21 6 1.27 3.7 0.78 0

24/02/2017 8:39 2.18 10 1.27 3.7 0.78 0

24/02/2017 8:39 2.15 10 1.26 3.7 0.79 0

24/02/2017 8:40 2.05 10 1.26 3.7 0.79 0

24/02/2017 8:40 1.94 10 1.25 3.7 0.8 0

24/02/2017 8:41 1.83 10 1.25 3.7 0.81 0

24/02/2017 8:41 1.73 10 1.24 3.7 0.81 0

24/02/2017 8:42 1.66 10 1.23 3.7 0.83 0

24/02/2017 8:42 1.51 10 1.23 3.7 0.83 0

139

24/02/2017 8:43 1.36 8 1.22 3.7 0.84 0

24/02/2017 8:44 1.28 0 1.21 3.7 0.85 0

24/02/2017 8:44 1.3 0 1.21 3.7 0.85 5.49

24/02/2017 8:45 1.33 0 1.2 3.7 0.79 5.16

24/02/2017 8:45 1.39 0 1.19 3.7 0.73 5.21

24/02/2017 8:46 1.43 0 1.19 3.7 0.65 5.23

24/02/2017 8:46 1.45 0 1.18 3.7 0.58 5.21

24/02/2017 8:47 1.48 0 1.17 3.7 0.53 2.48

24/02/2017 8:47 1.54 0 1.17 3.7 0.51 0

24/02/2017 8:48 1.58 0 1.16 3.7 0.52 0

24/02/2017 8:48 1.61 0 1.15 3.7 0.53 0

24/02/2017 8:49 1.65 0 1.14 3.7 0.54 0

24/02/2017 8:49 1.68 0 1.13 3.7 0.55 0

140

24/02/2017 8:50 1.73 0 1.12 3.7 0.57 0

24/02/2017 8:50 1.77 0 1.11 3.7 0.57 0

24/02/2017 8:51 1.8 0 1.09 3.7 0.57 0

24/02/2017 8:51 1.83 0 1.08 3.7 0.58 0

24/02/2017 8:52 1.84 0 1.06 3.6 0.6 0

24/02/2017 8:52 1.91 0 1.04 3.6 0.61 0

24/02/2017 8:53 1.94 0 1.02 3.6 0.61 0

24/02/2017 8:53 1.97 0 1 3.6 0.62 0

24/02/2017 8:54 2.01 0 0.98 3.6 0.63 0

24/02/2017 8:54 2.06 0 0.96 3.6 0.63 0

24/02/2017 8:55 2.09 0 0.94 3.6 0.64 0

24/02/2017 8:55 2.11 0 0.93 3.6 0.65 0

24/02/2017 8:56 2.15 0 0.91 3.6 0.65 0

141

24/02/2017 8:56 2.15 0 0.89 3.6 0.67 0

24/02/2017 8:57 2.15 0 0.87 3.6 0.67 0

24/02/2017 8:57 2.15 0 0.86 3.6 0.67 0

24/02/2017 8:58 2.16 2 0.84 3.6 0.67 0

24/02/2017 8:58 2.15 10 0.82 3.6 0.68 0

24/02/2017 8:59 2.02 10 0.8 3.6 0.68 0

24/02/2017 8:59 1.95 9 0.78 3.6 0.68 0

24/02/2017 9:00 1.94 9 0.77 3.6 0.69 0

24/02/2017 9:00 1.85 9 0.75 3.6 0.7 0

24/02/2017 9:01 1.82 9 0.73 3.6 0.7 0

24/02/2017 9:01 1.82 9 0.72 3.6 0.7 0

24/02/2017 9:02 1.66 9 0.7 3.6 0.71 0

24/02/2017 9:02 1.66 9 0.69 3.6 0.71 0

142

24/02/2017 9:03 1.52 9 0.67 3.6 0.71 0

24/02/2017 9:03 1.5 9 0.66 3.6 0.72 0

24/02/2017 9:04 1.5 9 0.64 3.1 0.72 0

24/02/2017 9:04 1.39 4 0.63 0 0.72 0

24/02/2017 9:05 1.32 0 0.64 0 0.73 0

24/02/2017 9:05 1.36 0 0.64 0 0.73 0

WASTEWATER AUTOMATION THE DEVELOPMENT OF A LOW … · automation system that is reliable, robust,...

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