Operating and Control Philosophy

OPERATING AND CONTROL PHILOSOPHY

Sunshine Coast Regional District Chapman Creek WTP On-Site Hypochlorite Generation System

JUNE 2021

CONFIDENTIALITY AND © COPYRIGHT This document is for the sole use of the addressee and Associated Engineering (B.C.) Ltd. The document contains proprietary and confidential information that shall not be reproduced in any manner or disclosed to or discussed with any other parties without the express written permission of Associated Engineering (B.C.) Ltd. Information in this document is to be considered the intellectual property of Associated Engineering (B.C.) Ltd. in accordance with Canadian copyright law. This report was prepared by Associated Engineering (B.C.) Ltd. for the account of Sunshine Coast Regional District. The material in it reflects Associated Engineering (B.C.) Ltd.’s best judgement, in the light of the information available to it, at the time of preparation. Any use which a third party makes of this report, or any reliance on or decisions to be made based on it, are the responsibility of such third parties. Associated Engineering (B.C.) Ltd. accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this report.

Table of Contents

i

TABLE OF CONTENTS

SECTION PAGE NO.

Table of Contents i

List of Abbreviations ii

1 Introduction 1

2 Process Description 1

3 Overall Control Requirements 1

3.1 Existing Plant PLC 1

3.2 OSHGS PLC and HMI 1

3.3 Plant SCADA 1

4 Operating Philosophy 2

4.1 OSHGS Control 2

4.2 SHS Storage and Metering Control 3

4.3 Online Water and Air Quality Instruments 5

5 Process Alarm and Control Parameters 6

6 Plant PLC Communications 9

7 OSHGS HMI Display 9

8 Operator Adjustable Controls at Plant SCADA 13

Certification Page 1

Sunshine Coast Regional District

ii

LIST OF ABBREVIATIONS

HMI Human-Machine Interface

SCRD Sunshine Coast Regional District

SHS Sodium Hypochlorite Solution

OSHGS On-Site Sodium Hypochlorite Generation System

PLC Programmable Logic Controller

SCADA System Control and Data Acquisition

WTP Water Treatment Plant


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1 INTRODUCTION

This document provides information to the Sunshine Coast Regional District (SCRD) regarding the operating

philosophy and controls of the Chapman Creek Water Treatment Plant (WTP). The purpose of this document is to

enable programming and configuration of the Plant PLC and Plant HMI.

2 PROCESS DESCRIPTION

The Chapman Creek WTP supplies drinking water to the residents of the Sunshine Coast by delivering treated water

via the Selma Zone 2 Reservoir. The WTP process includes flash mixing and flocculation with coagulant and polymer

addition; dissolved air flotation; dual media filtration (anthracite coal and sand); primary ultraviolet disinfection

followed by gas chlorination and pH adjustment with soda ash addition. The existing chlorine disinfection system will

be converted to an on-site hypochlorite generation system (OSHGS) for sodium hypochlorite solution (SHS) to

improve operator, maintenance personnel and public safety and to improve long-term WTP system reliability.

3 OVERALL CONTROL REQUIREMENTS

3.1 Existing Plant PLC

The Chapman Creek WTP utilizes an existing Allen Bradley SLC5/05 and iFix HMI.

3.2 OSHGS PLC and HMI

In order to communicate with the existing Allen Bradley Ethernet protocols, the OSHGS will utilize a MicroLogix 1400

PLC or Compact Logix (preference) and a Red Lion HMI.

The OSHGS will be able to operate independently of the Plant PLC other than communication of a Run signal,

Chlorine Dose, Treated Water Chlorine Residual, Raw Water Flow, Treated Water Flow from the Plant PLC. The

OSHGS will also support a manual operation mode whereby the operational parameters can be manually set in the

event of an issue with the WTP PLC. The WTP plant PLC will read system status information, alarms and set points

from the OSHGS PLC and be able to write set point changes to the OSHGS.

If the OSHGS controller and HMI cannot accommodate the additional control and visualization of the ancillary

components (e.g., transfer pumps, storage tank level, blowers, motorized valves) and above-mentioned manual

mode, a second PLC and HMI will be required and provided by the installing contractor’s team.

3.3 Plant SCADA

The new OSHGS will communicate to the existing SCADA system via the ethernet network using Allen Bradley

Ethernet.


2

4 OPERATING PHILOSOPHY

4.1 OSHGS Control

The SHS for chlorination at the Chapman Creek WTP is to be generated on-site using a brine (salt water) electrolysis

process. The on-site SHS generation (OSHGS) system is a batch electro-chemical process. The system components are

both skid-mounted and off-skid installed. The primary generation components are power supply/rectifier, control

panel including OSHGS PLC, water heater, water softener, brine tank, brine pump, electrolytic cell, hydrogen dilution

blowers, and ambient hydrogen gas detector.

Plant service water will be heated and softened for use in the OSHGS. Brine will be produced in the Brine Tank by

combining dry salt and softened water. Salt will be provided in 25 kg bags which will be stored in the OSHGS Room

near the Brine Tank and OSHGS. Salt bags will be manually emptied into the brine tank as required.

For Chapman Creek WTP, the lower elevation position of the OSHGS equipment in relationship to the elevated SHS

storage tanks (TK-350 and TK-370) requires the use of an intermediate transfer tank (TK-250) and transfer pumps (P—

260 and P-270) along with associated hydrogen dilution blowers (BLO-280 and BLO-290) located in the OSHGS

Room. The primary reason for the transfer systems is to reduce backpressure on the electrolytic cells and to ensure

efficient hydrogen gas dilution and venting.

The generation of SHS up to and including the transfer tank and transfer pumps and blower operation will be the

responsibility of the OSHGS manufacturer. As such, a complete process and control description for the OSHGS is to

be provided by the selected OSHGS manufacturer. The series of tag numbers between 400 and 499 are reserved for

use by the OSHGS manufacturer. The OSHGS manufacturer will be responsible for all interlocks to shutdown the

OSHGS. A series of status, process values and alarms are passed between the OSHGS PLC and the Plant PLC.

The following is a general description of how the OSHGS will be called to operate based on SHS storage tank levels.

Operation of the OSHGS is ultimately based on the quantity of SHS in storage tanks TK-350 and TK-370 through

levels in these tanks as measured by LIT-351 and/or LIT-371. The OSHGS will run based on the following:

• OSHGS Start: Tank level (LIT-351 or LIT-371) at 1.7 m (48%)

• OSHGS Stop: Tank level (LIT-351 or LIT-371) at 3.4 m (95%)

These start/stop values are set by the OSHGS PLC and will be shared with the Plant PLC. If the OSHGS PLC detects a

tank level of 3.6 m (100%) in both storage tanks, it will disable the transfer feed.

OSHGS generation will also operate based on management of SHS in the intermediate transfer tank (TK-250). SHS

generation is essentially at constant flow rate. Therefore, level in the transfer tank (as measured by LIT-251) will be

controlled to a setpoint level by setting the speed of the operating transfer pump (P-260 or P-270). P-260 and P-270

will alternate operation. High and low level alarms associated with TK-250, will notify of a problem and facilitate an

OSHGS shutdown. Hydrogen dilution blowers BLO-280 and BLO-290 will also be controlled by the OSHGS PLC and

will alternate.


3

The tank status of TK-350, and TK-370 (on-line or off-line) will be indicated in the OSHGS PLC in order for the

OSHGS to identify which hydrogen dilution blower (BLO-360 and/or BLO-380) and dilution air differential pressure

switch is active. Further information regarding the SHS storage tanks is provided in Section 4.2.1 below.

4.2 SHS Storage and Metering Control

4.2.1 SHS Storage Systems

The OSHGS, including the chemical dosing system and associated piping, will be designed for sufficient capacity to

deliver 0.8% SHS at the required chlorine dose for the maximum WTP production of 26.4 ML/d.

Two storage tanks, with a combined capacity of 20,000 L (TK-350 and TK-370), will be used for storing 0.8% SHS

produced from the OSHGS. In the event of a significant failure of the OSHGS, 0.8% SHS can be produced using the

dilution panel located near the SHS tanks. The dilution panel combines 12% SHS with plant service water. Operation

of the dilution panel is a manual procedure. The 12% SHS will be stored in a tote or drum brought to site and located

near the dilution panel outside the WTP.

A motorized valve (MV-331 and MV 332) and a manual ball valve with a locking handle is provided at the inlet of each

SHS storage tank as a measure to prevent 0.8% SHS from flowing into a full or out-of-service storage tank. A pressure

sensor (PSH-330) is installed upstream of the SHS storage tanks to send an alarm signal when a pressure setpoint is

exceeded, this would be in the case of SHS being transferred to the storage tanks while both the inlet valves (MV-331

and MV 332) are closed, which will trigger the OSHGS shutdown. The pressure sensor and associated control actions

will be configured in the OSHGS PLC.

A motorized valve (MV-356 and MV-376) is provided at the outlet of each SHS storage tank. These valves can be

remotely closed to isolate a storage tank and in an emergency should the level in a tank drop rapidly. The control of

these outlet valves is to be configured in the OSHGS PLC.

SHS storage tank level instruments (LIT-351 and LIT-371) should be configured as follows in the OSHGS PLC:

• Instrument range: 0 m (0%) to 3.6 m (100%, overflow condition)

• Normal high level: 3.4 m (95%)

• Normal low level 1.7 m (48%)

• Low level alarm: 0.7 m (20%)

• Low low level alarm: 0.4 m (10%) (shutdown metering pumps)

• High level alarm: 3.5 m (97%) (shutdown transfer pump #1 or #2)

• Rapid drop in level: >10% in 10 seconds: close corresponding outlet valve and report alarm to Plant PLC

Alarms that trigger an OSHGS shutdown are to be configured by the OSHGS manufacturer in the OSHGS PLC.

SHS Spill Containment Sump: In the event of a SHS spill or leak, a float switch (LSH-340) will be tripped. This delivers

an alarm to the OSHGS PLC, which is then relayed to the Plant PLC.


4

4.2.2 Metering Pump Control

For normal operating conditions using a chlorine dose of 1.4 mg/L at an average WTP flowrate of 17.6 ML/d, the SHS

flowrate equates to approximately 130 L/h. At the peak daily demand of 26.4 ML/d using a chlorine dose of 1.4 mg/L,

the SHS flowrate equates to approximately 200 L/h. Based on the potential for two application points being used as

discussed below, there are two duty metering pumps each sized at a minimum of 200 L/hr.

However, under the plant emergency bypass situation where the required chlorine dose is 4.0 mg/L, the instantaneous

SHS flowrate requirement increases to 550 L/h. Therefore, three (3) 200 L/h metering pumps (two duty and one

standby unit) of same capacity are installed. The duty-standby order is selected by the operator at the OSHGS HMI or

Plant SCADA system.

As required by SCRD, a 550 L/h SHS flowrate could be delivered to any of the following three application points:

1. Downstream of media filters in the effluent chamber (regular operation).

2. Upstream of filters (infrequent operation).

3. Downstream of the reservoir prior to distribution (infrequent operation and/or emergency WTP bypass).

For typical operation, a single metering pump can deliver 200 L/h to the regular application point at the filter effluent

chamber. Two solenoid valves at the metering pump skid (SV-822 and SV-823) are used to alternate between the two

delivery lines carrying SHS to the regular application point based on configurable time-based rate (1-24 hours).The

configuration will support Alternate, Primary/Backup modes as well as taking a pump "Out of Service" as selected by

either the OSHGS HMI or Plant SCADA.

The delivery of SHS to the two other injection points (a single delivery line each for application points #2 and #3) is

initiated manually by the operator using manual valves. The third metering pump will be configurable via the OSHGS

HMI or the Plant SCADA system to send SHS to the pre-filter or post-reservoir delivery lines via motorized valves. The

pacing source for metering pump speed will change based on the delivery location. The operation of more than one

duty metering pump to deliver to multiple application points is determined by the operator and selected at the OSHGS

HMI or Plant SCADA.

Metering pump speed will be paced on plant water flow as follows:

• Filter Effluent Chamber: Raw water flow provided by Plant PLC.

• Upstream of Filters: FIT Raw water flow provided by Plant PLC.

• Downstream of Reservoir: Distribution flow provided by Plant PLC.

• Target chlorine dose for each of the application points will be selected by the operator at the OSHGS HMI or

Plant SCADA system based on knowledge of the chlorine residual. The typical dose will be 1.4 mg/L. Assignment

of duty and standby pumps will alternate based on elapsed runtime hours.

The treated water chlorine residual (existing plant instrument) dropping below the minimum setpoint will initiate a

switch from the duty metering pump to the standby metering pump. In the case where the chlorine residual is still

below the minimum setpoint, the OSHGS will switch the delivery line for the regular SHS injection to the effluent

chamber (application point #1) by closing the solenoid for the operating delivery line valves (either SV-822 or SV-823 )

and opening the solenoid valves for the other delivery line valves (either SV-823 or SV-822 ). For all other injection

points (application points #2 and #3), the delivery line will need to be switched manually by the operator.


5

The calculated base (flow paced) pump speed with only the duty metering pump operating will be:

When more than one pump is operating at a time, the calculated pump speed for each pump will be:

Metering pump faults and alarms conditions are communicated to the OSHGS and Plant PLCs and HMIs.

4.3 Online Water and Air Quality Instruments

There are several on-line water quality and air quality instruments installed within the WTP. Water quality parameters

measured are:

• Chlorine residual measured at the following locations:

• Filter effluent chamber.

• Distribution, directly downstream of Selma Zone 2 Reservoir.

• Air quality parameters measured are:

• Ambient chlorine gas in the OSHGS room, AIT-660.

• Ambient hydrogen gas in the OSHGS room, AIT-650. This device is hardwired to the OSHGS PLC. The sensor

will be read back to the OSHGS PLC. There are no building mechanical (ventilation) interlocks.

These devices are important for operator safety. In addition to delivering an alarm, the hydrogen gas detector will

cause the OSHGS to shut down if the high alarm value is reached (to be configured by the OSHGS manufacturer). In

addition, one of the two hydrogen dilution blowers (BLO-280/BLO-290) will operate until hydrogen levels drop to

below the alarm level. The chlorine gas detectors will alarm on high level.

SCRD will integrate the OSHGS alarms into the existing WTP alarm notification system.

Pump speed [%] = [(𝑳𝑯𝒚𝒑𝒐

𝒉 ) ÷ (

𝑳𝑯𝒚𝒑𝒐

𝒉@𝟐𝟎𝒎𝑨 𝑪𝒂𝒍𝒊𝒃𝒓𝒂𝒕𝒊𝒐𝒏)] 𝒙 𝟏𝟎𝟎%

Where:

𝑳𝑯𝒚𝒑𝒐 @ 𝟐𝟎𝒎𝑨 𝒊𝒔 𝟐𝟎𝟎 𝑳/𝒉𝒓 (to be confirmed using draw down test)


𝒉= (

𝑳𝑯𝟐𝑶

𝒔 ×

𝟑𝟔𝟎𝟎𝒔

𝒉 ×

𝒎𝒈𝑪𝒍𝑻𝑶𝑻

𝑳𝑯𝟐𝑶 ) ÷

𝟖𝟎𝟎𝟎 𝒎𝒈𝑯𝒚𝒑𝒐

𝐋𝑯𝒚𝒑𝒐

Pump speed [%] = [ (


𝒉

𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐏𝐮𝐦𝐩𝐬 𝐑𝐮𝐧𝐧𝐢𝐧𝐠) ÷ (


𝒉@𝟐𝟎𝒎𝑨 𝑪𝒂𝒍𝒊𝒃𝒓𝒂𝒕𝒊𝒐𝒏) ] x 100%


6

5 PROCESS ALARM AND CONTROL PARAMETERS

The Plant PLC is to be configured according to the control philosophies presented in Section 4 and the information

provided in Table 5-1. All alarms are to be displayed at the OSHGS HMI and can be sent to Plant SCADA system.

Table 5-1 Control Parameters and Alarms

Control/ Monitoring Location/Parameter

Tag Instrument

Range Alarm Levels Time Delay Control Action

Chlorine Residual (communicated from Plant PLC)

AIT (Cl2) 0 - 5 mg/L

Low Chlorine residual: < 0.5 mg/L

Chlorine Out-of-Range +/- 25% of target dose

High Chlorine residual:

> 2 mg/L

120 sec.

120 sec.

60 sec.

Alarm. Switch metering pump. If

alarm remains, switch delivery line

for the regular injection point at the

filter effluent chamber.

Alarm

Alarm

Ambient Chlorine Gas in OSHGS Room

AIT-660 0-10 ppm High Chlorine: > 0.5 ppm 30 sec. Alarm

SHS Storage Tank #1 Level

LIT-351 0 – 3.6 m Low Level: 0.7 m

Low Low Level: 0.4 m

High Level: 3.5 m

Loss of Echo

30 sec.

30 sec.

30 sec.

30 sec.

Alarm Compare value to

LIT-371 If 371 not low,

switch duty tank

Alarm

Alarm

Alarm, Switch to duty tank and LIT-

371

SHS Tank #1 Inlet Valve

MV-331 N/A Fail to Open

Fail to Close

Immediate

Immediate

Alarm

Alarm

SHS Tank #1 Outlet Valve

MV-356

N/A Fail to Open

Fail to Close

Immediate

Immediate

Alarm

Alarm


7


Tag Instrument


SHS Storage Tank #2 Level

LIT-371 0 – 3.6 m Low Level: 0.7 m

Low Low Level: 0.4 m

High Level: 3.5 m

Loss of Echo

30 sec.

30 sec.

30 sec.

30 sec.

Alarm Compare value to

LIT-351 If 351 not low,

switch duty tank

Alarm

Alarm

Alarm, Switch to duty tank and LIT-

351

SHS Tank #2 Inlet Valve

MV-332 N/A Fail to Open

Fail to Close

Immediate

Immediate

Alarm

Alarm

SHS Tank #2 Outlet Valve

MV-376

N/A Fail to Open

Fail to Close

Immediate

Immediate

Alarm

Alarm

Liquid Level in Spill Containment Sump

LSH-340 As installed Yes, upon float switch trip

Immediate Alarm

SHS Metering Pump #1 Fault

P-710 N/A Fault Active Immediate Alarm

SHS Flow Rate for Metering Pump #1

FIT-717 0 – 600 L/h High Flow: > 550 L/h

Low Flow: < 50 L/h

Flowmeter Fault

30 sec.

5 sec.

Immediate

Alarm

Shutdown Pump

Alarm





Low Flow: < 50 L/h

Flowmeter Fault

30 sec.

5 sec.

Immediate

Alarm

Shutdown Pump

Alarm





Low Flow: < 50 L/h

Flowmeter Fault

30 sec.

5 sec.

Immediate

Alarm

Shutdown Pump

Alarm




8


Tag Instrument




Low Flow: < 50 L/h

Flowmeter Fault

30 sec.

5 sec.

Immediate

Alarm

Shutdown Pump

Alarm

Filter Weir Box Delivery Line #1 at Metering Pump Skid

SV-822 Open / Close

N/A N/A N/A

Filter Weir Box Delivery Line #1 at Injection Point

SV-824

Open / Close

N/A N/A N/A

Filter Weir Box Delivery Line #2 at Metering Pump Skid

SV-823

Open / Close

N/A N/A N/A

Filter Weir Box Delivery Line #2 at Injection Point

SV-826

Open / Close

N/A N/A N/A

OSHGS Vendor to Configure the Following Controls/Monitoring Locations/Parameters

Ambient Hydrogen Gas in OSHGS Room

AIT-650 0-2000 ppm High Hydrogen: > 1500 ppm Note: Dilution blowers sized

to keep hydrogen concentration to <25% of LEL

= 10,000 ppm

5 sec. Alarm, OSHGS shutdown via OSHGS PLC.

BLO-280 or BLO-290 to continue operation until hydrogen level

reduced.

SHS Transfer Tank Level

LIT-251 [vendor setpoints]

Low Level: [setpoint]

Low Low Level: [setpoint]

High Level: [setpoint]

Loss of Echo

30 sec.

30 sec.

30 sec.

30 sec.

Alarm

Alarm

Alarm, OSHGS shutdown per OSHGS PLC

Alarm

SHS Transfer Pump #1 Fault

P-260 N/A Fault Active Immediate Alarm. Switch to P-270.

SHS Transfer Pump #2 Fault

P-270 N/A Fault Active Immediate Alarm. Switch to P-260

SHS Storage Tank Pressure Sensor

PSH-330 [vendor setpoint]

High Pressure: > [setpoint] 30 sec. Alarm. Shut down OSHGS and shut

down transfer pumps.


9

6 PLANT PLC COMMUNICATIONS

The new OSHGS PLC will communicate to the Plant PLC utilizing Allen Bradley (AB) Ethernet messaging to

communicate the information that the SCRD requires to show on the existing Plant HMI and SCADA system. The new

OSHGS will coordinate the process of generating hypochlorite by completing its operation to fill the transfer tank.

The OSHGS PLC will coordinate the requirement to transfer new hypochlorite from the transfer tank to the plant main

storage tanks The OSHGS PLC will then be responsible for coordinating the injection of hypochlorite into the process

stream from the storage tanks while monitoring the condition of the entire hypochlorite process.

7 OSHGS HMI DISPLAY

The following equipment and sensor information is to be displayed on the OSHGS HMI (see Table 7-1). Six (6) Plant

HMI graphic sheets are to be developed using the P&IDs as a template configuration:

A. Main Screen

B. OSHGS Screen

C. Settings Screen

D. Trends Screen

E. Alarm Screen

F. Alarm Log Screen

The OSHGS HMI graphics do not need to be fully replicated on the Plant HMI. However, SCRD will replicate OSHGS

status and alarms on the Plant SCADA system.

Table 7-1 Information to be Displayed on OSHGS HMI

Instrument Tag Instrument Description Information to be Displayed

A. Main Screen

AIT-650-H2 Ambient Hydrogen Gas – OSHGS Room

H2 Concentration (ppm), high level alarm

AIT-660-Cl2 Ambient Chlorine Gas – OSHGS Room

High Ambient Chlorine Gas

B. OSHGS Screen

LIT-351 SHS Storage Tank #1 Level Level (m)


TK-350 TK-370

SHS Storage Tank Selector Switch Tank #1 Only; Tank #2 Only, Both Tanks

MV-331 SHS Storage Tank #1 Inlet Motorized Valve Position

Open, closed, auto


Open, closed, auto


10


MV-356 SHS Storage Tank #1 Outlet Motorized Valve Position

Open, closed, auto


Open, closed, auto

P-710 P-720 P-750

SHS Metering Pump Pump Operating status; Speed

P-710 P-720 P-750

Pump Selector Switch Duty and Standby Pump identified

FIT-717 FIT-727 FIT-757

SHS Metering 25mm line Flow Rate SHS flow rate (L/h); Totalized flow (L)

SV-822 SV-823

Filter Weir Box SHS Delivery Lines Solenoid Valve Position

Open, closed


H2 Concentration (ppm)



OSHGS (and ancillary equipment) To be provided by OSHGS vendor % Current Output, On/Off, Fault

C. Settings Screen

P-260 P-270

SHS Transfer Pump Selector – Duty-Standby

Duty and Standby pumps are selected

FIT-266 FIT-276

SHS Transfer Pump Flow Setpoint Transfer flow rate, range selectable.

P-710 P-720 P-750

SHS Metering Pump Selector – Duty-Standby

Dosage injection rate – automatic pump start (3 duty – 1 standby).

FIT-717 FIT-727 FIT-757

SHS Metering Pump Flow Setpoint Dosage requirement, range selectable.

Chlorine Dose Default: 1.4 mg/L Adjustment Range: 1.0 – 4.0 mg/L

OSHGS Disable Switch Auto, Off

D. Trends Screen


H2 Concentration (ppm)



FIT-717 FIT-727 FIT-757

SHS Metering 25mm line Flow Rate SHS flow rate (L/h); Totalized flow (L)


11


P-710 P-720 P-750

SHS Metering Pump Pump speed and dosing flow

P-710 P-720 P-750

Pump Selector Switch Pump speed and dosing flow



E. Alarm Screen


Failed to open, failed to close







LIT-351 SHS Storage Tank #1 Level Loss of echo

LIT-371 SHS Storage Tank #2 Level Loss of echo


H2 Concentration High


Ambient Chlorine Gas High

FIT-717 FIT-727 FIT-757

SHS Metering 25mm line Flow Rate Low/no flow.

P-710 P-720 P-750

SHS Metering Pump Pump Fault

OSG Failure Common OSG Alarm OSG Internal Fault

Communication Failure Network Connection Failure of Communication between plant and OSG

F. Alarm Log Screen










12


LIT-351 SHS Storage Tank #1 Level Loss of echo High level alarm Low level alarm

LIT-371 SHS Storage Tank #2 Level Loss of echo High level alarm Low level alarm

FIT-717 FIT-727 FIT-757

SHS Metering 25mm line Flow Rate Low/no flow.

P-710 P-720 P-750

SHS Metering Pump Pump Fault


H2 Concentration High


Ambient Chlorine Gas High

OSG Failure Common OSG Alarm OSG Internal Fault

Communication Failure Network Connection Failure of Communication between plant and OSG


13

8 OPERATOR ADJUSTABLE CONTROLS AT PLANT SCADA

Items accessible to the operator at the Plant SCADA HMI that are to be adjustable are listed in Table 8-1:

Table 8-1 OSHGS HMI – Controls and Setpoints Adjustable by Operator

Instrument Tag Instrument Description Control

P-260 P-270

SHS Transfer Pump Selector – Duty-Standby

Duty and Standby pumps are selected

FIT-266 FIT-276

SHS Transfer Pump Flow Setpoint Transfer flow rate, range selectable.

MV-356 MV-376

SHS Storage Tank Outlet Motorized Valves

Open or close

P-710 P-720 P-750

SHS Metering Pump Selector – Duty-Standby

Dosage injection rate – automatic pump start (3 duty – 1 standby).

FIT-717 FIT-727 FIT-757

SHS Metering Pump Flow Setpoint Dosage requirement, range selectable.

Chlorine Dose Default: 1.4 mg/L Adjustment Range: 1.0 – 4.0 mg/L

OSHGS Disable Switch Auto, Off


CERTIFICATION PAGE

This report presents our findings regarding the Sunshine Coast Regional District Chapman Creek WTP On-Site

Hypochlorite Generation System.

Respectfully submitted,

Associated Engineering (B.C.) Ltd.

Prepared by:

Derek Desaulniers, P.Eng.

Technical Lead – EI&C

Rachel Trower, EIT

Water Process Engineer

DD/MH/fd

Reviewed by:

Matthew S. Henney, P.Eng.

Project Manager

Senior Process Engineer

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