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LOGAN WATER ALLIANCE

EDENS LANDING HLZ PUMP STATION DETAILED PLANNING

TASK NUMBER: 90-11-96

JULY 2013

Edens Landing HLZ pump Station Detailed Planning

Document Number: 7600-000-P-REP-PL-8176

90-11-96 Date issued: 26/07/2013 of 34 Rev: 1

Approval Register

Date

Project Manager Submitted

Planning & Project Management Team Review

Program Review

Controlled Document – Change Register

Revision Section

Changed Change Description Initial Date

A Draft Report JT/BR

B All Format draft report for Program Review SS 24/06/2013

C All Incorporate Program Review Comments JT 12/07/2013

1 All Final format SS 22/07/2013




TABLE OF CONTENTS

EXECUTIVE SUMMARY ................................................................................................................................. 6

1. INTRODUCTION ................................................................................................................................. 9

1.1 Objectives ........................................................................................................................................ 9

1.2 Scope ............................................................................................................................................... 9

1.3 Business Drivers .............................................................................................................................. 9

1.4 Study Area ..................................................................................................................................... 10

2. PLANNING CONTEXT ...................................................................................................................... 11

2.1 Background .................................................................................................................................... 11

2.2 Previous Studies ............................................................................................................................ 11

3. METHODOLOGY .............................................................................................................................. 12

4. DATA SOURCES .............................................................................................................................. 13

5. ASSUMPTIONS ................................................................................................................................ 14

5.1 Population and Demand ................................................................................................................ 14

5.2 Desired Standards of Service (DSS) ............................................................................................. 14

5.3 Stakeholder Engagement .............................................................................................................. 15

5.4 Cost ................................................................................................................................................ 15

6. ELEVATED RESERVOIR ................................................................................................................. 16

6.1 Low Pressure Issues ..................................................................................................................... 16

6.2 High Pressure Issues ..................................................................................................................... 17

7. EXISTING EDENS LANDING HLZ PUMP STATION ....................................................................... 19

7.1 Existing pump characteristics ........................................................................................................ 19

7.2 Existing pump operation ................................................................................................................ 20

8. OPTIONS DEVELOPMENT .............................................................................................................. 21

8.1 Pump station upgrade options ....................................................................................................... 21

9. OPTIONS ANALYSIS ....................................................................................................................... 22

9.1 Do nothing / non-infrastructure option ........................................................................................... 22

9.2 Option 1 - Reticulation Booster / Elevated tank off line ................................................................. 22

9.3 Option 2 - Reticulation Booster / Elevated tank on line ................................................................. 23

10. OPTION EVALUATION ..................................................................................................................... 24

10.1 Cost Assessment ........................................................................................................................... 24

10.2 Risk ................................................................................................................................................ 24

10.3 Town Planning and Approvals ....................................................................................................... 24

10.4 Preferred Option ............................................................................................................................ 24

11. CONCLUSIONS ................................................................................................................................ 26

12. RECOMMENDATIONS ..................................................................................................................... 27




13. CAPITAL WORKS PROGRAM IMPLICATIONS .............................................................................. 28

14. REFERENCES .................................................................................................................................. 29

FIGURES

Figure 1-1: Edens Landing HLZ ...................................................................................................................... 10

Figure 3-1: Project Methodology ..................................................................................................................... 12

Figure 6-1: Elevated Properties and Logger Locations ................................................................................... 16

Figure 6-2: Logger Data................................................................................................................................... 17

Figure 6-3: Revised Zone Boundaries ............................................................................................................. 18

Figure 7-1: Existing Edens Landing Pump Station .......................................................................................... 19

Figure 7-2: Existing Edens Landing Pump Curve ........................................................................................... 19

Figure 7-3: Flow and Pressure Data ................................................................................................................ 20

TABLES

Table 5-1: Existing HLZ Population and Demand Forecasts .......................................................................... 14

Table 5-2: Key LCC Stakeholders ................................................................................................................... 15

Table 5-3: First Principals Cost Methodology .................................................................................................. 15

Table 6-1: Revised HLZ Population and Demand Forecasts .......................................................................... 18

Table 9-1: Option 1 - Cost Evaluation ............................................................................................................. 22

Table 9-2: Option 2 - Cost Evaluation ............................................................................................................. 23

Table 10-1: Option Cost Assessment .............................................................................................................. 24

Table 10-2: Revised HLZ Demand Forecasts ................................................................................................. 25

Table 13-1: PIP Capital Works Program ......................................................................................................... 28

Table 13-2: Tentative Capital Works Program Item ........................................................................................ 28

APPENDICES

Appendix A Figures

Appendix B DSS




ABBREVIATIONS

AD Average Day

AHD Australian Height Datum

BWL Bottom Water Level

DMA District Metered Area

DN Diameter Nominal

DSS Desired Standards of Service

EP Equivalent Persons

FF Fire Flow

GIS Geographic Information System

HDD Horizontal Directional Drilling

HLZ High Level Zone

IDM Infrastructure Demand Model

LCC Logan City Council

LWA Logan Water Alliance

mAHD Metres Australian Height Datum

MDMM Mean Day Maximum Month

MH Maximum Hour

PIP Priority Infrastructure Plan

VSD Variable Speed Drive

WSZ Water Supply Zone




EXECUTIVE SUMMARY

The existing Edens Landing High Level Zone (HLZ) water pump station supplies water to the Edens Landing

elevated reservoir and direct supply, servicing approximately 2,200 people. The Logan East Priority

Infrastructure Plan (PIP) indicated that the existing pump station has insufficient capacity to meet both the

existing demand and expected growth within the area and was recommended for immediate upgrade.

The objective of this study was to undertake the detailed planning for the upgrade for the existing Edens

Landing HLZ pump station to align the HLZ with Logan City Council‘s (LCC) Desired Standards of Service

(DSS).

Initial hydraulic modelling indicated that the HLZ currently experiences low pressure issues (below 22 m)

around the immediate area of the reservoir as well as a high point along Gardner Rd. The HLZ also contains

properties that experience pressure above the maximum desired pressure (55 m) stipulated in the DSS in

the west of the existing zone.

In order to mitigate the low pressures, the operations team are currently running the reservoir between 65%

and 95%. This however, adds to the high pressure issues experienced in the low lying areas of the HLZ.

After investigation, and in conjunction with the Logan Water Alliance (LWA) Logan East Water Supply – DMA

and FF – Detailed Planning 90-11-92 project, it was found that the HLZ could be reduced to exclude the

properties experiencing high pressures. These properties can be serviced by the adjacent gravity network

which will form part of the DMA proposed under that investigation (DMA63). The DMA has been designed

with the inclusion of these properties to maintain DSS. Also, by decreasing the size of the HLZ, the

population (EP) and water demand also decreases, as do the pump and reservoir sizing requirements. The

table below displays the original and revised population and demand forecasts for the proposed HLZ.

Edens Landing HLZ Demand Forecast 2011 2016 2021 2026 2031 Ultimate (2061)

Original Population (EP) 2192 4572 4891 4951 5053 5729

Revised Population (EP) 1508 3765 4046 4106 4209 4758

Original Average Day (ML/d) 0.6 1.2 1.3 1.3 1.3 1.5

Revised Average Day (ML/d) 0.4 1.0 1.1 1.1 1.1 1.2

Option Developments

Two infrastructure options and a non-infrastructure option were evaluated to determine the augmentations

required to meet the LCC DSS.




Do nothing / non-infrastructure option

A hydraulic analysis of the Edens Landing HLZ system and field data has shown that the existing network

configuration (where the Edens Landing HLZ pump station supplies the elevated reservoir), will continue to

have both low and high pressure issues that do not meet the DSS requirements.

Option 1 - Reticulation Booster / Elevated tank off line

Option 1 considers taking the elevated reservoir off line, and reconfiguring the existing Edens Landing HLZ

pump station into a reticulation booster to directly supply the HLZ. The cost of this option is approximately

$251,517, and includes the installation of:

two variable speed drives (VSD)

diesel generator

switchboard upgrade

jacking pump / diaphragm tank

Option 2 - Reticulation Booster / Elevated tank on line

Option 2 considers retaining the elevated reservoir on line, and constructing a new dedicated reticulation

booster pump station to supply the elevated areas currently experiencing low pressures. The cost of this

option is approximately $495,517, and includes:

228 m of DN150 pipe

5 kW booster pump

Conclusions

This current study has demonstrated that:

a “do nothing” option is not viable because it does not remedy the low pressures (19 to 20 m) in

two elevated areas within the zone to meet the DSS requirements (22 m)

the current high level zone can be reduced in size to alleviate high pressure issues in the area

west of Gardner Road. The existing Waterford lots served by Edens Landing pumps can be

transferred to the existing gravity network serviced by Wuraga ground level storage.

under Option 1 (removing the elevated reservoir from use and reconfiguring the HLZ pump

station to operate as a reticulation booster), no further changes are required to the capacity of

the pump station until approx. 2026/2031 maintaining a duty/standby regime. This capacity can

service to the ultimate planning horizon in a duty/assist configuration, subject to the PIP growth

projections.




the capital cost for Option 1 of $215,517 is significantly lower than the cost for Option 2 of

$495,517 (retaining the current network configuration and creating a dedicated pump-boosted

zone for the two elevated areas)

there are no town planning or approvals considerations for either option

based on both cost and standards of service outcomes, Option one has been selected as the

preferred option

Recommendations

The Logan Water Alliance recommends that:

1. Logan City Council immediately revise the zone boundary for the Edens Landing high level zone

to transfer the low lying Waterford properties to the East of Gardiner Road to the adjacent gravity

network.

2. Logan City Council adopt an augmentation strategy to reconfigure the existing Edens Landing

HLZ pump station and take the elevated storage out of service (Option 1) at an estimated capital

cost $251,517. It is recommended that this work in added to the Capital Work Program for

2013/14.




1. INTRODUCTION

The existing Edens Landing High Level Zone (HLZ) water pump station supplies water to the Edens Landing

elevated reservoir and direct supply, which services approximately 2,200 people. The Logan East Priority

Infrastructure Plan (PIP) indicated that the existing pump station has insufficient capacity to meet both the

existing demand and expected growth within the area.

This detailed planning study examines the works required to augment the pump station to meet the Desired

Standards of Service (DSS).

1.1 Objectives

The objective of this study was to undertake the detailed planning for the Edens Landing HLZ pump station,

including:

pump performance requirements

approvals required for proposed works

preferred pumping arrangement in terms of minimising operational and maintenance costs

1.2 Scope

The scope of this detailed planning report includes the following activities:

review the previous planning for the study area

review and document the business drivers for the proposed works

assess a “do nothing” approach and non-infrastructure solutions

develop and assess options to meet the project objectives

select a preferred option to progress to preliminary design (if applicable)

develop unit rate cost estimates for the proposed works

1.3 Business Drivers

The business drivers for this project include growth and improvement.

Existing Deficiencies. The existing pump capacity fails to meet DSS and pressure issues are

experienced within the zone.

Growth. Growth is identified for the Edens Landing HLZ in accordance with the most recent

Infrastructure Demand Model (IDM).




1.4 Study Area

The extents and location of the existing Edens Landing HLZ, pump station and elevated reservoir are shown

in Figure 1-1.

Figure 1-1: Edens Landing HLZ




2. PLANNING CONTEXT

2.1 Background

The Logan East PIP identified that the Edens Landing HLZ pump station and reservoir do not meet the DSS

and are currently undersized. The upgrade works are tentatively included in Logan City Council’s (LCC)

capital works program as item W0094 with a value of $251,000. Further discussion on the status of this

upgrade is discussed in Section 13.

The Logan East Trunk Water Network Project Development report (90-11-29) identified a cost of

approximately $205,000 (pump replacement only) for undertaking this upgrade (PIP ID: LE_U5004.1) and

required for delivery in the 2013/14 financial year.

2.2 Previous Studies

The following previous planning studies were considered during this study:

Logan East PLMP and Fire Flow Scoping Report (LWA 2012)

Priority Infrastructure Plan: Water Planning Report - Logan East ( LWA 2011)

Summary Report - Logan East Proposed DMAs (Allconnex Water)

Logan East Water Network Detailed Planning Report (LWA 2012)




3. METHODOLOGY

Figure 3-1 describes the methodology undertaken in this study. The project has been split into four phases,

with the tasks in each phase listed below.

Figure 3-1: Project Methodology

• Project familiarisation and review of background planning

• Review available drawings and operational information

• Meet with Logan Water staff to discuss issues and known constraints

Phase 1 - Project Appreciation

• Confirm project drivers and document business case

• Investigate both “do nothing” and “non-infrastructure” options

• Determine whether infrastrutcture options are required

Phase 2 - Project Justification

• Undertake a site visit to confirm site constraints / opportunities

• Develop preliminary infrastructure options

• Consider staging or deferring works where feasible

• Develop options for assessment

• Undertake hydraulic modelling to determine option outcomes

• Prepare cost estimates

• Review Town Planning, Environment, and Community issues

Phase 3 - Option Development and Assessment

• Undertake sensitivity analysis (if applicable)

• Identify preferred option

• Determine all approvals necessary for implementation of option

• Document investigation, findings and recommendations

Phase 4 - Recommendations and Requirements




4. DATA SOURCES

The following data was used for this study:

population and water demands for Logan East were obtained from the 2010 IDM, Version 5 (LWA

Aug 2011). The methodology used to convert forecasts of residential and non-residential growth into

demand is outlined in the Priority Infrastructure Plan Infrastructure Demand Model Report (LWA Mar

2011).

site Inspections: Inspection of existing pump station

as-Constructed Information: As-Constructed drawings of existing infrastructure

GIS data: Logan City Council GIS Database

H20Map model: as prepared by the Logan Water Alliance for the Logan Water Development

Services team

previous Planning reports (outlined in Section 2.1)

Stakeholder Engagement was limited to discussions with Logan City Council departments, primarily the

Water Operations and Infrastructure Branches.




5. ASSUMPTIONS

5.1 Population and Demand

The water demand forecasts for the existing Edens Landing HLZ were obtained from the Priority

Infrastructure Plan: Water Planning Report - Logan East (LWA Aug 2011). The forecast population is

represented as an Equivalent Person (EP) and then converted to a projected water demand based on the

DSS average day demands for the supply area.

The projected population, and average day (AD) and maximum hour (MH) water demand forecasts for the

HLZ for each planning horizon are presented in Table 5-1.

Table 5-1: Existing HLZ Population and Demand Forecasts


Population (EP) 2192 4572 4891 4951 5053 5729

AD (ML/d) 0.6 1.2 1.3 1.3 1.3 1.5

AD (L/s) 6.6 13.8 14.7 14.9 15.2 17.2

MH (L/s) 25.1 52.3 55.9 56.6 57.8 65.5

5.2 Desired Standards of Service (DSS)

The relevant DSS are included in Appendix C and were obtained from the Desired Standards of Service

Review (LWA Sep 2010). The most significant DSS water supply design criteria include:

Pumping capacity

o Pump servicing an elevated reservoir

(6MH - Operating Volume) / (6x3600)

o Reticulation Booster Pumps / Pumped System

MH+FF (fire flow)

o Standby pump capacity – to match duty, except where more than one pump or as

determined by risk assessment

Service Pressures

o Minimum operating pressure

22 m at property boundary

o Maximum operating pressure

80 m at property boundary

55 m – target maximum pressure




5.3 Stakeholder Engagement

Table 5-2 summarises the key stakeholders that were consulted during this study.

Table 5-2: Key LCC Stakeholders

LCC Branch Name Position Level of Consultation

Water Operations Lester Bridgham Mechanical and Electrical Operations Supervisor

Presentation for discussion of options and recommendations, site visit

Water Operations Darshan Udayaratna Assistant Supervisor

Mechanical and Electrical Operations

Presentation for discussion of options and recommendations, site visit

Water Development Services

Marco Bonotto Water Development Services

Program Leader

Confirmation of population projections within the study area

based on latest development information

Water Infrastructure Planning

Sandy Veeren Water Infrastructure

Planning Program Leader Overall planning and capital works

5.4 Cost

As the unit rates do not provide good coverage on the items considered for this task, a first principles

approach was used for costing infrastructure requirements identified in this report. The values were obtained

from the Logan Water Alliance Design team and are detailed in Table 5-3.

Table 5-3: First Principals Cost Methodology

Augmentation Type Construction Size Cost /

Meter Start Up Contingency Total

Water Main PE 600mm Enveloper

HDD (horizontal directional

drilling)

<450 mm $2000

45% 30%

$3500

Trench <450 mm $1000 $1750

VSD

Water - 20 kW - - - $15,000

Generator Diesel - 130 kVA - - - $50,000




6. ELEVATED RESERVOIR

The Logan East PIP planning report identified that the elevated reservoir currently servicing the Edens

Landing HLZ is undersized. The subsequent Logan East Water Network Planning (LWA 2012) report

recommended that the elevated reservoir not be upgraded, in favour of upgrading the existing pump station

by converting it into a booster pump station (to directly supply the Edens Landing HLZ and bypassing the

reservoir).

6.1 Low Pressure Issues

Hydraulic modelling indicated existing low pressure issues in the immediate area of the reservoir and at a

high point along Gardner Rd. Pressure loggers were installed by LCC Operations in the areas indicated by

the model to be experiencing low pressures, as noted in Figure 6-1.

Figure 6-1: Elevated Properties and Logger Locations

The data recorded by the pressure loggers confirmed the low pressures indicated by the model as

demonstrated in Figure 6-2.




Figure 6-2: Logger Data

The low pressures experienced in the elevated areas are primarily due to the physical configuration of the

reservoir. The bottom water level (BWL) of the elevated reservoir is 108 mAHD, with the ground level of the

elevated properties ranging between 88 mAHD and 92 mAHD. Although there is the potential for pressures

to drop to 16 m in the elevated area, the operation of the reservoir limits the minimum pressure to 19 m when

the pumps are not operating.

6.2 High Pressure Issues

6.2.1 High Pressure Properties

The western section of the Edens Landing HLZ experiences pressures that are close to or above the

maximum pressure of 80 m stipulated in the DSS. This is primarily due to a ledge that runs through the zone,

which has a sharp fall off to the western side to ground elevations of approximately 30 mAHD. Based on the

BWL of the elevated reservoir (108 m), the maximum pressure is likely to be around 78 m in low demand

periods; however, when the Edens Land HLZ pump station is operating, the maximum pressure is likely to

exceed 85 m.

A concurrent District Metered Area (DMA) detailed planning project for Logan East (Logan East Water

Supply – DMA and FF – Detailed Planning, Task 90-11-92) identified that the boundaries of the HLZ could

be altered to incorporate the western area currently experiencing high pressures into neighbouring DMAs.

Isolated areas in the east of the current HLZ are also able to be transferred to neighbouring supply zones.

The resulting decrease in the size of the zone will reduce the pump and reservoir requirements.

Figure 6-3 illustrates the proposed boundary changes.

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Figure 6-3: Revised Zone Boundaries

6.2.2 Revised Population Projection

The reduced HLZ boundary will be used for all options considered in this study, with the revised population

and demand data presented in Table 6-1.

Table 6-1: Revised HLZ Population and Demand Forecasts


Population (EP) 1508 3765 4046 4106 4209 4758

AD (ML/d) 0.4 1.0 1.1 1.1 1.1 1.2

AD (L/s) 4.5 11.3 12.2 12.4 12.7 14.3

MH (L/s) 17.2 38.3 41.6 42.3 43.4 49.7




7. EXISTING EDENS LANDING HLZ PUMP STATION

Figure 7-1: Existing Edens Landing Pump Station

7.1 Existing pump characteristics

Three water pump sets are currently installed at the Edens Landing pump station (Figure 7-1), a duty, a

standby pump for normal operation, and a diesel pump to maintain supply in the event of a power failure.

The existing pumps can deliver a range of flows from 15.3 to 47.5 L/s with a nominal design head of 50 m.

The pump curve for both a single pump and the two pumps combined are shown in Figure 7-2.

Figure 7-2: Existing Edens Landing Pump Curve

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7.2 Existing pump operation

The operation of the existing pump station retrieved from the ClearSCADA system is presented in Figure 7-3.

Figure 7-3: Flow and Pressure Data

The information presented highlights the actions the LCC’s Operations team are taking to attempt to align

the HLZ with the DSS. The pumps are turning on at a higher rate, approximately 10 times a day, than would

be expected of a pump station supporting storage. This is due to the Operations team keeping the elevated

reservoir at a high level due to the BWL of the reservoir not being high enough to supply the minimum

required pressure (22 m) to the surrounding areas.

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8. OPTIONS DEVELOPMENT

8.1 Pump station upgrade options

A “do-nothing” (or non-infrastructure solution) as well as two infrastructure options were developed to ensure

that the Edens Landing HLZ can meet the DSS.

8.1.1 Do nothing / non-infrastructure option

An analysis of the Edens Landing hydraulic modelling and field data indicates that the existing pump station

and elevated reservoir (working as a pump servicing an elevated reservoir) cannot alleviate low pressure

issues within the zone due to the physical configuration of the reservoir. The pump station has sufficient

capacity to meet the demand for the Edens Landing HLZ until the 2031 planning horizon without any

changes or modification; however, the elevated reservoir is undersized, and does not meet the DSS for

storage requirements.

As the “do nothing” (or non-infrastructure) option does not strictly meet the DSS, it is not considered viable.

8.1.2 Option 1 - Reticulation Booster / Elevated tank off line

Option 1 considers taking the elevated reservoir off line, and reconfiguring the existing Edens Landing HLZ

pump station into a reticulation booster pump station. The low pressures in the zone are experienced when

the elevated reservoir is supplying the area. This is due to the BWL of the reservoir not being high enough to

service the properties in the two elevated areas. By taking the reservoir off line, the low pressures in the two

elevated areas can be nullified by using an increased pressure control for the pump station

Some key considerations for this option were:

The pump station reconfiguration to a reticulation booster will put increased strain on the pump

station. A risk assessment of the pumps and a jacking pump / diaphragm tank may be required.

Variable Speed Drives (VSD) will be required for the existing pumps to meet the range of flow

characteristics.

8.1.3 Option 2 - Reticulation Booster / Elevated tank on line

Option 2 retains the elevated reservoir and Edens Landing HLZ pump station in the current configuration,

with the two elevated areas to be serviced via a small dedicated booster pump station. This option requires

additional pipe work to create the elevated zone, as indicated in Figure 1 Appendix A.




9. OPTIONS ANALYSIS

This section discusses the options developed in this study. The options have been developed to ensure that

adequate levels of service are achieved based on the proposed growth in the study area, while maximising

the capacity and asset life of the existing infrastructure, and optimising any short-term augmentation works.

9.1 Do nothing / non-infrastructure option

A hydraulic analysis and field data for the Edens Landing HLZ system indicated that the existing pump

station and elevated reservoir will continue to create low pressure issues within the zone. This option has not

been considered any further.

9.2 Option 1 - Reticulation Booster / Elevated tank off line

Option 1 involves the conversion of the existing pump station into a reticulation booster to directly supply the

Edens Landing HLZ.

9.2.1 Costs

This option will require minor works to reconfigure the existing pump station to operate as a reticulation

booster. Both existing pumps will need to be retro-fitted with a variable speed drive (VSD). The diesel pump

will also need to be converted into a diesel generator to ensure continuous operation of the main pumps

during any loss of power.

A small jacking pump (with a diaphragm tank) will be required to pressurise the system when the flows are

too small for the existing pumps. The LWA design team was consulted to develop an appropriate cost. The

cost includes an allowance for upgrading of the switchboard (including telemetry) in the instance it is

required.

Table 9-1 details the cost for Option 1.

Table 9-1: Option 1 - Cost Evaluation

Infrastructure Cost per item Quantity Total cost

VSD Units $15,000 2 $30,000

Diesel Generator $50,000 1 $50,000

Jacking Pump / Diaphragm Tank

$96,517 1 $96,517

Switch Board Upgrade $75,000 1 $75,000

Total $251,517




9.2.2 Risk

This option carries the risk of no storage, fire flow or otherwise. In the case of the primary pump requiring

repairs or failure, the standby pump can still operate. If power to the site fails, the diesel generator will power

either the duty or standby pump. The reconfiguration of the pumps from a pump serving an elevated

reservoir to a reticulation booster, will result in the pumps operating continuously at a range of speeds as

opposed to operating intermittently to fill the reservoir, and a detailed risk assessment should be carried out

to ensure appropriate risk mitigation measures are employed.

9.2.3 Town Planning and Approvals

The town planning and approvals team were not consulted for this option, as all infrastructure requirements

would be undertaken in the existing pump house.

9.3 Option 2 - Reticulation Booster / Elevated tank on line

Option 2 retains the elevated reservoir to service the majority of the current HLZ, with a small (5 kW)

reticulation booster pump station to supply the two elevated areas.

9.3.1 Costs

Some additional pipe work is required to create the new dedicated boosted area, as indicated in Appendix A.

Table 9-2 details the costs for Option 2.

Table 9-2: Option 2 - Cost Evaluation

Infrastructure Cost per item Quantity Total cost

Pipe (Trench) $1750 / m 228 m $399,000

Pump (5 kW) $96,517 1 $96,517

Total $495,517

9.3.2 Risk

Option 2 adds minimal risk to the existing pump arrangement. The small booster pump station servicing the

elevated areas will require additional operation controls in the case of a fire event and a bypass to allow fire

flows to be supplied from the reservoir

Although the elevated reservoir would not service the same number of properties, and therefore have a

reduced demand, it would still not meet the requirements stipulated in the DSS.

9.3.3 Town Planning and Approvals

Although this option requires the construction of approximately 228 m of water mains, the Town Planning

and Approvals teams were not consulted as all of the additional pipelines would be constructed in fully-

developed areas on previously-disturbed land.




10. OPTION EVALUATION

The required infrastructure associated with each option is assed in the following section against both cost

and non-cost criteria.

10.1 Cost Assessment

A first principles cost assessment was undertaken for each option based on the assumptions outlined in

Section 5. The assumed construction method is noted in the table, with ‘Trench’ referring to conventional

open trench construction.

Table 10-1 displays the costs associated with each option.

Table 10-1: Option Cost Assessment

Option Augmentation Description Cost Total Cost

1

2 x Pump VSD $30,000

$251,517

Generator Diesel $50,000

Pump Jacking Pump / Diaphragm Tank

$96,517

Switch Board Upgrade - $75,000

2

228 m of 150 mm Trench Pipe $399,000

$495,517

5 kW Pump Station $96,517

10.2 Risk

There are risks associated with both options; however, Option1 carries a higher risk due to the lack of

storage. In consultation with LCC Operations, the mitigation measures (installation of a diesel generator)

proposed are considered acceptable. Option 2 has a lower associated risk; however, the existing elevated

tower would still be undersized in Option 2, even with the reduced zone boundaries.

10.3 Town Planning and Approvals

No consideration was given to town planning or approvals for either option.

10.4 Preferred Option

10.4.1 Option Selection

The preferred option is primarily based on cost, with Option 1 approximately half the cost of Option 2.

Although the risk is marginally higher for Option 1, the risk mitigation measures and a risk assessment of the

pump station amounted to an acceptable level of risk.




10.4.2 Pump Assessment

The existing pumps converted to a booster pump station, set up in a duty / standby arrangement should,

according to the IDM, be able to supply the Edens Landing HLZ until approximately the 2026 / 2031 planning

horizon. After that point a duty assist arrangement for maximum hour and fire fighting flows may be required.

Table 10-2 below shows the duty points for each planning horizon, assuming development rolls out as per

the IDM.

Table 10-2: Revised HLZ Demand Forecasts

Edens Landing HLZ Demand Forecast

2011 2016 2021 2026 2031 Ultimate (2061)

MH (L/s) 17.2 38.3 41.6 42.3 43.4 49.7

Fire Fighting 30 30 30 30 30 30

Required Pump Head (m) 28 38 40 40 42 52




11. CONCLUSIONS

This current study has demonstrated that:

a “do nothing” option is not viable because it does not remedy the low pressures (19 to 20 m) in

two elevated areas within the zone to meet the DSS requirements (22 m)

the current high level zone can be reduced in size to alleviate high pressure issues in the area

west of Gardner Road. The existing Waterford lots served by Edens Landing pumps can be

transferred to the existing gravity network serviced by Wuraga ground level storage.

under Option 1 (removing the elevated reservoir from use and reconfiguring the HLZ pump

station to operate as a reticulation booster), no further changes are required to the capacity of

the pump station until approx. 2026/2031 maintaining a duty/standby regime. This capacity can

service to the ultimate planning horizon in a duty/assist configuration, subject to the PIP growth

projections.

the capital cost for Option 1 of $215,517 is significantly lower than the cost for Option 2 of

$495,517 (retaining the current network configuration and creating a dedicated pump-boosted

zone for the two elevated areas)

there are no town planning or approvals considerations for either option

based on both cost and standards of service outcomes, Option one has been selected as the

preferred option




12. RECOMMENDATIONS

The Logan Water Alliance recommends that:

3. Logan City Council immediately revise the zone boundary for the Edens Landing high level zone

to transfer the low lying Waterford properties to the East of Gardiner Road to the adjacent gravity

network.

4. Logan City Council adopt an augmentation strategy to reconfigure the existing Edens Landing

HLZ pump station and take the elevated storage out of service (Option 1) at an estimated capital

cost $251,517. It is recommended that this work in added to the Capital Work Program for

2013/14.




13. CAPITAL WORKS PROGRAM IMPLICATIONS

The requirement to upgrade this pump station was initially identified in the master planning for Logan East

and documented in Priority Infrastructure Plan: Water Supply Planning Report– Logan East (LWA 2011). The

need was further verified as part of another project and documented in Logan East Trunk Water Network,

Project Development (LWA 2012), which recommended that detailed planning be undertaken.

Liaison with Logan City Council's Capital Program Development Coordinator during this project identified that

this works was not included in the current Capital Works Program. This has been tentatively added until such

time as a Project Brief has been approved by the Water Infrastructure Manager.

The item details originally provided as part of the master planning are presented in Table 13-1. The

implications of this detailed planning study on the value and scope currently reflected in the capital works

program are shown in Table 13-2.

Table 13-1: PIP Capital Works Program

PIP ID Project Name

Project Description Project Status

Total Project Cost

Year Implications of this Study

LE_U5004.1

Upgrade Edens Landing HLZ PS

An upgrade to the existing pump station of 27 kW pumping capacity

Master Planning

$205,671 2009 Refer to Table 13-2.

Table 13-2: Tentative Capital Works Program Item

CWP Ref.

Project Name Project Description Project Status

Total Project

Cost Year

W0094 Edens Landing HLZ Pump Station (WPS53) Upgrade

The objective of this project is to convert the existing pump station into a reticulation booster to directly supply the Edens Landing HLZ. The scope of works includes the installation of 2 x Variable Speed Drives (VSD) units, a diesel generator, jacking pump/diaphragm tank and the upgrade of the switchboards. Asset ID: WPS000037

Detailed Planning

$251,517 2013




14. REFERENCES

Logan Water Alliance 2011, Priority Infrastructure Plan: Water Supply Planning Report – Logan East, (Task

90-10-57)

Logan Water Alliance 2012, Logan East Pressure and Leakage Management Program and Fire Flow

Scoping Report (Task 90-11-38)

Logan Water Alliance 2012, Logan East Trunk Water Network Project Development (Task 90-11-29)

Logan Water Alliance 2012, Logan East Water Supply – DMA and FF – Detailed Planning (Task 90-11-92)



90-11-96 Date issued: 26/07/2013 Rev: 1

Appendix A Figures



90-11-96 Date issued: 26/07/2013 Rev: 1

Appendix B DSS



90-11-96 Date issued: 26/07/2013 Rev: 1

WATER NETWORK DSS

Parameter Criteria

Water Demand

Average Day demand

On demand areas - 260 L/EP/d. Based on 230 L/EP/d + allowance for leakage/losses (30 L/EP/d).

Constant flow areas - 180 L/EP/d. Based on 130 L/EP/d + allowance for leakage/losses (50 L/EP/d).

Peaking factors MDMM/AD MD/AD MH/AD

Residential detached 1.4 1.7 3.8

Residential attached 1.3 1.6 3.1

Rural residential 1.4 1.7 CF services 70 L/hr/ET

Commercial 1.2 1.3 2.0

Industry 1.2 1.3 1.7

Parks / Open Space 1.2 1.3 1.7

System planning

Bulk supply and reticulation

3 days of MDMM. Reservoirs to have a net positive inflow and capable of continuous operation and not fall below the emergency level. 3 days of MD. Reservoirs should not fall below the emergency level. 5 days of AD. Reservoirs should fill from empty to full

Minimum service pressure

Minimum operating pressure at MH

On demand areas – 22m at the property boundary based on reservoir at minimum operating level (MOL). MOL defined as 15% of storage height or top of emergency storage

Constant flow areas – 10m at the property boundary based on reservoir at minimum operating level (MOL). MOL defined as 15% of storage height or top of emergency storage.

Maximum operating pressure 80 m at the boundary based on the reservoir at TWL

Target pressure 55 m at the property boundary based on the reservoir level at TWL

Fire fighting

System pressure

On demand areas – 12 m minimum at property boundary

Constant flow areas – no fire service provided

Fire flow Residential – 15l/s for 2hrs Commercial & Industrial – 30l/s for 4hrs Special risk / hazard to be advised by Allconnex Water

Background demand 2/3 MH (as per DERM requirements)

Reservoir level MOL

Number of fires <5000 EP – single fire for residential or industrial / commercial >5000 EP – simultaneous single residential fire plus single commercial / industrial fire for sizing trunk mains



90-11-96 Date issued: 26/07/2013 Rev: 1

WATER NETWORK DSS

Parameter Criteria

Reservoir storage

Ground level storage capacity

3 (MD - MDMM) + (Greater of emergency storage/fire fighting storage) Emergency Storage = the greater of 4hr MDMM demand in zone or 0.5ML whichever is greater. Where Fire Fighting Reserve is: > 4800EP:

CF services for rural residential 72kL (2 x 5L/s x 2hrs);

for industry, business 540kL (i.e. 30L/s x 4hrs + 15L/s x 2hrs) otherwise 210kL (2 x 15L/s x 2hrs).

< 4800 EP:

CF services 36kL (15L/s x 2 hrs); for business & industry 432kL (30L/s for 4hrs); otherwise 150kL (= 15L/s for > 2hrs).

Elevated storage capacity

6(MH - 1/12 MDMM) + minimum fire fighting reserve. Where fire fighting reserve is: > 4800EP:

CF services for rural residential 72kL (2 x 5L/s x 2hrs);

for industry, business 54 kL (i.e. 30L/s x 4hrs + 15L/s x 2hrs)

otherwise 210kL (2 x 15L/s x 2hrs). < 4800 EP:

CF services 36kL (15L/s x 2hrs);

for business & industry 432kL (30L/s for 4hrs);

otherwise 150kL (= 15L/s for > 2hrs).

Pumping capacity

Pump supplying a ground level reservoir

MDMM over 20hrs

Pump supplying an elevated reservoir

(6MH – operating volume) / (6 x 3600)

Standby pump capacity To match duty, except where more than one duty pump or as determined by risk assessment

Reticulation booster pumps/pumped system

MH + fire flow

Pipeline design

Main capacity

Raw water mains & trunk feeding ground level reservoir : MDMM for a gravity supply and MDMM over 20hrs for a pumped supply Trunk Mains feeding elevated reservoir: capacity of pumps Reticulation Mains: MH + fire flow

Mains size

Constant flow areas - where mains terminate in short runs such as cul de sacs minimum sizes that may be acceptable are: DN 63 up to 150m from main DN 80 up to 350m from main

On demand areas - minimum reticulation main 100mm in residential areas and 150mm in commercial and industrial areas

Friction default values

Hazen Williams Existing assets will use the below table to determine the C value.

Pipeline Type Pipeline Age

(All diameters) < 10 Years 10 to 25 Years > 25 Years

MSCL 150 140 130

DICL 140 130 120

DI 140 125 110

CICL 140 130 120

CI 140 125 110

UPVC 150 145 140

Asbestos Cement 140 130 120

Concrete 140 130 120



90-11-96 Date issued: 26/07/2013 Rev: 1

WATER NETWORK DSS

Parameter Criteria

New infrastructure will use the following more conservative C values due to uncertainty in material type at the master planning stages. Distribution: <300mm, C=110 300mm – 600mm, C=120 >600mm, C=125 Reticulation: <= 150mm, C=100 200mm - 300mm, C=110 >300mm, C=120

Maximum velocity 2.5 m/s

Water quality

Drinking water quality Drinking water to comply with the NHMRC Australian Drinking Water Guidelines – 2004.

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