INNOVATIONS ON THE HIMATANGI BEACH COMMUNITY SEWERAGE SCHEME Mike - - PowerPoint PPT Presentation

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Aug 21, 2023 94 likes •342 views

INNOVATIONS ON THE HIMATANGI BEACH COMMUNITY SEWERAGE SCHEME Mike Fletcher MDC Project Manager Present the key innovations that were able to deliver an affordable scheme for the Himatangi Beach Community Innovations delivered 15% in

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INNOVATIONS ON THE HIMATANGI BEACH COMMUNITY SEWERAGE SCHEME

Mike Fletcher – MDC Project Manager

SLIDE 2

Present the key innovations that were able to

deliver an affordable scheme for the Himatangi Beach Community

Innovations delivered 15% in capital savings

SLIDE 3

Overview

The Himatangi Beach

Community Sewerage Scheme

Design Innovations
Design Approach

SLIDE 4

The Himatangi Beach Community Sewerage Scheme

The Himatangi Beach

Community

Key Drivers
Procurement Methodology

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The Himatangi Beach Community

Approx. 400 dwellings + Holiday

Park + Community Facilities

440 Permanent residents but

Increases to 2500 during peaks

Deprivation Index 10
Limited community support so

connection is voluntary

294 dwellings signed up plus

Holiday Park & Community Facilities

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Key Drivers

Growth
Environmental
Regulatory
Availability of funding

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Procurement Methodology

Expressions of Interest
Tender
Contract award

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Design Innovations

Sharing of pump

stations

Electrical connections

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Type %age of Peak flow

No. Days/year

%age of year Christmas Holidays 31%-100% 30 8% Other Long Weekends 50% 13 4% Other Typical Weekend 34% 86 24% School Holiday Weekdays 33% 30 8% Normal Weekday 23% 206 56% TOTAL 365 100% Summary of Peak Flow Estimates and Duration for Design

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Alarm Level - 160 Litres Run Level - 120 Litres Empty Level - 50 Litres

Parameter Value Pressure limit 60m Duty Flow 1 l/s Tank Capacity 900 litres Pump start level 170 litres Pump stop level 50 litres High level alarm 330 litres Emergency capacity 570 litres Selected Pump Station Unit Characteristics

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Public Road

On-lot pumping station Private gravity drainage Private rising main Public rising main

Key

Public Road

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Electrical Connections

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Design Approach

Scope and design

development

Dynamic modelling

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Scope and Interfaces

Project Phase

On-lot Works Interface Reticulation Interface WWTP Interface Irrigation

Design

Client - gravity drainage, PSU and pressure laterals locations

Upstream of boundary kits

Contractor (Designer - Beca)

Upstream of screen

Client (MDC) (Process and Treatment Pond)

Wet Well

Contractor (Irrigation Services Ltd) Contractor (Mono - Pump Supplier) - Hydraulic, civil, structural

Construction

Contractor (HIL) Contractor (HIL) Contractor (Civils - HIL) Contractor (Irrigation Services Ltd) M&E (ADG) FTM (Waterclean Technologies)

Commissioning

Contractor (HIL) Contractor (HIL) M&E (ADG) Contractor (Irrigation Services Ltd)

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Dynamic Modelling

Considers pumps performance
Increased system optimisation
Modelling of system spatially
Allows system operation to be assessed

Source: Beca Infrastructure Ltd (20 12) “Himatangi Beach Community Sewerage Scheme: Design Report”

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Reticulation Layout

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50 63 75 90 110 125 180

0% 20% 40% 60% 80% 100% 120% 140%

50 100 150 200

Relative increase in installed cost (%) PE Pipe Diameter (mmOD)

Relative Increase in Pipe Installed Cost vs Pipe Diameter

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System Assessment

Identify sections in network reticulation over 6

bar

Identify which PSUs may not empty due to

sustained system pressures

Pipe velocities
Retention times

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Scheme Costs

Project value $9.25m (based on 500 HUEs)
Unsubsidised cost per connection $18,500

c.f. Typical costs for other NZ schemes range between $25,000 to $35,000

Subsidised cost per connection $8,500

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Summaries

1. Several key drivers ensured that the project

received support from the community

2. The key design innovations produced significant

capital cost savings

3. With defined scope and interfaces, the project

team was able to optimise and test the system under future scenarios

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Conclusion

By using a collaborative approach with a focus innovation, the project was able to deliver an affordable sewerage scheme for the Himatangi Beach community

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The Future post SWSS???

SWSS ended June 2013
MoH have no plans to replace scheme
TLA’s need to lobby MoH for new

central government funding to make these schemes affordable for property

wners and TLAs