As part of its Western Irrigation Network (WIN) Project, two major pump stations are to be installed at the Melton Recycled Water Plant and at Parwan.

The Melton PS will transfer recycled water from the Melton RWP storages to the head of the Parwan-Balliang irrigation district (currently being developed), and the Parwan PS will transfer recycled water to the customers boundaries for irrigation.

Western Water intends to conduct a two-part procurement process commencing with a request for Expressions of Interest from which a small number of tenderers will be selected and invited to submit fully costed design and construct tenders.

The works will involve design, construction, commissioning and performance proving of the two pump station facilities which are expected to generally comprise the following:

1. At the Melton PS facility

• A High Lift Pump Station (HLPS), supplied from a break tank, capable of transferring recycled water through a 13.5km DN600 GRP pipeline to Parwan (the pipeline is to be built under a separate contract);
• Maximum and minimum flows for the HLPS are planned to be staged as follows:

                  Until 2035: 200 L/s to 400 L/s @ 173m
                  Ultimate flow beyond 2035: 200 L/s to 800 L/s @ 173m
Designs will be required to provide the 2035 flows, with provision within the site layout and key installations for the future upgrade in capacity

• A multipurpose Low Lift Pump Station (LLPS) that will transfer recycled water from the two winter storage dams at the Melton Recycled Water Plant to the HLPS break tank, to on site irrigation assets and also between the storages themselves;
• The ultimate combined flow rate of the LLPS is approx. 1250 L/s
• The supply from the LLPS is unfiltered recycled water and as such a filter and backwash system is required between the LLPS and the break tanks;
• A 720kL HLPS break tank in between the filtration unit and the HLPS, with provision for a second break tank beyond 2035;
• Associated suction and discharge pipework and fittings, both above and below ground;
• Pumps, MCC and associated electrical equipment, instrumentation, controls and buildings to house these components;
• Communication to both Parwan Pump Station and Western Water Central SCADA System.

1. At the Parwan PS facility

• A pump station operating to maintain a constant pressure irrigation system capable of transferring recycled water through the DN675 Parwan-Balliang irrigation pipeline to customer offtakes, with a lift of approximately 45m;
• Staging

                   Interim for the first 15 years of demand (2l/s to 400l/s @ 45m)
                   Ultimate for projected future demands beyond Year 15 (2l/s to 850l/s @ 50m)

Designs will be required to provide the interim flows, with provision within the site layout and key installations for the future upgrade for ultimate requirements.

• A 2ML balance tank to collect flows from multiple sources including the Melton PS
• Associated suction, discharge, overflow, and drainage pipeline, both above and below ground
• Building to house pumps, electrical, instrumentation, and controls
• Communication via radio to Western Water base station and customer offtakes with information relayed to Western Water’s Central SCADA System.
• Integrated with future additional 2ML balance tank and 1GL lagoon storage facility at the same location

All materials will be supplied by the contractor and all materials installed must be in accordance with Western Water’s approved pipe products as set out in the MRWA web portal http://www.mrwa.com.au/Pages/Home.aspx or approved by Western Water if product type is not covered by the MRWA portal.

All work under the contract will be required to be complete prior to Dec 2021 and an earlier finish will be requested.

An industry briefing/site visit is proposed and questions during the tender period (until end of Period for questions) can be directed via the Buying for Victoria website.

The contract will be a lump sum contract based on AS4300 (as amended).

The current program indicates the following key dates.

Activity                                                      Date **

EOI Release                                         Start August

Industry Briefing                                   2nd week of August

EOI Submission close                          Early September

RFT issued                                           End September

Tender briefing                                     Mid September

End of period for questions                  7 days prior to tender close

Tender Closing time