Expression of Interest - Cragieburn Sewage Transfer Hub

Melbournes Northern Growth Area (NGA) is expected to accommodate an additional 128,000 properties by 2040. Sewer flows from the area will exceed that which can be treated and re-used locally. As a result excess sewer flows require transfer to the metropolitan sewerage network for treatment at the Western Treatment Plant.

Sewage generated in the NGA will flow into the site of the existing Craigieburn Sewage Treatment Plant (STP) via the Amaroo Main Sewer, which is currently under construction, and the existing Aitken Creek Branch Sewer. The existing sewerage network between this location and the Northern Interceptor Sewer does not have capacity to accept peak sewer flows from the NGA. As a result the Craigieburn Sewage Transfer Hub (Transfer Hub) is required to transfer flows downstream and store flows temporarily when there is insufficient capacity in the downstream network. This is expected to occur during and/or immediately following wet weather events.

The Transfer Hub is a Sewer Flow Control Facility, with additional future functionality to split flow between two downstream catchments. In dry weather operation of the facility is typical of that of a Sewage Pump Station. The facility is to be constructed in a staged manner to allow for progressive expansion; stages will be timed to match the increase in sewer flows as the NGA develops. The initial stage of this project (Stage 1), is the subject of this Tender.

This project is part of Yarra Valley Waters broader sewage servicing strategy for the NGA, which includes new and upgraded sewage treatment facilities, new main and reticulation sewerage infrastructure and capacity upgrades within the existing sewerage network.

The Transfer Hub is located primarily at the site of the existing Craigieburn Sewage Treatment Plant at 420 Hume Hwy, Craigieburn. Initially the facility will have and capacity to transfer flows downstream at up to 300L/s and will include 30ML of storage capacity.

The Transfer Hub includes the following key elements:
* Excavation of approximately 120,000m3 of rock
* Stabilisation of cut batters and retaining wall construction
* Concrete works including manhole, sewage pumping facility, emergency relief structure and tank foundations slabs
* Site roadworks and drainage
* Sewage macerator, pumps and associated pipework valves and fittings
* Two 15ML circular storage tanks with sealed roof
* Air treatment facility
* Site electrical works and;
* Assorted site steelwork