Dunedoo STP Upgrades Civil and Structural Works

Warrumbungle Shire Council (WSC) plans to undertake a program of works to upgrade the Dunedoo Sewerage Treatment Plant located at 92 Golden Highway, Dunedoo NSW 2844.

Sewage treatment at Dunedoo STP is via an intermittent activated sludge process with maturation pond for disinfection. The existing treatment plant consists of A Pasveer channel with horizontal brush aerators, A catch pond, A baffled maturation pond with effluent flow meter, two sludge lagoons & three sludge drying beds (not operational).

The program of works proposed by WSC includes but is not limited to:

• New site amenities, site office and control building
• New chemical dosing system for chemical phosphorus removal;
• Sludge lagoon improvements;
• New sludge drying beds;
• New supernatant return pumping station;
• Catch pond refurbishment;
• Maturation pond baffle upgrades;
• Upgrades to Waste Activated Sludge (WAS) pump(s) and pipework;
• Electrical upgrades including new switchboard, control, instrumentation and monitoring systems;
• New pipework, pits, conduits and services associated with the proposed upgrades.

The upgrade program has been broken into a number of packages of work, and will generally be delivered via the following packages of work/contracts:

• Site amenities building (In progress);
• Earthworks, Civil and Structures (This Package) for Construction of the majority of structures, pipelines and other civil works
• Electrical, Instrumentation and Control
• Process and Mechanical, and
• Various other minor works.

The work included in this package is for the Construction of various structures, civil works and pipelines, including but not limited to the supply, construction/installation of the following:

• Supernatant pumping station, including supply and Installation of a new concrete wet well, pump, fittings and pipework;
• Chemical dosing building including reinforced concrete slab, engineered structural steel frame, cladding and fittings, including supply, installation and certification of an electrically operated monorail crane
• Demolition / removal of existing sludge drying beds and associated pipework, pits and equipment;
• Reinforced concrete sludge drying bed
• Catch pond with Polyethylene (PE) liner
• Electrical pits and conduits
• Gravity drainage pipework, pits, associated structures and fittings
• Various pressure pipelines, valving, fittings and connections, including HDPE, DICL, Schedule 80 PVC and Stainless Steel
• Conduits for chemical dosing lines;
• Concrete pads, above ground pipework, fittings and supports associated with the various pipelines, pits and infrastructure installed under this contract
• Removal of various items of abandoned pipework
• Co-ordinating site access, shutdowns, cut-ins and operation of the existing Sewage Treatment Plant with the Principal to facilitate ongoing operation and upgrades at the site.

The Dunedoo STP is an operational Sewerage Treatment Plant and must remain fully operational throughout delivery of the works. Warrumbungle Shire Council holds an Environmental Protection Licence issued under the Protection of Environmental Operations Act (POEO) for operation of the works and is required to continue to meet obligations of this licence throughout the project.

The Contractor is to work with the Principal to ensure work under the contract does not interfere with the performance of the treatment process or delivery of other works associated with the broader STP upgrade project. This will require co-ordination of some activities with the Principal and also require some works to be delivered in a specific order (refer to section 'Order of Work' for further information).