Installation Of Leachate Management Infrastructure at Woogaroo Closed Landfill

⁠⁠⁠Overview

Ipswich City Council is seeking a suitably qualified contractor to undertake construction services for the enhancement of the leachate management system at the Woogaroo Closed Landfill. The works will facilitate a long-term leachate pumping trial and improve environmental management outcomes at the site.

About

To support delivery of the project, Council has undertaken a range of preliminary works and has engaged specialist contractors to complete associated infrastructure and environmental management activities. The following works have either been completed or are currently being delivered under separate contracts.

Electrical Works

The site has been connected to the electricity network, and the following electrical infrastructure has been installed:

• A new 3-phase, 63A mains power connection to the site
• A property pole incorporating a connection point and mains connection box
• A pole-mounted Main Switchboard (MSB) in accordance with Council requirements, including a 3-phase main switch, RCBO protection for a 15A DIN rail-mounted outlet, and two 32A three-phase RCBO-protected circuits for future use
• Mains cabling and associated cable protection between the mains connection point and the MSB, including a new earth electrode and earthing conductor
• Electrical pits and conduits required for future infrastructure connections
• A P5 pit with concrete surround and two 80 mm conduits extending from the MSB to the pit, including conduit stubs for future works
• Metal conduit protection installed on the property pole beneath the MSB to a height of two metres

Contaminated Land Management Works

A Suitably Qualified Person (SQP) has been engaged to undertake contaminated land management activities associated with the project. Completed and ongoing activities include:

• Sampling and assessment of site materials to determine appropriate reuse and disposal options
• Identification and assessment of environmental, health and safety considerations associated with the historical use of the site
• Preparation of a draft Construction Environmental Management Plan (CEMP)
• Obtaining a trade waste agreement to facilitate the discharge of leachate to the sewer network
• Management of approvals associated with soil disposal requirements
• Provision of specialist contaminated land support during construction activities as required

Plumbing Works, External to the Site

A separate plumbing contractor has been engaged to deliver external water and sewer infrastructure works, including:

• Preparation and submission of designs and approvals required for water main extensions, water meter installation and sewer property connections
• Management of all associated application fees and authority charges
• Construction of approximately 50 metres of water main infrastructure, including associated fittings and connections
• Installation of a new water service and water meter
• Completion of chlorination, pressure testing, bacteriological testing and live connection works
• Backfilling, compaction and reinstatement of disturbed areas, including topsoil and turfing where required
• Preparation of detailed design documentation and certification
• Delivery of as-constructed documentation, surveys and certification

Plumbing Works, Internal to the Site

A separate plumbing contractor has also been engaged to undertake internal site plumbing and associated civil works, including:

• Obtaining all required plumbing approvals and permits
• Supply and installation of a reduced pressure zone (RPZ) device
• Installation of a new potable water service extending from the water meter to the nominated tap locations
• Excavation of service trenches between the existing decanting manhole and the proposed discharge tank location
• Installation of gas-resistant membrane protection within trenches where required
• Installation of the rising main between the proposed pumps and discharge tank
• Installation of electrical and control cable conduits within shared service trenches
• Installation of sewer infrastructure connecting the new property connection to the discharge tank, including associated inspection and venting components
• Backfilling, compaction and reinstatement of disturbed areas, including topsoil and turfing as required

Tenderers shall coordinate their activities with the SQP and the separately engaged contractors to ensure the efficient and safe delivery of the remaining project works.

Scope

The Contractor shall undertake the following works as part of the project delivery:

Construction Works

• Complete construction works in accordance with Drawing Nos. 12525412-H001, 12525412-H002, 12525412-H100, 12525412-H101 and HSE040, noting that some works identified in the background information have already been completed or are currently being undertaken by others
• Install two (2) x 100 mm diameter HDPVC electrical conduits in trench, with Conduit 1 running directly to the pump control panel and Conduit 2 passing the tank and entering the combined trench (the combined trench will be excavated and reinstated by the plumbing contractor)
• Install one (1) x 100 mm diameter HDPVC electrical conduit in the shared trench and one (1) x 50 mm diameter conduit for control cables
• Design, supply, install, test and commission the pump control panel
• Design, supply, install, test and commission the pumps and rising main
• Design, supply, install, test and commission the leachate pump discharge tank
• Design, supply, install, test and commission potable water supply taps

Site Rehabilitation Works

• Backfill the existing subsidence hole, strip the surrounding area and re-contour the surface to facilitate effective site drainage
• Re-turf all disturbed areas and undertake a 12-month turf establishment and maintenance program to ensure successful turf growth and effective weed control

Location

• Site: Woogaroo Closed Landfill
• Map: View on Google Maps