Hogan's Pocket Landfill
Hogan’s Pocket Landfill is an accelerated, stabilised, engineered landfill which was constructed to replace Mackay's previous landfill site at Bayersville.
Hogan’s Pocket Landfill (Cell 1) commenced operation in 2006 and was decommissioned in 2012.The official opening of Hogan’s Pocket Cell 2 occurred on 29 August 2012.
There is no public access to Hogan's Pocket Landfill. Some commercial, industrial and regulated waste such as asbestos is directed to the landfill at council's discretion.
The New Landfill Cell 2
In April 2012 Mackay Regional Council completed construction of cell 2 at Hogan’s Pocket. Cell 2 was constructed in accordance with Australia’s best practice landfill design guidelines to provide maximum efficiency and environmental protection.
The project cost $5.7 million and included the following constructions:
- Two sediment ponds with a total capacity of 70ML
- A new 10ML leachate pond
- A new 3Ha landfill cell (Cell2)
- A clean water diversion system
- A silty water management system
- An access road to the new cell
- Removal of the existing leachate pond, sedimentation pond and associated infrastructure.
Extensive engineering was carried out to ensure the environment was protected. This included a complex engineered liner that incorporates a groundwater diffusion system, compacted clay liner and second geo-synthetic clay liner (double liner).
In addition the base of the landfill is graded so that any contaminated liquids are captured and drained through a sophisticated underground leachate collection network. A new 10 mega litre leachate dam has been constructed with four engineered layers of protection. The liner is constructed of compacted clay, geo-synthetic clay and third high density polyethylene (HDPE) plastic liner to protect from leakage. The dam has a HDPE plastic lid to prevent the infiltration of clean surface water.
All water that comes in contact with waste onsite is collected and gravity fed to this holding facility. This liquid is then recirculated through the landfill cell further enhancing the landfills operating efficiency. This high level of protection provided to the cell and leachate dam ensures no contamination leaves the landfill site.
Control of surface waters
Runoff water is managed by directing sediment laden water into the network of onsite dams. Water that has contacted disturbed soil onsite is channelled into a 30ML sedimentation pond which once full overflows into another 40 ML sedimentation pond downstream via a natural bio-filtration system. This water if required can be recirculated through the dams for further polishing. No water leaves the site unless it meets strict environmental discharge parameters.
All clean water that contacts the upstream catchment of the landfill is diverted away from the landfill footprint ensuring the receiving waters are protected.
The Mackay Regional Council has installed landfill gas capture management at Hogan’s Pocket in accordance with the Waste Management Strategy and Commonwealth Government clean energy legislation. Initially Mackay Regional Council will flare gas to reduce the environmental impact and long term if financially viable will generate electricity from the gas captured.
Council will commence a project in 2013 to cap the first landfill (Cell 1). This will create landfill gas capture efficiencies and possible savings to the community.
Cross Section of Hogan’s Pocket Landfill- Cell 2
A cross section of Hogan’s Pocket Landfill Cell 2 is attached below illustrating the complex engineered liner below the waste and the multiple covers and final capping applied over the waste.