The Mindarie Regional Council has taken a significant step toward closing the Tamala Park landfill site by submitting two crucial applications to environmental regulators. These submissions represent critical milestones in the council's plan to cease operations at the northern suburbs waste facility by the 2028-29 financial year.
Essential Works for Timely Landfill Closure
Without these approved works, the council acknowledges it would face substantial challenges in closing the landfill both on schedule and in accordance with environmental best practices. The proposed measures will enable final capping of the landfill footprint and address the persistent issue of leachate accumulation that has complicated odour management efforts.
Leachate, which forms when rainwater permeates through waste material, has been building up within the landfill over time. This accumulation creates two significant problems: it obstructs pipelines designed to collect landfill gases that cause odours, and it prevents the council from achieving the final landform required for proper rehabilitation.
Piggyback Liner: A Critical Environmental Protection Measure
The closure plan requires installation of a piggyback liner, an impermeable barrier that will be placed over existing waste mass to allow additional material placement above it. This solution addresses a historical issue dating back to the 1990s when landfilling occurred in an unlined cell at Tamala Park.
Without this protective liner, rainwater and leachate could seep into the unlined waste mass below, potentially contaminating the underlying ground. The piggyback liner will prevent this environmental risk by enabling proper collection, management, and disposal of these liquids.
Permanent Leachate Management Infrastructure
Tamala Park stands as the only landfill in Western Australia lacking permanent leachate management infrastructure. After evaluating all alternatives, the council and independent consultants have determined that constructing permanent evaporation infrastructure represents the only viable solution to reduce leachate volumes effectively.
The proposed evaporation ponds, covering approximately 3.5 hectares, will replace the previous method of irrigating and evaporating leachate across 13 hectares of operational landfill area. While smaller in footprint, these permanent facilities will provide more effective leachate management, ultimately improving odour control and enabling landfill closure by the projected 2028-29 timeline.
The council is encouraging community members who support these environmental improvement goals to contact the Department of Water and Environmental Regulation to express their endorsement of the applications.
