Port Macquarie Hastings Council landfill expansion project

Global Synthetics assists Port Macquarie Hastings Council with this landfill expansion project

The project

Port Macquarie’s Cairncross landfill site is currently expanding, under a proposal that will allow the landfill to continue operations until 2056.

The first stages of the multi-million dollar project have been approved by Port Macquarie Hastings Council, who recently released sections 1A, 1C and 1E for construction earlier this year. These three new sessions adding approximately 9 more years of landfill life for the Port Macquarie Hastings LGA.

As with many landfill expansion projects, getting the right geosynthetics is critical to the long-term success of the site. Global Synthetics was pleased to be awarded the supply of geosynthetics products for this project, including engineered geotextiles, geonet drainage geocomposite and geosynthetic clay liners.

The challenges

Expanding a landfill site typically involves stabilising and encapsulating the area and ensuring an effective waste leachate collection system is in place. This assists in managing pollution runoff and ensures landfill operators can meet their environmental requirements.

With the existing landfill expected to reach capacity in 2020, it was critical to begin the progressive construction, operation and rehabilitation of the landfill, and the contractors reached out to the Global Synthetics team for a selection of geosynthetic solutions.

The solution

For this project, the contractors installed 67,000m2 of BENTOFIX® geosynthetic clay liner (GCL) to line each cell BENTOFIX® is the original needle-punched, thermally locked GCL introduced globally by the NAUE company of Germany in 1987. This robust, versatile product provides the highest safety standards and cost efficiency available. Once hydrated, BENTOFIX® is an effective barrier against liquids, vapours and gases, making it ideal for applications such as landfills.

This safe, carcinogenic-free GCL liner is made from powdered sodium bentonite, which can outperform significantly thicker layers of compacted clay.

The immediate swelling characteristics of BENTOFIX GCLs, provide a long-term barrier that can self-seal and re-heal, meaning the GCL can swell to fill potential punctures and rehydrate, renewing and improving the barrier system.

In addition, 111,000 m2 of GEOFIRMA® 1000g/m2 cushion and filtration geotextile fabrics. GEOFIRMA® non-woven geotextiles are available in a range of weights, strengths and filtration characteristics for different engineering applications. In this case, GEOFIRMA® provided the filtration capacity required to manage the landfill leachate, offering drainage and separation to the site.

Finally, 10,000 m2 of TRANSNET® 8mm geocomposite drainage geonet was placed on top of the coated GCL to provide surface water drainage. TRANSNET® is lightweight and easy to install, offering an environmentally friendly solution to traditional drainage materials such as granular stones, gravel and sand.

This geonet is widely used in landfill drainage, leak detection and leachate collection systems, providing high flow and high compressive strength characteristics. Plus, because of its polypropylene nonwoven construction, it is highly durable to a wide range of leachate types.

For engineering advice, partner with Global Synthetics

The combination of BENTOFIX® GCL, GEOFIRMA® non-woven geotextile fabric and TRANSNET® geonet has proven to be an effective solution for this application. The Global Synthetics engineering team is here to provide support for your next landfill project - get in touch with us today for technical datasheets or to request a quote on our range of specialist geosynthetics.