Browns Plains Cell 2E Landfill

Project Background

The Browns Plains Waste and Recycling Facility is one of the most advanced and innovative waste facilities in Queensland. It offers both landfill and recycling facilities. The facility is dedicated to minimising the risk to locals and the environment by reducing gas emissions, avoiding groundwater contamination and reducing the space utilised by the landfill.

Problem

The Browns Plain Facility needed to ensure the construction of new cells minimised pollution streams such as waste leachate. The designer needed to develop a plan for providing a cost effective low permeable lining system based on the latest available technologies. In addition, the designer needed to check potential systems and research the findings to ensure the chosen system would meet local landfill guidelines. Most importantly,  they needed to control potential risks to ensure that any potential pollutants were addressed.

Solution

After reviewing different options and completing a risked based assessment of the preferred options, the use of PE Coated GCL was selected and approved as the final lining system. Bentofix® X5F NSP4900 over a 300mm compacted clay layer was chosen as the most suitable choice, providing extremely low permeability and a range of other benefits.

The lining system was then protected with a ProFab® nonwoven cushion geotextile and covered with 300mm drainage aggregate. Furthermore,  AceGrid® reinforcement geogrid was used on top of the cushion geotextile in the batters in order to provide the required stability for the drainage gravel.

Bentofix® X5F NSP4900 Coated GCL is a needle punched GCL with 500g/m2 of extra Polyethylene (PE) coating applied to the GCL surface as a hot melt fluid during the manufacturing process. This allows the PE coating to become a part of the GCL as one of its components, and provide an integrated high-performance multi-component lining system with extra advantages compared to standard non-coated GCL.

Some of the extra advantages that Bentofix® X5F NSP5900 Coated GCL provides include:

• 1,000 times lower permeability compared to a standard noncoated GCL, and 100,000 times lower permeability compared to Compacted Clay.

• Protection against desiccation (e.g. in low confinement applications such as landfill caps, landfill batters, leachate ponds, etc.)

• Protection against downslope bentonite erosion (e.g. on exposed batters beneath a geomembrane)

• An instant gas barrier (e.g. landfill caps)

• A root barrier (e.g. landfill gas)

Bentofix® is the first and original needle punched GCL innovated and produced by German manufacturer NAUE GmbH & Co. KG since 1987. It has been used in a range of Australian projects since 1994, providing high-quality long term solutions many times over.

Bentofix® GCL fulfils the performance and permeability requirements of national and international GCL specifications and is an approved GCL product by environmental agencies (EPAs) including DES in QLD. It has been successfully used in various environmental projects such as landfills, contaminated lands, mining and tailings dams, and in oil and gas applications.

Results

The Coated GCL Bentofix® X5F NSP4900 with extra PE Coating not only provided a high-performance barrier, but also reduced the risks and improved the long-term performance of the lining system. The suggested design provided a significant reduction in costs, carbon footprint and construction time.