Kooragang Island Waste Emplacement Facility - Eastern Ponds

Project Summary:

The Kooragang Island Waste Emplacement Facility was previously used by BHP Newcastle Steelworks as a landfill site from the late 1960’s up to 1999 when BHP ceased operations. The NSW Government took possession of the site in 2002 and has been undertaking progressive capping and related environmental improvement works to close the landfill. 

The Kooragang Island Eastern Ponds project involves the Closure works to support similar levels of vegetation and providing similar surface water flows to surrounding ponds and habitat areas with a reduced contaminant load migrating from the fill material to the surrounding environments.

Scope:

The Kooragang Island Eastern Ponds project involves the Closure works to support similar levels of vegetation and providing similar surface water flows to surrounding ponds and habitat areas with a reduced contaminant load migrating from the fill material to the surrounding environments.

The Project involves the following specific activities:

• Clearing and Vegetation removal
• Bulk Earthworks - Importing of General Fill material
• Cut to Fill to regrade existing site
• Installation of Gas Drainage
• Installation of LLDPE liners
• Stormwater Drainage
• Re-grading of the site to a minimum 1% grade to prevent ponding of surface water;
• Drainage Improvements;
• Provisions of a capping layer to achieve a minimum thickness of 0.5m, minimum grade of 1% and permeability of 1 x 10-7;
• Rehabilitation using low nutrient and Chytrid free growth medium; and

These closure works are to be undertaken within a sensitive and complex environmental context. In particular, the works need to be delivered in a manner which:

• Complies with regulatory requirements;
• Avoids direct impacts to Matters of National Environmental
• Significance (MNES) in particular Green and Golden Bell Frogs (GGBF);
• Carefully manages indirect impacts to MNES through avoidance of spread of chytrid fungus and predatory aquatic species and through avoiding impacts to water quality of surrounding waterbodies; and
• Manages fill material such that higher risk materials are appropriately isolated from surface waters.

Challenges:

• Site contamination associated with the former BHP Steelworks and management of risks associated with the potentially contaminated materials;
• La Nina weather event rainfall whilst working on an already saturated area;
• Dewatering site after extreme weather inundations;
• Design adaptations to suit ground conditions;
• Gas encountered during excavation of existing basin – Redesign to link into gas drainage system;
• Environmental management and protection of protected species mainly Green and Gold Bell Frog; and
• Stakeholder management of neighbouring industrial land and operations.