Clayton Regional Landfill Joint Venture engaged Geotesta to supervise earthworks to rehabilitate the landfill to avoid to odours and ground water pollution.
The operators were made up of five municipal councils; City of Boroondara, City of Stonnington, City of Glen Eira, City of Monash and the City of Whitehorse.
Geotesta provided Level 1 Earthwork Supervision of the North Area 1 final capping with a low permeability clay layer (LPCL) and soil sub-base layer to provide a seal on top of the landfill waste, which included:
- Verification testing to environmental and geotechnical standards;
- In-situ material testing to meet required density specifications;
- Ensuring the LPCL was smooth with no desiccation and free of clay clods;
- Ensuring the Soil Sub-base was free of rubble and large particles.
Due to the large volume of clay required which was challenging to source, the clay materials were obtained from many locations. When clay dries, it shrinks and in hot conditions it dries out fast, this meant that the placement of compacted clay layers had to be completed in a timely manner.
The test results achieved the required criteria as did the grades, level and thicknesses of the LCPL layer and subbase layer.