EnviroScience Solutions was engaged by a Sydney-based Council to assess landfill leachate, groundwater, and landfill gas and also review two leachate treatment plants (LTP).
Mark of EnviroScience said, “the site was a former landfill and is currently being developed as a major access route by Transport for NSW. The works involved were highly specialised and demonstrate EnviroScience’s skills and capability.”
The works comprised the assessment of a new leachate treatment plant (LTP), which was constructed and operated by Transport for NSW in order to construct new access roads into Sydney Airport and a former LTP constructed and operated by the local Council.
EnviroScience was also commissioned to review the leachate management system (pumping pits and associated pipework) and the groundwater monitoring network.
The assessment of the LTPs comprised a technical and commercial review of the operating performance and costs of both plants in order to determine which plant should be adopted following completion of the Sydney Gateway works.
Issues were raised about the performance of the leachate management system, due to the age and capacity of the pumps within the six pumping pits located along the bentonite wall, which attenuated leachate migration between the former landfill and a waterway.
The leachate and groundwater quality along the bentonite wall was reviewed in order to identify any changes to the baseline water quality and its current quality. Improvements and localised deterioration in water quality were identified along the length of the bentonite wall and reasons for these changes were assessed and identified.
A comprehensive appraisal of landfill gas concentrations and flows were undertaken to determine any potential changes in the landfill gas regime due to the construction works overlying the former landfill. The data provided identified localised changes in the landfill gas regime in a number of wells located in the commercial complex to the north of the Sydney Gateway project, and reasons for these changes were provided.
Delivery of this project demonstrates the expertise of EnviroScience Solutions to deliver a thorough review of landfill gas concentrations and flows, leachate and groundwater impact and the appraisal of leachate treatment plants to deliver value for the client. This involved accessing multiple sources of data to assess environmental conditions and provide bespoke advice on large-scale urbanised land quality.