Peer Review Services - Wellington Sludge Minimisation Project

Details

Wellington City Council requires a fundamental change in the management of sewage sludge, to allow it to be ‘de-coupled’ from the existing disposal to the Southern Landfill. Sewage sludge is produced as a by-product from Wellington City’s two wastewater treatment plants (WWTPs) at Moa Point and Karori (also known as the Western WWTP) and is currently dewatered to remove some water content before disposal at the Southern Landfill.

The current volume and composition of the sludge is a significant inhibitor to enabling waste minimisation efforts in Wellington City, because so much solid waste is needed to mix with the sludge in its current form. Presently the Southern Landfill requires a 4:1 ratio of solid waste to sludge due to operational requirements and engineering stability concerns. By reducing the amount of sludge to landfill greater solid waste minimisation initiatives can be implemented, which reduces the amount of solid waste sent to Southern Landfill. This in turn has the potential to decrease carbon emissions in Wellington City.

A preferred process and site option was selected, which is a thermal hydrolysis, digestion and thermal drying plant located at Moa Point. This plant involves the integration of internationally sourced plant and equipment into an integrated process system, to be installed within a constrained site. The project is technically complex, and no similar plant has been delivered in New Zealand to date.

Given the technical complexity, a design consortium consisting of a multi-disciplinary design consultant (Beca) and an international process engineering consultant (Black & Veatch) have been engaged to provide preliminary design services at this time.

This procurement relates to the provision of Peer Review Services for the Wellington Sludge Minimisation Project.
Given the technical complexity and unfamiliar process, Wellington City Council seeks the services of a suitably qualified supplier to act as peer reviewer providing an independent review of deliverables produced by the design team.

We want to take a proactive approach to peer review for this project. We therefore seek a collaborative peer review team who will challenge the core design team by being proactively involved in design workshops at the early stage of the development of deliverables, rather than just reviewing design outputs.