Centralised Biosolids Stabilisation Business Case

Looking to advance its net zero ambitions, the City of Gold Coast (CoGC) needed a more sustainable way to treat and reuse biosolids. They engaged us, along with WSP, as part of the Gold Coast Professional Services Partnership (PSP), to develop a centralised biosolids stabilisation business case. Together, we developed a long-term strategic vision for the treatment and reuse of biosolids for the city.

With the challenges of increasing biosolids management costs, emerging contaminants of concern such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) and microplastics—along with an uncertain regulatory future—the project team needed to develop a solution that both capitalized on current opportunities for improved efficiency and maintained flexibility to adapt to future challenges.

PSP is proud to continue the collaborative working relationship with CoGC, moving into concept design and detailed costing of a biosolids facility. Once operational, the facility will represent a step-change in biosolids management for the CoGC. It will more than halve the production of biosolids while producing a Grade A stabilised, pathogen-free biosolid that can be reused in the Queensland agricultural industry. The project is also aligned to CoGC’s net zero targets—providing a reduction in greenhouse gas emissions and a doubling of renewable green energy production.

CoGC is now confidently moving forward with a centralised advanced digestion facility including thermal hydrolysis. The system can be expanded to include thermal drying and carbonisation downstream of the new digestion process should the need or market opportunity arise in the coming years.