Food scraps to soil conditioner: Processing food waste onsite at UTS

What is the Problem?

Did you know that almost half of household waste destined for NSW landfills consists of food and garden organic waste? At the University of Technology Sydney Ultimo Campus, approximately 5 tonnes of organic waste is produced per month from student and staff kitchens and campus cafés and this waste stream is expected to increase by 20% to 30% over the next two years with new cafés coming on-line, increasing numbers of staff and students of UTS and more effective source separation and collection of food waste.

What is the Solution?

UTS is leading the implementation of a practical food waste recycling scheme to tackle this problem. The ambitious goal is to act as an exemplar for how food waste might be separated and recycled on-site for use as a soil conditioner in gardens in the Sydney precinct.

Practical implementation

The project has accessed NSW Government grant funding to install new Closed Loop rapid food waste decomposers in two UTS buildings to manage 100% of the organic food waste streams produced onsite. The project will separate and process all uncontaminated food waste collected from 22 staff/student kitchens, public waste bins servicing approx. 34,500 full-time students, 11 individual cafés and a concourse area housing 5 separate food outlets. Separated food waste is currently being processed using the decomposer system and transported to Earth Works to generate energy and produce nutrient-rich fertilizer, the ultimate goal being to productively use the processed food waste in local parks and gardens in close proximity to the university. UTS has the potential to convert in excess of 50-60 tonnes of raw organics into 5-6 tonnes of soil conditioner per year.

Food waste bins in basement.

In preparation for the installation of the Closed Loop decomposers, over the last 2 years UTS has implemented a system for separating and collecting food waste from general waste via a green bin system in staff/student kitchens and cafés on campus. Green bins are then collected daily by cleaning and café staff in dedicated 120 litre wheelie bins which are then weighed and documented before being emptied into two Closed-Loop decomposer systems installed in sites across the university via automated bin lifters to minimise manual handling.

As a way of ensuring the long-term sustainability of the systems, UTS is monitoring and evaluating different aspects of the system including volumes and contamination rates of food waste collected, energy consumed by the decomposer systems and sampling of pathogens from the processed outputs. This data has the potential to enable comparison of technologies on the market based on evidence-based data and the ability of other organisations interested in food waste management systems to benchmark such technologies for their own use in the future.

Selecting the decomposer technology

The UTS facilities management and the Institute for Sustainable Futures (ISF) teams thoroughly investigated a range of food waste management technologies currently on the market taking into consideration; cost, size, capability, additional processing needed, Australian Standards compliance, energy consumption, carbon reduction, and whether the manufacturer is actively seeking testing and regulation for the outputs from their system from the EPA. This research included on-site visits of decomposer systems in operation, as well as desktop research and discussions with a range of technology providers.

Ian McInnes showing students the decomposer.

The “Closed Loop Solution” was identified as the most viable solution for UTS with two models selected (CLO300 and CLO100) to meet the needs of a growing inner city campus. The Closed Loop system is an in-vessel, aerobic, continuous feed composting system which utilises heat, agitation, airflow and a microbial starter material, reducing the volume of food waste by 80-90%. This means the final product will meet requirements of AS 4454 (soil conditioner). Closed Loop Organics supplied and installed the two systems; (1) 600kg/day capacity and (2) 200kg/day capacity units in two separate building basement sites at UTS with the unit fitted with an ozone deodoriser eliminating odour. The expected lifespan of the technologies is 10+ years.

Waste regulation

Key to this project’s goal of productively using the processed food waste as a soil conditioner on land in close proximity to UTS was obtaining a ‘resource recovery exemption’ (RRE) from the NSW EPA for the Closed Loop system. The RRE provides details of how the processed food waste should be tested and sampled and how the processed food waste can be applied to land.

Beyond practice

The real value for money in this project is in the flow-on effects. ISF and UTS seek to influence the broader community in managing organic waste streams more sustainably and therefore diverting foodwaste from landfill. Engaging staff and students in the process of recycling organics through an education and behavoural change campaign is the cornerstone of the project’s legacy.

Not only are facilities management at UTS involved in installing and operating the technologies but the project also deliberately sought to educate, raise awareness and change behaviours through:

Development and inclusion of procedures in cleaning, faculty and café staff induction manuals about the organic waste collection and treatment system and how and why organic waste is being collected
Monitoring of contaminants in organic waste collection across the three waste streams i.e. staff/students kitchens, cafés and public bins with feedback to those producing high levels of contaminated organics
Development of communication strategies i.e. signage and staff/student communications explaining why diverting food waste to land fill is important but also how UTS is doing this and what the results have been i.e. feedback to café staff, cleaning staff and faculties involved in separating organic food waste and their respective contamination rates

As a way of integrating the operational side of waste management at UTS with applied teaching and learning, ISF have been actively involved in designing and implementing a ‘Lab’ for Design students over the last two years to design improvements to the current system. Experts on organic waste management including representatives from the NSW EPA, Closed Loop, UTS Facilities Management, local council and academics from Western Sydney have engaged students through expert panel and Q&A sessions and the review of final student work as a way of sharing their respective views on current and future organic waste management issues in NSW and Sydney. Outputs from student projects have included signage and communications, app designs, competitions and alternative bin design (see: https://wealthfromwaste.wordpress.com) to inform staff/students of the system and reduce the percentage of contaminated waste collected from UTS.

Dr Dena Fam with Facilities Management staff, design students and cleaners visiting the organics processing system in the basement of building 10.

Replicability

As a high profile Sydney university committed to sustainable outcomes in all areas UTS seeks to deliver broad benefits from this project. UTS is well placed to also communicate and disseminate the results from this project to influence other organisations such as local Councils and universities to move toward more closed loop cycles of organic waste management.

UTS prides itself on setting new standards of sustainable leadership within the waste, water, energy and building sectors with a number of awards won including the Banksia award and Green Globe awards in environmental innovation and leadership. The communication strategy for the project has sought to share both the successes and challenges of processing organics on-site in urban Sydney. The associated value of increased awareness through the education campaign is the inevitable outcome of finding new ways to increase recycling rates of other waste streams such as glass and plastics etc.

UTS will make a significant and highly public contribution to reducing the environmental and economic costs of food waste in landfill and greenhouse gas emissions and aims to lead by example. Over a 10-year period, at current capacity approximately 60 tonnes of food waste has the potential to be processed per year.