Food scraps to soil conditioner: A case study in onsite processing at UTS
Dr Dena Fam and Fiona Berry, Institute for Sustainable Futures, University of Technology Sydney | 6 April 2017
CASE STUDY: Following is a case study of how university staff and students decided to tackle the problem of growing food waste on its campus in inner city Sydney.
What is the problem?
Almost half of household waste destined for NSW landfills consists of food and garden organic waste. The University of Technology Sydney’s Ultimo Campus alone produces about five tonnes of food waste each month from student/staff kitchens, and campus cafes.
This waste stream is expected to increase by about 20 per cent over the next two years with new cafes, increasing staff and student numbers, and more effective food waste source separation and collection.
What is the solution?
To tackle this problem, UTS has implemented a practical food waste processing system. The ambitious goal is for the university to act as an exemplar for how food waste might be separated and processed onsite for use as a soil conditioner in local parks and gardens in the local Sydney precinct.
With grant funding of $201,900 from the Environmental Trust as part of the NSW EPA’s Waste Less, Recycle More initiative, funded from the waste levy, new closed loop rapid food waste decomposing systems were installed in two UTS buildings with the aim of eventually managing 100 per cent of the organic food waste streams produced onsite.
Over the past three years the operations staff at UTS have implemented a food waste separation system to facilitate the collection of uncontaminated food waste from 22 staff/student kitchens, public waste bins servicing about 34,500 full-time students, 11 individual cafes and a concourse area housing five separate food outlets. Separated food waste is then processed using the rapid food waste decomposing system and transported to Earth Works to generate energy and produce nutrient-rich fertiliser. Before the processed outputs from the system can be used on land a rigorous testing and sampling regime will be conducted to ensure the outputs are safe. The ultimate goal of this project will be to productively use the processed food waste as a soil conditioner in local parks and gardens close to the university.
In preparation for the installation of the closed loop decomposers, UTS has spent the last two years implementing a system for separating and collecting food waste from general waste via a green bin system in staff/student kitchens and cafes on campus. Green bins are then collected daily by cleaning and café staff in dedicated 120 litre wheelie bins that are then weighed and documented before being emptied into the food waste decomposing systems via automated bin lifters.
Selecting the rapid food waste decomposing technology
The UTS facilities management staff and the Institute for Sustainable Futures (ISF) investigated a range of food waste management technologies on the market, taking into consideration cost, size, capability, processing, Australian Standards compliance, energy consumption, carbon reduction, and testing and regulation of outputs. This research included onsite visits of systems in operation, as well as desktop research and discussions with technology providers.
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 utilising heat, agitation, airflow and a microbial starter material, reducing the volume of food waste by 80-90 per cent.
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 odour-eliminating ozone deodoriser. The expected lifespan of the technologies is 10+ years.
Key to this project’s goal of productively using the processed food waste on land close to UTS was obtaining a “resource recovery exemption” from the NSW EPA for the closed loop system.
The exemption framework provides details of how the processed food waste should be tested and sampled. Sampling the outputs from the systems is a necessary stage in the process with the outputs currently being sampled every three weeks to ensure the outputs are free from a range of pathogens (determined by the NSW EPA).
Once UTS is confident the outputs from the system are safe for application to land we will be seeking local partners and sites, such as community gardens and parks, to productively use the outputs for land application as set out in the conditions of the exemption.
As a way of ensuring the long-term sustainability of the systems, UTS is continually monitoring and evaluating different aspects of the system including volumes of waste collected, contamination rates and energy consumption. This data has the potential to enable comparison of technologies on the market using evidence-based data to facilitate other organisations to benchmark food waste management systems for their own on-site applications.
However, 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 food waste streams more sustainably and therefore diverting food waste from landfill for a more productive use. By engaging staff and students through an education and behavioural change campaign the project will have a lasting legacy.
Not only are UTS facilities management staff involved in installing and operating the systems but are also actively involved in educating, raising awareness and changing behaviours through:
- Development and inclusion of procedures in cleaning, faculty and cafe staff induction manuals about the food waste separation, collection and treatment system and how and why food waste is being collected
- Monitoring of potential contaminants in food waste streams i.e. staff/students kitchens, and cafes with feedback to those producing high levels of contaminated food waste with other streams
Development of clear communication strategies, such as signage and staff/student communications explaining why diverting food waste to land fill is important, how UTS is doing this and what the results have been i.e. feedback to cafe staff, cleaning staff and faculties involved in separating food waste and their respective contamination rates
As an educational institution the project also provided the valuable opportunity of integrating the operational side of waste management at UTS with applied teaching and learning.
A “Lab” for design students was developed and delivered over the past two years that provided students with the change to engage with experts on food waste management from the NSW EPA, Closed Loop, UTS Facilities management, a local council and academics from Western Sydney.
Students engaged through participation of an expert panel and Q&A sessions and review of final student work by the expert panel as a way of sharing their respective views on current and future food waste management issues in NSW, Sydney and UTS more specifically.
The outputs from the Design Lab included visual communications, signage, an education campaign, an “app” for incentivising students of different ethnic and language groups, university-wide competitions and food waste bins. (see: https://wealthfromwaste.wordpress.com & Instagram page: wealthfromwaste).
Key to the project is its potential for sustainability outcomes in all areas including operations and management and teaching and learning. The communication strategy for the project has sought to share both the successes and challenges of processing food waste on-site in urban Sydney with other interested organisations including local businesses (through the Smart Locale network: https://www.smartlocale.com.au) and other universities through publications and conferences to facilitate a transition to more closed loop systems of organic waste management. With this in mind we would be very happy to hear other organisations experiences of innovative ways they are managing waste streams.
This project is financially supported by the NSW Environmental Trust and NSW EPA as part of the Waste Less, Recycle More initiative, funded from the waste levy.
Dr Dena Fam is research director, Institute for Sustainable Futures, UTS
Fiona Berry is senior research consultant, UTS