Sustainability Report 2006/07Managing biosolids
Melbourne Water’s strategy for the beneficial use of biosolids is to focus on energy recovery for biosolids produced and stored at the Western Treatment Plant, geotechnical fill applications for biosolids stored at the Eastern Treatment Plant and land application for biosolids produced in future, provided the quality of the biosolids is acceptable.
A feasibility study into energy recovery for the stored biosolids at the Western Treatment Plant continued during the year. The study confirmed the suitability of the stored biosolids as a fuel, scoped the necessary equipment and associated costs for processing facilities, and identified the need for pilot trials to demonstrate the effectiveness of the proposed technologies.
At the Eastern Treatment Plant, Melbourne Water progressed the concept for use of biosolids as a geotechnical fill in road construction and other civil works.
Melbourne Water has worked with EPA Victoria to develop guidelines for environmental management of projects using biosolids as a fill, and will proceed once these guidelines have been finalised.
An extensive sampling and analysis program was completed at the Eastern Treatment Plant. Data collected will be used to assess the acceptability of Melbourne Water’s biosolids for various recycling schemes.
Assisting Barwon Water
Melbourne Water also agreed to extend its memorandum of understanding with Barwon Water in relation to biosolids management until June 2011. Barwon Water biosolids have been stored and dried at the Western Treatment Plant (for subsequent beneficial use) for the past three years until a permanent biosolids processing facility is built at its Black Rock Treatment Plant. Management practices have ensured that no significant odour impacts have been detected at the Western Treatment Plant boundary.
In May, Barwon Water began transporting dried biosolids to two farms in the Balliang area for use as fertiliser.