Sewage effluent undergoing secondary treatment in holding ponds before being irrigated onto plantations.

Sewage effluent undergoing secondary treatment in holding ponds before being irrigated onto plantations.

Sustainable application of effluent and biosolids in Australian forests

CSIRO’s research investigating the application of effluent and biosolids to forests has significantly benefited the sustainable management of waste in Australia.

  • 14 January 2009 | Updated 14 October 2011

Effluent and biosolids (sewage sludge) can be a valuable resource for forest plantations, however each needs proper and different management.

CSIRO researchers have spent a combined period of 10 years studying sustainable application of effluent and biosolids to Australian forests. We provide significant expertise for clients regarding land application of waste.

Our research

The Wagga Wagga Effluent Plantation Project, which ran from 1991 to 1997, intensively studied irrigation of effluent to tree plantations and the fate of water, nutrients, and salt.

The Wagga Wagga Effluent Plantation Project won CSIRO’s Chairman’s Medal in 1999.

The project won CSIRO’s Chairman’s Medal, the highest award available for CSIRO research, in 1999.

The study was independently audited for its impact and was assessed as having a benefit:cost ratio of 44:1.

A major outcome of this research was the publication Sustainable effluent-irrigated plantations: An Australian guideline (1999).

This 293-page reference book and accompanying software are designed to assist planners, designers and operators of effluent-irrigated plantations, environmental regulators, local governments and industries to design and manage effluent-irrigated plantations sustainably.

The Sustainable use of biosolids (sewage sludge) in plantation forests Project was undertaken in pine forests in Wingello State forest, New South Wales, Australia, with the support of Sydney Water. 

From this study, a generalised model of the interaction of biosolids with soil and site characteristics was developed.

Information from the research has been integrated into regulatory and management guidelines for the sustainable use of biosolids in forestry plantations.

Learn more about CSIRO’s Forestry research.