LONG-TERM EFFECTS OF MUNICIPAL SEWAGE ON SOILS AND PASTURES

ABSTRACT

Land application of municipal wastewater is widely practised worldwide as a means of treating wastes and obtaining a benefit from the water and nutrients by growing pastures, trees, and sometimes edible crops such as vegetables, fruit and fibre, etc. Irrigation of pastures by treated and untreated sewage near Melbourne, Australia, for more than a century has increased heavy metals concentrations in the soil, but appears not to have increased their concentrations in the herbage and in animal tissues of animals grazed on these pastures. There seem to be sound reasons why this practice may be sustainable.

Keywords:

• Sewage irrigation
• Heavy metals accumulation in soils
• Uptake by vegetation
• Sustainability

ACKNOWLEDGMENTS

We are grateful to Melbourne Water for permitting us to use the unpublished data of the 17 year monitoring period. Dr. Nick Uren, Honorary Senior Research Fellow, La Trobe University, Melbourne, provided helpful comments on the draft of this paper.