[1] Sustainable Management of Leakage from Wastewater Pipelines D. DeSilva 1 , S. Burn 1 , G. Tjandraatmadja 1 , M. Moglia 1 , P. Davis 1 , L. Wolf 2 , I. Held 2 , J. Vollertsen 3 , W. Williams 4 and L. Hafskjold 5 1 CSIRO Manufacturing & Infrastructure Technology, Highett, Victoria, Australia 2 Department of Applied Geology, Karlsruhe University, Karlsruhe, Germany 3 Aalborg University, Aalborg, Denmark 4 WRc Plc, Wiltshire, UK 5 SINTEF, Trondheim, Norway Abstract Wastewater pipeline leakage is an emerging concern in Europe especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritise proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilises these models to predict the condition of pipes in individual zones, and to optimise the utilisation of rehabilitation resources by targeting the areas with the highest leakage rates. Keywords AISUWRS, CARE-S, wastewater, leakage, pipe deterioration, prioritisation. Introduction The increasing volume of wastewater generated by increasing population densities in many cities around the world contributes to a growing range of negative environmental consequences. Wastewater leakage is one of these consequences and as the infrastructure ages and is a growing concern, particularly in areas where ground water is used for potable water consumption (Wolf et al. 2003). The ultimate solution to minimise leakage is the rehabilitation of pipelines. However, the established reactive strategies and methods of rehabilitation are both expensive and require capital-intensive technology. Rehabilitation of pipelines is an affordable option for developed countries, and some have succeeded in controlling pollution of receiving water and reducing sewer leakage levels. However, for many countries the cost of pipeline rehabilitation is prohibitive and a desired level of rehabilitation cannot be achieved, consequentially a low quality of service is delivered to customers and there is a negative impact on the environment. The chemical characteristics and stability of the soil environment are the principal factors that contribute to external deterioration and loading of pipes. Although pipe materials vary in a sewer networks (i.e. vitreous clay, concrete, PVC, asbestos-cement, some ductile iron and cast iron), the soil chemical composition (pH, sulphates, chlorides) together with moisture and aeration levels influence the deterioration of these pipe types, albeit in different manners (DeSilva et al. 2001). The external deterioration combined with unplanned stresses from soil