Assessment of the sustainability of alternatives for the disposal of domestic sanitary waste

When attempting to assess the relative sustainability of a process or practice, it is important to be able to use measures which are appropriate. Sustainability can be viewed at different levels. At one level for any given process, the closing of cycles in terms of resource use and outputs (products and waste) may be an aspiration, and make that process in itself sustainable. However, the process may be intrinsically unsustainable when considered within a broader context accounting for all of the economic, ecological and socio-political implications. Traditionally sustainable indicators have been used as a measure to assess increasing or decreasing sustainability, following detailed analyses to define what the appropriate indicators should be. A current UK project investigating the options for the most sustainable means of disposal of domestic sanitary wastes requires measures to assist in the evaluation of the options. This paper reviews the use of indicators in the context of the current project and municipal water systems, and illustrates how an integrated approach may be envisaged incorporating economics, life cycle analysis and risk assessment as part of a framework to assist decision makers when deciding whether changes to systems or practices are likely to be more or less sustainable. A major conclusion is that any moves to introduce sustainable systems can only be made in conjunction with the system users - the public, who must be involved in the formulation of any new practices which require a change in lifestyle. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.