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This project has studied the appropriateness of the ABR for on-site primary sanitation in low-income communities. The baffled design of the ABR ensures high solids retention resulting in high treatment rates, while the overall sludge production is characteristically low. Effluent COD values measured from a 3 000 l pilot ABR using domestic wastewater at a wastewater treatment works were consistently below 200 mgCOD/l at an HRT of 22 h, and a 1 log reduction of pathogen indicator organisms (E. coli and total coliforms) was observed. Analysis of results indicates that the operating flow rate was too high to allow complete fermentation of particulate COD; it is expected that better COD and pathogen removal will be obtained at smaller hydraulic/organic loads. This paper presents results obtained for a 5 month analytical period at a single operating point. Operational and institutional issues relating to the appropriateness of the technology for on-site sanitation are explored, as well as the acceptability of the technology to target communities. Health related aspects associated with reuse of the effluent for agricultural purposes are discussed.

This paper reviews the use of environmental life-cycle assessments (LCAs) in the water industry internationally and locally. An LCA conducted on the water supply, treatment and recycling in the eThekwini Municipality is used for demonstrative purposes. Many of the LCAs reviewed, including the case study, have demonstrated that in the treatment of water (potable water and wastewater) most of the environmental impacts are traced back to the use of energy -in most cases the use of electricity. Therefore, it is proposed that for South Africa the electricity consumption of different water treatment processes can be used as an environmental indicator of impacts. Advantages and limitations in using electricity consumption as an indicator are also presented.

The objective of this study was to generate information on the environmental profile of the life cycle of water, including treatment, distribution and collection and disposal (including recycling), in an urban context. As a case study the eThekwini Municipality (with its main city Durban) in South Africa was used. Another aim of the study was to compare the environmental consequences for the provision of normal, virgin potable water vs. recycled water to industry in Durban. Therefore, a series of environmental life cycle assessments (LCAs) were performed and environmental scores were calculated for the processes involved in the treatment, recycling and disposal of water and wastewater. In order to enable the addition of these scores the same approach was adopted and the same methodology was used and a final environmental profile was produced.This study shows that a system approach as well as a process approach is needed for the integral assessment of the environmental performance in the provision of water and wastewater services. From the LCAs of individual processes involved in the provision of water and wastewater in the eThekwini Municipality, it emerged that the process with the highest contribution is the activated sludge process -used in the treatment of wastewater. However, when considering the entire system and including the losses in the distribution network for potable water, the process with the highest contribution became the distribution itself. An improvement analysis was performed and is presented. It takes into account a series of possible interventions and their consequences. Most notably, one conclusion of this study is that recycling as currently undertaken in Durban, has positive environmental impacts.

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