Amparo Flores

Selecting sanitation systems for sustainability in developing countries.

This paper presents a methodology for systematically incorporating multi-dimensional sustainability considerations into the selection of wastewater options for developing countries and the evaluation and comparison of these options. Appropriate technologies for developing countries were screened based on their function and their use of operational sustainability features; this list of technologies can then be used to elaborate design options. Sustainability indicators are used to enable a parallel comparison of the options from environmental, economic, and socio-cultural perspectives. For illustration, the indicator approach is applied to a case study of the sanitation options for peri-urban/rural areas of the eThekwini Municipality in South Africa.

Evaluating the Sustainability of an Innovative Dry Sanitation (Ecosan) System in China as Compared to a Conventional Waterborne Sanitation System

The use of sustainability indicators for evaluating sanitation systems is applied to the Erdos EcoTown Project (EETP) in China for illustration. The EETP is the largest urban settlement in the world employing ecological sanitation, which incorporates separation of waste streams, dry toilets, and resource recovery. The EETP’s dry sanitation system is compared against the Dongsheng District’s conventional sewer and centralised STP. The two systems are compared based on technological, environmental, economic, and societal indicators. Overall, the two systems perform reasonably well from a technological perspective. The conventional system performs significantly better than the dry system with regards to land and energy requirements, and global warming potential; it also performs better based on freshwater aquatic and terrestrial ecotoxicity potentials, but by a smaller margin. The dry system has superior environmental performance based on water consumption, eutrophication potential, and nutrient and organic matter recovery. The dry system is a more costly system as it requires greater infrastructure and higher operational costs, and does not benefit from economies of scale. The waterborne system performs better based on the societal indicators largely because it is a well-established system.