Multiple criteria decision analysis for sanitation selection in South African municipalities

Frances Salisbury,Dave Still,Chris Brouckaert,Chris Buckley

doi:10.4314/wsa.v44i3.12

Frances Salisbury, Dave Still + Show 2 more

Open Access

https://doi.org/10.4314/wsa.v44i3.12

Copy DOI

Journal: Water SA	Publication Date: Jul 31, 2018
Citations: 7	License type: cc-by

Affiliation: University of KwaZulu-Natal

Abstract

A multiple criteria decision analysis (MCDA) was developed for the selection of sanitation systems. This decision support system was aimed at assisting municipal engineers to design and implement sustainable solutions to meet a municipality’s obligation to provide free basic sanitation (FBS). Multi-attribute value theory (MAVT) was selected as the method most suited to the problem under consideration. Criteria which determine the sustainability of sanitation were selected from the literature and a spreadsheet-based MCDA with stakeholder and expert user interfaces was developed. Stakeholders determine the weighting of each indicator and expert users determine the values to be entered for the alternatives against each indicator. The partial values are aggregated using a weighted sum function. Research carried out into the implementation of FBS by the eThekwini Municipality that includes the city of Durban was analysed. This informed the allocation of indicator values to the sanitation alternatives under consideration: ventilated improved pit latrines (VIPs) and urine diversion dehydrating toilets (UDDTs). An innovative scenario analysis method was used to determine the effect of different weightings and/or values, representing changes in stakeholder involvement, resource recovery and political support for ecological sanitation. The MCDA was found to provide a guiding framework for municipal engineers in their efforts to implement sustainable sanitation. The process of deriving values for the MCDA is likely to prove even more useful than the overall value scores of the options under consideration.

Highlights

In South Africa, the Free Basic Sanitation policy (FBS) was developed to ensure that the country’s poorest citizens have access to hygienic excreta disposal facilities (DWAF, 2003)
It is important to note that the scenarios presented here are only intended to demonstrate how a municipal engineer might use the multiple criteria decision analysis (MCDA), not to give definitive answers to the relative value of ventilated improved pit latrines (VIPs) and urine diversion dehydrating toilets (UDDTs) in any situation
MCDA presents a number of challenges if it is to be implemented in a rigorous manner

Summary

Introduction

In South Africa, the Free Basic Sanitation policy (FBS) was developed to ensure that the country’s poorest citizens have access to hygienic excreta disposal facilities (DWAF, 2003). Conventional waterborne sewerage is very successful in removing excreta from the vicinity of those producing them but it has some limitations (Panesar and Werner, 2006). Sewers require a reliable and plentiful water supply, a high level of maintenance by skilled personnel, and an effective system of treatment for the waste products (Flores et al, 2008). A system which dilutes human excreta with large amounts of potable water and attempts to reclaim this water downstream is hard to justify in water-scarce countries (Panesar and Werner, 2006). In South Africa, the wastewater treatment works are already under severe strain and sanitation has yet to be extended to 11% of the population (DWA, 2012). There is a failure of many systems introduced in the past 20 years (Austin, 2003; DWA, 2012; Montgomery et al, 2009; Starkl et al, 2013)

Objectives

Methods

Results

Discussion

Conclusion