Generalised Model and Framework of Analysis of Sanitation and Wastewater Management and Intrinsic Value Recovery from Wastewater

 Prvoslav Marjanović1, Cornelius (Chris) Reynders2

 

 

1 Institute for the Development of Water Resources “Jaroslav Cerni”, Belgrade, Serbia
2 C Reynders Consulting, Private Bag X43, Wilropark, 1731 South Africa, e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

Abstract

The problem of sanitation and wastewater management is under the influence of a diverse set of drivers that need to be fully understood in the process of development of an appropriate sanitation and wastewater management strategy. Such a framework is presented and is used for the purpose of evaluating intrinsic value recovery from wastewater in the context of wastewater being viewed as a resource rather than a liability. The develped framework is applied to a case study of Gauteng Province in South Africa using the distance function approach for the valuation of wastewater as a resource. The paper concludes that distance function valuing provides a methodology for evaluation of economic effects and implication together with corresponding economic efficiency rankings as input to strategic decision making, with respect to: a) different wastewater management system configurations accompanied by their potential for wastewater reclamation, reuse and recycling, b) the effects of different technology option choices within any system configuration and switching from one management system configuration to another or from one set of technology options to another.

Keywords: wastewater management, wastewater reuse, wastewater treatment, intrinsic value recovery, sanitation, decentralized wastewater management

 

 

 

 

Introduction

The problem of sanitation and wastewater management is under the influence of a diverse set of drivers that need to be fully understood in the process of development of an appropriate sanitation and wastewater management strategy.

Within this context is important consideration with respect to the choice of an appropriate system and technical solution to a sanitation and wastewater management problem. The general framework for the selection process is presented in Figure 1.

The generalised framework presented in Figure 1 allows one to establish the relationship and interaction pyramid between different aspects of water and sanitation systems all contributing to the Sanitation and Wastewater Management Strategy for a particular Municipality (Figure 2).

The choice of technology is driven by the user needs and socio-political and legal environment and constrained by the physical and economic environments in which the systems are located and being implemented (Figure 3). This implies that user needs as articulated through the socio-political and legal system may or may not be met in a manner that is sustainable or economically and environmentally feasible.

Furthermore, within the context of dual water quality management approach as practiced (Figure 4, combination of effluent and ambient water quality standards) the necessary interventions at the municipal level and in settlements are inclusive of waste and impact minimisation, pollution prevention and treatment in a 3-step strategic approach to wastewater management (Gijzen et al. , 2006).

The conventional supply-side water supply management approach causes increased wastewater generation with accompanied increased pollution loads requiring higher levels of mitigation of environmental pollution. Where disposal of wastewater treatment effluent takes place in rivers and natural water bodies, the lack of adequate natural compensating capacity of such water bodies typically results in ecological damage of the aquatic environment. With a shift of emphasis to a sustainable demand sided management approach (as opposed to a supply sided one), the avoided water wastage and reduction of high volumes of wastewater generation represent both resource conservation and environmental protection benefits that contribute to overall sustainability.