Traditionally sewerage service provision relies on large scale centralized treatment technologies. Recently new sanitation, or decentralized approaches, to sewerage services emerged as a solution to the problems inherited from the past (Figure 1). New sanitation has a many advantages related to:·
- Economics (reduced pumping costs and cost reduction through resource recovery)
- Sustainable resource use (recovery of N, P and energy from wastewater)
- System resilience (decentralized systems are less vulnerable to disturbance and can grow incrementally)
Despite the benefits of new sanitation systems progress towards the adoption and implementation of these systems is slow. The ‘lock in’ of wastewater service providers into existing investment has been identified as one of the key barriers to adoption of innovative wastewater solution. Other key barriers include the uncertain and prohibitive regulatory frameworks for decentralized systems and the organizational challenges for utilities managing multiple dispersed assets.
In addition to these barriers, it is also questionable whether a transition to new sanitation is indeed desirable and cost effective in all circumstances and what technologies are best suited in different circumstance.