Tuesday 14 September 2010

Back-end users

Here’s an interesting commentary on sanitation: Back-end users: the unrecognized stakeholders in demand-driven sanitation by Ashley Murray and Isha Ray of UC Berkeley (recently published online in the Journal of Planning, Education and Research). This is the Abstract:

Inadequate wastewater and fecal sludge treatment, disposal, and end use systems are arguably the greatest obstacles to achieving sustainable urban sanitation in unserved regions. Strategies for planning and implementing urban sanitation are continually evolving. Demand-driven sanitation with household and community participation is broadly thought to be the way forward. We are skeptical that more time and resources spent garnering household and community demand for sanitation will amount to the much-needed improvements in the treatment and end use components of sanitation systems. We propose shifting the incentives for sanitation from “front-end users” to “back-end users,” thereby leveraging demand for the products of sanitation (e.g., treated wastewater, fertilizer, alternative fuel) to motivate robust operation and maintenance of complete sanitation systems. Leveraging the resource value of wastewater and fecal sludge demands a reuse-oriented planning approach to sanitation, an example of which is the Design for Service approach presented in this commentary.

“Design for Service” is defined as “a five-step planning approach that results in a site-specific, reuse-oriented sanitation scheme. The ultimate reuse (or “service”) of the wastewater/fecal sludge is the starting point for the planning process”. The five steps are:

1. Generate a list of all of the potential “services” (e.g., irrigation, fertilizer, energy generation) that wastewater, fecal sludge, and treatment by-products can provide.
2. Assess the demand for these services in and around the city of interest.
3. Assess the business-as-usual performance of the provision of these services according to economic, social, and environmental indicators.
4. Design sanitation infrastructure for the provision of that service where it can have the greatest marginal impact.
5. Assess the intrinsic environmental and cost characteristics of the technology options available for rendering the wastewater/fecal sludge/treatment by-products suitable for the service of choice.

The paper details the rationale for each of these five steps.

As the authors say in their Conclusions, “designing for reuse exacts a nontrivial time and resource cost on sanitation planning processes” − but, if it increases the chance of system success/sustainability, then it’s clearly worth doing. Up to now we’ve concentrated on the “front-end users”. It’s clearly time to bring the “back-end users” into the sanitation planning process.