Use of the waterharmonica for conversion of treated waste water into a natural resource in the developing world [draft paper for conference Ecological Engineering for Integrated Water Management (Oct. 30 - Nov. 2, 2003) Harvard Graduate School of Design,

In the Netherlands the need for treatment technologies that form a link between municipal wastewater treatment plants and (re)use of treated wastewater is more and more acknowledged. A lot of experience has been gathered with the design and operation of wetland systems, however, the evaluation and spin-off of these experiences has been limited so far. As such, the “Waterharmonica” is being developed as an instrument to include ecologically engineered “linkage-systems” as an integral part of design for the renovation and extension of municipal wastewater treatment plants with the aim of using this water for nature and recreational development, and replenishing of ground water sources. The concept has resulted in a research and implementation programme named “Waterharmonica”(2003-2004) which is financed by the Dutch Foundation for Applied Water Research (STOWA) and the Dutch Water Board Hollands Noorderkwartier. Part of the Waterharmonica programme focuses on exchanging knowledge and experiences with developing countries. A short survey concludes that the latter countries have practically no cases similar to the Waterharmonica. Municipal wastewater treatment facilities are either lacking or at least do not have an engineered, planned and controlled, ecological system for biological reanimation of the treated wastewater prior to disposal or (re)use. However, unless disposal is in an affluent body of water like the sea, direct or indirect use of raw or partially treated wastewater is generally, more or less controlled or uncontrolled, a daily practice in many developing countries. Each case has its own contextual dynamics, such as land and water rights issues, governing the fate of water, nutrients and pollutants. Each case requires a life-cycle approach to facilitate stakeholder negotiation processes, indicating mutual benefits and responsibilities that can or must be shared. Hence, a flexible framework is developed for sustainable and integrated development of sanitation, wastewater collection, -treatment and (re)use of water and nutrients, with emphasis on the role of natural treatment processes.