AguaClara Concept Paper

Overview

AguaClara is a Cornell University project that is improving drinking water quality through innovative research, knowledge transfer, and design of sustainable and scalable water treatment systems. AguaClara water treatment plants are designed to treat turbid surface waters at the municipal scale, built using local materials, and operated without electricity. AguaClara partners with local institutions who build, operate, train, transfer, oversee, and monitor the water treatment plants to ensure long term sustainability.
AguaClara plants have a one-time construction and capacity-building cost of less than $20 per person. The monthly fee for maintenance and supplies needed to keep the plant operational is approximately $1 per family.

The Challenge, Approaches, and the AguaClara Niche

Six million children a year, mostly under the age of five, die from lack of access to clean water and sanitation. Distributing untreated surface waters as drinking water is one of the causes of waterborne disease. Point of Use and municipal scale treatment schemes are two potential solutions. In recent years, centralized large-scale water treatment and supply systems have been seen as an unsustainable expensive strategy to provide safe drinking water in low-income countries. Often, conventional technologies developed for use in the first world have been inserted in third world settings, which lack ready access to supply chains, trained technicians, and sufficient capital. These systems so frequently fail.

Point of Use Treatment Systems

Point of Use treatment systems became the favored solution for providing safe water, but the challenges of training every household, the impossible task of monitoring water quality, and high cost of replacing failed units has led to the realization that municipal scale water treatment systems provide compelling advantages.
We recognize that POU solutions may be the only viable option in rural communities where piped distribution systems would be too costly or where water scarcity makes managing a distribution system difficult. The AguaClara team is proposing a corrective to the current overemphasis on POU technologies where municipal scale treatment and distribution would be more economical, sustainable, and would better meet the needs of the poorest members of the communities.
Some Point of Use advocates emphasize deficiencies in municipal scale treatment and distribution systems and encourage consumers to not trust tap water, in order to promote their own solutions. Loss of confidence in municipal water systems undermines public willingness to finance such infrastructure, which even POU users count on for their water source. POU water treatment is more expensive per person, treats only the drinking water rather than all water entering a home, and is often unobtainable by the poorest members of a community. There are numerous advantages to working at the municipal level including economies of scale, fewer maintenance people to train, and treating all of the water that goes into a home, not just the drinking water.

Municipal Scale Treatment Systems

A series of shortcomings has prevented municipal water treatment plants from becoming an effective tool for meeting the Millennium Development Goals. The lack of empirical experience or a theoretical basis for the design of small scale (communities less than 50,000) hydraulic flocculators has forced a reliance on simplistic designs using electric power. No technology has been available for gravity powered dosing systems that could be calibrated and easily used to deliver chlorine and aluminum sulfate. Environmental process engineers have viewed each installation as a customized design and the resulting engineering costs easily exceed the construction costs for small water treatment plants.
The AguaClara team has addressed each of these shortcomings. The team has developed designs for hydraulic flocculators that are economical to construct. These designs are based on a combination of fundamental fluid mechanics as well as ongoing research. The team has invented a gravity powered flow control module that delivers a constant flow rate and that is adjusted simply by raising or lowering a flexible tube. The AguaClara team has committed to open source engineering (freely sharing all of our research findings and our design algorithms). Our strategy to reduce the engineering design costs is to both publish our design algorithms and create an automated, web-based, design tool that will enable partner organizations to obtain detailed design documentation including 3-D CAD drawings of an AguaClara plant that is customized to the size of local materials that will be used for construction. Although the AguaClara design process is sophisticated, the resulting designs appear deceptively simple and use components that can be repaired and replaced by the plant operators.

Our successes

AguaClara has already proven to be successful at treating turbid surface water on the municipal scale. Working with Agua Para el Pueblo, a Honduran NGO, AguaClara has designed a water treatment plant that is working effectively and providing safe, clean water to 2000 people in Ojojona , Honduras. Two more plants are under construction in the towns of Marcala (serving 5400 people) and Tamara (serving 3500 people), also in Honduras.

Our goals

Having shown that our plants are successful in Honduras, we plan to expand to additional municipalities in Honduras and worldwide. Our goal is that five AguaClara plants be constructed in Honduras by the summer of 2009. Recognizing the global need for this technology we are developing a network of partners who are dedicated to knowledge transfer and capacity building and who can help disseminate the technology in other countries and who are willing to share their experiences with the network.