During the 1980s, Prof. Monroe Weber-Shirk, civil and environmental engineering, volunteered in Latin American refugee camps. At the time, he was convinced that he would devote the rest of his life to development work in Latin America, but his plans were thwarted by a diagnosis of Hodgkin’s disease and his return to the U.S. for treatment. While pursuing a Ph.D. at Cornell, he placed his aspirations of improving the quality of life in Latin America on the back burner. A few years ago, he received a serendipitous phone call that put into motion an engineering project that would make his decades-long dream come true.

Another professor was interested in working on water supply in Latin America, and Weber-Shirk directed the group towards Honduras based on connections he had from his volunteer work. The initial project involved writing software that used GPS technology to collect information on the elevation and location of various components in a water supply system. Agua para el Pueblo, a Honduran nongovernmental organization, would then use the software to design and build a system for a local community. A successful software package never materialized, but during the ongoing collaboration, Jacobo Nuñez, director of Agua para el Pueblo, asked Weber-Shirk about the quality of the water being supplied to the small towns they served. He did not know the answer, but he made up his mind to find out. He decided to start by teaching a course on drinking water treatment in the developing world: Sustainable Small Scale Water Supply.

Weber-Shirk realized that the time demands of creating a new curriculum would mean that he could not continue to manage a project in Honduras with students, but they effectively vetoed his decision by arranging for a water treatment plant to be built. His class took the initiative to contact Fred Stottlemeyer, who had experience with water treatment both in the U.S. and Honduras, and successfully recruited him for their project. “That ended up being the origin of AguaClara, the beginning of this whole project,” Weber-Shirk said. The group’s first design was built in 2005, and in years since a new plant has been built every year. “Every plant is a new generation,” incorporating the latest insights and newest technologies, Weber-Shirk said.

The focus of AguaClara’s research has been on optimizing a treatment process of flocculation and sedimentation that has been in use for over 100 years. To understand the treatment process, one must first understand the desired output: clean water. Standards, of course, do vary around the world, but Weber-Shirk said that the basic guidelines are “no pathogens, toxic metals, pesticides, herbicides or industrial chemicals that could cause harm.” Another component is the inorganic matter that enters the water supply through river or creek flow and rainfall erosion. Inorganic matter, like clay, determines the water’s turbidity — a measure of cloudiness. Be they organic or inorganic, undesirable compounds are all particles that can form aggregates under the influence of a coagulant.

For water, it appears that looks do matter — removing the elements from water that make it unsafe to drink makes it aesthetically pleasing as well. In the first step of the treatment process, dirty water — chock full of organic and inorganic particles — is treated with the coagulant aluminum sulfate and sent through the flocculator. In the flocculator, the “differences in velocity between particles causes them to collide and stick together,” forming aggregates known as flocs, Weber-Shirk said. During sedimentation — the next step of the process — the flocs “settle out of the water faster than the original particles,” leaving behind clean water that is then treated with chlorine for disinfection as it exits the treatment process.

Unfortunately, the communities in Honduras beset with clean water problems do not have the resources to build and maintain “a high-tech plant that uses computers and electricity and pumps and all kinds of sensors to run things,” Weber-Shirk said. The only energy available to them is potential energy in the form of gravity.

The group’s task is made somewhat simpler by the fact that is not responsible for the whole water supply — just the drinking water supply — and the fact that the optimal treatment system can be applied to many different locations.

The other weight off the group’s shoulders is that “the difference within each site is greater than the difference between sites,” Weber-Shirk said. The system has the versatility to be implemented across Honduras, and hopefully beyond, granted that it is flexible enough to accommodate the wide range in the quality of water that enters the system at any given site.

AguaClara has been an “incredible opportunity to take research all the way to its full application,” Weber-Shirk said. This project has convinced him that the best way to learn is by entering into a cycle of (re)designing, implementing the design, receiving feedback and starting the cycle again. Beyond becoming better engineers, this process allows students to have a real impact on people’s lives. They never question why they have to learn the material “because it’s so obvious; the context is so applied,” Weber-Shirk said.

As a researcher, he enjoys quipping that he publishes in concrete because each treatment plant is “the real proof that what we’re doing is working.” As a professor, he is most proud of helping his students make the connection between real human need and engineering.

To Weber-Shirk, the great irony of AguaClara’s success is that he is able to create positive change in Latin America on a level that far exceeds what he would have been able to accomplish had he not developed cancer. He is working harder than he has ever before in his life, and when people ask him what comes after AguaClara, he responds that the dream is to spread the program’s success beyond Honduras.

Monroe Weber-Shirk