First Flush System at El Cisne de Conchan, Ecuador

I'm a member of WPI's chapter of Engineers Without Borders, an philanthropic organization whose chapters assist in-need communities in countries around the world with various projects related to water security, sanitation, infrastructure, energy, and agriculture. WPI EWB has been working in the community of El Cisne de Conchan, Ecuador, a village in the mountains just outside of Cuenca, since 2016. The community is reliant mostly on contaminated spring water and bottled water from Cuenca, which led the WPI EWB chapter to install a rainwater harvesting system (RHS) capable of storing 40,000 liters of water, before I was a student at WPI. However, that project was not fully completed; it was missing a piece called a first flush, which diverts the first 15 dirtiest gallons of rainwater during a rainstorm that contains the most dirt and grime washed off of the roofs initially. This means the collection tanks were collecting lots of grime, even though there are intermediate filters to catch larger particulate matter. 

In late 2020, I was elected the Tech Lead for the five person First Flush project team, making me responsible for completing the design and testing of the system, making trainings and directions for the community, and coordinating the purchasing of the necessary materials in Ecuador. However, WPI did not allow travel, so the entire project had to be completed remotely. This proved to be very challenging.

The initial design of the first flush itself contained two tubes, and one system for each side of the Community Center. This was selected initially because of a miscommunication about the availability of 6" PVC pipes in Ecuador, leading to this complex two-tube design. Eventually, it was found that 6" PVC was available in Ecuador, and the design was modified to use a single long tube of 6" PVC for the main body. To make the system stable, a T connection was added at the bottom to allow for supports and better cleaning. I completed the CAD designs for the entire system and contributed to the design of the system. 

In addition to the actual design of the first flush system, a pre-implementation report was required by the national EWB organization before the project could be completed, and another post-implementation report was required after the construction was concluded. These required technical writing skills, and were written by the project team, where I completed the design, calculations, methodology, drawings, and materials sections, among others. 

The actual construction happened in early September of 2021, and the quality of the water coming from the system improved. In addition to the two systems installed on the community center, the community built a third one on their church which has another rainwater harvesting setup. This is exactly the goal of EWB, where we engineer a system, and the community is able to maintain and expand on the system. Sustainability!

The next step of the project happened in Fall 2022: Right now the community either chlorinates or boils the water from the system to clean it, but slow sand filters offer an easier and cheaper way to clean the water. Slow sand filters were prototyped on campus, and either a travel or remote implementation will happen soon to provide the community with these filters.