GZA recently awarded a grant to the University of Rhode Island Chapter of Engineers for a Sustainable World (URI-ESW), an organization formed in the summer of 2010, with the goal of providing sustainable, affordable and effective solutions to global engineering problems in developing regions, while simultaneously providing students with hands on experience.
The first project for the group is located in the community of San Mateo Ixtatan, Guatemala and consists of the development of a wastewater treatment system for the Seed of Wisdom School, the only high school in the town of 20,000 people. The school, as well as the rest of the community, currently discharges all of their raw sewage directly into a local river. The school had requested that we develop a wastewater treatment system that can reduce the impact of their wastes, be constructed of locally available materials and be simple enough for the school to use as a model for the community to reproduce on their own in the future.
In August of 2011, Dr. Oyanedel-Craver and Philip Virgadamo of GZA accompanied the URI-ESW to San Mateo Ixtatan, Guatemala to perform a site assessment and obtain the necessary information to develop a design for an effective and affordable solution to the village’s sanitary waste disposal needs. With the assistance of Dr. Oyanedel-Craver and Phil Virgadamo the URI-ESW identified the community school as the most effective location to implement a solution, addressing one of the group’s core values of educating the communities they assist.
With the data collected during the August 2011 trip, a simple septic system was designed during the winter of 2011-2012. The system design could not use infiltration for a disposal option as the soils in the Guatemalan mountains are primarily clay and volcanic ash. The final design concept called for a multi-compartment septic tank followed by dosing siphons and a secondary treatment component prior to discharging to the local river. Designs considered for secondary treatment included single pass sand filters and constructed vegetated wetland.
With the conceptual design completed, a materials list was developed, funding for travel and materials was secured from the University of Rhode Island-College of Engineering, GZA GeoEnvironmental, Inc. and several fundraising events. In August of 2012, URI-ESW returned to Guatemala with Dr. Oyanedel-Craver and Stephen Andrus, of GZA’s Providence office, to install the first phase of the system, the septic tank and evaluate the availability of materials to construct secondary treatment system with. Numerous problems were encountered during the 2012 trip including unstable soil conditions, excavation support and dewatering, availability of materials, working at a high elevation (elevation 8,500) and limited resources, but the group was successful, and finished one day ahead of schedule. Before leaving, they were able to flush a toilet that, for the first time ever in the community of 20,000, did not go directly to the river.
After returning from the 2012 trip to Guatemala, URI-ESW worked to complete the design of the secondary treatment systems for the septic tank effluent, to design a hand operated pump that could be constructed in Guatemala and used to empty the septic tank and designing dosing siphons that can be constructed of materials available in Guatemala. At that time URI-ESW had conceptually designs for two types of secondary treatment: a single pass sand filter and constructed wetlands. The maintenance costs for both types of system are low, the materials are available locally, and the technology is simple enough for the community to understand. In order to evaluate the feasibility of constructing and operating these systems in Guatemala, we proposed to build a scale model of each system and, working with the school, operate and monitor the systems.
As both of the proposed systems must be dosed without the use of electricity, we have been working to develop siphon dosing chambers that can be constructed from local materials and replicated by the students and community member.
Once again they received funding from the University of Rhode Island-College of Engineering, GZA GeoEnvironmental, Inc. (from a newly established internal grant program) and several fundraising events In August of 2013, they traveled to San Mateo to:
- Observe the conditions of the septic tank installed in 2012 and analyze the effluent for biological oxygen demand (BOD) to determine the treatment provided by the tank;
- Construct manually operated pumps that can be used to move wastewater to the dosing siphon and to pump septic tanks;
- Construct and test dosing siphons; and
- Prepare and present lessons to the students on basic hydraulic principals and wastewater treatment. Hands on lessons in basic hydraulics, pump assembly and dosing siphons were presented to the students
- We also discussed hygiene and working with wastewater safely.
Their trip was a success in many ways. The group was able to construct a pump and empty the liquid waste from the septic tank for inspection. The inspection revealed that the tank had not settles or cracked, and the solids accumulation was minor and appeared to be consistent with the volume of solids anticipated from the design flow. We were also successful in constructing an incubator and performing BOD analysis. The dosing siphons did not work out, although the siphons had worked at URI, they did not work as expected in Guatemala.
The area proposed for the secondary treatment was marked out in the field and we are waiting for the school committee to approve the installation of the system. If approved we plan to install a single pass sand filter and a vegetated wetland in the summer of 2014.
To help with future funding for the project in December of 2012 the URI-ESW, Dr. Oyanedel-Craver, and Stephen Andrus applied for an EPA P3 – People, Prosperity, and the Planet—grant. The EPA’s P-3 program is a unique college competition for designing solutions for a sustainable future. P3 offers students quality hands-on experience that brings their classroom learning to life. The competition has two phases. For the first phase of the competition, teams are awarded a $15,000 grant to develop their idea. They bring the design in April to the National Sustainable Design Expo in Washington DC to compete for the P3 Award and a grant of $90,000 to take their design to real world application. In September of 2013 the URI-ESW was awarded a Phase-1 $15,000 grant to continue their work in Guatemala. After the completion of the first phase, they will compete for a second phase and $90,000.
To check out the photos from the 2013 trip >CLICK HERE