Mechanical Engineering Department
BS in Mechanical Engineering
This report documents the research, ideation, and development of a solution, implemented by the Cal Poly India Sanitation Team per the request of Mr. Harish Bhutani, to solve the problem of hazardous human waste management in poor villages in India. The sponsor envisioned a universal design that would give each household in those villages access to a private toilet system because the current solution is open defecation in water sources and farming fields. The initial constraints required the project be low cost, not use of electricity or water, have the ability to cater to an 8-10 person household, and be easily manufacturable and maintainable. Investigating this problem began with research into both the culture of India and the existing solutions. Our initial observations indicated some barriers that would add to the constraints of the design. The research showed that there were many ideas existing that have been either already established or in the early stages of laying the groundwork, but there was an interesting trend with the success rate and contingencies of these past projects. The past projects have not lasted very long due to poorly educating the users, lack of an infrastructure to handle continued maintenance, and lack of efficacy in the users to care for the systems. This last point had a lot to do with cultural taboos of touching human waste and being seen as a low class citizen. With all of this in mind, the brainstorming led to a design that is a hybrid of the past projects. The design implements a concrete-lined pit latrine with a hand pump used every six months to empty the pit and move the waste to an offsite facility. The user will have access to a personal shelter, made of compressed earth blocks, to safely defecate. A key feature includes a water bottle light to magnify the existing light in the shelter. This idea considers the user interaction with the waste, which will be no contact at all. The hope is that this design will also create job opportunities for people when the removal is needed. This would form a tight infrastructure that is integral to the success of this design because the people will be able to make this structure a part of their daily lives without this waste disposal system seeming like a burden. After this design was finalized, construction for the prototype began. The necessary part were ordered and the parts were manufactured to size and assembled. Design considerations that changed during this process included changing the internal metals to steel because of availability and militating on the tooling needed. The prototype was then tested for cyclical performance, as well as strength testing and materials testing. Some final conclusions drawn from the this project are that this a simple manufacturing process and easily maintainable, but in order to have this implemented in a region there needs to be a waste education done as well as continued supervisor and teaching of the users on how to properly care for this system.