There are millions of pit latrines throughout the developing world, which all have one thing in common… They will all fill up. When this occurs in urban areas, where digging a new pit is not an option, users are given the difficult task of having their pit emptied. Typically, the user can not afford the services of a vacuum truck that we are accustom to in the developed world. If they can, the truck often cannot gain access to the pit in dense urban areas or difficult rural terrain. Consequently, pits are often emptied manually as shown above. If manually emptying is not done properly, it can lead to the spread of diarrheal diseases through fecal contamination at the pit, during transport, and through improper disposal. Improper pit emptying eliminates the hygienic progress provided by the pit latrine, consequently taking a step backwards in the movement for better global sanitation.
In response, several technologies have been developed in an effort to better the art of pit emptying. Several challenges face these technologies as pit emptying is not simple task. The makeup of the waste, water vs. wiper cultures, access to and into the pit, and the presence of trash are just some of the factors that make this a difficult enterprise. The Excrevator was developed keeping the following criteria in mind:
– Portable – easily able to access most any pit latrine location
– Sanitary – provides hygienic protection of the operator and pit users
– Effective – quickly removes a wide range of waste
– Affordable – produced with cost effective and easily replaceable materials
– Maneuverability – easily operated by two or less people within the pit
– Modularity – ability to be assembled within a latrine superstructure
Several considerations must be taken into account through the development of the Excrevator. Through lab and field testing here at NC State to field testing in South Africa, Malawi and India, we feel we are on a great track to meet most if not all of these criteria and produce a viable pit emptying option in the near future.