The Earth Auger Toilet: A Solution for the Masses?
By: Samira Y Salifu, Knowledge Manager, PSI-Ghana
Sub-Saharan Africa remains one of the primary regions with the least improvement in accomplishing the Millennium Development Goal (MDG) on sanitation by 2015, with only a 30% coverage and an increase of 4% since 1990. In most parts of the region, open defecation is an easier and cheaper alternative, as improved sanitation facilities, which ensure hygienic separation of human excreta from human contact, are either non-existent or too expensive.
PSI works towards encouraging healthy behaviour and making markets work for the poor, a vision it is pursuing through the Sanitation Service Delivery program, where it is collaborating with PATH and Water & Sanitation for the Urban Poor (WSUP). The multi-partner team is testing and iterating on toilet design models that meet the needs of low-income urban consumers in terms of affordability, hygiene, adequacy and desirability.
One such toilet design is the Earth Auger toilet, a low-cost, easy-to-use toilet that diverts urine and feces into separate systems, thereby making it easier for the fecal sludge to be treated and turned into compost. The toilet comes in seated and squat models, as the diagrams below illustrate.
How a Pedestal Toilet Works
Source: Critical Practices, LLC
How a Squat Toilet Works
Source: Critical Practices, LLC
The technology was developed by Dr. Chuck Henry, President and Design Engineer of the US company Critical Practices LLC, former Research Professor at the University of Washington, and international consultant. Dr Henry has extensive experience in composting and the use of organic residuals as fertilizers, and to restore productivity of damaged or contaminated soils; design and installation of compost systems, and wastewater treatment and reuse.
Early this year, the team, in partnership with Dr Henry, launched live prototypes of the Earth Auger toilet in Benin and Ghana. These live prototypes will be used to collect consumer feedback and investigate demand for the Earth Auger design.
In Benin, toilets are being tested in a number of low-income households in the lagoon area of Cotonou, which is known for its numerous sanitation and hygiene challenges. In Ghana, tests are being run in a number of households within the peri-urban areas of the Ga West municipality, where access to water and the money needed to purchase a toilet are a perpetual challenge. In addition, the team and Dr Henry facilitated training for artisans in the installation of the Earth Auger toilet. These artisans were able to quickly assemble the toilet, put together from pieces made of injection molded plastic, then design and build appropriate superstructures to house the toilet.
Getting Feedback from Consumers
Through household visits, the team discovered that consumers appreciate the Earth Auger toilets for the convenience and comfort provided by the seated model, in particular; the absence of odors, flies and other insects; and the fill-up time of the receiving bucket (see diagram above). Also, neighbors of the pilot-test households mentioned their interest in acquiring an Earth Auger too.
Of course, as with any good human-centered design intervention, there have been suggestions for improvement. For one, the seat size was not optimal: it may be too big for children, while too small for large-sized users. Dr. Henry quickly solved this problem by developing a larger seat.
Other challenges seem to be occurring because of misuse or poor motivation to adhere to operational instructions. For instance, although the Earth Auger toilet was originally designed for four to six users, up to fifteen users were found to be using monitored toilets. Overuse can adversely affect the stability of the compost created by the toilet. In another case, an error in the construction of the floor of the superstructure meant that the superstructure did not completely surround the toilet, which caused the pedal to malfunction.
Continuing to Innovate
PSI and its partners, with the objective of creating a final product better adapted to the needs and purchasing-power of end-users, continues to work in partnership with Dr. Henry to test the Earth Auger toilet. We are also:
- identifying and testing other potential toilet models for use in Benin, Ghana and Cote d’Ivoire;
- developing potential supply chain models for the collection and treatment of fecal waste;
- developing ways to test fecal waste in order to evaluate the levels of pathogens, including helminthes; and
- seeking ways to increase private sector involvement in sanitation and fecal sludge management in West Africa.
The Sanitation Service Delivery (SSD) program, a five-year USAID funded program in Ghana, Cote d’Ivoire and Benin, aims at improving sanitation outcomes through developing and testing scalable, market based models that contribute to structural change within the region’s sanitation sector. The program is being implemented by PSI, in collaboration with PATH and WSUP.June 15, 2016