The Bill & Melinda Gates Foundation launched the “Reinvent the Toilet Challenge” in 2011 to create innovative solutions for the more than 4.2 billion people who do not have safely managed sanitation options. The challenge called for solutions that could operate "off the grid" without connections to water, sewer, or electricity, and that could transform liquid and solid waste into valuable resources such as disinfected water and energy. The systems would also needed to be affordable, operating on less than $.05 per person per day, and designed so that people would actually want to use them.
A team of engineers and researchers under the direction of Dr. Brian Stoner accepted the challenge. After several years of user-centered design and engineering, including valuable feedback from thousands of households to better understand cultural norms and preferences, the first prototype sanitation systems were tested in Ahmedabad, India, in 2016. Subsequent systems have undergone further field-testing in Durban, South Africa, and Coimbatore, India. WaSH-AID’s technology pairs electrochemical disinfection for liquid waste processing with a solid waste process adapted for the use case. Solutions are modular and scalable: liquid waste is turned into non-potable water that can be reused for flushing, washing, or crop irrigation, and the solid waste can be processed for safe disposal and/or conversion to fuel.
Two technologies evolved out of WaSH-AID's research and engineering to develop off-grid sanitation solutions. The Reclaimer - a compact, automated technology designed to rapidly treat blackwater and greywater to ISO 30500 standards, and the S.H.E. (Safe Hygiene for Everyone) - a fully automated, sterile, sanitary pad disposal unit, designed to provide waste reduction, dignity and privacy. The Reclaimer is currently undergoing field-testing in India and the S.H.E. is scheduled for field-testing in the fall of 2019.
Potential commercial applications of both the Reclaimer and the S.H.E. are immense: from natural disaster recovery and caring for displaced persons to military bases and large-scale civic events, the systems can scale for use in shared public spaces around the world. The technologies aim to improve human health and well-being, conserve critical resources, and improve gender equality.