The Bill & Melinda Gates Foundation, USA, has announced the launch of a strategy to help bring safe, clean sanitation services to millions of poor people in the developing world. In a keynote address at the 2011 AfricaSan Conference in Kigali, Sylvia Mathews Burwell, president of the foundation’s Global Development Program, called on donors, governments, the private sector and the NGOs to address the urgent challenge, which affects nearly 40% of the world’s population. Flush toilets are unavailable to the vast majority in the developing world, and billions of people lack a safe and reliable toilet or latrine.
The foundation has also announced $42 million in new sanitation grants that aim to spur innovations in the capture and storage of waste, as well as its processing into reusable energy, fertilizer and fresh water. In addition, the foundation will support work with local communities to end open defecation and increase access to affordable, long-term sanitation solutions that people will want to use. The foundation and its partners are working to develop new tools and technologies that address every aspect of sanitation – from the development of waterless, hygienic toilets that do not rely on sewer connections to pit emptying to waste processing and recycling. Many of the solutions being developed involve cutting-edge technology that could turn human waste into fuel to power local communities, fertilizer to improve crops, or even safe drinking water.
The Reinvent the Toilet Challenge (RTTC) is a key part of this effort because it encourages the development of waterless and hygienic toilets that do not require piped water or a sewer connection. The research funded by this initiative explores innovations in toilet technology based on chemical engineering processes for energy and resource recovery from human waste. The goal is to develop clean, safe, durable and affordable toilets for the poor that cost less than five cents per user, per day and do not need to be connected to a sewer.
The foundation is investing in projects that focus on the treatment and collection of waste. For example, one grantee is working to develop building blocks made of a biodegradable material that would replace conventional brick or cement constructions for pit latrines. The goal is to create a latrine that would decompose once the pits are filled, allowing for the eventual conversion of the land into farming and other uses. Another grantee is developing an algae-based water treatment system that would use bacteria to treat a community’s waste while producing renewable resources: a nutrient-rich fertilizer for agricultural use and bio-methane to power the sanitation facility as well as the neighbouring community.
Solution for overflowing pit latrines
Piped sewage systems and wastewater treatment plants serve only a small fraction of those in developing countries, leaving the poor with on-site systems, such as pit latrines, to collect and store their waste. However, waste does not decompose fast enough or completely, so the pits fill up, leading to flies, odors, and unpleasant conditions. Because replacing or emptying full pits is difficult and expensive, many people resort to defecating outdoors, which poses serious health risks and is socially demeaning.
The foundation has given a $4.8 million grant to the London School of Hygiene and Tropical Medicine (LSHTM) to support Sanitation Ventures, a three-year project aimed at finding ways to speed up the decomposition process in pit latrines. The project’s primary focus is on biofilter technology, which is currently the most effective, commercially viable approach to solving the problems associated with pit latrines.
Biofilters are contained units that have an active layer near the surface where worms such as tiger worms, along with other organisms, digest solid waste as it enters the system. Beneath this layer is a filtration bed where the liquid waste is further treated by aerobic bacteria, resulting in highly treated sewage that can be safely discharged into the environment. The advantages of this system are that it produces low residual waste, uses a small amount of water, takes up less space than a septic tank, and is affordable to purchase and maintain. These types of systems have already been studied extensively and are being produced commercially in developed countries. Because the Tiger Toilet is both affordable and easy to use, it will meet the needs of people in developing countries without access to sanitation, be adopted by a large number of people, and make a dramatic difference in their lives.