What We Do

Water, Sanitation & Hygiene

Strategy Overview


Users with membership cards at a community toilet for women in an urban slum in Pune, India.

our goal:

to enable universal access to sustainable sanitation services by supporting the development of radically new sanitation technologies as well as markets for new sanitation products and services.

The Challenge

At A Glance

 In the developing world, 2.5 billion people practice open defecation or lack adequate sanitation facilities; an additional 2.1 billion urban residents use facilities that do not safely dispose of human waste.

Poor sanitation contributes to about 700,000 child deaths from diarrhea each year.

Improved sanitation—including waste treatment and resource recovery—is essential to a healthy and sustainable future for the developing world.

The foundation focuses on groundbreaking innovations in sanitation technology and new ways to deliver sanitation products and services, particularly in densely populated areas of South Asia and Sub-Saharan Africa.

Our Water, Sanitation & Hygiene strategy is led by Brian Arbogast, director, and is part of the foundation’s Global Development Division.

The need for better sanitation in the developing world is clear. Forty percent of the world’s population—2.5 billion people—practice open defecation or lack adequate sanitation facilities, and the consequences can be devastating for human health as well as the environment. Even in urban areas, where household and communal toilets are more prevalent, over 2 billion people use toilets connected to septic tanks that are not safely emptied or use other systems that discharge raw sewage into open drains or surface waters.

Poor sanitation contributes to about 700,000 child deaths from diarrhea each year. Chronic diarrhea can hinder child development by impeding the absorption of essential nutrients and reducing the effectiveness of life-saving vaccines.

Creating sanitation infrastructure and public services that work for everyone and that keep waste out of the environment is a major challenge. The toilets, sewers, and wastewater treatment systems used in the developed world require vast amounts of land, energy, and water, and they are expensive to build, maintain and operate. Existing alternatives that are less expensive are often unappealing because they don’t kill disease-causing pathogens, have impractical designs, or retain odors and attract insects.

The Opportunity

By improving how we deal with human waste, we can save lives, improve child health, and ensure greater dignity, privacy, and personal safety, particularly for women and girls. Better sanitation also contributes to economic development, delivering up to $5 in social and economic benefits for every $1 invested through increased productivity, reduced healthcare costs, and prevention of illness, disability, and early death.  

Emptying a pit latrine in an apartment block in Nairobi, Kenya.

Solving the sanitation challenge in the developing world will require radically new innovations that are deployable on a large scale. Innovation is especially needed in densely populated areas, where billions of people are only capturing and storing their waste, with no sustainable way to handle it once their on-site storage—such as a septic tank or latrine pit—fills up.

Groundbreaking improvements in toilet design, pit emptying, and sludge treatment, as well as new ways to reuse waste, can help governments and their partners meet the enormous challenge of providing quality public sanitation services.

Our Strategy

The Bill & Melinda Gates Foundation’s Water, Sanitation & Hygiene program focuses on developing innovative approaches and technologies that can lead to radical and sustainable improvements in sanitation in the developing world.

A sanitation facility in the Kibera slum in Nairobi, Kenya, that was built by a public-private partnership to improve urban sanitation.

This requires understanding issues across the entire sanitation service chain, including waste containment (toilets), emptying (of pits and septic tanks), transportation (to sewage treatment facilities), waste treatment, and disposal/reuse.

Because the innovations we support can be most immediately valuable in densely populated areas, our main focus is on urban sanitation. Our priorities include developing non-sewered sanitation approaches, identifying new delivery models, and advocating for public policies that support improved sanitation in densely populated areas.

Ultimately, better sanitation will be a key to ensuring healthy, sustainable cities in the developing world, and the approaches that prove successful can be adapted and extended to rural communities.

We support many clean water and hygiene projects that have and will deliver significant results, but sanitation is our top priority because we have identified it as a neglected area in which we can spur significant change.

Most of our sanitation projects are in South Asia and Sub-Saharan Africa, where the burden of inadequate sanitation is greatest.

Areas of Focus

We focus our grantmaking in five complementary areas: transformative technologies, urban sanitation markets, building demand for sanitation, policy and advocacy, and monitoring and evaluation.

Transformative Technologies

A key part of our effort to radically improve sanitation in the developing world is our Reinvent the Toilet Challenge (RTTC). We are funding research to develop truly aspirational “next-generation” toilets that do not require a sewer or water connection or electricity, cost less than 5 cents per user per day, and are designed to meet people’s needs. Most of the projects use chemical engineering processes for energy and resource recovery from human waste.

A prototype toilet designed by Loughborough University researchers that extracts biological charcoal, minerals, and clean water from human waste.

Since 2011, we have awarded 16 RTTC grants to research organizations around the world. In 2013, we launched two country-specific RTTC programs in India and China. Both of these programs are designed to harness strong in-country research and development capabilities to solve this global challenge.

At the same time, we are developing market-driven ways to stop the dumping of fecal sludge into the environment. The Omni-Ingestor program is developing technologies to make servicing and maintenance of existing sanitation infrastructure—including latrine pits and septic tanks—easier and more affordable for private companies, public utilities, and municipalities. The Omni-Processor program is developing low-cost approaches for processing fecal sludge and the combined processing of fecal sludge and solid waste. The goal is to develop processors that are smaller than traditional treatment plants, with each processor supporting some 100,000 residents. Ideally, processed waste will be converted into products, forms of energy, or fertilizers and other soil amendments, which can generate revenue and thereby offset waste collection costs and increase people’s standard of living.

Urban Sanitation Markets

New sanitation technologies require new market structures and service models. In key urban markets, we are testing innovative approaches for their appeal to people in real-world settings. We are also working with local governments, service providers, and community-based organizations to foster a policy and regulatory environment that supports the use of new sanitation products and delivery methods.

These toilets in the slums of Nairobi, Kenya, are distributed through local entrepreneurs, who collect the waste for use in generating electricity and producing fertilizer.

We see particular promise in approaches that allow private-sector providers to profit from byproducts that have market value, including energy and fertilizer generated from fecal sludge. We recognize that in the near term, such revenues may not fully cover collection and treatment costs or generate traditional rates of return, so the public sector will continue to have an important role to play—not only to provide regulation and oversight but also to supply some of the services.

Building Demand for Sanitation

A household toilet built as part of a community sanitation project in Badsu village in Himachal Pradesh, northern India.

In addition to investing in improved technologies and urban market conditions, we support initiatives that help stimulate user demand for improved sanitation. Part of this effort involves working with sanitation providers and partners to help them adopt more evidence-based practices so they can deliver sanitation services that meet people’s needs. It also includes promoting incremental shifts in social norms around toilet use that will lead to higher demand for better sanitation products and services as they become available.

Policy and Advocacy

We work to improve the policy and regulatory environment for sanitation through partnerships with all levels of governments, multilateral organizations, community-based nongovernmental organizations, service providers, and others.

Monitoring and Evaluation

We invest in monitoring and evaluation to understand the effectiveness of various sanitation approaches. We use this information to report on our progress, assess the impact of our grantmaking, and share lessons that we learn with our partners.

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