Reinvent the Toilet Challenge (RTTC, Round 1 and 2), Grand Challenges Explorations (Round 6 and 7)
Request for proposals, grant conditions, Seattle exhibition fair program and exhibitor guide

Published in: 2012

Bill & Melinda Gates Foundation, Seattle, USA


Content - Summary

The challenge presently posed to humanity’s best and brightest is to develop practical ways and means for giving the “bottom billion” people access to safe and affordable sanitation that is pleasing to use and effectively removes human waste from the environment while recovering components that can be recycled.

The Reinvent the Toilet Challenge:
The initial phase of the Reinvent the Toilet Challenge involves offering grant support to exceptionally qualified, highly focused, innovative individuals and teams at selected universities with recent records of extraordinary engineering excellence in pertinent areas. The challenge is to commence the prototyping, conceptualizing, and designing of highly innovative ways and means of disposing of human waste in the high-value-engineered circumstances demanded by potential widespread, near-term adoption in the developing world.

Note that this Challenge is a separate process from the open calls for proposals issued by the Foundation as part of its “Grand Challenges Explorations” grant process.

Capabilities of primary interest to this challenge include acceptably disposing of the bodily wastes of a typical human adult for a total cost (capital and operating) of less than $0.05 per day. This “stretch goal” represents a large advance in cost-efficiency over contemporary “best available means” (e.g., those of life-support systems in underwater or space-going vehicles) even after taking credit for plausibly steep learning curves and mass production on indicated scales. Nonetheless, they represent the levels of economic efficiency that must be attained in order to have real potential for major favorable impacts on the human condition in the developing world during the next few decades.

The Reinvent the Toilet Fair (14-15 August 2012, Seattle, USA) showcased innovations from around the world that are creating a new vision for the next generation of sanitation.

The fair aimed to inspire collaboration around a shared mission of delivering a reinvented toilet for the 2.5 billion people worldwide who don’t have access to safe and affordable sanitation.

The fair featured the foundation’s Water, Sanitation & Hygiene team’s earliest technology bets — most of the work presented received funding just over a year ago. During that time, grantees and partners have made some promising progress. The exhibits include efforts to reinvent the toilet, and approaches to improve the collection, treatment, and disposal of human waste. The fair was meant to spur partnerships and conversations about how we can work together to bring sanitation to those who need it most.


The following projects are included in the Exhibitor Guide with detailed factsheets:

Fecal Sludge Omni-Ingestor

Improved latrine pans for pour-flush systems

An energy-producing, waterless toilet system

A high-efficiency sanitary toilet with sewage treatment

A self-mixing biogas generator

Developing fortified fertilizer pellets from human waste Sewage Containment and Mineralization device (SeCoM)

Tiger Toilet & Black Soldier Fly Larvae Collection System

Bioelectric Toilet

Developing chemicals to self-clean and disinfect toilets

Modeling the next generation of sanitation systems

A toilet that converts human waste to fuel gas

The Microflush Biofil Toilet

Diversion for safe sanitation

Promoting sanitation and nutrient recovery through urine separation

A community bathroom block that recovers clean water, nutrients, and energy

A toilet that produces biological charcoal, minerals, and clean water

A device that sterilizes fecal sludge

The Earth Auger Toilet: Innovation in waterless sanitation (el taladro de la tierra)

A toilet that sanitizes feces and urine to recover resources and energy

Safe sludge project

A vortex bioreactor that processes fecal sludge and wastewater

A device to improve pit latrine emptying


The following organisations are the grantees (lead organisations):

AGI Manufacturing, DCI Automation, Synapse Product Development, and Beaumont Design Inc.

American Standard Brands

Loowatt Ltd.


Frontier Environmental Technology

International Water Management Institute

Institute for Residential Innovation (IResl)

London School of Hygiene and Tropical Medicine

University of Colorado Denver

American Environmental Systems, Inc.

University College London

Delft University of Technology

Ghana Sustainable Aid Project

Swiss Federal Institute of Aquatic Science and Technology (EAWAG)

University of KwaZulu-Natal

Loughborough University

Oklahoma State University

Fundación In Terris

University of Toronto

University of California Berkeley

Plymouth Marine Laboratory

North Carolina State University


This library entry contains three documents:
1 - Reinvent the Toilet Challenge - requst for proposals (Feb. 2011)
2 - Program of the Fair (Aug. 2012)
3 - Exhibitor Guide (Aug. 2012)
4 - Short overview of the conditions for grants under the RTTC and GCE schemes

Bibliographic information

BMGF (2012). Reinvent the Toilet Challenge (RTTC, Round 1 and 2), Grand Challenges Explorations (Round 6 and 7) - Request for proposals, grant conditions, Seattle exhibition fair program and exhibitor guide. Bill & Melinda Gates Foundation, Seattle, USA


1 - Reinvent the Toilet Challenge Round 1 - Request for Proposals (Nov. 2011) (pdf) • Size: 0.22 MB

2 - Reinvent the Toilet Fair Program (Aug. 2012) (pdf) • Size: 0.57 MB

3 - Exhibitor Technology Guide (Aug. 2012) (pdf) • Size: 4.13 MB

3 - Short overview of grant conditions for RTTC and GCE schemes (pdf) • Size: 0.35 MB