Updated May 31, 2019

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Meeting the need of billions: a efficient and hygienic pit emptying device.


Jocelyn Tsai

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Stage 3: Proof of Concept

The Flexcrevator team is currently testing prototypes in Kenya and Lusaka. We will then partner with manufacturers on the African continent to create a small scale manufacturing run. The initial units will prepare us for our transition to scale.

Registered as a Non-Profit in United States.

Focus Areas:

Water Sanitation and Hygiene (WASH) and Waste Management

Water Sanitation and Hygiene (WASH) and Waste ManagementSEE LESS

Implemented In:

South Africa, India and Zambia

South Africa, India and ZambiaSEE LESS

Key Partners
Countries Implemented In
Funds Raised to Date


Nearly two billion people on earth use pit latrines as the primary way to defecate and urinate. Pit latrines fill up quickly with human waste and large amounts of trash including rags, plastic bags, bottles, and hair. People often remove waste manually, exposing workers to a host of human pathogens without sufficient protection. While mechanized ways to remove fecal sludge such as vacuum trucks exist, these devices are expensive and clog from high volumes of garbage.



The Flexcrevator is a portable vacuum system coupled with a trash excluding attachment. Our unique device aspirates fecal sludge while simultaneously leaves trash in pits. By separating fecal sludge from trash during operation, we reduce the risk of jamming in the vacuum hoses. This makes the overall process of emptying more sanitary and hygienic. If the pit latrine emptier already has access to a vacuum truck, they have the option of pairing it with the trash excluder alone.

Target Beneficiaries

Our pit emptying device serves low and medium-income countries in Asia, Africa, South and Central America. Possible customers include small scale entrepreneurs, sanitation entrepreneurs, cities (such as Lusaka, Zambia or Blantyre, Malawi, among others), development agencies, international donor agencies (such as GIZ, The Red Cross). The number of people affected by the technology would be in the billions, who currently pay for pit emptying every six months or every 1-4 years.

Mission and Vision

Manual emptying of pit latrines using buckets and shovels is is a high-risk, unsanitary, and undignified job that should not exist today. The presence of large amounts of trash, and access to and within the pit are crucial barriers to development of a single pit emptying technology that can empty a high percentage of pits at a competitive cost. We aim to overcome these barriers, improve existing sanitation practices, and dignify pit emptying work worldwide through our low cost technology.

Innovation Description

The Flexcrevator is comprised of two main components – a portable vacuum system and an external trash excluder. When a pit emptier uses the full Flexcrevator system, fecal sludge is vacuumed into storage tank via a hose attached to the external trash excluder. The trash excluder in its current version is a rotating auger that pushes trash away during fecal sludge pumping. The operator empties fecal sludge from the vacuum tank and into sealed plastic barrels for safe storage and processing off site. The pit emptier also has the option of connecting the trash excluder directly to a vacuum truck. Although trash in pits typically interferes with a vacuum truck's ability to remove fecal sludge, our innovative trash excluder allows trucks to empty pit latrines very high trash concentrations.

Competitive Advantage

The Flexcrevator surpasses manual emptying by providing a safe, hygienic process for workers. When using the Flexcrevator, pit latrine emptiers have less opportunities for direct contact with raw fecal sludge. Our unit has competitive advantages over vacuum trucks as its small, modular, footprint allows workers access to pit latrines in narrow alleyways that usually restrict vacuum truck access. In terms of price point, the overall device is 10-20x cheaper than a vacuum truck. Unit's cost is nearly 50x cheaper than the standard vacuum truck under commercial production levels. While vacuum trucks are typically imported into developing regions, we designed the Flexcrevator with local manufacturing and sourcing in mind, allowing for lower maintenance costs. Finally, if a vacuum truck operator uses a trash excluder on an existing truck, the operator gets a competitive advantage over other truck operators as our excluder opens new business opportunities to empty trash filled pit latrines.

Planned Goals and Milestones

We strive to create the most hygienic product and process possible; we will incorporate new storage and safety features to further reduce fecal sludge exposure risk during operations and storage. We also will redesign the device to improve ergonomics to ensure that operators work in comfortable conditions. Finally, to reduce cost and weight of the overall unit, we will explore how to drive the unit using a gas engine.
Funding Goal500,000
New Implemented CountriesMalawi, Senegal, Kenya
Recruit2-3 Commercialization partners to help manufacture and distribute our device
New FeatureIncorporate hygiene and ergonomic features into the overall design and create a gas powered Flexcrevator


Mar 2018
Recognition ReceivedPENDING
ORGANIZATIONUnited NationsUnited Nations
as part of
STI Forum 2018
Nov 2017
New Country Implemented In
Jun 2012
New Country Implemented In
South Africa
May 2011