The problem
- Many communities rely on pit latrines that fill up and need regular emptying.
- Vacuum trucks often cannot access dense settlements or narrow latrine spaces.
- Fully manual scooping is slow, messy and can put operators and neighbours at risk.
How it works
The Gulper 1 is a semi-mechanized hand pump first developed in 2010 and introduced to the market by Water For People. Direct hand pumping lifts wet sludge up a rising pipe and out through a T-outlet into a bucket or drum. Performance depends on pit depth, sludge thickness and the amount of trash in the pit.
- Rising pipe: about 2 m long and extendable so the pump can reach further into the pit.
- Plunger and valves: a plunger runs through the pipe; a one-way valve at the base works with the pumping action to lift sludge, with a cage to limit debris entering the mechanism.
- T-outlet: a junction at the top directs sludge out at about 45° into a container placed underneath.
- Handle: raising and lowering the handle opens and closes the valves in series to lift and discharge sludge.
See it in the field
Video series produced by CAWST (Centre for Affordable Water and Sanitation Technology) with Opero, covering how the Gulper works and how operators use it in Kenya and Uganda.
What it can and cannot handle
- Effective for watery sludge up to a limited depth when the pit is accessible for hand pumping.
- Difficult with thick waste; trash in the pit can block or slow the pump.
- Higher risk of sludge exposure than closed vacuum systems, so appropriate PPE is recommended.
Cost and upkeep
The open design lets a skilled fabricator build a unit for less than US$200, which keeps it an affordable option for many emptying teams. Metal parts can corrode and may need replacement over time. Like any emptying technology, success also depends on enabling factors such as disposal facilities, financial incentives and support from authorities.
Key specifications
Gulper key specifications| Type | Manually operated (semi-mechanized) pump |
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| Also known as | Gulper 1 |
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| First developed | 2010 |
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| Introduced by | Water For People |
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| Rising pipe | About 2 m; can be extended for deeper pits |
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| Main components | Rising pipe, plunger, base one-way valve with debris cage, T-outlet, handle |
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| Best suited to | Wet or partially wet pit latrines |
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| Fabrication cost | Under US$200 for a skilled fabricator (open design) |
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Training at Opero
Opero includes Gulper training at the Kisumu WASH Technology Hub alongside the PuPu Pump and PitVaq, with a focus on safety, dignity and service quality. Opero and CAWST also co-developed a technical brief on the Gulper 1; more detail is available in theCAWST WASH Resources review.
Learn and enquire
