London School of Tropical Hygiene and Medicine
The Gulper is a manually operated pump to empty contents from pit latrines that can be constructed using locally available materials.
The Gulper is a manually operated pump to empty contents from pit latrines. A standard Gulper will reach 1m-1.5m into the pit and an extendable Gulper will reach up to 2m into the pit. The Gulper can pump semi-solid sludge, be constructed using locally available materials, be paid off through fees charged by emptiers for their services, and work in confined spaces. The design is open source, and has been trialled in many countries.
The Gulper can be manufactured globally using locally available materials, and has been implemented by a number of organizations including Engineers Without Borders, Water for People, SEB Engineering, Programme Solidarite Eau, Irish Aid, and Water Aid.
Costs vary depending on local materials, approximately 160 USD.
Other emptying products including the Vacutug, the Diaphragm Hand Pump, vacuum trucks, and the Dung Beetle.
Goal 6: Clean water and sanitation
Product can be manufactured using locally available materials.
The Gulper can be manufactured by local entrepreneurs using available materials or can be distributed by humanitarian organizations.
Liters of fecal sludge that can be hand or mechanically pumped from the pit per hour
Type of accessories needed
If transported, how the fecal sludge is moved
Speed in km/hr of the fecal sludge transportation
Volume of fecal sludge storage in liters of the transportation mechanism
There are three main components of the Gulper, the rising pipe, the plunger, and the bottom valve. The rising pipe is about 2m in length (can be increased to allow for further pit reach). It is constructed from 4 inch plastic drainage pipe (the thickest available) and has a 45° T-junction allowing sludge to be directed out (into a barrel). Footrests are attached using a clamp and a collar halfway down the pipe. The plunger runs up and down the inside of the rising pipe. At the base is a one way valve which works with the bottom valve to allow sludge to flow up in to the rising pipe. Clamped to the top of the rising pipe is a cap with a rubber grommet attached by a cap (stopping sludge from squeezing out as the plunger is raised). The bottom valve (attached by a collar) includes a cage to stop debris from entering the pipe and causing a blockage
Users are expected to maintain the product on their own.
General performance targets include production locally, can work in confined spaces, lower initial and operation and maintenance costs than other emptying technologies, and effective pumping of semi-solid sludge.
In the initial pilot by WaterAid in Tanzania only two of the four community-based organizations (CBOs) continued using the Gulper at the end, and lessons learned included adjustments to the formerly solid waste management business models to adapt them to fecal sludge management, and the importance of leadership and decision making in the selection of CBOs.
A willingness-to-pay survey conducted in Tanzania found 96% indicated willingness-to-pay of at least TSH 5000 (4.30 USD), and 57% of respondents willing to pay at least TSH 20,000 (17 USD).
A modified pedal Gulper in Malawi trailed has a flow rate of 0.00058 m3/s and if the trash content was low, a latrine with a volume of 1-4m3 could be emptied within 1-2 hours. However the success rate was ~17% (5 out 30 sampled lined pit latrines were successfully emptied).
The operator should not come into contact with the fecal sludge, and must dispose of it according to regulations. Personal protective equipment should at least include a protective suit, face mask, waterproof boots, gloves, and safety googles for the operator. Avoid sparks, such as lighting a cigarette, near the pit.
A barrel or other storage item is needed for pumped fecal sludge, and personal protective equipment is needed for the user.
Godfrey, A., Mtitu, F., 2015, Pit emptying business model: lessons from Dar es Salaam, Tanzania. 38th Water and Engineering Develop Centre (WEDC) International Conference.
Jenkins, M.W., et al., 2015, Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar es Salaam, Tanzania. International Journal of Environmental Research and Public Health 12(3), pp. 2588-2611.
Chipeta, W.C., et al., 2017, Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi). Physics and Chemistry of the Earth, 100, pp. 336-342.
Radford, J.T., et al., 2015, Latrine desludging pump development using a simple test for simulant strength: A case study from Uganda. Journal of Water, Sanitation and Hygiene for Development, 5(4), pp. 620-624.
Still, D., Foxon, K., 2012, Tackling the challenges of full pit latrines. Water Research Commission. Vol. 1.
Thye, Y.P., et al., 2011, A critical review of technologies for pit latrine emptying in developing countries. Critical Reviews in Environmental Science and Technology, 41(20), pp. 1793-1819.
Rogers, T.W., et al., 2014, Power earth auger modification for waste extraction from pit latrines. Journal of Water, Sanitation and Hygiene for Development, 4(1), pp. 72-80.
Regulations are context-specific and potential implementers should explore relevant laws, standards, and practices
A second Gulper model is being piloted in Uganda.
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