Omni-ingestor Worksops

Grant No. OPP1148684:


OI workshop - Dealing with Trash

March 2016 to August 2016

Project Description:

Pit latrines and in particular ventilated improved pit latrines (VIPs) are the most basic form of improved (acceptable) sanitation. However when the pit becomes full the facilities are no longer functional. Options include reverting to open defecation, abandoning the facility and building a new one or emptying the pit and safely disposing of the contents. The first two options are not considered as acceptable to the users from a health perspective. The majority of pit latrines have been constructed with no thought given to the emptying process. In addition the latrines are often used for solid waste disposal and contain up to 25 % non-faecal material. The viscosity of the sludge in the pits varies from water-like to thick (spadable) clay. The safe and efficient removal of the pit contents is an essential stage in the process chain leading to safe and sustainable faecal sludge management.

A number of initiatives have attempted to address the problem but have not found universal application due to issues such as maneuverability, suction power, clogging due to detritus (trash) and reliability.

The objective of the project wasto assemble a team of experts to investigate the challenges and to develop concepts and mock-ups of possible equipment to overcome these challenges.

Two workshops, together with relevant field trips were held in Durban, South Africa and Bangalore in India in which technical people with knowledge, experience or interest in designing equipment to empty pit latrines were brought together in order to:

(i)              view a variety of pits in different locations (Zambia, Tanzania, Durban and India) to gain a context of the problems associated with the challenge of emptying pits;

(ii)            (visit the faecal sludge characterization laboratory at the PRG (Durban) to become familiar with the facilities;

(iii)           participate in facilitated workshops to conceptualize and design appropriate mock-ups of equipment for emptying the different types of pit latrine sludge.

These events took place from the 18th to 29th April 2016 (Africa) and the 12th to 19th June 2016 (India).

The workshops were facilitated by Jon Shaw from Jon Shaw and Associates, and the core team members were selected from the USA, Africa, India, Bangladesh, the Netherlands, UK and Madagascar. Local experts from each of the countries visited joined the core team on site and participated in the discussions in order to provide local contextualisation and expertise.

The field visits and workshops provided valuable insight into the issues related to the emptying of pits, particularly in areas with limited access and where the pits contain a significant amount of trash.  Some designs for pit emptying equipment was proposed and costed, but further work is required in order to take these ideas further.  


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