This report presents the design, development and testing of a number of prototypes of portable pit
emptying technologies that were developed as part of Water Research Commission research project
K5/1745. It is preceded by two other reports in the Tackling the challenges of full pits series:

Volume 1: Understanding sludge accumulation in VIPs and strategies for emptying full pits
Volume 2: How fast do pit toilets fill up? A scientific understanding of sludge build up and
accumulation in pit latrines

The designs which have been explored to date have been the pit screw auger, which uses a
motorised soil auger to lift sludge from a pit, the Nano Vac and e Vac, which use piston pumps and
vane pumps to suck relatively wet sludge from pits. In addition, a pressure vessel has been
developed which can be used for collecting sludge or for pumping water or air into a pit to aid
removal.

Being portable by two people these technologies do overcome the issue of access and have proven
viable when trialled on pig slurry. The eVac has in addition been used successfully to empty wettish
pit latrines in the field, which it does with little difficulty. Being the most robust and the most
compact of the devices, the eVac appears to have the most potential on pit latrines in the field, and
should be the focus for further research and development work.