We recently received funding from the Bill & Melinda Gates Foundation to IHE Delft Institute for Water Education to look at how safe the pre-cast pit latrine slabs (floors) are on the local market here in Malawi. As the need for fecal sludge to be treated offsite increases, prescriptive specifications are even more important but as of now we have no national regulation of these sanitation businesses and this research has shown we have a quality assurance problem.

Can a precast pit latrine concrete floor withstand emptying operations? An investigation from Malawi
Journal of Water, Sanitation and Hygiene for Development
By: Joshua Mchenga and Rochelle H. Holm

Abstract
For fecal sludge from households in low- and middle-income countries to be treated offsite it needs to be removed, which can be greatly affected by the pit latrine floor design. However, it is unclear whether precast pit latrine concrete floors (latrine slabs) can withstand emptiers and their equipment. To investigate this issue, 28 prefabricated latrine slabs were purchased in two cities of Malawi. They were first visually evaluated, and then their compression strength was tested. Additionally, each seller was asked a series of questions to better understand their business, training and construction practices. Results showed that households should perform due diligence to ensure that they are purchasing a safe precast latrine slab. Commonly reported problems included nonstandard reinforcement material and spacing in addition to slabs that were not thick enough or were not large enough in diameter. The results of this research illustrate the inherent complexity in ensuring high-quality decentralized sanitation solutions and how one component, the user interface, if implemented poorly, can affect the rest of the value chain. The findings from this work can help inform training and initiatives that engage artisans and suppliers who play a role in the provision of onsite sanitation service delivery.

The paper is open access, and can be read for free here: iwaponline.com/washdev/article/doi/10.21...rete-floor-withstand