Our second publication under the "Solutions for Pit Desludging and Subsequent Sludge Management in Low Income Urban Settlement in Malawi” project with support from the Water Research Commission of South Africa has been published.

Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi
by: Charles F. C. Chirwa, Ralph P. Hall, Leigh-Anne H. Krometis, Eric A. Vance, Adam Edwards, Ting Guan and Rochelle H. Holm
Int. J. Environ. Res. Public Health 2017, 14(2), 87; doi:10.3390/ijerph14020087

Abstract
Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology.

To help you access the full article which is open access, please visit www.mdpi.com/1660-4601/14/2/87 .

Of coruse. Do you want to message me your e-mail address and I'll put you in touch with Damian?

Well, I am hoping to use almost the same procedures. Do you mind sharing some challenges for the sake of planning. As I have indicated in my post, I will conduct the tests on 300 latrines and I am hoping to start this January.

We also had good experiences using a cone penetrometer. Do watch Damian's talk at fSM4 and let us know if you have any questions!

I will used the cone penetrometer test. This is the only device we currently have at Mzuzu Univesrsity.

Hi Charles,

Thanks for this update. What is your method for assessing sludge strength?

Alison

Note by moderator: This thread is related to this research project:
forum.susana.org/component/kunena/99-fae...ty-and-policy-issues
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I am Charles Chirwa and pursuing my Masters studies in Sanitation with Mzuzu University. I am working on a study aimed at assessing the strength of pit-latrine sludge which focuses on peri-urban areas of Mzuzu City. This will culminate in development of a digital system to be utilised in sanitation monitoring.
With the increasing demand for improvement in pit emptying efficiency, the need for understanding of physical properties of in-situ feacal sludge needs to be well documented to assist in planning. The focus of this study is the understanding that most pit emptying technology fails to efficiently remove the wastes from pit latrine due to variability in sludge strength which affects the effectiveness of pit emptying equipment relying on suction to remove sludge. This is compounded by poor understanding of the strength of the sludge and the composition of the sludge which tend to block the equipments. In most cases, pit emptying is done without the knowledge of the strength of the sludge contained in the latrine. As a result, most emptying exercise only achieve partial removal of sludge which results in accumulation of thick sludges in the pit over time which becomes more difficult to remove. Results from this study are going to be utilised in planning for emptying services. For case, data on sludge strength will help in planning for procedures to utilise in sludge fluidisation of pit sludge. Availability of data on sludge strength combined with the development of the monitoring system for sanitation monitoring is likely to provide a better understanding of prevailing sludge characteristics that will be utilised in planning for emptying services.
For my study I will investigate 300 pit latrines from around Mzuzu. The sample size has been chosen to get a clear view of sludge strength from around Mzuzu. The households from the sampled households will be interviewed on their sanitation practices and their knowledge on sanitation services. This will help in understanding some of the factors affecting the physical properties of latrine sludge. Results from household interviews will also be utilised in identifying key aspects to be included in the monitoring system I am intending to develop.
The monitoring system will combine both feacal sludge management and some components of domestic waste management. The system aims at equipping members to be able to recognise the sanitation challenges and empower them to take actions to trigger quick response by responsible authorities such as latrine emptiers and city assembly garbage collectors. A central data processing system will be established within the city assembly department where members can lodge their sanitation concerns that require immediate attention.
Any feedback on my approach would be appreciated.