Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi

Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi. Int. J. Environ. Res. Public Health 2017, 14(2), 87; doi:10.3390/ijerph14020087

• Full text

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.

Characterization of pit latrines to support design and selection of emptying tools in peri-urban Mzuzu, Malawi

Characterization of pit latrines to support design and selection of emptying tools in peri-urban Mzuzu, Malawi. Journal of Water, Sanitation and Hygiene for Development | in press | 2017

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Authors: Rashid Chiposa, Rochelle H. Holm, Chimuleke Munthali, Russel C. G. Chidya and Francis L. de los Reyes III

The urban areas of many low-income countries must balance a rising demand for pit latrines for household sanitation provision against limitations in space, resulting in a need for pit latrine emptying services.

This study was undertaken in the peri-urban neighborhood of Area 1B in the city of Mzuzu, Malawi, to examine the characteristics of household pit latrines for designing and selecting pit latrine emptying tools. We used 150 structured household surveys and field observations. From this, a subset was selected and 30 manual cone penetrometer tests were conducted at full latrines. Chemical oxygen demand analysis was also performed at 14 pit latrines.

The results indicated that in addition to serving as a disposal for fecal matter, 90% of households also used pit latrines for domestic waste. Only 10% of the studied pit latrines were lined. The filling rate in the study area is calculated to be about three years, and no respondents reported previous emptying.

It is suggested pit latrine emptying technology development focuses on a maximum tool diameter of 10 cm to fit through the keyhole (squat hole) and height of 146 cm to fit inside the superstructure, as well as supporting unlined pits and the ability to pump trash.

Extra funding for “breathable membrane” linings for pit latrines

Roof latrine. Photo: Steve Dentel, University of Delaware

A team at the University of Delaware has received US$ 250,000 in additional funding to continue its research on “breathable membrane” linings for pit latrines.

The breathable fabric helps to prevent groundwater pollution, while also protecting sanitation workers from exposure to pathogens. Heat from biodegradation of the feces or from the sun gradually expels water vapour, but prevents the escape of particulate or dissolved constituents.

Professor Steve Dentel, who leads the research, explained how it all works in webinar held in February 2014. A  write-up of the presentation and discussion was posted on the SuSanA forum.

The first phase of the research (November 2011 – October 2013)  was funded through the Bill & Melinda Gates Foundation’s Grand Challenges Explorations Fund.

Dentel is piloting the membrane technology in the slums of Kanpur, India, in collaboration with WaterAid. He wants to get them in place before the beginning of the rainy season in June. Since the membrane is reusable, the cost of using susch a sophisticated technology can be reduced.

At the same time, Dentel is working with UD engineering colleagues Daniel Cha and Paul Imhoff to apply the technology in wastewater treatment facilities in the USA and South Korea.

For more information you can follow and take part in a discussion about the research with Prof Dentel on the SuSan Forum.

Source:  Karen B. Roberts, Bacteria fighting fabric, UDaily, 17 Apr 2014

 

 

BRAC WASH latrines will power business to turn faecal waste into energy

The BRAC WASH programme in Bangladesh is to conduct detailed planning to convert faecal matter from pit latrines into commercially viable fertiliser, biogas and electricity. The aim is to complete the sanitation chain by making material from millions of pit latrines safe and economically productive.

Babar Kabir, Senior Director of the BRAC WASH programme, says that there is a sound business case for investment in bio-energy units that could generate electricity on a large scale, but believes that investors must be in this for the long-term and that the most important payback will be improved health and sanitation.

Research call for commercially viable processing of pit latrine contents

IRC International Water and Sanitation Centre announces a research call for: Commercially viable processing of pit latrine contents: using a mix of human faeces, chicken manure and silage material.

This call is part of the BRAC WASH II programme in which EUR 1.5 million will be used for innovative research, tendered to consortia of leading European and Bangladeshi research organisations.

The planned duration of the research project will be 12 months. The anticipated cost of the project is EUR 325,000.

Guidelines for research call

Application form

Send full proposal application forms to bracactionresearch@irc.nl by 30 August 2013

Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review. Environ Health Perspect, March 22, 2013. doi:10.1289/ehp.1206028

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Jay P. Graham and Matthew L. Polizzotto.

Department of Environmental and Occupational Health and Department of Global Health, George Washington University School of Public Health and Health Services, Washington, DC, USA

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Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that pit latrine discharges of chemical and microbial contaminants to groundwater may negatively affect human health.

Objectives: Our goals were to 1) calculate global pit latrine coverage, 2) systematically review empirical studies of the impacts of pit latrines on groundwater quality, 3) evaluate latrine siting standards, and 4) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines.

Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books and reports identified using Web of ScienceSM, PubMed, Google, and document reference lists.

Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another.

Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines.

Rwanda, Kigali: more connections to sewerage system planned

Kigali Eco-Toilet. Photo: Eugene Dusingizumuremyi / SuSanA

The capital city of Rwanda has turned a delay in funding into an opportunity to revise its plans so that more areas get connected to a new centralised sewerage system. Construction of a US$ 70 million wastewater treatment plant in Giti Cyinyoni, Nyarugenge District, was due to start in 2012 but has been delayed by one year.

The lack of a centralised sewage system in Kigali (pop. 1 million) has been forcing real estate developers to provide onsite sewerage systems for new housing units. Schools, hospitals and other public buildings are already required by law to have their own sewerage systems. In future all these onsite systems will be connected to the new centralised system.

In 2008, according to a survey, 80% of the people in Kigali still used pit latrines [1]. These have proved to be not only hard to maintain, but also expensive to manage in the long run. That’s why the city council recently passed a bylaw that instructs developers to install flush toilets connected to septic tanks.

[1] Hohne, A., 2011. State and drivers of change of Kigali’s sanitation : a demand perspective : paper presented at the East Africa practioners workshop on pro-poor urban sanitation and hygiene, Laico Umbano Hotel, Kigali, Rwanda, March 29th – 31st 2011 . [online] The Hague, The Netherlands: IRC International Water and Sanitation Centre. Available at: <http://www.irc.nl/page/64586>

Related website: Kigali City – Water and Sanitation Programmes

Source:

• Susan Babijja, City Council reviews sewage management plan, New Times, 26 Oct 2012
• Rwanda: Kigali sewage system delayed by funds, Rwanda Express /  allAfrica.com, 14 Jun 2012
• Eric Didier Karinganire, Sewage in Kigali still an issue of concern, Rwanda Focus, 09 Apr 2012

A practical guide for building a simple pit latrine

Cavanna, S., Debus, J-P., and Nikiema, L.Z.P. (2011). A practical guide for building a simple pit latrine : how to build your latrine and use it hygienically, for the dignity, health, and well being of your family. Hardware Quality Project, Regional Global Water Initiative (GWI) West Africa Programme. 23 p.

Download the guide as a PDF file or view online on the CRS web site
Also available in French

This technical do-it-yourself guide provides step-by-step instruction on building simple pit latrines. It was designed for use at the individual household level to assist families in West Africa who have already decided to build their own latrines.

Low-Cost Options for Sludge Management in Madagascar

Low-Cost Options for Sludge Management in Madagascar, 2011.

• English (pdf)
• French (pdf)

WASHplus partner, Practica Foundation, conducted a feasibility study of various technological options for hygienic sludge removal at two public-private toilet/shower sites in Madagascar. Both are currently emptied by informal sector workers under cover of dark, who face serious health hazards and engage in questionable disposal practices, with sludge dumped into waterways or buried nearby in shallow pits.

The assessment combines technical analysis and sociological observation and reporting, giving a vivid picture of the current state of sludge removal and potential for improvements and the impact on the environment and public health. It proposes innovative low-cost options for fecal management methods in three areas: sludge removal/transfer, transportation, and disposal/treatment.

Bike-powered poop pump is redefining low-cost sanitation

A bike-powered poop pump is redefining low-cost sanitation, April 2011, by Robert Goodier, Engineering for Change.

Meet the next generation of bicycle-powered devices for developing countries: a pit latrine pump. It’s the offspring of locally available parts—a bucket, a hose, a bicycle—and a modified bike-powered corn sheller, which is itself a field-tested time saver. The pump is still in testing, But so far, it seems to represent the kind of inventiveness and repurposing of parts needed to achieve extreme affordability. The brains behind it are a team of MIT engineers and business students who formed Sanergy, an organization working to redefine low-cost sanitation.

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