Tag: corrosion

Functionality of water supply handpumps in Cameroon (Central Africa): a review of data from 310 councils

Handpumps have revolutionized access to safe and reliable water supplies in Sub-Saharan African countries, particularly in rural areas. They constitute a healthy and viable alternative solution when surface water is contaminated. Danert (2022) estimates that 200 million people in sub-Saharan depend on 700,000 handpumps to supply themselves with drinking water.

Unfortunately, many handpumps service face performance issues or premature failure due to technical or installation defects in the borehole or pump, operational and maintenance weaknesses, or financial constraints (World Bank, 2024). Statistics on the functionality of handpumps in Cameroon are very sparse and dispersed with very little data available. However, some studies show that 25% to 32% of handpumps in Cameroon are inoperative (RWSN, 2009; Foster et al., 2019).

Previous reviews of handpumps functionality data in Cameroon have been conducted, including RWSN (2009) and Foster et al. (2019). However, these estimations were based on partial data and thus may not reflect the situation in the country as a whole. In addition, the number of handpumps installed each year is constantly increasing, and there is a need to update functionality data. Thus the interest of the study.

The methodological approach used in this study was based on online searches. To do so, we searched, collected, and analyzed relevant data from the 310 Councils Development Plan (CDP) that had been collected from 2010 to 2022. Information sources included data sets and documents available online through the data portals of the National Community-Driven Development Program (PNDP).

Overall, based on the data analysed, the number of handpumps used as the main source of drinking water supply in Cameroon is 20,572, of which 9,113 are installed in modern wells and 11,459 in boreholes. Approximately 8.2 million people in Cameroon rely on a handpump for their main drinking water supply, which is equivalent to 36.8% of the population of Cameroon. Findings indicates that one in three handpumps in Cameroon is non-functional, which in 2022 was roughly equivalent to 6,724 inoperative water points. To put this in perspective, this number is about 33% of the total number of handpumps, enough to supply 2.7 million people, assuming 400 inhabitants per handpumps. According to this estimate, it is about 44.8 billion CFA francs, or 66.8 million USD, was invested in the construction of water points that are immobilized and do not generate any benefit (improved health, nutrition, or education).

Figure 1 presents estimations of non-functionality in the ten regions of Cameroon. This figure shows that the region that had the highest level of non-functional handpumps is the Adamawa region (43%), followed by the East region (39%), the Littoral (37%), the North (35%), the South (35%), the West (32%), the South West (31%), the Center (30%), the North West (30%), and the Far North (28%).

Figure 1 | Handpump functionality rate for Cameroon

The handpumps, like the Community Based Management, seem not to have given the expected results. The fact that some handpumps fail prematurely seems to indicate that technical defects (poor quality components and rapid corrosion) contribute to handpump failure and underperformance. Further, this review notes that questions related to the quality of handpump material and the corrosion of handpumps have not been sufficiently taken into account in the various research studies in Cameroon and Sub-Saharan Africa. Thus, Future research should focus on physical audits of handpumps, and handpump rehabilitation campaigns in order to shed light on these issues. Finally, preventing rapid corrosion of handpumps through regulations should be implemented in order to improve the performance of handpumps. Regulations may be implemented at the national, regional, or local levels, and it is advised to employ a pH threshold of less than 6.5 as a corrosion risk indication. Once they are more precisely defined, additional risk factors such as salinity, chloride, and sulphate levels can be added.

About the author:

Victor Dang Mvongo, MSc is a PhD Student at the University of Dschang (Cameroon) and an independent consultant in WASH. He conducted the work featured in this blog at the Faculty of Agronomy and Agricultural Sciences.

Further reading:

Mvongo D.V, Defo C (2024) Functionality of water supply handpumps in Cameroon (Central Africa). Journal of water, sanitation and Hygiene for development. https://doi.org/10.2166/washdev.2024.085

References:

Danert, K. (2022) Halte aux dégradations Rapport I : Fiabilité, fonctionnalité et défaillance technique des pompes à motricité humaine. Recherche-action sur la corrosion et la qualité des composants des pompes à motricité humaine en Afrique subsaharienne. Ask for Water GmbH, Skat Foundation et RWSN, St Gallen, Suisse.

Foster, T., Furey, S., Banks, B. & Willets, J. 2019 Functionality of handpump water supplies: a review of data from sub-Saharan Africa and the Asia-Pacific region. International Journal of Water Resources Development 36 (5): 855–69. https://doi.org/10.1080/07900627.2018.1543117

RWSN 2009 Handpump data, selected countries in sub-Saharan Africa. RWSN, St Gallen, Suisse. https://www.ruralwater-supply.net/_ressources/documents/default/203.pdf

The presence of a handpump does not mean that people have access to reliable and sustainable water services. Here’s how we tried to show it in eight councils in the Mvila Division, South Region of Cameroon.

By Victor Dang Mvongo, MSc, a PhD student at the University of Dschang (Cameroon) and an independent consultant in WASH. He conducted the work featured in this blog at the Faculty of Agronomy and Agricultural Sciences.

Handpumps, the most common rural water supply equipment in sub-Saharan Africa, are a symbol of the sustainability issue facing rural water services. According to Macarthur (2015), handpumps are a lifesaver for 184 million people living in rural sub-Saharan Africa. Sub-Saharan African statistics on handpumps’ functionality indicate that 36% of them are broken, with country-level rates varying from 10% to 65% (RWSN 2009).

In Cameroon, little data are available on the functionality of the handpump. However, Deal and Furey (2019) estimate that 32% of handpumps are non-functional. Thus, for the impacted rural areas, this means that the anticipated returns on investment—better health, nutrition, and education—are jeopardized. In order to mobilize the necessary national and international efforts in the region, this study intends to give local information on the functionality of handpumps in the Mvila Division (Southern Region of Cameroon).

Continue reading “The presence of a handpump does not mean that people have access to reliable and sustainable water services. Here’s how we tried to show it in eight councils in the Mvila Division, South Region of Cameroon.”

When stainless steel is not stainless steel

Stop the Rot during ZAWAFE 2023 Zambia – 2/4

This blog is part of a four-part series covering the presentations given at the 11th Zambia Water Forum and Exhibition. The event, themed “Accelerating Water Security and Sanitation Investments in Zambia: Towards Agenda 2023 through the Zambia Water Investment Programme”, lasted three days.

Our blog series takes a focused look at the presentations and discussions that revolved around “Addressing Rapid Hand Pump Corrosion in Zambia – Stop the Rot!”, which was co-convened by UNICEF and WaterAid,  together with Ask for Water GmbH and the RWSN, hosted by Skat Foundation.

Continue reading “When stainless steel is not stainless steel”

History of the Rapid Hand pump Corrosion Problems in Zambia and Potential Next Steps

Stop the Rot at ZAWAFE 2023 Zambia – 1/4

This blog is part of a four-part series covering the presentations given at the 11th Zambia Water Forum and Exhibition. The event, themed “Accelerating Water Security and Sanitation Investments in Zambia: Towards Agenda 2023 through the Zambia Water Investment Programme”, lasted three days. 

Our blog series takes a focused look at the presentations and discussions that revolved around “Addressing Rapid Hand Pump Corrosion in Zambia – Stop the Rot!”, which was co-convened by UNICEF and WaterAid,  together with Ask for Water GmbH and the RWSN, hosted by Skat Foundation. 

Cover Photo: Removal of corroding riser pipe in Hoima District, Uganda in 2012 (source: Larry Bentley). In 2018 the Government of Uganda issued a directive to prevent further use of galvanised iron riser pipes throughout the country.

First session:

History of the Rapid Hand Pump Corrosion Problems in Zambia and Potential Next Steps

In Sub-Saharan Africa (SSA), an estimated 200 million people rely on a handpump for their main source of drinking water. They most likely use about 700,000 handpumps (Danert, 2022). Although the popularity of other technologies is growing, handpumps are likely to remain important in the region for decades to come, particularly in areas that are remote or with low population density. Unfortunately, many handpump services perform poorly or fail prematurely due to technical or installation defects with the borehole or the pump, as well as weaknesses with operation and maintenance or financial constraints. 

In Zambia, it has been estimated that handpumps are the main source of drinking water for 19% of the urban and 32% of the rural population. It is worth to highlight that all metallic components that are submerged in water, or move in and out of water will eventually corrode, and so corrosion must be considered as part of the long-term maintenance of water wells with handpumps (or motorised pumps). 

About rapid handpump corrosion

Rapid handpump corrosion occurs when aggressive groundwater reacts with galvanised iron (GI) riser pipes and rods of a handpump, and the India Mark II in particular. The materials corrode, with the pumped water becoming bitter in taste, with an unpleasant smell and a rusty colour. This not only renders the water unfit for drinking from a user perspective but also considerably reduces the pump lifespan. In Zambia, the main cause of rapid handpump corrosion is contact between groundwater with a pH of less than 6.5 and GI pipes and rods. However, salinity is also a problem in some parts of the country and can result in rapid corrosion too. 

The use of alternative materials to GI, particularly stainless steel (SS) riser pipes and rods and uPVC rider pipes fitted with stainless steel connectors, can prevent rapid handpump corrosion. While rapid handpump corrosion was documented in West Africa in the late 1980’s ((Langenegger, 1989), and actions to prevent it have been taken in some places, the phenomenon still occurs in over 20 countries in sub-Saharan Africa. Zambia, with an estimated 22,000 handpumps in use, serving 32% of the population with their main drinking water supply, is among these countries. 

Figure 1: Soil reaction map (pH) map of Zambia, 2014. (Shitumbanuma et all, 2021)

Figure 2: Zambia’s Agro-Ecological Zones (1987) and the 10 Provinces (Makondo & Thomas, 2020) 

Figure 3: History of efforts in Zambia in relation to rapid handpump corrosion – Overview

In Zambia, while the geographical extent of aggressive water is not fully understood by water sector professionals, it has been documented and explained with respect to soils.  A Soil Survey by the Mount Makulu Research Station from 1990 presents the situation clearly, with extreme soil acidity in the north, and soil acidity in the central parts of the country. Further, in Zambia the traditional Chitemene – ‘slash and burn’ – method of cultivation in the high rainfall region has been used since time immemorial to neutralise low pH in soils in order to cultivate crops. Leaching from these highly acidic soils affects the pH of the groundwater. 

The problem of rapid corrosion in handpumps in Zambia has been known for more than 30 years (Pitcher, 2001) and is well documented, including in the following: 

  • The Central Province Rural Water Supply Project (CPRWSP) (1985 – 1996) – which installed 564 handpumps with stainless steel riser pipes rather than using GI to prevent rapid corrosion. 
  • The North-Western Province Rural Water Supply and Sanitation Project (2004 – 2009) – over 350 handpumps were installed with stainless steel riser pipes, also in response to the same issue. 
  • In Luapula Province under the Japan International Cooperation Agency (JICA)-supported Groundwater Development Project (2007 – 2010), some Afridev handpumps with uPVC riser pipes were installed. The project rehabilitated existing, corroded handpumps which the community had previously abandoned. Replacing the GI pipes with uPVC stopped the iron problem, indicating that in these boreholes, using iron pipes had been the cause of corrosion. Iron removal plants were also installed on some boreholes. 

However, while solutions were implemented at scale in the aforementioned projects in Central and North-Western Provinces, as well as the study in Luapula, the use of GI riser pipes and rods still continued in subsequent projects in the same areas.

Some stepbacks

  • There was a change in the ministry responsible for drilling works. The period 1985 – 1996 saw borehole drilling under the Department of Water Affairs, while the Department of Infrastructure and Support Services under the Ministry of Local Government and Housing took on this role after it had been created in 1995. 
  • National Guidelines for Sustainable Operation and Maintenance of Handpumps in Rural Areas (MLGH, 2007) includes neither aggressive water as a criterion for handpump selection nor the use of stainless steel riser pipes, and so the use of GI pipes in aggressive water as the cause of the ensuing rapid corrosion was in effect further supported. 

Initiatives undertaken in the last 10 years

  • Under the SOMAP 2 project (2012 – 2013), the JICA-supported programme carried out pipe replacement of GI at 20 sites in four provinces (Luapula, Copperbelt, Central and the North Western) whereby GI pipes were removed, the boreholes flushed and then installed with uPVC pipes. The replaced handpumps performed well without the water turning rusty, and the communities continued to draw water from them, whereas previously they had been abandoned. 
  • UNICEF also carried out pipe replacement in Mansa and Milenge districts of Luapula Province. In the study, India Mark II handpumps GI pipes at 45 sites were replaced with uPVC riser pipes. After the pipe replacement of GI riser pipes, the community used the handpumps that had previously been abandoned, with unsafe water sources being used instead. The pipe replacement study was successful, with the water users returning to previously abandoned boreholes which had clear, rust-free water. 
  • There is some evidence of other projects and organisations starting to use either stainless steel riser pipes, or uPVC riser pipes with stainless steel connectors in their projects, but documentation is limited. While stainless steel riser pipes have been used effectively, there are also some outstanding technical issues – particularly in relation to the removal of narrower diameter riser pipes, which require suitable tools that are not in the standard India Mark II toolkit. Further, the use of uPVC pipes has also been found to be problematic, as they need to be cut on removal and cannot easily be re-threaded. However, at least one NGO in Zambia has been using an alternative, comprising uPVC with stainless steel couplers which is available on the Zambian market. A further complication is that some parts of Zambia appear to exhibit naturally occurring iron. Tests are available to determine whether iron is naturally occurring or a result of corrosion, but there is no comprehensive map to indicate areas at risk of high levels of geogenic iron.

While stainless steel riser pipes have been used effectively, there are also some outstanding technical issues – particularly in relation to the removal of narrower diameter riser pipes, which require suitable tools that are not in the standard India Mark II toolkit. Further, the use of uPVC pipes has also been found to be problematic, as they need to be cut on removal and cannot easily be re-threaded. However, at least one NGO in Zambia has been using an alternative, comprising uPVC with stainless steel couplers which is available on the Zambian market. A further complication is that some parts of Zambia appear to exhibit naturally occurring iron. Tests are available to determine whether iron is naturally occurring or a result of corrosion, but there is no comprehensive map to indicate areas at risk of high levels of geogenic iron.  Despite all of the efforts to date, and notwithstanding the widespread nature of rapid handpump corrosion of GI riser pipes and pump rods, the problem still persists in 2023. 

Potential Next Steps for GRZ / International Donor Community / Universities 

  1. Revise the National Water Policy to include aggressive groundwater in community boreholes 
  2. Restrict Types of Handpumps to Certain Regions. 
  3. Enact a Law and a Statutory Instrument on Aggressive Groundwater in Community Boreholes. 
  4. Incentivise the private sector for provision of corrosion-resistant pipes and rods 
  5. Regulation of Quality of Handpumps by Zambia Bureau of Standards. 
  6. Standardise Handpumps Used in Zambia. 
  7. Further studies and replacement of galvanised iron riser pipes. 
  8. Further Research Studies on the phenomenon of naturally occurring iron in ground and surface water and 
  9. Research Studies on Saline Water in Western Province

You are invited to access the presentations HERE, along with the session’s concept and the study report:  Nkhosi. J and Danert, K. (2023). ‘Stop the Rot: History of the Rapid Handpump Corrosion Problem in Zambia and Potential Next Steps. Action research on handpump component quality and corrosion in sub-Saharan Africa’. Ask for Water GmbH, Skat Foundation and RWSN, St Gallen, Switzerland. https://doi.org/10.13140/RG.2.2.27489.28006.

If you would like to dive deeper into the enriching exploration of water challenges and solutions through the Stop the Rot initiative, visit this page.

About the author:

 Javan Nkhosi presenting at ZAWAFE 2023

Javan Nkhosi is a Zambian water professional. He has worked in the rural water sub-sector for more than 25 years on many water supply projects funded by the government, NGOs and donor agencies as a private consultant across Zambia. He has a passion for improving water supply to the unreached areas of rural Zambia. He holds a Diploma in Agricultural Engineering from NRDC, Lusaka, Advanced Diploma in Water Engineering from the Copperbelt University and an MSc in Project Management from the University of Lusaka. He is a Registered Engineer with Engineering Institute of Zambia (EIZ) and also a member of the Association of Consulting Engineers of Zambia (ACEZ) , an affiliate of the International Federation of Consulting Engineers (FIDIC). 

References:

Addressing rapid handpump corrosion: the story of the Ghana Modified India Mark II

In 1983, I moved to live and work in Ghana – some 40 years ago now. Back then, I was the regional supervisor on the 3000 Well Maintenance Unit in Southern and Central Ghana which was funded by the German Development Service under the Rural Water Supply programme. The project was a pioneer of its time, and included drilling boreholes alongside the installation and testing of handpumps in six of Ghana’s regions, as well as the Nanumba district, Northern Region.

We initially installed India Mark II and Moyno pumps, before dropping the Moyno due to technical problems. However, we soon realised that the India Mark II pumps faced corrosion issues. Investigation and testing (as documented by Langennegger, 1989 and Langenegger, 1994) found that the Galvanised Iron components (rods and riser pipes), when installed in water with low pH, had a propensity to rapidly corrode – leading to discolouration of the water and affecting taste, but also causing the pumps to fail prematurely as the rods broke and riser pipes developed cracks and holes and even fell into the borehole. The envisaged idea of maintenance by communities, with assistance from mechanics who could reach villages by motorcycle, was simply not feasible with such installations. Another significant issue related to corrosion of hand pump parts was the water contamination and bad taste of the water. As a result, the water coloured the food and therefore caused the  population to stop using the borehole water and forced them to go back to unsafe water sources

We, therefore, had to seek alternatives. This involved field testing and collaborating with the Materials Testing Institute of the University of Darmstadt.

We looked into replacing the galvanised iron components with stainless steel. To ensure the pipes were light, we considered using 3 – 3.5 mm thick pipes, and used a threading that at the time was used in the drilling industry , known as the “rope thread”. Although Atlas Copco had patented this threading type at the time, it was later manufactured in India after the Atlas Copco design period (patent) ended.

Figure 1: Rope thread (Claus Riexinger)

The pump rods presented some challenges as well, since the AISI Stainless Steel grade 316 that we were using was subject to breakage, including the threaded parts. In collaboration with our partners at the University of Darmstadt, we were able to find ways to make this grade of stainless steel more elastic by adding 2-3 % Molybdenum. Other issues with the rods related to the use of rolled thread, which we learned was more durable than cut thread. Incorporating these materials and techniques, we were able to reduce the rod diameter from 12 mm down to 10.8mm, resulting in lighter rods which did not corrode. The only drawback was that the threads could not be cut in the field, but this was not such an issue, as there was no need to cut them when they were installed, or upon maintenance.

Figure 2: Pump installation (Claus Riexinger)

After switching to stainless steel riser pipes, we encountered another issue: -galvanic corrosion between the pipe and the water tank. This type of corrosion occurs when two dissimilar materials come into contact in solution. It was yet another challenge! Fortunately, we were able to solve this problem by replacing the existing flange with a new one made of stainless steel with an insulating gasket, into which the riser pipe could be screwed and prevent any further galvanic corrosion.

Figure 3: Ghana Modified India Mark II Handpump – water tank, spout and flange

After conducting extensive testing and collaborating with the University of Darmstadt over a period of around 4 years, we managed to solve the problem of rapid corrosion of handpumps in Ghana. The improved pump design came to be known as the Ghana Modified India Mark II, and was officially adopted by the Government of Ghana in the 1990s. Its specifications can be downloaded here.

Designing and publishing the specifications for a new pump is one thing, but the other is ensuring that these are adhered to.  A series of meetings with government, donors, and NGOs working in the water sector in the 1990s, led to the agreement to no longer use Galvanised Iron. All stakeholders were on board with the change.

Of particular importance was the tremendous support and buy-in of the major donor at the time – KfW (Germany). They agreed to pay for the increased costs of the Ghana Modified Pump on new installations, which at the time was about three times more expensive than the version using Galvanised Iron.  KfW also supported the rehabilitation and replacement of the pumps that had previously been installed using Galvanised Iron. As a result, we were able to remove and replace the corroded installations systematically, rather than addressing the issue in a piecemeal manner.

It is estimated that over 4,500 Ghana Modified India Mark II handpumps had been installed in Ghana by the time I left the 3000 Well Maintenance Unit in 1992.  Anecdotally, I would say that 90% were working, and of the 10% out of use, they were down for maintenance/repair.

KfW took this design to Cameroon, while Danida took it to Burkina Faso and Zambia. I am not fully aware of what happened next, but I do know that ensuring the quality of stainless steel was a problem in Burkina Faso.

I am very pleased to see that Ghana Modified India Mark II handpumps are now available through the Rural Water Supply Network (RWSN), and hope that these can be of use to other countries that are struggling to overcome the rapid handpump corrosion problem.

Figure 4: Example factory inspection Modified India MKII (Claus Riexinger)

However, I have a work of caution too. Although specifications, standards, and clear procurement documents are essential, they are rendered meaningless in the absence of inspection. During my time with the 3000 Well Maintenance Unit and later as an independent consultant, I traveled to India and other places for pre-shipment inspections. I also oversaw the rejection of consignments from India and Europe due to poor quality or manufacturing mistakes. And so, I urge all of you involved in handpump procurement and installation to make sure that you ensure the quality, especially through inspection and material testing.

Ghana Modified India Mark II Drawings and Specifications

More information about Ghana Modified India Mark II (external website)

About the author: Claus Riexinger is a rural WASH expert and freelance consultant with over forty years of experience in development cooperation with Government organisations, private companies, and development agencies mainly in Botswana, Lesotho, Malawi, Germany, India, Tanzania, and Ghana.

Photo credits: Claus Riexinger

Corrosion de la pompe à main et qualité des matériaux : Un défi pour le Burkina Faso et le reste du monde

Au Burkina Faso, le nombre élevé de forages équipés d’une pompe à motricité humaine (PMH) qui dysfonctionnent ou qui nécessitent de grosses réparations quelques années seulement après leur construction est alarmant. Les audits techniques effectués en 2013 et 2014 au Burkina Faso sur des forages équipés de PMH ont révélé des situations préoccupantes en termes de qualité de l’eau, de matériel inadapté aux profondeurs des puits et de pompes non-conformes. Dans plus d’un tiers des cas, les forages équipés de PMH dysfonctionnent ou deviennent même totalement inutilisables en moins de quelques années. Entre 0.6 milliards de FCFA (0.9 million d’€) et 2.9 milliards de FCFA (4,5 millions d’€) d’investissements annuels seraient ainsi perdus du fait de l’installation de PMH de qualité médiocre et de diverses malfaçons lors des travaux de construction. Chaque année, plus de 130 000 personnes bénéficient d’un service d’approvisionnement en eau dont la pérennité n’est de ce fait pas assurée au-delà des premières années.

La corrosion des PMH est un phénomène connu depuis plus de 30 ans ; elle demeure pourtant un problème majeur au Burkina Faso car les gouvernements successifs et les agences d’aide au développement ont continué d’installer des pompes fabriquées à partir de matériaux inadaptés. Ces pratiques ont généré des coûts d’entretien élevés, de multiples pannes et le rejet de nombreux points d’eau par les communautés car l’eau y était de mauvaise qualité. La corrosion des PMH est un problème mondial majeur, dont le secteur EAH ne s’est jusqu’à présent toujours pas saisi à sa juste mesure, et qui risque d’empêcher la réalisation de l’Objectif du Développement Durable n°6 au Burkina Faso comme dans d’autres pays. Sur les forums de discussion en ligne du Réseau pour l’Approvisionnement Rural en Eau (RWSN), les experts internationaux font notamment remonter comme principales préoccupations à ce sujet : des matériaux et des pièces composantes de qualité inadaptée, un manque de contrôle qualité, des prix anormalement bas, et des pratiques d’achat et de commande problématiques.

Une enquête sur la qualité des composants des pompes manuelles au Burkina Faso a été lancé début 2017. Des échantillons de la conduite principale montante et de la tige de la pompe ont été achetés auprès de fournisseurs à Ouagadougou, et d’autres échantillons provenaient de pompes en service ou abandonnées. Tous les échantillons ont été testés pour leur composition chimique. En 2019 des tests de composition chimique ont été réalisés sur l’ensemble de ces échantillons. L’analyse des résultats de ces tests révèle que : cinq des six colonnes d’exhaure et deux des quatre tringles ne sont pas conformes aux normes internationales de composition de l’acier inoxydable du grade indiqué. La faible teneur en nickel de ces échantillons signifie notamment que les pièces analysées ont en réalité une résistance à la corrosion moindre que celle qu’elles devraient avoir si elles étaient effectivement du grade indiqué.

Les 13 pièces composantes qui ont été testées dans le cadre de cette étude forment un trop petit échantillon pour s’avérer statistiquement représentatives de la situation du Burkina Faso dans son ensemble.  Cet échantillon corrobore toutefois les inquiétudes du Gouvernement et des foreurs. Il y a quelque chose qui ne va pas avec certains composants disponibles sur le marché, malgré le fait qu’ils soient vendus comme étant de l’acier inoxydable. L’ampleur du problème reste inconnue à ce stade au Burkina Faso ou dans d’autres pays. Comme le montre ce rapport publié par la Fondation Skat, le constat est celui d’un échec du « marché » à fournir systématiquement des matériaux de haute qualité. Afin de rectifier cette situation, il est nécessaire de trouver des solutions à la fois au sein des pays d’importation, comme le Burkina Faso, et au niveau international.

Cette étude rapide a révélé pour le Burkina Faso et au-delà une série d’enjeux interconnectés:

  1. Il est nécessaire de poursuivre les recherches sur l’utilisation des pièces composantes en acier inoxydable afin d’éviter la corrosion des pièces de PMH immergées dans des eaux souterraines agressives.
  2. La norme indienne pour les modèles India Mark II et III comprend quelques erreurs, et aucune option n’est proposée pour les cas d’eaux souterraines agressives. Les normes internationales (notamment celles publiées par SKAT/ Le Réseau pour l’Approvisionnmenet Rural en Eau-RWSN) portant sur les matériaux des pièces de PMH adaptés aux eaux souterraines agressives pourraient être améliorées.
  3. De nombreuses entreprises en Inde vendent des PMH et des pièces de modèles India Mark II et III. Les prix de vente pratiqués par certaines de ces entreprises sont si bas qu’il semble impossible que la qualité de ces pompes et pièces soit conforme aux normes internationales.
  4. Il n’existe aucun organisme international chargé de contrôler systématiquement la qualité des matériaux de PMH, et le rôle et l’activité du Bureau de Normalisation International à ce sujet ne sont pas clairs ni évidents.
  5. Lorsque les PMH sont achetées dans le pays où elles doivent être installées, la longue chaîne d’approvisionnement (souvent anonyme de surcroît du fait de la multiplicité des intermédiaires) fait qu’il n’existe pas ou peu de lien entre les fabricants (situés majoritairement en Inde) et les installateurs des PMH en question. De plus, l’absence de compilation systématique des problèmes rencontrés préalablement signifie que les agences, les entreprises et les ménages s’engagent dans l’installation de PMH sans saisir l’ampleur de ces soucis de qualité et ne s’en rendent compte que trop tard.
  6. De nombreuses PMH utilisées en Afrique sont importées d’Inde (et visiblement du Nigéria également), donc les efforts menés pour résoudre cet enjeu de garantie de qualité doivent absolument inclure l’Inde ainsi que plusieurs pays africains.
  7. L’intérêt des financeurs pour l’équipement des PMH est probablement actuellement au plus bas depuis 30 ans, il s’avère donc très difficile de mobiliser à grande échelle pour développer un processus de certification internationale ou financer davantage de recherches à ce sujet. Une telle initiative nécessiterait d’une part des investissements supplémentaires et d’autre part des engagements de long terme de la part des principales agences et des gouvernements qui financent et mettent en œuvre des programmes d’installation et d’entretien de PMH.

Nous espérons que cette courte étude attirera l’attention des gouvernements, des organismes de recherche et des agences internationales d’aide au développement et les incitera à travailler sur la résolution des problèmes pressants que sont la corrosion et la mauvaise qualité des pièces composantes des PMH. Si rien n’est fait la communauté mondiale de l’approvisionnement en eau, par négligence ou désintérêt, prive de fait les populations rurales du Burkina Faso et d’ailleurs des bénéfices d’un approvisionnement en eau élémentaire et fiable.

L’étude complète peut être téléchargée ici : Qualité et corrosion des pièces composantes des Pompes à Motricité Humaine au Burkina Faso et au-delà (anglais et français)

Crédit photo: Colonnes montantes corrodées photographiées au Burkina Faso dans le cadre de l’audit d’équipements d’approvisionnement en eau in situ. (Kerstin Danert)

 

 

Handpump corrosion and material quality: A challenge for Burkina Faso and globally

In Burkina Faso, concerns have been raised regarding the high number of handpump boreholes that have failed, or need to be rehabilitated within a relatively short time of their initial construction. Physical audits of handpump boreholes in 2013 and 2014 raise concerns over water quality, inappropriate handpump for deep water and non-conformant pumps. In more than one third of cases, the handpump boreholes will function poorly, or cease to function completely within a few years. It is estimated that investments of between FCFA 0.6 billion (€0.9 million) and FCFA 2.9 billion (€4.5 million) per year are lost due to the installation of poor quality handpumps and other aspects of the construction. In one year, over 130,000 people were provided a water supply service that is likely to break down within a few years.

Despite knowledge of handpump corrosion for over 30 years, it remains a problem in Burkina Faso, as governments and aid agencies have continued to install pumps manufactured with unsuitable materials, leading to high maintenance costs, pump failure and rejection of water sources due to poor water quality. Handpump corrosion is a major global problem which the WASH sector has so far, systemically failed to address, and which will impede the realisation of Sustainable Development Goal 6. Concerns cited by experts from a range of countries on the Rural Water Supply Network (RWSN) online discussion platforms include the following: inadequate quality of materials and components, lack of quality control, unrealistic (low) prices and problematic purchasing practices.

A renewed call to investigate the quality of handpump components in Burkina Faso was raised in early 2017. Samples of the rising main and pump rod were purchased from suppliers in Ouagadougou, and additional samples were from pumps in use or abandoned. All samples were tested for their chemical composition. Analysis showed that of the samples, five of six riser pipes, and two of four pump rods did not conform to international standards for the composition of stainless steel of the specified grade. In particular, the low nickel content means that the components have less corrosion resistance than they would if they were of the specified grade.

The small sample size of 13 components tested in this study is not a statistically representative of the situation in Burkina Faso as a whole but it verifies concerns raised by the Government and drillers themselves. Something is not right with some components available on the market, despite the fact that they are being sold as stainless steel. What we do not know is the extent of the problem, in Burkina Faso, or other countries. What is being witnessed, as documented in the new study published by Skat Foundation, is a failure of “the market” to guarantee high quality materials. Addressing this failure requires solutions from within importing countries, such as Burkina Faso, but also internationally.

This short study has shed light on a number of interconnected issues for Burkina Faso and beyond including:

  1. There is no international body systematically controlling handpump material quality.
  2. The need for further research on the use of stainless steel components to prevent the corrosion in aggressive groundwater is needed.
  3. Many of the handpumps used in Africa are imported from India (and apparently Nigeria too). There is often no connection between manufacture (primarily in India) and installation of the pump (in African countries). Agencies, companies or households installing handpumps are not aware of the extent, and scale of quality problems until it is too late.
  4. Donor interest in handpump hardware is arguably at its lowest in 30 years, and so galvanising interest to develop an international certification process or fund research is extremely difficult. Such an initiative would require not only investment, but also long-term commitment from the large agencies and governments that fund and implement programmes installing handpumps and their maintenance.

It is hoped that this short study will trigger interest by governments, and by research organisations, and international development agencies to explore ways to solve the problems of corrosion and poor quality handpump components. If this is not done, by inadvertent neglect, the global water supply community is arguably preventing rural populations in Burkina Faso and beyond from the benefits of a reliable, basic drinking water supply.

The full study is available for download here: Concerns about corrosion and the quality of handpump components in Burkina Faso and beyond (English and French).

Photo credit: Corroded rising mains being photographed as part of a physical audit of water facilitiesin Burkina Faso (Kerstin Danert).