Stop the Rot: History of the Rapid Corrosion Problem in Zambia and Potential Next Steps

Stop the Rot: History of the Rapid Corrosion Problem in Zambia and Potential Next Steps

Report by Javan Nkhosi and Kerstin Danert

A collation of observations by professionals, technical audit reports, evaluations, consultancy reports and academic research has found evidence of rapid corrosion in at least 22 countries in sub-Saharan Africa. The phenomenon appears to be widespread, and, in many countries, is ongoing. Unfortunately, neither the histories of this phenomenon nor the geographic extent of it have been well documented.

This report, published in July 2023, presents the history and geographic extent of the rapid handpump corrosion phenomenon in Zambia. It describes the fragmented and seemingly forgotten solutions that have taken place since the 1980s. The report charts when and where the phenomenon became evident in the country, the measures taken (or not), and what was learned (or not), and proposes next steps for the Zambian government and its cooperating partners to tackle this pervasive problem.

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, 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.

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, e.g.:

  • Central Province Rural Water Supply and Sanitation Project – CPRWSSP (2000 – 2007), which drilled or rehabilitated over 3,400 boreholes and installed GI riser pipes. Rehabilitated handpumps may have in fact even replaced some of the stainless steel riser pipe handpumps that were installed under the CPRWSP outlined above.
  • Both GI and stainless steel components were availed through the spare parts shops supported by the Sustainable Operation and Maintenance Project – SOMAP 2 (2007 – 2010).
  • The Zambia Social InvestmentFund(ZAMSIF)projectinstalled India Mark II pumps with GI pipes and rods in Luapula province. They were subsequently rehabilitated by a JICA project (2000 to 2005).

This study has not able to uncover the reasons for this unfortunate turn of events, but it is worth noting that:

  • 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, 2007b) 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.

In the last ten years, further initiatives to understand and address the problem have been undertaken, including:

  • 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.

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. There is no government policy position on the problem or solutions, nor is there any standardisation of which handpumps to use in areas affected by aggressive groundwater.

The report provides a number of recommendations for consideration by the Government of the Republic of Zambia (GRZ) in order to mitigate, reduce and ultimately eliminate rapid corrosion of GI riser pipes and pump rods as follows:

  1. revise the National Water Policy to include aggressive water in community boreholes;
  2. restrict types of handpumps to certain regions, with due consideration of suitable technologies for water depth;
  3. enact a law and a statutory instrument on aggressive groundwater in community boreholes;
  4. incentivise the private sector for provision of quality, corrosion-resistant riser pipes and rods;
  5. standardise handpumps used in Zambia.

The study also recommends further research on:

▪ replacement of GI riser pipes,
▪ the phenomenon of naturally occurring iron in ground and surface water and
▪ saline water in Western Province.

You can download the full report here.

Stop the Rot III: Handpump standards, quality and supply chains with Zambia case study

Handpumps have revolutionised access to safe, reliable water supplies in low-income countries, particularly in rural areas. They provide a viable alternative to contaminated surface water, open wells and unprotected springs. It is estimated that almost 200 million people in SSA (18.5% of the total population) rely on about 700,000 handpumps to provide them with their main drinking water supply. Handpump reliance is highest in Malawi, South Sudan, Zimbabwe, Guinea and Burkina Faso, ranging from 42% to 61%. The India Mark II pump and the Afridev pump are the two most common community handpumps, while the Vergnet pump is probably the third most common pump. The people of Zimbabwe rely on the Bush Pump. 

Published or grey literature in the public domain on handpump component quality is limited, but physical audits undertaken in Burkina Faso in 2013 and 2014, as well as recent studies in Ethiopia, Malawi and Uganda, indicate non-conformance issues in components for between 32% and 90% of samples. While no conclusions over wider prevalence within these four countries or beyond can be drawn from these figures, they do provide a stark warning of potential widespread risk. This is particularly concerning given that participants of the 2021 RWSN groundwater survey expressed concerns about the quality and durability of handpump parts in 13 SSA countries. 

Broken hook on Afridev pump in Malawi, source: Larry Bentley

Concerns about handpump component quality collated by this study concern riser pipes, pump rods, the steel plate, cylinder assemblies, centralisers, seals, joint to hook or eve, hook, eye, plunger and foot valve, centraliser, head assembly, bearings and flanges – in fact most handpump components. Inexpensive, poor-quality and fake/counterfeit parts, cost-cutting measures and corrosion-related issues were the most common issues cited by respondents to the recent RWSN survey.

Estimates for component life of the Afridev components are available, and the expected fast-moving parts for India Mark handpumps are documented. However, in the three decades of experience of handpump installation since the end of the UN Water Decade in 1990, field data on the service life of handpump hardware and different components remains lacking. This may reflect the lack of asset management and lack of preventative maintenance with respect to handpump technology and services in SSA.

Weld failure in riser pipe, source: Tony Beers.

In order to improve the supply chains of spare parts, many countries have standardised on a few public domain and/or propriety handpump models. In the case of public domain handpumps developed for community use, international specifications are available freely in the public domain. However, analysis of the international specifications for the Afridev and India Mark handpumps as well as the Indian Standards for the India Mark pumps reveals five concerns: (i) documents that are difficult to navigate; (ii) errors in the current specifications, including reference to international standards that have been withdrawn; (iii) gaps, particularly in relation to rapid corrosion; (iv) potential difficulties in interpreting the specifications; and (iv) high levels of lead in some of the brass/bronze components. 

There have been attempts to improve the design of the India Mark and Afridev handpumps, including making use of modern manufacturing techniques and limited field testing. However, a lack of formal oversight mechanisms for the international handpump specifications, which have essentially been frozen since 2007/8, coupled with very limited interest in funding handpump technology development makes it extremely difficult to address or validate these problems, or to incorporate design innovations.

Guidance is available for quality control and inspection of the Bush Pump, Afridev pump and India Mark pump. More guidance materials are available on quality assurance for the Bush Pump, including manuals in written form for end inspection as well as photo illustrations and videos. Although there are no inspection videos for the Afridev, the guideline document for quality control is detailed and extensive, covering manufacturers, independent inspection agencies and buyers. Unlike the more recently published Bush Pump inspection manuals, the Afridev guidance contains very few photographs. Of the three pumps, the India Mark pump has the least number of guidance materials available to support quality control. The international specifications for the India Mark and Afridev both contain a section on visual and dimensional tests, routine tests and conformity criteria. Short training modules on quality control are also available.

Screen shot of video explaining Bush Pump components and installation
Source: Peter Morgan, Aquamore, Zimbabwe.

The guidelines for quality control and quality assurance of the Afridev provide details on: 

(i) internal quality control (for manufacturers); 

(ii) external quality control/quality assurance/pre-delivery inspection by an inspection agency; and 

(iii) end inspection of delivered goods.

The guidelines also emphasise:

(iv) pre-qualification of suppliers; and 

(v) the placement of a clearly defined purchase order.

The 2021 RWSN survey of groundwater pumps found that of the 33 responses by those that buy handpumps directly, there are a diversity of practices, with 33% having no procedures in place. Of the 25 respondents that buy handpumps as part of a borehole drilling package, only 36% stated that they inspect the pump before and after installation, while 48% only inspect the pump before installation and 12% only inspect it after installation. Only one respondent did no inspection. A total of 22 out of 32 respondents (69%) have received feedback or complaints about pump quality, indicating that there are feedback mechanisms in place for some handpump buyers, as well as quality concerns. What was striking in the survey were the variety of opinions, even for the same country of government regulation and activity of regulators, indicating varying levels of awareness and understanding. The Government of Zimbabwe does undertake quality control of the Bush Pump, including inspections at the premises of the manufacturer. In 2020, these inspections raised concerns about various components and resulted in the replacement of non-conforming parts.   

Figure: Organisational procedures for checking handpump manufacturing specifications
Source: Furey and Danert, 2022

Despite the RWSN’s previous long involvement in handpumps since it was established in 1994, very little effort to examine or strengthen handpump supply chains have been undertaken since the mid-2000s. Documentation or knowledge sharing on handpump supply chains appears not to have been undertaken by the World Bank, The United Nations Children’s Fund (UNICEF) or any other organisation operating in SSA or beyond after 2014. 

Most handpumps seem to be manufactured in India, with pumps or pump components also imported into SSA from France, the USA and China. There is also manufacture in Zimbabwe and Tanzania. There are at least five links in the supply chain of handpumps or handpump spares – raw materials, handpump manufacture, in-country retailer, drilling contractor, community – and there may be more. There are dozens of handpump manufacturers in India, some of whom claim to be certified by the International Organization for Standardization (ISO). Anecdotal evidence indicates that poor-quality handpumps and components do enter markets in SSA. Given the importance of quality control at point of manufacture, questions remain regarding the responsibilities and activities of the Bureau of Indian Standards (BIS) and factory inspection (if any), the issuing of licences (and potential blacklisting) and incentives to ensure quality of exports. 

An ideal supply chain would have quality assurance mechanisms in place at manufacture and a secure tracking of goods throughout, with only certified suppliers allowed to import. However, the case study from Zambia illustrates that this is not the case, with numerous importers and retailers operating, and regulation and quality control procedures are weak or non-existent. According to a small number of stakeholders interviewed, there are both high-quality and poor-quality handpumps available on the market, and capacity among buyers to tell the difference is limited.

Figure: Schematic representation of ideal handpump supply chain – from import to distribution in country X

Complementing the recommendations from Report II of the Stop the Rot initiative on rapid handpump corrosion, this report recommends that:

  • RWSN, other global platforms and funding agencies should:
    • Raise awareness and understanding of the important yet under-recognised issue of poor handpump quality with network members and (in the case of funding agencies) grantees.
    • Encourage organisations to produce user-friendly guidance in the form of illustrative manuals and videos for ensuring quality, including end inspection by buyers.
    • Document and share good procurement practices and feedback mechanisms, including evidence of their effectiveness.
    • Encourage investment in raising the capacity of handpump buyers (i.e. governments, drilling contractors, non-governmental organisations and private users) to identify key defects and quality in accordance with specifications and standards.
    • Undertake a study to document quality controls at point of manufacture and export from India, including the setting out of responsibilities and activities of the BIS and factory inspection, the issuing of licences and other incentives to ensure quality for export.
    • Encourage rigorous research on the expected service life of handpump components, with the results published and available in the public domain. 
  • Lead international agencies should establish an action group on handpumps (perhaps incorporating other groundwater lifting methods). In addition to the recommendations outlined in Report II (Danert, 2022b), the action group should provide a platform for exchange on mechanisms of improving handpump quality, and could include the issue of brass/bronze components containing high levels of lead. The action group force should also engage organisations that have been working (with very limited funding) to improve handpump design and ensure that handpump manufacturers and standards agencies are brought into dialogue to develop improvements.
  • Skat Foundation, which published the international specifications, or another suitable organisation should:
    • Republish international handpump standard specifications to address errors and make them more accessible and searchable online.
    • Issue recommendations on alternatives to the India Mark handpumps with galvanised iron for areas where there is corrosive groundwater (especially low pH, salinity and chloride), including information regarding experiences, concerns and unknowns about these alternatives to date.
    • Develop detailed guidelines for end inspection of India Mark handpumps to include, for example, guidance around component weight and make reference to X-ray dispersive analysis, which is a standard test for measuring coating/plating composition and thickness and other mechanisms.
  • National governments should
    • Explore how to start or improve the regulation of handpump imports, in-country fabrication (if appropriate) and in-country supply chains, drawing on examples from other industries. Initiatives should be documented so that others can learn from them.
    • Establish an effective feedback mechanism for communities and users to register their experiences of poor handpump quality and use this information in efforts to improve handpump quality.
    • Ensure that rehabilitation programmes systematically collect data on the reasons behind handpump failure, including data on hardware problems such as – but not limited to – corrosion. 

Explore asset management mechanisms that can incorporate expected component lifetime to support preventative and reactive maintenance programmes, thus helping to alleviate unrealistic burdens on communities.

For more details, you can access the full report: Stop the Rot Report III: Handpump standards, quality and supply chains with Zambia case study. Action research on handpump component quality and corrosion in sub-Saharan Africa’. Ask for Water GmbH, Skat Foundation and RWSN, St Gallen, Switzerland

This is the third of a series of three reports to bring about action to Stop the Rot.

All three reports are also available in French.

Stop the Rot Report II: Rapid corrosion of handpumps

Corrosion is the attack of the surface of materials by chemical processes and affects concrete, glass, plastic and materials that contain iron. In water supply distribution systems, corrosion is the partial dissolution of the materials that make up the treatment and supply systems. In certain circumstances, all water can be corrosive. Corrosion may lead to structural failure and leaks, as well as deterioration of chemical and microbial water quality. The World Health Organization (WHO) does not provide guideline values for iron in drinking water. The WHO acknowledge that corrosion control is an important aspect of the management of a drinking water system but does not explicitly refer to corrosion concerns in the case of handpumps or sources that rely on other groundwater water-lifting technologies.

Rusted pipe on an India Mark II handpump (Source: Larry Bentley)

Research into corrosion in West Africa within the Handpumps Project of the World Bank in the 1980s concluded that: (i) total iron concentration in natural groundwater is rarely greater than 1 mg/l; (ii) corrosion is usually the cause of the red water (iron) problem in handpump-equipped wells; (iii) galvanisation does not protect rising mains and pump rods from corrosion under the prevailing groundwater conditions in the subregion (pH < 6.5); and (iv) the less a corrosion-affected handpump is used, the more serious the iron problem becomes. All of these observations still hold true. In addition to low pH levels, high salinity and high chloride levels can also accelerate handpump corrosion, but less documentation on these phenomena is available. Recent research indicates that there may also be leaching of lead into groundwater from brass/bronze components.

This study finds that communities in over 20 countries in SSA still face the problem of rapidly corroding handpumps (see Figure S1 below). Evidence includes academic research, reports (both old and more recent) and observations that have been shared. To date, there have been relatively few systematic studies of this problem. 

There may be cause for optimism in some countries where, despite aggressive groundwaters, the ‘iron problem’ seems to have been addressed (notably The Gambia and Ghana). In some countries governments are taking action to prevent rapid corrosion, such as by banning or trying to prevent the use of galvanised iron (GI) pipes (e.g. Uganda, Zambia and Chad). However, the problem seems to be continuing in many other countries, with varying levels of documentation and research. In Niger, for example, there was a corrosion problem in the past but the current status is simply not known. In Burkina Faso the rapid corrosion problem is well documented but there is a lack of action. There are numerous other countries where the phenomenon has been observed and documented to a limited extent.

The combination of GI pipes or rods and water with low pH will cause the GI components to rapidly corrode. There have been observations of components requiring replacement within a few months to a couple of years, whereas they should last eight to 10 years. While there has been confusion about whether iron observed in groundwater is coming from the aquifer, or caused by the corrosion of the pump itself, simple tests do exist to determine the source. These involve measuring the change of colour in the pumped water. 

Preventing rapid corrosion of handpumps may not be as simple as it may appear. A key aspect is ensuring that materials other than GI for riser pipes and pump rods are used in water with low pH levels. Alternatives include certain grades of stainless steel (SS) or, for riser pipes only, unplasticised polyvinyl chloride (PVC). However, the International Specifications and Indian Standards for the India Mark pumps do not include these options and so guidance is quite limited. Furthermore, there are indications that the SS option may cause rapid corrosion of the water tank, while PVC can break and problems are faced with maintenance due to rethreading challenges. Where water levels allow, the corrosion-resistant option of the Afridev pump provides an alternative to the India Mark pump. There are also alternative corrosion-resistant propriety handpumps on the market (i.e. designs that are not in the public domain). Motorised pumps may also be an option, provided that non-corrosive riser pipes are installed. However, introducing a new pump into any setting requires consideration of capital and maintenance costs, supply chains for pumps, and spares and maintenance skills.

Despite its prevalence, rapid corrosion of handpumps is a topic that has remained on the margins of many in-country water supply policies and programmes. Despite the fact that handpumps will continue to remain important for decades to come – particularly for remote, rural populations – the rapid corrosion problem barely features in global discourse. The realities faced by many users have simply not been sufficiently heard. If the ‘iron problem’ continues to be ignored, those living in areas where groundwater has a low pH, high salinity or high chloride will simply be left behind and countries where this is widespread may actually witness drinking water supply coverage levels declining over time.

Rapid corrosion is not only an issue for handpumps, but also potentially for the riser pipes in motorised pumps used for point sources, or which feed into reticulated systems. The realities of rapid corrosion of all groundwater systems need to be better understood and taken into consideration in project design and implementation. Notably, corrosion is not simply confined to rapid or early-life corrosion. All components that are submerged in, or and out of, water will eventually corrode, and so corrosion must be considered as part of the long-term maintenance of handpump (or motorised pump) water supplies. 

In order to take the issues raised by this study forward, it is recommended that:

  • RWSN, other global platforms and international agencies should use the information in this report, as well as the other two reports from the Stop the Rot initiative, as a basis for raising awareness of:
    • The ongoing reliance on handpumps in SSA, despite growing interest in groundwater systems that use other energy sources, including solar, and in piped supplies.
    • The phenomenon of rapid handpump corrosion, including the causes, effects, impacts and mitigation measures (together with their ongoing challenges).
    • The importance of determining whether rapid handpump corrosion takes place in all SSA countries. 
    • The need to consider corrosion as part of the long-term maintenance of all water supplies that rely on groundwater, including handpumps.
  • Donor/funding agencies should:
    • Ensure that their grantees are aware of rapid corrosion of handpumps, report on it when it is observed or suspected (through monitoring or when undertaking rehabilitation programmes) and support the grantees to understand more about the extent of the problem and actively seek solutions. 
    • Support academic organisation(s) to develop a continental map and national maps that illustrate the likelihood of low pH values in SSA, incorporating data on population densities where this is available. 
    • Consider funding organisations and/or consultants to:
      • Document what has reduced or mitigated handpump corrosions in those countries where it has been addressed.
      • Investigate the performance of handpumps whereby components have been replaced in order to prevent rapid corrosion and examine whether the new solutions are viable in the short, medium and long term. Studies should include examination of possible galvanic corrosion of tanks and cylinders or failing UPVC. 
      • Document what is happening in countries where there is limited evidence of rapid handpump corrosion, which may be currently ignored. 
    • In all cases, the information should be made available in the public domain. 
  • National governments and their development partners, as well as other implementing organisations should:
    • Ensure that assessment and post-construction monitoring mechanisms incorporate questions about user perceptions of water quality such as taste, smell and appearance and, if concerns are raised, follow up with studies to identify the cause of the problem (which may include rapid corrosion). Ensure that any studies are placed in the public domain.
    • Consider the options available to prevent rapid corrosion or to mitigate its effects, such as installing a corrosion-resistant option of the Afridev pump (if required pump depth allows), installing another corrosion-resistant pump, use of SS pump rods and riser pipes or use of UPVC riser pipes and SS pump rods for the India Mark pumps, use of a motorised pump with non-corrosive riser pipes. If there is no option but to use GI pipes and rods, these need to be replaced more frequently. 
    • It may be necessary to review handpump standardisation policies and standards across the country. In case changes to the components are made that are not in the International Standards, there should be monitoring of pump performance before widescale rollout. Note that any changes in standardisation policy will require investments and support to ensure the availability of spare parts, and to ensure that handpump mechanics, drillers and pump caretakers are trained in the installation and maintenance of variants of existing pumps or new types of pump.
    • In the case of new sources, or for rehabilitation, always undertake water quality testing (including pH, electrical conductivity and turbidity) prior to installation to determine whether the groundwater source is aggressive and likely to cause rapid corrosion of GI pipes, pump rods and the pump cylinder. 
  • Lead international agencies should form an action group on handpumps (perhaps incorporating other groundwater lifting methods). The action group should comprise not only international agencies, but individuals and organisations that are trying to preventing rapid corrosion of handpumps in-country. The action group should: 
    • Provide a platform for learning and exchange on handpump issues (including corrosion) and advocate for investments into studies that examine the effectiveness of alternatives to the installation of GI riser pipe and pump rods. 
    • Engage in policy dialogue with governments, donor agencies, non-governmental organisations and academics that are working in the countries where rapid corrosion has been identified as a problem.
    • Where appropriate, make policy recommendations. 
  • The WHO should expand its guidance on corrosion control to include corrosion mitigation measures for handpumps (and other groundwater lifting installations) in their next update of the ‘Guidelines for drinking- water quality’ and incorporate this issue into the next edition of their ‘Guidelines for small drinking-water supplies’.

For more details, you can access the full report: Danert, K. (2022) ‘Stop the Rot Report II: Rapid corrosion of handpumps. Action research on handpump component quality and corrosion in sub-Saharan Africa’. Ask for Water GmbH, Skat Foundation and RWSN, St Gallen, Switzerland. 

This is the second of a series of three reports to bring about action to Stop the Rot.

All three reports are also available in French.

Stop the Rot Report I: Handpump reliance, functionality and technical failure

Handpumps have revolutionised access to safe, reliable water supplies in low-income countries, particularly in rural areas. They provide a viable alternative to contaminated surface water, open wells and unprotected springs. The India Mark II pump and the Afridev pump are the two most common community handpumps in SSA, while the Vergnet pump is most likely the third most common handpump in SSA. The people of Zimbabwe rely on the Bush Pump. Based on analysis of the most recent data published by the World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) through the Joint Monitoring Programme (JMP), it is estimated that almost 200 million people in SSA (18.5% of the total population) rely on about 700,000 handpumps to provide them with their main drinking water supply. Of this, urban reliance is estimated to be 7.3% whereas rural reliance is 25.9%. Reliance is highest in Malawi, South Sudan, Zimbabwe, Guinea and Burkina Faso, ranging from 42% to 61% of the population. 

Figure: Percentage of rural population using a borehole or protected well as their main drinking water supply 

PERCENTAGE OF RURAL POPULATION USING A BOREHOLE OR PROTECTED WELL AS THEIR MAIN DRINKING WATER SUPPLY

Despite their merits, much criticism has been directed to handpumps. Limited ability to transport large quantities of water, coupled with a lack of storage capacity at the home, means that water from handpumps is usually fetched on a daily basis. Handpumps have also made the headlines: in 2010, only an estimated two out of three handpumps in SSA were working; a decade later it was estimated to have only improved to three out of four. When water services fail, there are negative impacts on health and other human development gains, not to mention the burden on users of finding alternative sources.

Interest in other technologies, particular solar pumps and motorised piped schemes for SSA, is growing. However, the handpump asset base in SSA remains considerable and makes a significant contribution to safe and reliable water supplies. An estimated 23% of the SSA population (about 230 million people) still rely on unsafe and distant water sources and many could benefit from a handpump. Moreover, not all hydrogeological settings can support abstraction rates that are much higher than that of a handpump; motorised schemes may consequently be even more challenging to maintain than handpumps. To avoid backsliding in terms of drinking water access, handpumps should be considered alongside alternatives. 

There is ongoing interest in water point functionality, with a number of national estimates available that are based on different methods of collection and calculation. Despite the headline figures of non-functionality, there is need for caution in undertaking cross-country benchmarking. The headlines generated by the commonly used binary indicator (functional/non-functional) have stimulated interest and studies on handpump management and maintenance. However, functionality estimates do provide information on how handpumps are actually performing, or why sources are failing. 

Tested ways of measuring performance include assessing a sample of sources and using a tiered approach that considers yield, reliability and water quality. In a sample from Ethiopia, for example, although 82% of pumps were working, and thus considered functional, only 59% provided sufficient yield and only 45% were also reliable. Grading water point sources in terms of water availability and other sub-categories is another means of measuring performance. In a sample from within Sierra Leone, 56% of water points were found to be functional, with 17% functioning poorly and in need of repairs or replacement of parts, and 27% of water points were without water and categorised as having a problem with either the pump or the well.

A handpump breaks down for a very specific technical reason (such as the breakage of the chain or an O-ring failing) whereas its repair depends on the ability of the community to raise funds, organise a mechanic and source spare parts. In turn, these depend on other factors within the locality and country. 

Particular cause for concern is the sizeable drop in functionality in the first one to two years after installation, which is a common occurrence. This represents a premature technical failure, as even the fastest wearing parts in a handpump should last for the first year. Premature failure means that something went wrong with the engineering – such as the borehole siting, design and/or construction, pump quality or installation, or the pump use – or that there was vandalism or theft. Alternatively, the installation may have been rejected by the users from the outset (e.g. due to the handpump location, or the appearance or taste of the water).

There is a perception among sector stakeholders that handpumps, alongside community management, have not been performing as well as they should have, but to date there is no conclusive evidence or consensus as to which factors are most important for good performance. While there have been many studies into the causes of non-functionality, this report finds that engineering and hardware issues – handpump hardware issues in particular – have not been sufficiently considered in the literature. Based on anecdotal evidence shared by practitioners and some limited studies, premature handpump failure has continued to occur since the 1980s, with rapid corrosion and the installation of poor-quality handpump components among the key causes. However, these issues are not prominent in the global discourse on achieving universal access to safe water. Policy dialogue and political action to tackle these issues is lacking. Notable exceptions include Uganda, where the government has taken measures to militate rapid handpump corrosion. 

Rigorous examination of the quality of handpump hardware is not within the scope of assessment tools used today. Removal of the handpump from the ground and its inspection, alongside follow-up of user perceptions of water quality (taste and appearance), would provide useful insights into component quality, rapid corrosion and whether a handpump has actually reached the end of its service life. Not doing so has significantly compounded our understanding of the extent of the problem.  

This ongoing lack of emphasis on the physical condition of handpumps may be due to the shift of focus away from infrastructure towards service delivery in the rural water supply sector. With a few exceptions, handpump hardware quality seems to be largely taken for granted. 

For more details, you can access the full report Stop the Rot Report I: Handpump reliance, functionality and technical failure. Action research on handpump component quality and corrosion in sub-Saharan Africa’. Ask for Water GmbH, Skat Foundation and RWSN, St Gallen, Switzerland

This is the first of a series of three reports to bring about action to Stop the Rot.

All three reports are also available in French.

Stop the rot – action research on handpump quality in sub-Saharan Africa

Handpump use in Sierra Leone

Premature corrosion and failure of water supply hardware, particularly handpumps, is widespread in countries within Sub-Saharan Africa, but evidence is limited and largely anecdotal. If drillers are not assured of quality handpumps in country, how can they install pumps that provide water users with the services that they deserve? For the tens of millions of people in sub-Saharan Africa who depend on handpumps to meet their daily water needs, handpump failures threaten their health and livelihoods. 

In cases where communities receive a handpump or components of substandard quality, parts may rapidly wear. If components of the wrong material or inadequate quality are installed in aggressive groundwater, the water supply may not function properly or can fail. Alternatively, the water may not be suitable for drinking. If the handpumps fails, or if water is turbid, discoloured, or has a metallic taste, users may return to using distant or unsafe water sources. If handpump components wear prematurely, communities can incur unnecessary costs in trying to fix the problem. 

A new initiative by Skat Foundation and Ask for Water GmbH under the Rural Water Supply Network (RWSN) strives to find ways to ensure that handpump technologies and spare parts that are installed for drinking water in sub-Saharan Africa are consistently of high quality and can last.

The initiative runs up to March 2022 and will:

  • Document the scale and extent of the problem of handpump corrosion and poor-quality components in sub-Saharan Africa.
  • Understand the handpump supply chains for one country, analysing strengths and weaknesses.
  • Raise awareness of problems of handpump corrosion, poor-quality components alongside practical solutions for water users, drillers, governments, Non-Governmental Organisations (NGOs) and others.
  • Catalyse action through ongoing engagement of international organisations, national governments, research organisations and other stakeholders to catalyse actions to tackle the problem.

The initiative will examine corrosion (see box), quality assurance procedures and supply chains. It seeks to draw out successful or innovative ways of ensuring that users benefit good quality handpumps – consistently! If you would like to contribute to the initiative, especially by sharing your experiences and ideas, please contact Dr Kerstin Danert (ask @ ask-for-water.ch).

Box: Corrosion and handpump quality challenges

The twin challenges of how to ensure the quality of handpumps and how to prevent rapid corrosion of certain pump components have been discussed for over four decades. Corrosion of below-ground handpump components was documented in the 1980s. Research concluded that galvanisation of pump riser pipes and pump rods does not prevent corrosion where the pH < 6.5 and provides limited protection for pH 6.5 to 7. In light of this, programmes have switched riser pipes and pump rods to stainless steel or switched to uPVC riser pipes and stainless-steel pump rods, while some countries standardised on pumps which aims to be fully corrosion resistant by using a uPVC rising main and stainless steel, or fibre glass pump rods. Unfortunately, handpump corrosion problems and concerns over handpump component quality persist. The extent of the problem is not fully known because of relatively little research on this topic, coupled with a lack of information available in the public domain. 

This article first appeared in GeoDrilling International (March 2021).