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Exploring scalable models in provision of defluorinated drinking water

Published on: 08/06/2021

Providing safe water to hard-to-reach villages in a cost-effective way in Arusha.

Defluorination of drinking water in Arusha, Tanzania (photo Lukas Kwezi)

Arusha is a major international diplomatic hub, and well known as the safari capital of Tanzania's Northern Safari Circuit. But if you are visiting Arusha for the first time, it is not a coincidence to meet people with ‘roasted teeth’, caused by too much fluoride.

It is one of the nine regions in the rift valley zones in northern and southwestern Tanzania with the highest concentration of fluoride in their water sources. In many parts of Arusha, fluoride concentrations in water reserves have a contamination rate ranging between 5 and 30 milligrams per litre, well above the 1.5 milligram per litre recommended by the World Health Organization (WHO) and Tanzania Bureau of Standards (TBS).

Studies show that over 260 million people globally are drinking water from sources with high fluoride concentrations. The high level of fluoride in drinking or cooking water can cause serious health problems to people, irreversibly damaging teeth and bones. The effects of fluoride can be severe including premature aging, hard-bended backbone, bow-legged, bone fragility, crouching anatomies, large heads, and other permanent body disfigurations. It is also a source of stigma and embarrassment, especially when moving to a part of the country where residents have whiter teeth.

So, waters from most sources in the Arusha district must be defluorinated to be potable. Currently, the only available means of defluorination include bone char filters distributed to some of the communities at point of use, but these can only serve individual households and a small population. Through the Human Development Innovation Fund (HDIF), we have supported the development of Nanofilters which are used to filter bottled water. However, only a few people can access these technologies leaving large numbers still using fluoride water for domestic use.  Therefore, the need to have defluorinated water systems that serve a large population in diverse settings cannot be overstated.

To address the problem, the UK government recently supported the Government of Tanzania in implementing a £3.7 million water supply project, currently providing access to safe and clean water for 21,000 people across the five communities of Lengijave, Olkokola, Ngaramtoni, Seuri, and Ekenywa, in Arusha Rural District. The project is designed to serve up to 50,000 people.

It is the first of its kind at least in the Tanzanian water sector. The water feeding the system is from two deep boreholes and a natural spring. It has two Reverse Osmosis (RO) plants which treat water and effectively remove fluoride and other contaminants. It is run on a hybrid power system consisting of electric grid and solar power (to lower operational costs related to energy consumption), alongside a prepayment water system which helps to improve revenue collection efficiency and ensures funds are readily available to support timely repair and maintenance of the water system. The project serves communities in both rural and urban settings.

This is the first time we were directly involved in implementing a project of this nature, as most of our funding to the water sector is channelled through the Government of Tanzania and implemented using their own systems. Given the nature and complexity of this project, funds were channelled through WaterAid Tanzania. Our team is providing technical support throughout the implementation.

Experience shows that delivering a project of this nature can be daunting, requiring the involvement of a diverse set of stakeholders to work towards achieving a common goal. It also requires adequate project management skills to ensure all stakeholders, tools, human and financial resources are well streamlined to ensure successful delivery of the project. Below, I highlight a few lessons learned.

Diverse partnerships and effective collaborations

Bringing together different players to the project helped us tap into different expertise and strengths for successful project implementation. At the beginning, the Arusha District Council in collaboration with Community Based Organisation Tumaini Jipya, played an important role in identifying and developing the initial concept of the project back in 2015. But, given the size and complexity of the project, we needed an experienced partner for the delivery of the project. We contracted WaterAid Tanzania to lead the implementation but ensured that local authorities and communities were involved throughout the project implementation. This has helped to improve the capacity of the local partners and suppliers in managing and implementing similar projects in the future. 

The project also benefited from the expertise from research institutions. At the beginning, when we detected high concentrations of fluoride in the two boreholes and a spring, we brought in WISE-Futures, an African centre of excellence of the Nelson Mandela-Arusha Institute of Science and Technology (NM-AIST) to research and monitor water quality and advise on the selection of an appropriate technology for water treatment.

Further, given the complexity of managing this project, we needed to ensure there is adequate technical, managerial, and financial capacity to oversee the implementation as well as operation and maintenance of the post-construction phase.  As such, a decision was made to shift the management of project operations to the water utility Arusha Urban Water Supply and Sanitation Authority (AUWSA). AUWSA is a public utility responsible for water and sanitation service provision in Arusha city. Under AUWSA the project has high potential to achieve financial sustainability and cost recovery as it will be an integral part of a wider water supply network in Arusha City.

One way to ensure cost recovery is to improve efficiency in revenue collection. For this, we brought in a private technology company, eWATER, who installed prepaid water meters. Their technology is helping AUWSA to improve revenue collection, so that funding is adequately available to undertake timely repair and maintenance of the water network.

Equity in service delivery

Initially, the project aimed at supplying water to Lengijave village at an estimated cost of £1.6 million. Our assessment in 2017, found that the village had a population of 6,759 people with the lowest levels of water access (less than 20% coverage), due to a lack of reliable water sources and a dilapidated water infrastructure built in the 1960s.  Households in the villages are dispersed across 17 kilometres in a challenging mountain topography. With such a small population, the per capita costs of providing access to water to Lengijave would be £236. This was too high to guarantee value for money for such investments.              

In order to proceed with the project, we had to expand the scope to cover an additional four villages with a projection to serve 50,000 people. This resulted in an increase of investment costs to £3.7 million although it significantly reduced the per capita cost to £74. It is important to note that the average per capita cost for providing access to water in Tanzania is around £32. Nonetheless while £74 is high, we still think it represents good value for money especially when factoring in the need to serve such remote communities. 

This point clearly shows the relative high costs for providing water access to hard-to-reach villages where there are also challenges in finding reliable sources of water to meet current and future demands. Notably, in this project 80 percent of the project costs were for the construction of the 36 kilometre main transmission line in conjunction with a 57 kilometre distribution network in the five villages. This indicates that in serving hard-to-reach communities, the main cost drivers are associated with construction. Hence, to achieve value for money, such communities should not be looked at in isolation but rather as part of a large network to achieve the economy of scale required to justify investments and sustain services. 

The cost of Reverse Osmosis 

A further analysis of the project costs indicates that compared with other components, the investment costs of Reverse Osmosis (RO) are relatively low, only accounting for 10 percent of the total project costs. This shows that in areas with high concentrations of fluoride, RO systems could be economically feasible, especially when implementing medium to large scale water projects.

In such cases, however, the issue would be how to ensure sustainability and meet operation and maintenance costs for running the RO plants. Our analysis shows that the major cost drivers for running the two RO plants at full capacity are the costs of chemicals, energy and regular replacement of membranes and multimedia filters which account for 50, 30 and 10 percent of the running costs respectively. However, a life-cycle costing analysis and performance review of the two Reverse Osmosis (RO) plants, shows that the project has medium-high potential to achieve financial sustainability and cost recovery. For this project some of the measures we have put in place to guarantee sustainability include:

  • Installation of an electric grid-tied solar PV system to lower project operation costs . Available data shows that on average this design has helped to reduce energy costs by 60%. 
  • Installation of a prepayment system to ensure 100% efficiency in revenue collection, to guarantee fund availability to undertake repairs and major maintenance when needed. 
  • Mainstreaming the operation and management of the project under AUWSA. This helps to ensure the project benefits from AUWSA’s technical, managerial, and financial support when operated alongside the wider water network in Arusha city. 
Research and learning platform in the sector

Due the uniqueness of the project, WIFE-Futures has entered into a partnership with AUWSA to provide technical support on matters related to operation and maintenance. They will also undertake monitoring and research activities to measure the performance of the two RO plants with the intention to lower operational costs on energy, chemicals and costs related to replacement of membranes and multimedia filters.

Also, the Tanzania Rural Water Supply and Sanitation Agency (RUWASA) has decided to include the project in its capacity development programme. The project will be one of the learning hub model projects that will be used to develop new processes, tools and appropriate skills for RUWASA and its staff to improve efficiency and managerial performance in the planning and delivery of water and sanitation projects and services.

Disclaimer: Lukas Kwezi currently works for the UK Foreign Commonwealth and Development Office (FCDO) as Water and Sanitation Adviser, based in Dar es SalaamHe writes blog posts in his spare time. Though he may talk about the work he does in the sector, this is neither a corporate nor a political blog and the opinions and ideas expressed here are solely his own, not those of his employers. 

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