Zambia: Study Finds Shallow Groundwater Unsafe.

Kabwe is a transport hub and old mining town in central Zambia. One resident, Joseph, recounted how when he was growing up in the town in the 1970s, most houses had a tap and a reliable water supply from the municipal system. Few children in the town now have this luxury; in the 1980’s the world price of copper collapsed and the mines closed. Many of the townspeople could no longer afford their water bills, and the lack of investment led the municipal water system into a spiral of decline.

Today, the town continues to grow, in a haphazard way and sanitation is poor – only 11% of low income households have access to a latrine or toilet. Most of the poorer residents get water from shallow wells, and richer households have given up on the unreliable municipal water system and have their own deeper boreholes. But are these self-supply water sources safe? Does the risk change between the wet season and the dry? Is there a safe distance between latrine and well that would prevent the water from being contaminated? These are just a few questions that hard-pressed local government staff need answers to urgently, but they just can’t get data from enough wells and boreholes during the year.

Poor water quality continues to pose a major threat to human health

Many types of bacteria found in wastewater and sewage cause diarrhoeal diseases and cholera, which kill 1.8 million people every year, 90% of whom are children under 5 according to the World Health Organisation (http://www.who.int/water_sanitation_health/publications/factsfigures04/en/ ) . These bacteria are hard to measure directly, so the most common method used is to focus on bacteria, called E. Coli, which is an indicator of how unsafe water is. However, this test takes time, skill and a laboratory because the E. Coli have to be encouraged to grow so that they can be counted. What is urgently needed is a quick, cheap, accurate way of measuring this type of pollution to guide efforts to provide safe drinking water.

An answer may now be available, for Kabwe, and for water supplies all over Africa and beyond: a team, led by Dan Lapworth, from the British Geological Survey (BGS), along with colleagues from the University of Zambia, University of Surrey and Lukanga Water and Sewerage Company Ltd has been collaborating to develop a new way to measure groundwater pollution. It is a new probe that measures a protein called tryptophan and this was the first study to investigate the biological quality in groundwater using this technique.

This research was funded by DFID, NERC and ESRC through the UPGro: Unlocking the Potential of Groundwater for the Poor programme (http://upgro.org )

What they found in the wells and boreholes of Kabwe was that the amount of tryptophan measured by the probe corresponded very closely with bacteriological contamination. It confirmed that most of the shallow groundwater, which the poorest people in the town were using, was unsafe throughout both the wet and dry season, but that the deeper groundwater is generally free from faecal pollution, unless the borehole had not been sealed properly.

The advantage of the tryptophan probe is that it is quick, needs no special chemicals and cheap, so it can enable rapid surveys across dozens of wells and boreholes across the town, that just isn’t practical with traditional E. Coli testing.

The Principal Investigator, Dan Lapworth: “In a place like Africa where data scarcity and institutional capacity is a massive issue this could quickly provide a step-change in our understanding of spatial and temporal water quality risks in drinking water sources, the processes that control these and be used as a tool to monitor interventions and water quality failures.”

Although the research from the UPGro Catalyst grant has finished, others are taking an interest: the US-based charity, Water for People, asked BGS to trial the probe in rural areas of India undergoing sanitary interventions. Here, the sensor was equally successful at identifying bacteriological contamination in drinking water and the team was able to rapidly test up to 6 different supplies per hour.

Having access to safe water and basic sanitation is vital to everyone's life

In Kabwe it is now possible for the health risks from groundwater to be monitored, both across the town and over time.

Dan said “There are a number of different sensors available which can map groundwater quality risks – we have done our research on what we think is the most sensitive of these, but there is certainly room for improvement and development of this technology further for practical field based applications.”

As the international community attending the Stockholm World Water Week turns its attention to the new Sustainable Development Goals – which include achieving universal access to safe water – it is practical contributions, like the tryptophan probe that can make all the difference. For the people of Kabwe, it offers the hope that future investment in water and sanitation will deliver reliable and safe water to meet their needs.

James Sorensen, from BGS, said “These sensors were the best indicators of bacteriological contamination and water supplies could be tested within seconds”

WaterSan Perspective

Water Journalists Africa (WJA)
August 18, 2015

Kabwe is a transport hub and old mining town in central Zambia. One resident, Joseph, recounted how when he was growing up in the town in the 1970s, most houses had a tap and a reliable water supply from the municipal system. Few children in the town now have this luxury; in the 1980’s the world price of copper collapsed and the mines closed. Many of the townspeople could no longer afford their water bills, and the lack of investment led the municipal water system into a spiral of decline.

Today, the town continues to grow, in a haphazard way and sanitation is poor – only 11% of low income households have access to a latrine or toilet. Most of the poorer residents get water from shallow wells, and richer households have given up on the unreliable municipal water system and have their…

View original post 715 more words

Groundwater Resources and Supplies in Africa

24th February 2015

Two research-based presentations by: Joy Obando (Kenyatta University, Kenya) and Dan Lapworth (British Geological Survey, UK). With a focus on selected sites in in Comoros, Tanzania and Kenya, Obando’s presentation sets out key social and economic issues with respect to groundwater resources in coastal East Africa. Lapworth’s presentation examines the changes in water access and realities of groundwater resources in Kabwe, Zambia. The examples, combined with the lively exchange with participants, provide insights into the realities of drinking water for the poor in urbanising Africa. The webinar is facilitated by Jan Willem Foppen (UNESCO-IHE, Netherlands).

A tale of two cities: How can we provide safe water for poor people living in African cities?

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Dan Lapworth, Jim Wright and Steve Pedley are working to find out.

Reproduced from Planet Earth Winter 2014, p 22-23

Across much of Africa, cities are growing quickly. Current projections estimate that by 2050, 60 per cent of the population will be living in urban areas – half of them in slums. Many of these people have little access to services such as clean water and sanitation, and the UN has identified fixing this as a major priority.

Continue reading A tale of two cities: How can we provide safe water for poor people living in African cities?

Poster presentations about work in Zambia and Kenya (Video)

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At the IAH Congress, we asked two of the UPGro researchers to present their posters:

Jacob Mutua, Rural Focus Ltd, Kenya, describing the “Risks and Institutional Responses for Poverty Reduction in Rural Africa” Catalyst project

Dr Dan Lapworth talks about the project that he has been leading: “Mapping groundwater quality degradation beneath growing rural towns in SSA” in Zambia

Tracking pollution from a small town in Zambia

James Sorenson (BGS) walked us through his poster presentation for his Catalyst Project: Mapping groundwater quality degradation beneath growing rural towns in Sub Saharan Africa.

The story starts with a pesticide found in slug pellets, which was unexpectedly detected in UK groundwater. This prompted this research to look for similar chemicals in African groundwater, What was found was relatively high levels of DEET, known to many travellers as “Jungle Formula” for keeping mosquitos at bay.

The implications are that these potentially health impacting chemicals are not being tested for. The levels detected were low, but DEET, and similar pesticides break down very slowly, if at all. In larger urban areas, these chemicals could be entering water supply wells and boreholes at potentially harmful levels.

The level of risk is just not known yet, but this research has raised an important warning flag. However, relatively simple measures, such as well protection is critical, especially for shallow self supply boreholes.

A risk that is understood better is that from pathogens coming from sewage-polluted groundwater. This can lead to outbreaks of cholera, typhoid and many other diseases.The challenge is how to map and track this pollution to see where it is coming from and where it is going to.

Pathogens can’t be measured directly. The most common approach is to measure concentrations of faecal coliforms, but doing this has drawbacks: Coliforms are micro-organisms that have to be grown in ‘culture’ so that they can be counted. Coliforms also die more quickly than pathogens so groundwater sample tests may come back showing nothing, but in reality still be potentially harmful to health.

Field measurements of an amino acid, found in sewage, called tryptophan can be used to map and monitor pathogen contamination. Monitoring is done using fluorescence – shining a light through the water sample – so it can be done in realtime and doesn’t need regents. The work demonstraed that this monitoring method is quicker, cheaper and more accurate that than measuring faecal coliforms.

The fieldwork also showed that the drawdown from the supply wells is pulling in contamination from under the city, Kabwe. This has helped the town authority prioritise the control of informal settlements to the west of the town that is encroaching towards the well field for the town’s water supply.