World Water Monitoring Day: Making Accra’s water safe to drink

World Water Monitoring Day, on September 18th, aims to build public awareness and involvement in protecting water resources around the world by empowering citizens to carry out basic monitoring of their local water bodies. IWMI’s research is contributing to improved water quality of water resources.

World Water Monitoring Day: Making Accra’s water safe to drink
Photo: Luke & Kate Bosman on Flickr

Accra, the capital of Ghana is developing fast. New buildings rise up, new vehicles crowd the roads. And up and down the lines of shimmering, and often stationary, cars roam the water sellers. With buckets and bowls stuffed with pre-packed plastic pouches of drinking water, they fulfill a valuable role in a city where other sources of water are often suspect.

World Water Monitoring Day

Selling water is big business in West Africa’s cities – and with good reason. In Ghana 70% of all diseases are caused through unsafe drinking water. 12% of the children younger than five are reported to die from diarrhea. Rapid urbanization and outdated urban water systems have led to a lack of clean drinking water and sanitation systems in Ghana. Households without access to clean water are forced to use less hygienic sources.


In Ghana’s capital Accra the two water works that serve the city are unable to meet the water demand of the growing population. Failures in the treatment process and pollution threaten the quality of the water. Frequent interruptions in the supply have made people turn towards alternative sources from private traders or local wells.  But often these sources are not safe either. Water from traders is vulnerable to cross contamination as a result of unhygienic handling. Water quality from local wells is also reported to be unsafe, as there is no prior treatment.


Troubleshooting health risks

As Accra has no funds to serve the entire city through an extensive water distribution network a well planned investment scheme is needed to improve public health as much as possible.

Now a newly published study hopes to provide valuable guidance to city planners so that they can invest more effectively in water infrastructure. A team of researchers from UNESCO-IHE, including researchers from the International Water Management Institute (IWMI), assessed public health risks from drinking water looking at five risk pathways, namely household storage, private yard taps, communal taps, communal wells and water sachets.  The study was using a Quantitative Microbial Risk Assessment which involved the identification of hazards, exposure assessment, dose-response analysis (describing the effects of different doses of bacteria to humans) and risk assessment in the form of number of years lost due to ill-health, disability or early death.

“We assessed the risk that arises from microbial contamination and evaluated the cost-effectiveness of reducing the disease burden through targeted interventions”, explains IWMI researcher Liqa Raschid. “This is a novel integrated approach to prioritize investments in the water system.” The study followed a similar one on risks to households from non-drinking water sources and wastewater contaminated vegetable consumption in the same city.

As the water supply is irregular many people tend to store water at home. However the study identified this practice as the largest single cause of diseases.  The degree of contamination was increasing 60 times from the distribution network to the household storage. The risk for the population was estimated to be about 30 times higher than the risk through eating vegetables in Accra’s streets which are grown with polluted irrigation water.


Let the sun shine

Several interventions were analyzed, but the most cost-effective was to disinfect the water at household level, rather than to improve the whole water supply network. Disinfection at household level can be done through chlorination or solar disinfection, a method which requires water to be stored in plastic bottles and then exposed to sunlight. This method has proven to be especially successful to deactivate diarrhea causing organisms in drinking water.

However to make these interventions successful it will also be necessary to promote better storage practices and improve hygienic practices. Interventions such as cleaning water containers, improving domestic water handling practices, covering storage containers to avoid natural contamination from the domestic environment and biofilm growth in plastic containers as well as promoting hand washing with soap.

The researchers suggest that investments to improve the domestic water supply may be more effective than to improve the sanitation system if household based options are considered. A new finding compared to previous studies, but there are other risk sources that have to be addressed too. One previous study pointed in particular at children being exposed to unsafe water in drains while they play. Closing all street gutters, however, would be very costly. “That’s why for the moment simple interventions and educational efforts offer the most cost-effective solution to Ghana’s health burden,” says Raschid.

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Machdar, E.; van der Steen, N. P.; Raschid-Sally, Liqa; Lens, P. N. L. 2013. Application of quantitative microbial risk assessment to analyze the public health risk from poor drinking water quality in a low income area in Accra, Ghana. Science of the Total Environment, 449(1):134-142.

Labite, H., I. Lunani, P. van der Steen, K. Vairavamoorthy, P. Drechsel, P. Lens. 2010. Quantitative Microbial Risk Analysis to evaluate health effects of interventions in the urban water system of Accra, Ghana. Journal of Water and Health 8: 417-430

Drechsel P and R Seidu 2011. Cost-effectiveness of options for reducing health risks in areas where food crops are irrigated with wastewater. Water International 36 (4) 535-548

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About the author:

Anna Deinhard is a Communications Fellow at the International Water Management Institute (IWMI).