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Improved water is not enough

Maximilian Leo Hirn's picture
Water bucket in Kinshasa, DRC

In Kinshasa, the capital and largest city of the Democratic Republic of the Congo (DRC), the vast majority of the population has access to “improved” water. This means sources such as piped networks, covered wells, boreholes, or protected springs, which are constructed to protect water from outside contamination, are widely available. Yet it is increasingly clear that “improved” water is not enough; when the 2017 DRC WASH Poverty Diagnostic tested water quality in over 1,600 households in Kinshasa, water samples from nearly 40% of improved sources were still contaminated with fecal E. Coli Bacteria at point of use.

The results for Kinshasa were among the best in the DRC. In the small Congolese town of Tchonka, for example, over 99% of samples were contaminated, even though the community has near universal access to an “improved” rural piped system. Perversely, improved infrastructure can become an efficient distributor of disease if not managed properly. Across developing countries, we find similar results: In Liberia’s capital Monrovia, over 50% of “improved” wells and two-thirds of piped sources were polluted with E. Coli at the source (Uhl, 2011). Testing done in the Indonesian city of Yogyakarta found that “nearly all sources of improved water were contaminated with E. coli” including 77% of piped supplies.

A recent study estimated that globally 1.8 billion people “use a source of drinking water which suffers from fecal contamination”, of which the majority in South East Asia (34%) or Africa (26%). The meta-analysis concluded that piped supplies tend to offer some protection relative to boreholes or unprotected groundwater sources (this was, after all, the basis for targeting "improved" water), but are nevertheless “often contaminated”. Systematic contamination of improved sources is common due to factors such as inadequate maintenance of infrastructure, interrupted supply, and improper disinfection, but also contamination during transport to and unsafe storage within households.

From a human development perspective, targeting “improved” water is thus simply not enough. What matters is whether water is truly clean when consumed, and this should be the objective.

Water Quality Testing in Kinshara, DRC

Ensuring water supply is not just “improved” but truly clean is a critical public health priority. This has been known for a long time. Over 150 years ago John Snow’s famous discovery of a fecally contaminated water-well as the source of a major 1854 cholera outbreak in London is often cited as the start of public health as a concern of public policy. Today, the impact of fecal water contamination remains grim. Best estimates indicate over 500,000 diarrhea deaths per year caused by inadequate drinking water globally.

The morbidity and mortality impact of contaminated water is not only due to diarrheal diseases and parasites directly, but interacts perniciously with childhood malnutrition. Uptake of nutrients is undermined by repeated bouts of diarrhea; in particular, if it leads a chronic intestinal inflammation known as “tropical enteropathy”, which undermines nutrient uptake in the long term. Data collected by the WASH Poverty Diagnostic for the DRC confirmed that while household access to improved water is not enough to achieve significant protective effects, access to “safely managed” (uncontaminated) water did significantly reduce the probability of stunting and anthropometric failures in children under 5.   

At the global policy level, the fundamental problem of water quality has been recognized in the new Sustainable Development Goals (SDGs). While the earlier Millennium Development Goals (MDG) merely aimed to increase access to “improved” water, the SDGs target “safely managed” water that is not just improved, but on premises, available when needed, and – critically – “free from contamination”.  
 
Applying this target to our work in the water sector in developing countries, a number of steps could be taken to improve our impact on the critical aspect of water quality: 

  • Updating Results Indicators: Despite the new SDGs, many sector interventions continue to target merely “improved” water. A simple step would be to replace “improved” water targets with the aim of “safely managed” water. This core indicator could then be matched by intermediate indicators targeting more specific quality related results, for example, regular water quality testing and publication of results by utilities and a certain percentage of samples confirmed to be clean at source or at point-of-use. A recently approved water supply project in the Central African Republic provides a good example for a possible E.Coli focused intermediate indicator.
  • More Testing:  We could support wider testing of water quality by utilities, in the form of dedicated water quality surveys, and as part of general household surveys. Testing of water quality both raises awareness that there is a problem, and allows for monitoring the quality of services provided. Water contamination tests have become cheap and simple. E.Coli bacteria are an excellent indicator of fecal contamination, and a petrifilm test for E.Coli contamination requires no electricity or special skills, and costs less than 1.5 US Dollars. The WHO-UNICEF Joint Monitoring Program has started to support water quality testing in multi-topic national household surveys, and other organizations could reinforce this with both dedicated water quality surveys and the integration of water quality into general household surveys. Publication of results in easily accessible places (e.g. utility websites) could also improve information of the public and accountability.
  • Adopting a WYDIY Mentality: Among sector professionals, a “would-you-drink-it-yourself” mentality should be promoted. If development professionals or utility employees report positive project results, yet still prefer bottled water to the local tap in meetings, hotel, and home, then clearly more still needs to be done!

Comments

Submitted by Lisa Hirsh on

This is an excellent post with which we certainly agree. The author's emphasis on focusing on "safely managed water" rather than "improved water" is well put and wise.

As the author emphasizes, it's crucial for water to be tested for microbial quality beyond the source. Enumerators need simple methods for on-site testing where they are and at all water points - at the point of use, point of consumption, in the household, where water is stored, where water is treated, etc.

We would politely add that 1 mL petrifilm tests, while incredibly inexpensive, detect E. coli at only 100/100 mL or higher, which is already unsafe drinking water. Therefore, petrifilm does not detect E. coli in the relevant ranges as specified by the World Health Organization Guidelines for Drinking Water Quality to determine the health risk of water, which is to test for E. coli in a 100 mL sample.

When a water sample has a mean E. coli concentration of 100 per 100 mL, there is a 37% probability that testing a single 1 mL volume will give a negative result (based on well-established Poisson probability applicable to such data). Hence, petrifilms do not provide sufficient information on the concentration of E. coli in a 100 mL volume of water unless one is willing to use a lot of 1 mL petrifilms for a single sample.

Responsible work on water quality projects in developing countries and other low-resource settings should incorporate microbiological analysis of drinking water in ways that are consistent with WHO Drinking Water Quality Guidelines, WHO Water Safety Plans and the water quality standards of most countries of the world.

The author provides much-needed data from the DRC demonstrating how "improved" water sources still contain high levels of fecal contamination. His suggestions for improving water quality in developing countries are practical and realistic. Thank you for publishing this!

Lisa Hirsh, Aquagenx

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