From a community well in east Africa to a standpipe in an urban slum, small water operators furnish vital supplies for billions of people the world over. 

Now, for the first time in nearly 30 years, the World Health Organization (WHO) has published new guidelines for drinking water quality for small water supplies with up-to-date advice on building resilient systems that ensure safe drinking water quality.

With the increased incidence of water-borne diseases such as cholera, “the need remains as acute as ever,” says Bruce Gordon, head of WHO’s Water, Sanitation and Hygiene programme (WASH).

The WHO recorded 40 900 cholera cases and 775 deaths in January alone and estimates that more than 500,000 deaths a year could be prevented through the increased provision of safely managed drinking water.

“Small water supplies have lacked competence and capacity,” he says, highlighting the dire need for professionalization and resources.  Against that landscape, prioritizing technically simple and affordable water quality solutions is critical, and that is what the WHO guidelines provide. 

New modes of operation are critical, he stresses, to get the world even partially back on track towards attainment of Sustainable Development Goal 6, ensuring the availability and sustainable management of water and sanitation for all by 2030. 

WHO guidelines: the product of a multi-year process 

The new WHO guidelines are the product of a multi-year process of evidence-gathering and evaluation. 

People served by small supplies are more at risk of exposure to waterborne pathogens as well as harmful chemical contaminants, which increases their risk of waterborne illness. 

The guidelines underlines the importance of protecting water quality along with testing water quality and ensuring sustainable financial and data management of small water systems.  

Protective measures can be as simple as ensuring fences are erected around a community water supply to ensure that humans and wild animals don’t encroach and contaminate the area, said Gordon. 

Ensuring that water pumping stations also are protected from flooding, and placed at a safe distance from latrines or other potential contamination sources are other examples of important preventive measures.

Water quality: frequent testing and risk assessments

The guidelines recommend that small water supplies prioritize the most important water quality parameters. 

“Small supplies need to be even more thoughtful about what kinds of parameters they choose to survey, monitor, and test for,” noted Gordon. Large water companies, for instance, can typically test for upwards of 50 chemical contaminants and even maintain a programme on emerging contaminants, as part of a rigorous water quality regime. 

But with small supplies, their capacity may be limited to testing only once or twice a year for both biological and chemical contaminants.  

The guidelines thus provide a list of the highest priority pollutants that biological and chemical tests need to cover. Top of the list is monitoring for Escherichia coli (E. coli), as an indicator of bacterial contamination, as well as heavy metals like lead and arsenic, in terms of chemicals. 

In resource-constrained settings that add chlorine as a disinfectant to their water supplies, WHO also recommends “free chlorine residual monitoring” between E. coli monitoring, as a proxy indicator of microbial water quality. 

When laboratory testing is not available, “regulations should allow the use of field test kits when performance has been validated. Field test kits offer an alternative to analysis in formal laboratory settings, and they often have the advantage of being simpler to use and less expensive than laboratory testing methods.”

When very frequent water quality testing is not feasible, then other sanitary inspection measures to identify and prevent potential sources of contaminant infiltration become even more critical, Gordon stressed.

“For instance, you need to make sure there are no cracks in your wellhead. If you have animals around, or even people, you need to put a fence around your supply. You need to make sure that there is adequate distance between the latrine and the supply, as well as ensuring some point of disinfection at the source or household,” he observes. “So we are really trying to get folks to focus on the basics.” 

Capacity building, financial management and data collection  

Guidance is tailored to different stakeholders, such as household, community or professionally managed supplies. Among those are recommendations for assessment “to inform system strengthening” including capacity-building of a professionalized workforce, rather than reliance only upon a network of volunteers. 

This follows a key theme of the sustainability of clean and safe small water supplies, primarily through building professional workforces, sustainable finance, and water quality data collection. 

Each stage of clean water delivery requires an accurate assessment of direct and indirect costs, and consistent financial review and planning, especially for surveillance activities. Costs range from staffing, mobilization, and water quality analysis, to training materials and office and laboratory space. 

“We want to encourage digitization,” noted Gordon. “There’s a lot of interest in the world with digitalization. When people are looking at allocating resources, having a good digital database and a structured and credible way of prioritizing needs is important.

“Water safety is a persistent problem but we have the tools to solve it. We need to finance, build capacity and organize.” 

Image Credits: Jouni Rajala, WHO , WHO Guidelines for drinking-water quality: Small water supplies.