Wednesday, March 29, 2017

The water children drink: regular testing to improve water quality

By Chanthea Chaing and Sam Treglown

Team leaders learn to use the tools they will need to test water quality
© UNICEF Cambodia/2016/Sam Treglown

PHNOM PENH, Cambodia, March 2017: As part of an on-going multi-year household study, UNICEF has been supporting the use of an innovative water quality testing system in Cambodia, to measure the presence of faecal material in drinking water given to children in their homes. The aim is to provide data that can be used to improve water quality in the future, and reduce the risk of exposure to viruses, bacteria, and other pathogens that can be harmful to health.


The multi-year longitudinal study involves collecting samples of drinking water given to children under 5 years old in selected areas in Phnom Penh, Kratie, and Ratankiri provinces. The water samples are taken both from the container from which the child drinks, and from the source from which that water was originally collected, for example the tap, or handpump, or bottled water container, allowing the points of potential contamination to be identified.

Heng Sovutha, is a team leader for the UNICEF supported study, and responsible for the collection and analysis of the water samples. Sovutha learned to use the testing system during a two-day training session conducted by UNICEF. The training covered how to collect water samples, how to do the testing and how to read the results. “I was happy to learn,” he said. “At first, I thought it was hard and I worried about conducting the testing” but Sovutha said the support of UNICEF staff made learning much easier.

Each morning Sovutha makes sure all the testing equipment and materials are prepared and ready to go – especially cool boxes, ice-packs to maintain the temperature between 1- 4 degrees Celsius, special water sample bags, hand sanitizer and permanent markers.

In the study areas Sovutha and his team collect water samples from between eight and 16 households per day which are randomly selected for testing. The family needs to have a child under the age of 5, and must give permission for the team to take the water samples.

Sovutha asks the parents to act just as they would when their child asks for a drink of water, and he then carefully takes a sample of the water that the child drinks in a special sterilized collection bag, and places it directly into a cool box for storage and transportation before testing.

To compare the quality of the drinking water given to the child with the water quality at the source from which the water was collected, Sovutha asks the parents to point to the source of the drinking water. He then asks permission to take a sample. This too is placed into the cool box right away.

Sovutha collects drinking water and places the sample in a cool box
©UNICEF Cambodia/2016/Chanthea Chaing

 The sample then is placed in a cool box
©UNICEF Cambodia/2016/Chanthea Chaing


At around 4 p.m. Sovutha and his team arrive back at their office at the Department of Fisheries, the Royal Government of Cambodia entity leading the multi-year early childhood study which the water testing is a part of.

The water samples are then tested using a ready-to-use testing product which does not require a sophisticated laboratory, allowing samples to be tested even in remote locations.

The team puts all the testing equipment and materials in the storeroom and while the rest of the team leave for the day, Sovutha stays behind to test the water quality. It takes about one to two hours to prepare each test, with the water sample filtered through a special membrane, which is then placed in the ready-to-use testing product dish, and incubated overnight.

The test detects the presence and measures the quantity of the faeces (poop) indicator bacteria, Escherichia coli, in the water. Where it is found, the presence of this faeces indicator bacteria in the water does not necessarily mean that the water contains harmful faeces germs, but it indicates that the water contains faeces (poop) material and that there is a route for harmful faecal germs to potentially enter the water and be drunk by children in the future.

This warning information can then be used as a diagnostic tool to identify where and what preventative actions need to be taken to improve water quality and safety and ensure that the water meets the microbiological quality standards set by the Royal Government of Cambodia.

The water quality is tested for bacteria
©UNICEF Cambodia/2016/Chanthea Chaing

About 22 to 48 hours after incubation, Sovutha is able to read the test results. It takes about 40 minutes to read the results of each survey day, which involves manually counting the number of colonies on each dish. The results, along with photographs of the test dish, loaded onto a tablet and sent to a server for processing and analysis.

At the end of each survey the results are compiled and analysed, allowing the locations and type of water sources where faecal material is present in the water to be identified.

UNICEF can then work with government officials, water service providers, and household members to interpret and validate the results, and improve future water quality.

Sovutha reads test results installed on a tablet
©UNICEF Cambodia/2016/Chanthea Chaing

Sovutha says, “Having water quality testing is good, as people need water to drink every day. If their drinking water is poor quality, and even if they have good food, they risk suffering from diarrhoea. This can result in malnutrition, especially in children.”

With future testing in the same study areas in the coming years, it will be possible to track how water quality changes at different times of the year, during the dry and rainy seasons for example, and how effective water quality improvement actions are to enhance the quality of the water children drink.

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