How do we know that we are delivering clean, disease free water?

This question was asked early in the life of this project and the obvious answer was to test the water quality. Upon investigating options it was realized that the facilities for testing water were non-existent outside Phnom Penh… nearly 200 miles and many hours away by road. The decision was made to develop our own capability to test the essential parameters to ensure the quality of the water delivered by the bio-sand filters. The Siem Reap Water Quality Laboratory concept was born.

With funding from many sources and expertise from Drs Bill Duke formerly with the University of Victoria, British Columbia and Kevin Curry, Bridgewater State College, Massachusetts the lab became a reality in July 2007. They traveled to Siem Reap to assist in setting up the equipment, writing laboratory test protocols and training Mieko in the techniques for testing and evaluating water. They have both returned for follow up visits and assisted the team in evaluating results. By October Mieko Morgan, Water-test Lab Manager, and Seang Seur, our field supervisor, were sampling and testing water from bio-sand filter installations.

Each tested installation has a sample of source water (well, stream, pond etc.), filtered water (straight from the filter outlet) and stored water tested. All water samples are checked for E-coli, salinity, pH, turbidity, conductivity and total dissolved solids. Selected samples may be tested for the presence of iron, phosphorus, manganese and nitrates. If results indicate a reading that isn’t satisfactory then the filter team will follow up and resolve the cause.

By Spring of 2010 more than 1000 filter installations and wells were tested and this data forms the basis of understanding the effectiveness of the bio-sand filters. This information also aids in identifying areas where training in installation, use and maintenance, must be strengthened.

In mid-2009, the lab was relocated to our new office and manufacturing site on the road to the Anakorian Temples. Then in January of 2010, Peang Sok Heng joined the lab staff as the lab's testing technician. Sok Heng came with prior water testing experience at the RDI laboratory in Phnom Penh.

The photo (left) is an actual set of test results taken directly from a village home. Each day our field supervisor Seur travels to selected homes and collects samples of source water (Sample A), filtered water (Sample B) and stored water (Sample C).

He puts them in specially designed sterile sample bags and transports them in a cooler filled with ice. They are taken back to the lab where testing begins. While collecting the samples he also interviews the family to gain demographic, health and hygiene data as well. As shown in the photo to the right, the results are very clear: sample A shows a very large number of E-coli bacteria colonies… each dark dot represents a colony. Sample B is directly from the outlet tube of the filter… its condition speaks for itself. Sample C is a water sample taken from the household storage container. Upon very close examination a small amount of bacterial contamination is evident. This is in the generally acceptable range but indicates a problem commonly seem in some households… recontamination of water in storage containers. Lab testing has revealed this unexpected result and the training, monitoring and follow up efforts have concentrated on eliminating it as a problem.