Delivering clean water in Thailand


When you turn a tap on in developed countries you have an obvious expectation; a steady stream of pure, clean water. Around the world today in many developing nations this unfortunately is not a readymade assumption.
In late 2008, when NDY’s Brisbane-based Senior Hydraulics Engineer Darrel Cooper set off to work on a water filtration and distribution project in a village in Thailand, the mandate was clear - to develop a water filtration system to provide the villagers with a reliable water supply from the village’s dam year around. A goal he and his team achieved in 12 months.
“The one thing that was highlighted as a slight change in priority was the need to provide the village with clean water due to the identified contamination in the water,” says Cooper. “The village is part of a district that has a total of five villages. Bangkluanok had the highest rate of dysentery of the five villages at the time and it appeared that the water supply quality was the lowest of this area.”
Bangkluanok Village in the Ranong Province is around three hours drive north of Phuket. It is a sprawling community, consisting of around 200 houses each consuming 50 litres of water per day.
Before the project, the villagers accessed water from four primary sources, including a dam, two separate bores and a stream that fed the dam. The water supply from these sources in general was known to be unreliable and polluted by bacterial matter. Nearby farmers had taken connections from a pipe that transported water to the village for their farming needs and people took water illegally, depleting the bore water supplies and also drawing water from the most remote users of the system.
Cooper identified an effective three stage solution that was rolled out in rapid succession: slow sand filters for each dwelling, interconnection of all current water supply piping (excluding the dam water) and construction of a large slow sand filter. Along with this work, the local health workers and regional health service provided the villagers with hygiene and preventative health measures for around the home.
Stage 1 - Slow sand filters for each dwelling
The first and most immediate requirement was the installation of slow sand filters at each dwelling. This involved the construction of the filters primarily from small sections of concrete pipe joined and sealed. The filters are made up of a concrete container that has enclosed layers of sand and gravel that trap and remove sediments, pathogens and other impurities from the water. Positive results were achieved from this initiative, with water generally tasting and looking like bottled water after refrigeration with no adverse health effects on the locals.
Stage 2 – Large scale slow sand filter
A large scale filter was constructed to process up to 10,000 litres per day. This filter provides clean water for clothes washing and human bathing, and is used in conjunction with the slow sand filters at each dwelling. The infrastructure consists of four x 3000 litres poly tanks sourced locally. Two are roughing filters removing large-scale debris whilst the other two are the slow sand filters.
The water to the unit is taken from the dam outlet pipe to pick the water up from within the dam at a lower level. Once the water is purified it travels through a new pipe from the filter down into the village and then into the water tower. It is then distributed via a revised village pipe reticulation, allowing the village to have a continuous water supply.
Stage 3 - Interconnection of all current water supply piping (excluding the dam water)
Another immediate requirement was the interconnection of all existing water supplies. Due to water theft, some parts of the village were not able to access enough water even in times of plentiful supply. Hydraulic losses also slowed the delivery of the water.
The decision was made to exclude the connection of the dam water pipe line until later in the process to prevent contamination of the relatively clean bore supplies. The dam water was connected directly to the water tower. As all the other water sources were also connected to the water tower, the town now has year round water and at a relatively good pressure.
According to Cooper, the participation of locals in the process has been key to this project’s success.
“The empowerment of women in this particular region is well entrenched and they have really embraced the health and hygiene issues of the village. It is these women that continue to oversee the installation of individual water filter units along with educating villagers on hygiene in and around the home. This is what it’s all about, changing lives at the community level.”
(Note: funding for this project was provided by Life Aid Australia).