EMPOWERING CHANGE through drinkable WATER
Water is an indispensable part of healthy living. The people in Laos do not have access to clean drinking water. Their sources of water come from the Mekong River and mountainous areas. Water from these sources are rich in calcium carbonate. Prolonged drinking will lead to kidney stones and eventually kidney failure. Most locals could not afford medical care and even if they do, healthcare is limited. Sad to say, they will eventually succumb to their illness.
The Bio-Sand Filtration is a simple system that allows the locals to access to clean drinking water. This method is adapted from the Centre for Affordable Water and Sanitation Technology (CAWST) which is based in Calgary, Canada.
benefits of bio-sand filtration system
Removes 100% of harmful parasites.
Remove up to 97% of bacteria.
Removes turbidity, iron and manganese.
Easily fabricated from local materials.
No weird taste.
Low set-up and no recurrent cost.
No electricity required.
Easy to maintain.
How it works: filtration process
The unsafe drinking water will enter the tank and passes through the diffuser. It will then percolate slowly down through the sand and to the gravel where the water is filtrated and safe for consumption. Below are some diagrams that clearly explain the filtration process.
HOW TO SET UP?
The material of a water tank MUST be:
non-toxic food grade material (FDA approved specifications for drinking water)
Laying the foundation for water tank:
1. Clear out the areas where the water tank foundation will be situated.
2. Build the foundation for the water tank where the source of water comes from.
Choose correct piping size.
Cut and join the pipes. Branch extension at the base is better for collection of water as gravity pushes the filtered water up the outlet pipe (siphoning effect).
Prepare pipping and connect to the water source.
Run an electric wire for the water pump (optional).
*use UV rated water pipes.
Collect pebbles and choose the right size.
Wash the pebbles.
To prevent the filtration sand from entering the outlet pipe, fill the base of the tank with pebbles (ratio: 20% pebbles, 80% sand).
Sand is the main medium where the filtration process will take place.
Collect sand, sieve and wash it.
Fill the tank with the sand (ratio: 20% pebbles, 80% sand).
A perforated diffuser plate or basin is used to protect the biolayer from disturbance when water is poured in. Sometimes, a basin or plate is used.
Fill the tank with water. Turn on the tap for clean drinking water!
1. Turn off the "ON/OFF" valve. Stir the water gently to agitate the sediments that had settled on top of the sand. Dispose the cloudy water either by scooping it or siphoning it off.
2. Turn on the "ON/OFF" valve and repeat the action until the surface of the sand becomes visible.
1. Turn off the "ON/OFF" valve. Gently scoop 1mm/2mm off the surface of the sand.
2. Turn on the "ON/OFF" valve and resume normal operation.
3. Wash the extracted sand until the sediments are gone. Dry it in a hygiene condition and store it in an airtight container when dried.
1. Turn off the "ON/OFF" valve. Gently scoop 1 cm off the surface of the sand.
2. Wash the extracted sand until the sediments are gone.
3. Return this sand, together with the sand extracted 6 months ago into the tank and gently spread them evenly over the surface of the sand. Turn on the "ON/OFF" valve and resume normal operation.
1st project mylaowater
built by mylaohome
Water collected from the first Bio-Sand Filtration system built and tested by MyLaoHome in Luang Prabang was collected to test in Singapore against strict and high standard. Jestyn Koh, a representation from YMCA, whom is our project partner assisted us to receive the test report as below.
The water obtained from the Bio-Sand Filtration system is proven to be physically, chemically and bacteriologically satisfactory, making it safe for drinking.
The students carried out Project MyLaoWater based on the village that we had identified. They will then be divided into various groups such as cooking, building the Bio-Sand Filtration system and teaching English to the children (depending on the needs of the village). Furthermore, the students visited the Special Education Needs School for the Deaf and Mute. Lastly, they enjoyed some recreation activities before leaving Luang Prabang.
Schools that had embarked on Project MyLaoWater:
Nanyang Technological University (NTU)
National University of Singapore (NUS)
Ngee Ann Polytechnic