Letter to the editor – water shortage Koh Samui
The Kingdom is currently suffering its worst drought in living memory. Here on Koh Samui some parts of the island are already experiencing water supply restrictions, there’s still no real sign of any rain and it is becoming an annual problem.
Like many people I have a private water well to my Villa but for convenience I use the governments supply for our domestic needs and purchase bottled drinking water. We use our well to fill and top up our swimming pool, ornamental fish pond and water the garden.
On average we use around 12L of bottled drinking water a day @ just over 17 baht/L is 200 + baht per month, or 6,500 per year. Our domestic consumption of around 30/35,000L per month, or 7,500 baht per year making a total of 14,000 + baht a year minimum.
Since the threat to the water supply by demand is becoming very real and will only get worse and whilst the government water is cheap, the supply carries lot of sediment which contaminates pipe work, cisterns, and leaves an unsightly brown stain at the water line in the loo. It also affects the performance of washing machines and dishwashers and you can’t drink it.
I thought I would investigate becoming self-sufficient from a well we already own. The first problem is riding the well water of a pungent stink (bad eggs) which is in fact a harmless bacterium confined to the well itself this gives off Hydrogen Suphide and the cause of the smell. I disinfected our well by calculating the volume of water it held (piexDxH) and added sufficient domestic unscented bleach to raise its chlorine levels to 200ppm. Cap off the well for 48 hours and pumped the chlorinated water to waste (soak away) not your cesspit until the chlorine smell goes away or you can check it with your pools water chemistry meter. The water will then be free of smell, you can add if you wish a special KDF filter cartridge to your filter sump that will remove any smell there after.
I purchased two 700L above ground plastic food grade water storage tanks, one accepts water from the well head pump via a 10 inch 15 micron Omnifilter sand filter controlled through a standard one inch ball cock. The second adjacent tank is filled through a 35mm balance pipe 300mm from the bottom joining both tanks. The sumps created by the balance pipe collect any debris missed by the filter and if you add a dump coke they can be flushed out annually. A feed from the second tank enters the domestic water pump to the Villa after first passing through a pair a 20 inch 5 Micron filters connected in series before entering the Villa. In our utility room I tapped into the dishwasher feed and ran a supply to a 5 stage Mazuma water purification system comprising of a granulated carbon, resin, ceramic, solid carbon filters and finally a UV lamp to kill any remaining bacterium. The filters of course require changing at around six month intervals and it will be a year or so to cover my initial outlay but we no longer have the threat of an interrupted water supply replacing it with a healthier wholesome option and is also something we have complete control over. You can purchase all the equipment you need from HomePro but almost everything is much cheaper if you shop around around the island and its good fun.