My understanding of the hydrology of islands is that the fresh water in the ground (water table, aquifer) can be above salt water located below it. Sometimes called a lens

http://geography.about.com/library/misc/ucghyben.htm

it is not a simple layer between salt and fresh water on an island like Samui but will vary according to layers in the ground that affect the movement of underground water. I have been told that some wells in Lipa Noi became brackish during the last prolonged rainy period. Does anybody know about this occurring on Samui? Can the salt water get above the sea level? As I watch the water level in ponds and wells dropping and more and more water trucks roaring around I wonder how this might affect me as I live by the sea and depend on a well for water.

All you need to do is look at koh Tao as an example ,

I have a plot of beachland on Phangan and had a 15 ring well put in a number of years ago because that is what the thai neighbours next door had done they use it for everyday purposes washing, cooking and drinking they did tell me only to go down 15 ring as any deeper would bring the salt water ,they have lived on there land for many years indeed the lady who is 50 years old was born in the same house. As I have not built on the land I have only used the well as I planted the borders with various plants and trees but if they have no problems with it then it then it would be good enough for me. I do have a property on Samui and have to use a water truck because the best views and for tranquility you need to go off the beaten trac and that means no Governement water but that is what I chose to do . I pay 600 baht for 6,000 litres that is very cheap for a truck that has to drive some 4 ks from the ring road up some steep roads I also collect water from my rainwater system !!!!!!!!!!!!!!

I forgot to meniton that there has been constructed a very big desalination centre in Baan Tai, Koh Phangan which brings water from the sea to the unit to turn it into fresh water it is not completed as yet however I expect it to be in operation in the very near future maybe Samui should look at doing the same thing !!!!!

I forgot to meniton that there has been constructed a very big desalination centre in Baan Tai, Koh Phangan which brings water from the sea to the unit to turn it into fresh water it is not completed as yet however I expect it to be in operation in the very near future maybe Samui should look at doing the same thing !!!!!

Has been for some years.

There is a desalination plant on Soi Tongsai off Plai Laem (after Big Buddha). Build by Anglia Water if memory serves me.

I forgot to meniton that there has been constructed a very big desalination centre in Baan Tai, Koh Phangan which brings water from the sea to the unit to turn it into fresh water it is not completed as yet however I expect it to be in operation in the very near future maybe Samui should look at doing the same thing !!!!!

Has been for some years.

There is a desalination plant on Soi Tongsai off Plai Laem (after Big Buddha). Build by Anglia Water if memory serves me.

I know that's been there for quite some time. Do you know if it produces and who do they sell too as it's an expensive setup and to maintain.

Yes it definitely produces.

As to your other questions - sorry, no idea.

As there seems to be no visible attempt to replicate or increase the process, one might assume that it is expensive. However, watch this space when alternatives become more scarce.

Having lived on Samui for 12 years, this is the second real drought. Government water supply can be sporadic even in times of plenty. Many a time at Songkhran one can hear the cry of "No water from Government".

So - if there is a problem every 10 - 12 years, it probably will not be fixed in a hurry.

Yes it definitely produces.

As to your other questions - sorry, no idea.

As there seems to be no visible attempt to replicate or increase the process, one might assume that it is expensive. However, watch this space when alternatives become more scarce.

Having lived on Samui for 12 years, this is the second real drought. Government water supply can be sporadic even in times of plenty. Many a time at Songkhran one can hear the cry of "No water from Government".

So - if there is a problem every 10 - 12 years, it probably will not be fixed in a hurry.

i heard that this plant produces about 5 percent of samuis water and it can produce much much more ,however as its a private company its not permitted to supply more

sounds about right ,private companies regulated by government and not allowed to make too much profit