Water Supply - Where From?

Different domestic water sources compared

I recently received an email asking about water supply and particularly thinking of a well. There are choices when it comes to sourcing our water so perhaps we should consider the options. The following spring to mind (so to speak):

1 A spring.

2 A stream.

3 A well, a hand dug hole in the ground usually about 1 metre in diameter.

4 A bore, ie a drilled hole in the ground usually 6 or 8 inches (yes inches) in diameter.

5 Government water supply which is often only available in built up areas.

So which is best?

Natural Spring

Well, if you live in a pristine country area with sweet pure water coming from a natural spring this must be the best choice with healthy water in its natural state complete with all the minerals your body needs. However, trying to find spring water that has not been contaminated in some way, may not be quite as easy as it sounds.

It is probably best to have spring water tested before use to make sure it has no fecal or mineral contamination. Some time ago I was asked about taking a domestic water supply from a nearby spring but, unfortunately, when we tested the water it was seriously contaminated from a nearby pig farm.

Streams and Rivers

Streams are to be avoided unless you have a reliable serious filtration system such as a reverse osmosis plant. It’s the brown trout you see. In the quieter country areas local people tend to use streams and subaks as their toilets. “Not so subtle” deposits find their way down these waterways into the rivers (including the white water rafting rivers) and eventually to the sea.

Dug Wells

For centuries dug wells were the standard water sources. Wells are hand dug, usually 1 to 2 metres in diameter and up to 20 metres or so deep. Digging wells can be very dangerous with risk of collapse if the diggers don’t know what they are doing. Carbon dioxide poisoning is another danger as the diggers use up all the oxygen down the hole while they dig. The bottom of the well must be at least 2 metres below the water level and digging that last 2 metres can be quite challenging. The level of water in the well will vary between the wet and the dry season so wells should be dug at the end of the dry season when the water table is at its lowest.

Wells need to be lined. The lining is important to stop the well from collapsing. These days we tend to use precast concrete rings which can be inserted in the well progressively as it is dug, this acts as ‘shoring’ preventing the well from caving in.

More importantly, a lining is needed to stop surface water entering from the sides of the well and contaminating the water. I remember a case of a woman with very sick children. We tested the water and discovered that slurry from the pig sty next door was running through the ground and into her unlined well.

A properly constructed well is designed to filter the water. The lining means that water can only enter the well from the bottom. By this stage it has been filtered through 20 metres or so of earth. Unfortunately it is very difficult to seal the lining of a well and make it watertight.

I do not recommend the digging of wells. The digging process is dangerous if not done properly. a reasonable maximum depth for a well is 20 metres, an absolute maximum of 30 metres (that is deep - nearly 100 feet - the height of a ten storey building! Installing a water tight lining is very difficult and having an open 1 metre diameter hole is a bit of a health hazard.

Drilled Bores

In recent years bores have become more popular than wells. Bores work in the same way but are usually far more effective than wells because they tend to be much deeper. In rice field areas a bore may be 30 to 50 metres deep while in limestone areas such as the bukit they may be up to 130 metres deep.

Bores are lined with thick walled PVC pipe known as a casing. The casing stops the hole collapsing but also acts in the same way as the lining of a well only allowing water to enter at the bottom where it has been filtered through many metres of ground before it enters the bore.

Bores may be drilled by hand with four very active men using a hand turned drill. Very dramatic to see. More likely these days bores are drilled using a small diesel engine with a gearbox which turns a steel shaft with a drill bit on the end. A water pump is used to pump water down the hole to clean out the debris as drilling proceeds.

Bores are cheaper, quicker and safer than wells and their greater depth yields more reliable, cleaner water.

Town Water Supply

Before thinking about wells or bores I would suggest you consider the town water supply if you can before anything else. While people may advise against drinking government water in your area in fact it is treated with chlorine. Government water is good when it’s good but can be unreliable depending on where you are. The supply may improve over the years and will continue to improve as polythene pipes take over from steel ones. Steel pipes are difficult to repair and so leaking pipes are always a problem. Leaks in pipes can be sources of water contamination.

Variations in pressure in the government supply is another common problem and may vary according to the time of day. Years ago I came across a house where in the middle of the night the water pressure was so high it burst the pipe connections while at busy times (7 in the morning) the supply simply dried up.

Particular locations may have their own unique problems. In recent years some people on the bukit have reported that they have been struggling with an unreliable government supply.

If you do have a government supply and have pressure variations it is a good idea to have an underground storage tank. The government supply fills the ground tank then a small pump is used to distribute the water around your property. This avoids pressure variations in the government supply.

If you have a town water supply the water usage will be measured by a water meter and you will, of course, be charged accordingly. If the government supply is directly connected to your household water system and the system has a leak this may cost you a lot of money and there will not be a pump switching on and off to warn you that you have a problem. It is a good idea to turn all water usage off from time to time and check that the water meter is not turning. I came across a man once who was getting a huge bill for water each month, a broken pipe was irrigating his whole neighbourhood!