: : LEARN ABOUT WATER :

There are only four to five generic forms of water purification technology available despite the existence of different brands:

PROBLEMS

Water is arguably the second most important element for survival, next to oxygen. Without water life is not possible. Rapid population growth, increasing development and water demand have chronically led to short supply of clean water resources.

The Earth's surface is 71% water but most of it is seawater. Seawater contains 3% to 4% dissolved solids and we all know it is too salty to drink. In fact drinking water should be no more than 0.05% solids so it is 70 times too high in solids. About 2.5% of the Earth's water is freshwater (i.e. not sea water) and about 1.5% is under polar ice caps, continental ice sheets and glacier which leaves only 0.5% for potential drinking purposes. There are only two sources of fresh water, i.e. surface water and ground water.

In 1961, the average domestic consumption, for all household purposes - not just drinking - was 90 litres per person per day. Today it is 140 litres and it continues to rise. This is only individual consumption for personal care, laundry, toilet, dishes, garden, drinking and cooking.

But, only less than 5% or 7 litres are used for drinking (2-3 litres) and cooking purposes. So, although it all has to be treated to drinking water quality standards, only 2% of the domestic supply is really needs to meet those requirements - the rest is used for personal care, laundry, toilets, washing, gardening etc. And that doesn't include water supplied to industry and agriculture - which is about as much again. So, in effect, only 1% of the water supplied by the municipal water treatment plant needs to be suitable for drinking but it all has to be supplied to that standard.

The World Health Organization has laid down two standards for public water quality. One is regarded as an essential minimum standard and the other a desirable standard. Many water supplies worldwide fail to reach either standard.

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CAUSES

Water is well known for its universal solvent characteristics whereby it can easily dissolve any substance it touches. Consequently what comes into contact with it can also easily contaminate it.

In the Earth's water cycles, water evaporates from rivers, lakes and seas and is reprecipitated as rain or snow. Some falling on land, returns to these rivers, lakes and seas. Some percolates through soil and substrata and is retained in aquifers and underground reservoirs. Whether we take our fresh water from rivers or lakes (surface water) or underground reservoirs (ground water), the pure rain and snow will have picked up other pollutants and materials as it passes over atmosphere and through the ground. Some of these pollutants and materials are beneficial: for example calcium dissolved by the water as it passes through chalk is an important mineral to human and animal bone structure. However, others, bacteria from animal decay for example, can cause sickness or even death.

There have been rising incidences of complaints regarding aesthetic nature of water problems and impurities such as the taste, odour, colour and turbidity from our taps. After the treated water leaves the water treatment plant but before it reaches a premise, it will come into contact with many different substances along the extensive but ageing distribution pipe network, such as gases, mineral, organic and inorganic matters, micro-organisms and chemical compounds. Traces of all these substances and particles contaminated the water, causing aesthetic water problems such as taste, odour, colour and turbidity, and health water problems such as contaminations of chemical compounds and micro-organisms.

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Contaminant

Furthermore, modern society's contribution is the contamination of our water sources by industry and agriculture in the in the form of fertilizers, pesticides and industrial waste. These can affect the aesthetic quality of the water, but more seriously, can give rise to long-term adverse health effects.

CONTAMINANTS
They can be categorized under the following headings

NOTE: The list of contaminants is not exhaustive and growing rapidly and the above list is intended only to provide an indication of what may be present in today's drinking water.
Many of the above contaminants would require lengthy explanations to define their harmful effects to the health of the consumer.
It is however true to say that under ideal conditions none of them are desirable in drinking water.

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SOLUTION

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