Water Supply

Water can be derived from lakes, seas, rivers and underground rivers. However, these sources of waters are often not fit for consumption. As such, it is important to clean and purify these waters.

Water can be retrieved from the sea in the form of saline water. These water can be stripped of its salt content via the process desalination. In this process, excess salt and mineral is removed from the water body, making the water fit for consumption or irrigation.

Most of the time, the sea water is boiled and then condensed to retrieve the filtrate, which is the distilled form of the water. Another way to obtain clean water from saline water is to use reverse osmosis. This process uses high pressure to force the saline water through a partially permeable membrane, producing clean and purified water at the other end. This is the exact opposite of osmosis, where water will move from a region of higher water potential to a region with lower water potential. Reverse osmosis is a much cheaper and common way of cleaning saline water as compared to distillation, since the latter is extremely expensive for large scale operation.

Surface water is water in the river, lake or fresh water wetland. These waters are naturally supplied and replenished by rain or melting icecaps on the mountains. The water obtained from surface water requires little treatment since they are quite clean, and often just needs to be boiled to be fit for consumption.

Surface water is often the dominant source of water in most community, since they are readily available and easy to manage. These waters can also be easily stored in large quantity via reservoirs and lakes, which makes it convenient for human to gain access to them.

However, humans are slowly destroying this source of water via pollution. When we dump our waste into the rivers, they get polluted. This causes the water to be unfit for consumption unless it undergoes intensive amount of treatment, which will make it extremely expensive.

Water that exists underground in underground rivers is called groundwater. These waters can be retrieved via wells, which provide most homes with water in rural parts of the world. Water from the surface will not stay there for long, and will eventually seep through the soil to gather in underground caverns called aquifers, a type of groundwater store. This source of water is also very popular, since it requires little treatment and can be acquired easily (via wells).

However, this source of water is not as good as surface water due to several reasons.

1. First and foremost, the store of water is unseen, so we do not know how big the store is, nor what is going on down there. By drawing water from aquifers, the water store may move lower down since water do not seep as fast from the surface to replenish the water store. This will force us to dig deeper wells. Sometimes these aquifers go so deep that it is eventually out of reach by us, making us look for another aquifer.

2. Aquifers are also extremely prone to pollution, since anything that leaks onto the ground will end up in aquifers. Unlike rivers, which are out in the open, aquifers are deep underground, which makes cleaning up difficult and costly. Most people eventually abandon the polluted aquifers, which will also affect the environment indirectly.

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DO YOU KNOW?

- The human’s body is made up of almost 60% of water while the brain is made up of almost 70% of water.

- Salt in the ocean comes from rocks found on land.

- To this day, the Earth still has the same amount of water as before it was formed.