COVENANT UNIVERSITY

College of Science and Technology

Department Of Civil Engineering

Canaan Land, Ota, Ogun State.

2008/2009 ALPHA SEMESTER

CVE 410: WATER & WASTEWATER ENGINEERING (UNITS);

OCCURRENCE OF WATER

Water, water, everywhere...

"WATER, water everywhere, not any drop to drink." That was how the famous English poet, Samuel T. Coleridge, put it in his epic poem, The Ancient Mariner. But in Nigeria's case, one could have a pun on this famous line by simply asking, "water, water everywhere, but how many are fit to drink?"

Water is necessary for all life on Earth. Humans can survive for several weeks without food, but for only a few days without water.

A constant supply is needed to replenish the fluids lost through normal physiological activities, such as respiration, sweating and urination. Water forms about 70 per cent of the human body constitution by weight and plays an important role in the prevention of disease.

The human brain is made up of 95 per cent water, blood 82 per cent and lungs 90 per cent. A mere 2 per cent drop in our body's water supply can trigger signs of dehydration: fizzy short-term memory, trouble with basic math, and difficulty focusing on smaller print, such as a computer screen. Mild dehydration is also one of the most common causes of daytime fatigue.

The Earth's surface consists of 70 per cent water, but only a few have access to potable or drinkable water. In Nigeria in particular, many people do not, even in urban areas. And, over the years, the growing consciousness to have access to safe drinking water has brought about the emergence of a burgeoning commercial water business in the country- a big growing sector in the food and beverage industry.

This crave for potable drinking water has, however, led to the proliferation of commercial drinking water supply, at first in sachets (pure water) and now in bottles, so much so that over 30 brands are jostling for the consumer's purse in the market and everyday, many new entrants are still debuting.

Potable water could be stored rain-water, natural water from a river, streams, lake, well or borehole but has to be treated to make it drinkable. Potable water must be free of pathogens (disease causing organisms), have a desirable taste, odour (smell), colour, turbidity (cloudiness) and contain no harmful chemicals.

A little knowledge about the different types of bottled water will go a long way in helping the consumer to decide on what brand to go for.

Table water- Table water or potable water is treated water that meets the quality standard for human consumption and other uses. Potable water may be packaged or unpackaged.

In today's Nigeria, table water includes treated water that is packaged in plastic bottles or sachets-popularly known as "pure water."

Sparkling water- also known as Carbonated water, is potable water into which carbon dioxide gas has been dissolved, and is the major and defining component of most "soft drinks."

Today, sparkling water is produced by passing pressurised carbon dioxide through potable water. The pressure increases the solubility and allows more carbon dioxide to dissolve than would be possible under standard atmospheric pressure.

When the bottle is opened, the pressure is released, allowing the gas to come out of the solution, thus forming the characteristic bubbles.

Spring water- as the name implies, is the water flowing out of the ground from a natural spring. A spring is a point where ground water flows out of the ground, and is thus where the aquifer surface meets the ground surface.

Aquifers are rock layers that permit ground water flow in appreciable quantities. Spring water may form into a pool (reservoir) or flow downhill, or in surface streams. Minerals become dissolved in the water as it moves through the underground rocks.

This may give the water flavour and even carbon dioxide bubbles, depending upon the nature of the geology or rock structure through which it passes. Springs that contain large amounts of dissolved sodium salts, mostly sodium carbonate, are called 'soda springs."

Mineral water-is water containing minerals or dissolved substances that alter its taste or give it therapeutic value. Salts and gases, such as carbon dioxide are among the substances that can be dissolved in the water.

Mineral water can often be effervescent. Mineral water can be made or can occur naturally. Mineral water must be obtained directly from natural or drilled sources from groundwater bearing strata or aquifer.

Of recent, with the growing health consciousness among Nigerians, many have been debating about which type of water to drink: spring water/bottled water or tap/borehole water.

Since water is a key component in flushing out impurities and toxins in the body, it is very important to know what one is drinking. Sometimes spring water and bottled water could be safer than tap and borehole water.

Most medical and nutrition research reports have shown that spring water is the most hygienic and cleanest form the human body can ingest.

on how spring water is produced, Scientist explained that "natural spring water treatment does not usually undergo flocculation but an aeration process may be done if necessary followed by a multi-stage microfiltration filtration process and then disinfected with ozone or UV sterilisation followed by bottling.

"Natural spring water is not treated with any chemicals including chlorine and is not usually permitted to be packed in sachets." They highlighted one of the major health benefits of drinking natural spring water. "Spring water serves as a ready natural source of important micronutrients (minerals) essential for good nutrition. These minerals are required to help the body to work properly and stay healthy. As such, spring water is best choice for health conscious individuals, who want to live active and healthy lives