What’s in the water?
In its purest form, water is simply H2O; that is, two atoms of hydrogen attached to each atom of oxygen. Because water is such a good solvent, in the environment it will always contain dissolved or suspended impurities.
The types of impurities found in water can be divided into four groups: microbial (microorganisms), physical, chemical, and radiological.
Having impurities in drinking water is not necessarily a bad thing — many constituents of normal drinking water are harmless or even desirable. For example, the minerals calcium and magnesium, which can enter water from soil and rocks, are good for human health and give the water a pleasant taste.
Other impurities can affect the aesthetic qualities of water such as appearance, taste, smell and ‘feel’. Such impurities are not necessarily hazardous to human health. In fact, the taste, smell and appearance of water is not a good guide to its safety. Water that is cloudy, has a distinctive odour or has a strong taste is not necessarily harmful to health, while clear, pleasant tasting water may still contain harmful microorganisms.
While not all impurities are a problem, some have serious health consequences.