Why should we test our drinking water

We get potable or drinking water in our cities through water   stored in water towers or that comes from a public resource such as a local lake or river which in turn is replenished from Ground Water, Surface Water or Rainwater. There is no guarantee that the water coming through these sources are free from any sort of contamination. When we drive by that lake or river and see people swimming and boating in that water, or when we see livestock in that water, we know that what comes out of animals goes right into the water that flows into the pipes that come to our homes or offices.
 
Water is in continuous movement on, above, and below the surface of the earth. As water is recycled through the earth, it picks up many things along its path. Water quality will vary from place to place, with the seasons, and with the various kinds of rock and soil it moves through.
For the most part, it is largely natural processes that affect water quality. For instance, water moving through underground rocks and soils may pick up natural contaminants, even with no human activity or pollution in the area. In addition to nature's influence, water is also polluted by human activities, such as open defecation, dumping garbage, poor agricultural practices, and chemical spills at industrial
 
 
Water testing can help let us know if the water we use is safe to use and healthy. In absence of a mechanism to confirm the quality of water, the likelihood is high that contaminated water can get through to our homes and introduce dangerous contaminants that could cause wide-ranging health problems. Many health issues that we blame on illness or allergies or that we have no explanation for at all are being caused by contamination in the water that could contain anything from farming fertilizer to pesticides to pharmaceutical products to animal feces.
Even though water may be clear, it does not necessarily mean that it is safe for us to drink. It is important for us to judge the safety of water by taking the following four  qualities into consideration
 
                   1.Microbiological – bacteria, viruses, protozoa, and worms
                   2.Chemical – minerals, metals and chemicals
                   3.Physical – temperature, color, smell, taste and turbidity
                       Safe drinking water should have the following microbiological, chemical and physical qualities:

• Free of pathogens
• Low in concentrations of toxic chemicals
• Clear
• Tasteless and colorles
             4. Radioactive contaminants – Uranium, Radium

When considering drinking water quality, microbiological contamination is the main concern in most cases since it is responsible for the majority of illnesses and deaths related to drinking unsafe water. 
 
In developing countries most of the diseases such as gastroenteritis, diarrhea, dysentery, cholera, enteric fever, etc. prevail due to unsafe drinking water clubbed with poor environmental sanitation. Water borne diseases cause many serious health problems to human around the world. The problem has more significance to the developing and under developed world, particularly in Africa, Asia and South America prevalence of water borne diseases is related to generally poor and unhealthy sanitary conditions as well as polluted environmental conditions.