Quality of Water
Quality of water is the most important aspect. There are international and nationalstandards for the quality of water to be supplied for human consumption. The stategovernments may have a slight relaxation in the standards depending upon the localconditions but in general they are the same throughout the country.The main aim of the public health engineering departments or the environmentalengineering departments as they are called these days is to supply safe and palatable(good in taste) water to the consumers. Water should also be free from any odour.The temperature of water should be reasonably good. It should neither be corrosivenor scale forming and should be free from minerals that can produce undesirablephysiological effects. For achieving this ideal condition the minimum standards ofquality are to be established. The evolution of standards for the control of qualityof public water supplies has to consider the limitations imposed by the local factorsin the different regions of the country. As per the Manual on Water Supply andTreatment published by the Government of India, the main objective is to makewater absolutely free from risks of transmitting disease, means safety is compulsorywhere as the other qualities are to be maintained within a specified range. Forexample water may have dissolved solids upto 500 mg per litre but cannot haveany bacteria or other micro organism. Actually water is a very good carrier of manydiseases producing organisms (pathogens) as there are all chances of its gettingcontaminated (infected by pathogens). If a small drop of urine or fecal matter(excreta, nightoil) is mixed in a body of water (canal, pond etc.) and the personcontributing it has some disease like cholera, gastroentitis, infectious hepatitis jaundice, typhoid, etc., it will infect the stream. Anybody using that water withouttreatment (disinfection) is liable to catch the same disease. Sometimes the foul wastewater (from latrines, toilets etc.) goes down the earth and gets mixed (at a shallowdepth) with the ground water it pollutes it. If this ground water lifted by a handpump or a tube-well is used again without disinfect ion it shall cause disease inthe person using it. Sometimes the dissolved salts may produce some other diseaseslike fluorosis (due to excessive fluoride) mathemaglobinemia (blue baby disease) dueto excessive nitrates in, infants) etc. So water must not have the physical, chemicaland bacteriological parameters beyond limits.
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