Housing and Space Management

Housing And Space Management 3(2+1)

Lesson 24 : Water Supply System

Water supply sources

• All water supplies originate as rainfall.
• Rain-water on reaching earth, part of it is held by the top soil to feed vegetation, but the remainder either falls upon impervious surfaces or percolates through the earth, and it is from these sources that we obtain water supplies.

  The various sources of water can be classified into two categories: Surface sources, such as Ponds and lakes; Streams and rivers; Storage reservoirs; and Oceans, generally not used for water supplies, The sources such as rivers, lakes or impounding reservoirs are a more common source of water for most metropolitan areas.

  Sub-surface sources or underground sources, such as springs; Infiltration wells; and Wells and Tube-wells. Ground-Water supplies seem to be more attractive from the water-quality standpoint. It has a relatively stable chemical composition, contains little or no bacteria, and is free from colour, turbidity and suspended matter. It often carries a substantial proportion of iron and manganese as dissolved salts. In addition, ground-water supplies are subject to water-level declines and are usually limited

• The domestic water supply system should provide water for drinking, cooking, washing, laundering, water-closet flushing, cleaning and the like and it could be through local system or central system.

Water Quality:

• The quantity and quality of the water that we have access to use is directly linked to health.
• About 85 % of rural population and in India is solely depended on ground water which is depleting at a fast rate, while 60 percent depend on surface water.
• Chemical contaminants namely fluoride, arsenic and selenium pose a very serious health hazard in the country and is estimated that about 70 million people in 20 states are at risk due to excess fluoride and around 10 million people are at risk due to excess arsenic in ground water.
• Also, pollution of ground and surface waters from agrochemicals (fertilizers and pesticides) and from industry poses a major environmental health hazard.
• Surface water generally requires treatment before consumption as it is easily contaminated by fecal and organic matter and carries silt. .
• Drinking water or potable water is water of sufficiently high quality that can be consumed or used without risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually consumed or used in food preparation.