Question

5. You are planning a water supply scheme in an area where you have both surface and sub-surface water resources. Disucss the factors which you will take into account to seclect one of the soruces for your scheme/project.

Answer 1

Taking surface sources of water into account, the factors affecting the planning of water supply scheme are the following

Surface water is any body of water above ground including streams, rivers, lakes, wetlands, reservoirs etc.

1.water quality

Water has a strong tendancy to dissolve other substance so that it is rarely fond pure in nature.In populated area surface water is contaminated due to pestisides, fertilizers, road deicing chemicals or motor oils. This can flow into the rin runoff and contaminate the surface water.

2. Health concerns

Organic chemicals, inorganic chemicals, micro organisms, turbidity and radio active substances are the impurities associated with the health concerns. water treatment process enables the system to reduce the concentration of impure substances in the water . The most important micro biological measure of drinking water is a group of bacteria called Coliforms.If coliforms are not found in water it is considereed as 0 pathogens water.

3. Aesthetic concerns

Color, taste, odour are are physical characteristics that are important for aesthetic reasons raher than health concerns. Color in water may be caused by decaying leaves or algae giving it a brown yellowish hue. Taste and odour may be caused by naturally occuring dissolved organics or gases.Dissolved metal imparts a bitter taste to water an chloride cause an objectionable salty taste.

4. Hardness

Hardness of water is nothing but the presence of minerals (calsium and magnesium). Hardwater does not cause nay harm to human health but it causes a small scal deposit in hot water pipe and also causes latherng of soap etc

5.Standards

Water quality standards set a limits to the concenteration of impurities allowed in water. standards also affects the choice of water treatment process and selection of water sources.

6. Municipal water consumption

Without making any harm to the nature we have to consume water for water supply scheme. consume the water resources as per the allowable standards and without violating any regulations. There are two type of consumtion : domestic demand and public demand however this two are depending upon the population of the area.

7.Water treatment
The water should crystal clear, with almost no turbidity, and it should be free from objectionable color, odour and taste. For domestic purpose water should be free from corrosive elements, should not cause any scale deposit on plumbing fixtures. industrial requirement may be even more stringent, many industries provide water treatmnet on thier own premises