Q. Write short notes on the following :

a) Points to be kept in mind while collecting water samples for testing from tap, stream & T/well separately.

b) Where and why foot valve, check valve & gate valve to be provided for efficient running of pumps & maintaining the discharge in pipe line.

c) What do you under stand by ‘Self Cleaning Velocity' in a sewer design. Explain how ‘Egg shaped' sewer lines are superior in comparison with ‘ Circular' sewer lines.

d) Explain so as to why provision of ‘Man holes' is considered important/ necessary in laying a sewer line net work system.

e) Explain the functioning of a ‘Septic tank' in a sewerage disposal system with a sketch.