Q.
a) Explain the two-pipe system for soil and waste disposal. (15 marks)
b) Explain using schematic diagram the water treatment process from intake source to consumer distribution. (10 marks)
(20 marks, 2017 Q5)
A.
a) 2-pipe system
Various types of pipe system is illustrated in
In the picture above, soil pipe (human waste) is independent of the domestic waste (bath water & kitchen waste) piping system. Two pipe system means these two wastes do not mix.
Two-pipe drainage system
Primarily found in houses built before the late 1950s, in a two-pipe system the WC waste is fed into a large diameter vertical soil pipe, separate to the other waste water. The key features of this system are:
- WC waste is fed into a large bore soil pipe, which leads directly to the sewage network, and often runs down the outside wall of a property
- Remaining waste waters from washbasins, bath and kitchen sink etc are combined via separate smaller bore branch pipes in a gully just below ground level
- To prevent back siphoning and to discharge any gases from the drains, the large soil pipe is vented to the outside above the guttering
- All appliances contain a u-bend trap full of water to prevent drain smells penetrating the house
- The waste from the gully finally meets the soil water a short distance from the property on its way to the sewers
- At this meeting point will be an inspection chamber with a manhole cover
b) Water treatment process.
Similar question was asked in
2013 Q2
Ref: