Internal Building Drainage

Question 1

Types of water to be disposed

Answer 1

1. Soil water: human waste
2. Waste water: without human waste
3. Rain water: rainfall collected from open areas

Question 2

Waste water

Answer 2

Mainly collected from wash basins, kitchen sinks, bath tubs, washing machines, etc…
The sanitary fitments discharging waste water is called waste fitments

Question 3

Soil water

Answer 3

Collected from soil sanitary fitments(closets, urinal bowls…) called soil fitments. Can be mixed with waste water (also soil water)

Question 4

Rainwater

Answer 4

Collected from open spaces. Outlets are provided at the open spaces for collecting. Excessive accumulation will increase structural load of the roof.

Question 5

Drainage pipework

Answer 5

1. Soil pipe material suitable for seawater, cast iron, vitrified clay pipe, uPVC pipe
2. Waste pipe galvanised steel pipe, cast iron pipe, uPVC pipe
3. Rainwater pipe: cast iron pipe, uPVC pipe, concrete pipe

Question 6

What is the problem with Kitchen Waste water? How to prevented?

Answer 6

Grease content may accumulate inside the drain pipe clogging the drain pipe.treated before connected to the drainage system

Question 7

Grease trap/ interceptor

Answer 7

Devise to separate the grease from the k.w.water.
Increases travel time
Provides longer time to allow the grease separate by bouyancy

Question 8

Grease trap retention time in Hk

Answer 8

20 min

Question 9

Remove grease period in HK

Answer 9

Once every 2 weeks. Manually of by vacuum machine

Question 10

When treat the Carpark waste water?

Answer 10

Treated before disposing to the soil waste water system