CHAPTER 7: Drainage system

How often must a cleanout be installed on a horizontal drainage pipe?

• a) Every 10 meters

• b) Every 15 meters

• c) Every 20 meters

• d) Every 25 meters

Where must an additional cleanout be installed?

• a) On any horizontal line exceeding a 90-degree offset

• b) On any horizontal line with an aggregate offset angle of more than 135 degrees

• c) At the highest point of a vertical stack

• d) Next to every plumbing fixture

What is the minimum slope required for horizontal excreta drainage piping less than 102 mm in diameter?

• a) 0.5%

• b) 1%

• c) 2%

• d) 5%

A 102 mm pipe or larger may have a reduced slope of 1% instead of 2% if:

• a) Approved by the Administrative Authority

• b) The slope exceeds 10%

• c) The pipe is installed underground

• d) There are no structural obstructions

How far must a fixture outlet be from a suds-producing fixture stack before connection?

• a) 1.2 meters

• b) 2.4 meters

• c) 3.6 meters

• d) 5.0 meters

If a fixture is below the upstream manhole invert level, how must it be protected?

• a) By installing an approved backwater valve

• b) By connecting directly to the main sewer

• c) By ensuring the fixture is at least 1 meter above the manhole level

• d) By using a vent stack

How many water closets are allowed on one vertical stack?

• a) 2

• b) 4

• c) 6

• d) 8

The minimum vent pipe diameter must be:

• a) 25 mm

• b) 32 mm

• c) 50 mm

• d) 76 mm

What type of cleanout should be installed where raised heads may pose a hazard?

• a) Standard cleanout plug

• b) Countersunk cleanout plug

• c) Blind cleanout plug

• d) Hubless cleanout

Which of the following buildings are EXEMPT from the 2.4m suds relief rule?

• a) Commercial buildings

• b) Apartment complexes

• c) Single-family residences

• d) Factories