Drainage Exam Questions With Complete Solutions
'Drain in common' meaning Correct Answers It is a drain that
serves several properties
150 drain is to be laid in a trench what is the minimum width of
the trench Correct Answers 350mm
A new installation is to have a waste pump list three conditions
regarding the waste product that should be considered in
selecting the typ of pump Correct Answers Temperature
Volume
Corrosive properties
A petroleum driven pump is to be used to dewater a trench give
two precautions that should be taken to safeguard workers
Correct Answers Motor will not discharge exhaust fumes into
the trench
Ventilate the trench
Check that dewatering does not make the trench walls unstable
A section of a drain has begun to regularly block give three
causes of this Correct Answers Tree roots.
Backfill.
Penetrations.
Aerobic Correct Answers Oxygen is present for the chemical
reaction
,All drains should be subjected to a visual inspection before other
test are done give four aspects that can be checked during the
visual inspection Correct Answers Pipes straight
Pipes are correct grade
Pipes not damaged
Anaerobic Correct Answers Oxygen is not present for the
chemical reaction
Anchor blocks are to be installed on a drain state two factors that
must be met with regard to where on the drain the anchor blocks
must be located Correct Answers 1. At the top and bottom
2. At intervals not exceeding 3m
AS/NZS 3500 part 2 sanitary plumbing and drainage gives
factors that must be considered when installing overflow relief
gullies Correct Answers Within the boundaries of the property.
External to the building.
So that the top of the gully is accessible.
Where the discharge will be noticeable.
150mm below the overflow/flood point of the lowest fixture.
Asbestos may be either friable or non friable give meaning of
each term Correct Answers Friable= the asbestos crumbles
Non-friable= the asbestos does not crumble
Black water meaning Correct Answers Water that contains
human waste
Describe safety precautions that must be taken prior to
resuscitation Correct Answers Make the area safe to work in it
, is important that a double accident doesn't occur. Turn off any
electricity and support or remove any crushing load
Describe the process of transpiration in relation to an effluent
disposal system Correct Answers Plants absorb liquid through
roots and then the liquid is released through the leaves
Describe the process that occurs in a septic tanks aerated
chamber Correct Answers Air introduced into the chamber so
that aerobic bacteria work more efficiently
Describe three situations when a foul water drain must be vented
Correct Answers Every main drain.
Septic tanks.
Grease traps.
When a boundary trap is installed
Describe two faults that may occur when a drain is not correctly
backfilled Correct Answers The pipe may flatten
The pipe may float
Joints in pipe may fail
Describe when the installation of a bubble up chamber is
required Correct Answers When the correct gradient cannot be
achieved
Displacement system/ charge system Correct Answers Holds
water all the time as new water flows in the stored water is
pushed out
'Drain in common' meaning Correct Answers It is a drain that
serves several properties
150 drain is to be laid in a trench what is the minimum width of
the trench Correct Answers 350mm
A new installation is to have a waste pump list three conditions
regarding the waste product that should be considered in
selecting the typ of pump Correct Answers Temperature
Volume
Corrosive properties
A petroleum driven pump is to be used to dewater a trench give
two precautions that should be taken to safeguard workers
Correct Answers Motor will not discharge exhaust fumes into
the trench
Ventilate the trench
Check that dewatering does not make the trench walls unstable
A section of a drain has begun to regularly block give three
causes of this Correct Answers Tree roots.
Backfill.
Penetrations.
Aerobic Correct Answers Oxygen is present for the chemical
reaction
,All drains should be subjected to a visual inspection before other
test are done give four aspects that can be checked during the
visual inspection Correct Answers Pipes straight
Pipes are correct grade
Pipes not damaged
Anaerobic Correct Answers Oxygen is not present for the
chemical reaction
Anchor blocks are to be installed on a drain state two factors that
must be met with regard to where on the drain the anchor blocks
must be located Correct Answers 1. At the top and bottom
2. At intervals not exceeding 3m
AS/NZS 3500 part 2 sanitary plumbing and drainage gives
factors that must be considered when installing overflow relief
gullies Correct Answers Within the boundaries of the property.
External to the building.
So that the top of the gully is accessible.
Where the discharge will be noticeable.
150mm below the overflow/flood point of the lowest fixture.
Asbestos may be either friable or non friable give meaning of
each term Correct Answers Friable= the asbestos crumbles
Non-friable= the asbestos does not crumble
Black water meaning Correct Answers Water that contains
human waste
Describe safety precautions that must be taken prior to
resuscitation Correct Answers Make the area safe to work in it
, is important that a double accident doesn't occur. Turn off any
electricity and support or remove any crushing load
Describe the process of transpiration in relation to an effluent
disposal system Correct Answers Plants absorb liquid through
roots and then the liquid is released through the leaves
Describe the process that occurs in a septic tanks aerated
chamber Correct Answers Air introduced into the chamber so
that aerobic bacteria work more efficiently
Describe three situations when a foul water drain must be vented
Correct Answers Every main drain.
Septic tanks.
Grease traps.
When a boundary trap is installed
Describe two faults that may occur when a drain is not correctly
backfilled Correct Answers The pipe may flatten
The pipe may float
Joints in pipe may fail
Describe when the installation of a bubble up chamber is
required Correct Answers When the correct gradient cannot be
achieved
Displacement system/ charge system Correct Answers Holds
water all the time as new water flows in the stored water is
pushed out
