1|Page
Water Treatment Plant Operation chapter 1 plant
operator QUESTIONS AND CORRECT DETAILED
ANSWERS VERIFIED ANSWERS) |ALREADY
GRADED A+
What is used as a chemical coagulant? - .....ANSWER
...✔✔ Alum
The correct order of treatment in a surface water plant
is... - .....ANSWER ...✔✔ Coagulation, Flocculation,
Sedimentation and Filtration
In determining the proper dosage of alum, the most
useful test is the____________ test. - .....ANSWER
...✔✔ Jar
If sludge is not continually removed from the
sedimentation basin, its accumulation results in? -
.....ANSWER ...✔✔ Turbidity
The most widely used coagulant is.... - .....ANSWER
...✔✔ Aluminum sulfate
,2|Page
Optimum flocculation requires: - .....ANSWER ...✔✔
Gentle Agitation
Dissolved iron in excessive amounts results in consumer
complaints about: - .....ANSWER ...✔✔ Turbidity
The most important raw water constituent for a surface
water plant is.... - .....ANSWER ...✔✔ Turbidity
Turbidity in water is cause by the presence of..... -
.....ANSWER ...✔✔ Suspended materials
The main purpose of the jar test is to determine the best:
- .....ANSWER ...✔✔ Coagulant dosage
The formation of chlorine ice affects chlorine feed rate.
This can be prevented by: - .....ANSWER ...✔✔
Decreasing the rate of chlorine withdrawal
The fusible metal plug on a chlorine cylinder is designed
to open at what temperature range? - .....ANSWER
...✔✔ 157F-162F
,3|Page
A lantern ring is a.... - .....ANSWER ...✔✔ spacer ring
in a pump packing gland
When backwashing a filter, the backwash valve should
be opened slowly to prevent.... - .....ANSWER ...✔✔
Sand boils
Suction lift refers to the pressure difference between the
center line of the pump.... - .....ANSWER ...✔✔ down
to the hydraulic grade line
The parameter used to describe the roughness of the
pipe interiors is called? - .....ANSWER ...✔✔ C factor
Prechlorination of raw water can lead to an interaction
of chlorine with organic matter which can form? -
.....ANSWER ...✔✔ Trihalomethanes
What is the main purpose of the coagulation and
flocculation process? - .....ANSWER ...✔✔ To remove
turbidity
, 4|Page
What conditions most affect coagulation performance? -
.....ANSWER ...✔✔ Velocity, water temperature,
detention time and coagulant dosage
What would be the best indicator that the filter should
be backwashed? - .....ANSWER ...✔✔ Filter effluent
turbidity
The most crucial element of effective filter performance
is... - .....ANSWER ...✔✔ proper backwashing
What is the chemical formula for calcium hypochlorite? -
.....ANSWER ...✔✔ Ca(OCI)2
A violation of the MCL for total trihalomethanes occurs
when? - .....ANSWER ...✔✔ The running average of
quarterly samples during the previous 12 months
exceeds the MCL.
CT is defined as.... - .....ANSWER ...✔✔ The product
of residual disinfectant concentration and contact time of
the disinfectant with the water.
Water Treatment Plant Operation chapter 1 plant
operator QUESTIONS AND CORRECT DETAILED
ANSWERS VERIFIED ANSWERS) |ALREADY
GRADED A+
What is used as a chemical coagulant? - .....ANSWER
...✔✔ Alum
The correct order of treatment in a surface water plant
is... - .....ANSWER ...✔✔ Coagulation, Flocculation,
Sedimentation and Filtration
In determining the proper dosage of alum, the most
useful test is the____________ test. - .....ANSWER
...✔✔ Jar
If sludge is not continually removed from the
sedimentation basin, its accumulation results in? -
.....ANSWER ...✔✔ Turbidity
The most widely used coagulant is.... - .....ANSWER
...✔✔ Aluminum sulfate
,2|Page
Optimum flocculation requires: - .....ANSWER ...✔✔
Gentle Agitation
Dissolved iron in excessive amounts results in consumer
complaints about: - .....ANSWER ...✔✔ Turbidity
The most important raw water constituent for a surface
water plant is.... - .....ANSWER ...✔✔ Turbidity
Turbidity in water is cause by the presence of..... -
.....ANSWER ...✔✔ Suspended materials
The main purpose of the jar test is to determine the best:
- .....ANSWER ...✔✔ Coagulant dosage
The formation of chlorine ice affects chlorine feed rate.
This can be prevented by: - .....ANSWER ...✔✔
Decreasing the rate of chlorine withdrawal
The fusible metal plug on a chlorine cylinder is designed
to open at what temperature range? - .....ANSWER
...✔✔ 157F-162F
,3|Page
A lantern ring is a.... - .....ANSWER ...✔✔ spacer ring
in a pump packing gland
When backwashing a filter, the backwash valve should
be opened slowly to prevent.... - .....ANSWER ...✔✔
Sand boils
Suction lift refers to the pressure difference between the
center line of the pump.... - .....ANSWER ...✔✔ down
to the hydraulic grade line
The parameter used to describe the roughness of the
pipe interiors is called? - .....ANSWER ...✔✔ C factor
Prechlorination of raw water can lead to an interaction
of chlorine with organic matter which can form? -
.....ANSWER ...✔✔ Trihalomethanes
What is the main purpose of the coagulation and
flocculation process? - .....ANSWER ...✔✔ To remove
turbidity
, 4|Page
What conditions most affect coagulation performance? -
.....ANSWER ...✔✔ Velocity, water temperature,
detention time and coagulant dosage
What would be the best indicator that the filter should
be backwashed? - .....ANSWER ...✔✔ Filter effluent
turbidity
The most crucial element of effective filter performance
is... - .....ANSWER ...✔✔ proper backwashing
What is the chemical formula for calcium hypochlorite? -
.....ANSWER ...✔✔ Ca(OCI)2
A violation of the MCL for total trihalomethanes occurs
when? - .....ANSWER ...✔✔ The running average of
quarterly samples during the previous 12 months
exceeds the MCL.
CT is defined as.... - .....ANSWER ...✔✔ The product
of residual disinfectant concentration and contact time of
the disinfectant with the water.
