Water Treatment Operator Test Questions with
Correct Answers
What is used as a chemical coagulant?
Alum
The correct order of treatment in a surface water plant is...
Coagulation, Flocculation, Sedimentation and Filtration
In determining the proper dosage of alum, the most useful test is the____________ test.
Jar
If sludge is not continually removed from the sedimentation basin, its accumulation
results in?
Turbidity
The most widely used coagulant is....
Aluminum sulfate
Optimum flocculation requires:
Gentle Agitation
Dissolved iron in excessive amounts results in consumer complaints about:
Turbidity
The most important raw water constituent for a surface water plant is....
Turbidity
Turbidity in water is cause by the presence of.....
,Suspended materials
The main purpose of the jar test is to determine the best:
Coagulant dosage
The formation of chlorine ice affects chlorine feed rate. This can be prevented by:
Decreasing the rate of chlorine withdrawal
The fusible metal plug on a chlorine cylinder is designed to open at what temperature
range?
157F-162F
A lantern ring is a....
spacer ring in a pump packing gland
When backwashing a filter, the backwash valve should be opened slowly to prevent....
Sand boils
Suction lift refers to the pressure difference between the center line of the pump....
down to the hydraulic grade line
The parameter used to describe the roughness of the pipe interiors is called?
C factor
Prechlorination of raw water can lead to an interaction of chlorine with organic matter
which can form?
Trihalomethanes
What is the main purpose of the coagulation and flocculation process?
, To remove turbidity
What conditions most affect coagulation performance?
Velocity, water temperature, detention time and coagulant dosage
What would be the best indicator that the filter should be backwashed?
Filter effluent turbidity
The most crucial element of effective filter performance is...
proper backwashing
What is the chemical formula for calcium hypochlorite?
Ca(OCI)2
A violation of the MCL for total trihalomethanes occurs when?
The running average of quarterly samples during the previous 12 months exceeds the MCL.
CT is defined as....
The product of residual disinfectant concentration and contact time of the disinfectant with
the water.
What would the pH of water be that had the highest concentration of hypochlorous
acid?
pH of 10, optimum range is pH of 5
What is the solution used to regenerate a zeolite softening unit?
Sodium chloride solution or NaCL
Langelier's index is used to determine
Correct Answers
What is used as a chemical coagulant?
Alum
The correct order of treatment in a surface water plant is...
Coagulation, Flocculation, Sedimentation and Filtration
In determining the proper dosage of alum, the most useful test is the____________ test.
Jar
If sludge is not continually removed from the sedimentation basin, its accumulation
results in?
Turbidity
The most widely used coagulant is....
Aluminum sulfate
Optimum flocculation requires:
Gentle Agitation
Dissolved iron in excessive amounts results in consumer complaints about:
Turbidity
The most important raw water constituent for a surface water plant is....
Turbidity
Turbidity in water is cause by the presence of.....
,Suspended materials
The main purpose of the jar test is to determine the best:
Coagulant dosage
The formation of chlorine ice affects chlorine feed rate. This can be prevented by:
Decreasing the rate of chlorine withdrawal
The fusible metal plug on a chlorine cylinder is designed to open at what temperature
range?
157F-162F
A lantern ring is a....
spacer ring in a pump packing gland
When backwashing a filter, the backwash valve should be opened slowly to prevent....
Sand boils
Suction lift refers to the pressure difference between the center line of the pump....
down to the hydraulic grade line
The parameter used to describe the roughness of the pipe interiors is called?
C factor
Prechlorination of raw water can lead to an interaction of chlorine with organic matter
which can form?
Trihalomethanes
What is the main purpose of the coagulation and flocculation process?
, To remove turbidity
What conditions most affect coagulation performance?
Velocity, water temperature, detention time and coagulant dosage
What would be the best indicator that the filter should be backwashed?
Filter effluent turbidity
The most crucial element of effective filter performance is...
proper backwashing
What is the chemical formula for calcium hypochlorite?
Ca(OCI)2
A violation of the MCL for total trihalomethanes occurs when?
The running average of quarterly samples during the previous 12 months exceeds the MCL.
CT is defined as....
The product of residual disinfectant concentration and contact time of the disinfectant with
the water.
What would the pH of water be that had the highest concentration of hypochlorous
acid?
pH of 10, optimum range is pH of 5
What is the solution used to regenerate a zeolite softening unit?
Sodium chloride solution or NaCL
Langelier's index is used to determine
