Grade 4 Water Treatment Exam Prep questions
and answers with solutions 2025/2026
In a pumping station where two complete pumping units are provided,
how much should a pump be capable of delivering?
a.) Average Flow
b.) Maximum Flow
c.) 1/2 the average flow
d.) 1/2 maximum flow - ANSWER A
When there is insufficient alkalinity present in water to react with the
coagulant, alkalinity should be supplied by
a.) Adding Lime
b.) Adding Turbidity
c.) Reducing plant flow
d.) Removing carbon dioxide - ANSWER A
Chlorine dioxide is generated on-site by the reaction of chlorine with
what chemical?
,a.) Oxygen
b.) Sodium Chlorite
c.) Salt Brine
d.) Carbon - ANSWER B
Why is carbon dioxide primarily used in the stabilization process?
a.) Decrease pH
b.) Increase pH
c.) Tie up scale forming ions
d.) Form a protective coating - ANSWER A
If fluoride is fed ahead of filtration what can occur?
a.) Some fluoride loss
b.) Problems with disinfection
c.) Increases in fluoride concentration
d.) Formation of precipitate - ANSWER A
Which of the following emergency leak repair kits should be on hand for
ton cylinders?
a.) Emergency Kit A
,b.) Emergency Kit B
c.) Emergency Kit C
d.) Emergency Kit D - ANSWER B
What will iron that remains in the ferrous state do?
a.) Be removed by filters
b.) Pass through the filters
c.) Precipitate in the reaction tank
d.) Settle out - ANSWER B
Short circuiting in the flocculation process can be corrected by
a.) Adjusting the pH
b.) Decreasing the flows
c.) Increasing coagulant dosages
d.) Providing several compartments in series - ANSWER D
What removes organic substances from depleted activated carbon?
a.) Degasification
b.) Recarbonation
c.) Reduction
, d.) Reactivation - ANSWER D
What is the purpose of an anti-siphon valve on a fluoride metering
pump?
a.) The same as that of the overflow connection on the supply
b.) To prevent fluoridated water from being siphoned into the feed
equipment
c.) To prevent potential overfeed of fluoride
d.) The same as that of a vacuum breaker on the potable makeup water
line - ANSWER B
A perfectly uniform sand would have a uniformity coefficient of
a.) 0
b.) 1
c.) 1.5
d.) 1.7 - ANSWER C
When handling any dry fluoride compound one important safety
precaution that should be observed is to
a.) Have another operator near by
b.) Keep all windows closed to prevent the escape of dangerous dusts
into the environment
and answers with solutions 2025/2026
In a pumping station where two complete pumping units are provided,
how much should a pump be capable of delivering?
a.) Average Flow
b.) Maximum Flow
c.) 1/2 the average flow
d.) 1/2 maximum flow - ANSWER A
When there is insufficient alkalinity present in water to react with the
coagulant, alkalinity should be supplied by
a.) Adding Lime
b.) Adding Turbidity
c.) Reducing plant flow
d.) Removing carbon dioxide - ANSWER A
Chlorine dioxide is generated on-site by the reaction of chlorine with
what chemical?
,a.) Oxygen
b.) Sodium Chlorite
c.) Salt Brine
d.) Carbon - ANSWER B
Why is carbon dioxide primarily used in the stabilization process?
a.) Decrease pH
b.) Increase pH
c.) Tie up scale forming ions
d.) Form a protective coating - ANSWER A
If fluoride is fed ahead of filtration what can occur?
a.) Some fluoride loss
b.) Problems with disinfection
c.) Increases in fluoride concentration
d.) Formation of precipitate - ANSWER A
Which of the following emergency leak repair kits should be on hand for
ton cylinders?
a.) Emergency Kit A
,b.) Emergency Kit B
c.) Emergency Kit C
d.) Emergency Kit D - ANSWER B
What will iron that remains in the ferrous state do?
a.) Be removed by filters
b.) Pass through the filters
c.) Precipitate in the reaction tank
d.) Settle out - ANSWER B
Short circuiting in the flocculation process can be corrected by
a.) Adjusting the pH
b.) Decreasing the flows
c.) Increasing coagulant dosages
d.) Providing several compartments in series - ANSWER D
What removes organic substances from depleted activated carbon?
a.) Degasification
b.) Recarbonation
c.) Reduction
, d.) Reactivation - ANSWER D
What is the purpose of an anti-siphon valve on a fluoride metering
pump?
a.) The same as that of the overflow connection on the supply
b.) To prevent fluoridated water from being siphoned into the feed
equipment
c.) To prevent potential overfeed of fluoride
d.) The same as that of a vacuum breaker on the potable makeup water
line - ANSWER B
A perfectly uniform sand would have a uniformity coefficient of
a.) 0
b.) 1
c.) 1.5
d.) 1.7 - ANSWER C
When handling any dry fluoride compound one important safety
precaution that should be observed is to
a.) Have another operator near by
b.) Keep all windows closed to prevent the escape of dangerous dusts
into the environment
