NEW JERSEY WATER TREATMENT OPERATOR T1
EXAM QUESTIONS AND ANSWERS | VERIFIED AND
WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE | EXAM
PREP | STUDY GUIDE | PRACTICE TEST
1. A surface water treatment plant experiences a sudden increase in raw water turbidity
following heavy rainfall. Which treatment process is primarily responsible for destabilizing
suspended particles before they are removed?
A. Coagulation
B. Chlorination
C. Fluoridation
D. Aeration
CORRECT ANSWER: A. Coagulation
RATIONALE :
Coagulation is the first major treatment step used to destabilize suspended particles by adding
chemicals such as alum or ferric salts. Once destabilized, the particles can combine into larger
flocs during flocculation and be removed through sedimentation and filtration.
2. What is the primary purpose of flocculation in a conventional water treatment plant?
A. Destroy microorganisms
B. Form larger, settleable flocs through gentle mixing
C. Increase water pressure
D. Remove dissolved oxygen
CORRECT ANSWER: B. Form larger, settleable flocs through gentle mixing
RATIONALE :
Flocculation follows coagulation and gently mixes the water so small destabilized particles
collide and form larger flocs that can settle more efficiently in sedimentation basins.
3. Which treatment process primarily removes suspended solids through gravity?
,A. Filtration
B. Sedimentation
C. Disinfection
D. Softening
CORRECT ANSWER: B. Sedimentation
RATIONALE :
Sedimentation allows heavier floc particles to settle to the bottom of the basin, significantly
reducing turbidity before filtration.
4. What is the primary function of rapid sand filtration?
A. Remove remaining suspended particles after sedimentation
B. Increase water hardness
C. Add disinfectant residual
D. Raise pH
CORRECT ANSWER: A. Remove remaining suspended particles after sedimentation
RATIONALE :
Rapid sand filters remove fine suspended particles that remain after coagulation, flocculation,
and sedimentation, producing clearer water before disinfection.
5. Which disinfectant is most commonly used to provide a residual disinfectant throughout
the distribution system?
A. Chlorine
B. Oxygen
C. Nitrogen
D. Carbon dioxide
CORRECT ANSWER: A. Chlorine
RATIONALE :
Chlorine is widely used because it effectively destroys pathogens and provides a measurable
residual that continues protecting water as it travels through the distribution system.
, 6. The cloudiness of water caused by suspended particles is called:
A. Turbidity
B. Hardness
C. Conductivity
D. Alkalinity
CORRECT ANSWER: A. Turbidity
RATIONALE :
Turbidity measures the amount of suspended material in water and is an important indicator
of treatment effectiveness.
7. Which chemical is commonly used as a coagulant in conventional water treatment?
A. Aluminum sulfate (alum)
B. Sodium chloride
C. Calcium carbonate
D. Sodium bicarbonate
CORRECT ANSWER: A. Aluminum sulfate (alum)
RATIONALE :
Aluminum sulfate (alum) is one of the most commonly used coagulants because it effectively
destabilizes suspended particles and promotes floc formation.
8. Why is filter backwashing performed?
A. To remove accumulated particles and restore filter efficiency
B. To disinfect the distribution system
C. To increase chlorine residual
D. To soften water
CORRECT ANSWER: A. To remove accumulated particles and restore filter efficiency
RATIONALE :
Backwashing reverses water flow through the filter to remove trapped solids, preventing
excessive head loss and maintaining filtration performance.
EXAM QUESTIONS AND ANSWERS | VERIFIED AND
WELL DETAILED ANSWERS | PLUS RATIONALES |
GUARANTEED PASS | LATEST EXAM UPDATE | EXAM
PREP | STUDY GUIDE | PRACTICE TEST
1. A surface water treatment plant experiences a sudden increase in raw water turbidity
following heavy rainfall. Which treatment process is primarily responsible for destabilizing
suspended particles before they are removed?
A. Coagulation
B. Chlorination
C. Fluoridation
D. Aeration
CORRECT ANSWER: A. Coagulation
RATIONALE :
Coagulation is the first major treatment step used to destabilize suspended particles by adding
chemicals such as alum or ferric salts. Once destabilized, the particles can combine into larger
flocs during flocculation and be removed through sedimentation and filtration.
2. What is the primary purpose of flocculation in a conventional water treatment plant?
A. Destroy microorganisms
B. Form larger, settleable flocs through gentle mixing
C. Increase water pressure
D. Remove dissolved oxygen
CORRECT ANSWER: B. Form larger, settleable flocs through gentle mixing
RATIONALE :
Flocculation follows coagulation and gently mixes the water so small destabilized particles
collide and form larger flocs that can settle more efficiently in sedimentation basins.
3. Which treatment process primarily removes suspended solids through gravity?
,A. Filtration
B. Sedimentation
C. Disinfection
D. Softening
CORRECT ANSWER: B. Sedimentation
RATIONALE :
Sedimentation allows heavier floc particles to settle to the bottom of the basin, significantly
reducing turbidity before filtration.
4. What is the primary function of rapid sand filtration?
A. Remove remaining suspended particles after sedimentation
B. Increase water hardness
C. Add disinfectant residual
D. Raise pH
CORRECT ANSWER: A. Remove remaining suspended particles after sedimentation
RATIONALE :
Rapid sand filters remove fine suspended particles that remain after coagulation, flocculation,
and sedimentation, producing clearer water before disinfection.
5. Which disinfectant is most commonly used to provide a residual disinfectant throughout
the distribution system?
A. Chlorine
B. Oxygen
C. Nitrogen
D. Carbon dioxide
CORRECT ANSWER: A. Chlorine
RATIONALE :
Chlorine is widely used because it effectively destroys pathogens and provides a measurable
residual that continues protecting water as it travels through the distribution system.
, 6. The cloudiness of water caused by suspended particles is called:
A. Turbidity
B. Hardness
C. Conductivity
D. Alkalinity
CORRECT ANSWER: A. Turbidity
RATIONALE :
Turbidity measures the amount of suspended material in water and is an important indicator
of treatment effectiveness.
7. Which chemical is commonly used as a coagulant in conventional water treatment?
A. Aluminum sulfate (alum)
B. Sodium chloride
C. Calcium carbonate
D. Sodium bicarbonate
CORRECT ANSWER: A. Aluminum sulfate (alum)
RATIONALE :
Aluminum sulfate (alum) is one of the most commonly used coagulants because it effectively
destabilizes suspended particles and promotes floc formation.
8. Why is filter backwashing performed?
A. To remove accumulated particles and restore filter efficiency
B. To disinfect the distribution system
C. To increase chlorine residual
D. To soften water
CORRECT ANSWER: A. To remove accumulated particles and restore filter efficiency
RATIONALE :
Backwashing reverses water flow through the filter to remove trapped solids, preventing
excessive head loss and maintaining filtration performance.
