AK WATER TREATMENT CONTRACTOR EXAM
QUESTIONS AND CORRECT ANSWERS (VERIFED
ANSWERS) Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a water treatment system?
A. Increase water hardness
B. Remove or control contaminants so water is suitable for its
intended use
C. Add suspended solids
D. Reduce water pressure
Correct answer: B. Remove or control contaminants so water is
suitable for its intended use.
Rationale: Water treatment is designed to reduce physical,
chemical, and biological contaminants and produce water that
meets applicable quality requirements.
2. Which characteristic describes water that contains visible
particles suspended throughout it?
A. Turbidity
B. Alkalinity
C. Hardness
D. Conductivity
Correct answer: A. Turbidity.
,Rationale: Turbidity is caused by suspended particles that
scatter light and make water appear cloudy.
3. What is the main purpose of coagulation in conventional
water treatment?
A. Kill all microorganisms immediately
B. Convert dissolved oxygen into chlorine
C. Destabilize and aggregate small suspended particles
D. Increase water temperature
Correct answer: C. Destabilize and aggregate small suspended
particles.
Rationale: Coagulants destabilize colloidal particles so they can
combine into larger particles during flocculation.
4. What is flocculation?
A. Rapid heating of water
B. Gentle mixing that encourages particles to form larger flocs
C. Removal of chlorine
D. Measurement of pH
Correct answer: B. Gentle mixing that encourages particles to
form larger flocs.
Rationale: Flocculation follows coagulation and uses controlled
mixing to bring destabilized particles together.
,5. What is the purpose of sedimentation?
A. Allow heavier floc particles to settle
B. Add oxygen to water
C. Increase hardness
D. Sterilize filters
Correct answer: A. Allow heavier floc particles to settle.
Rationale: Sedimentation removes settleable solids by gravity
before the water proceeds to later treatment stages.
6. Which treatment process is primarily designed to remove
suspended particles by passing water through a porous
medium?
A. Filtration
B. Aeration
C. Chlorination
D. Fluoridation
Correct answer: A. Filtration.
Rationale: Filters physically retain particles and may also
provide biological or chemical removal depending on the filter
type.
7. What is the main purpose of disinfection?
, A. Increase turbidity
B. Control disease-causing microorganisms
C. Increase suspended solids
D. Remove all minerals
Correct answer: B. Control disease-causing microorganisms.
Rationale: Disinfection reduces pathogenic microorganisms to
protect public health.
8. Which chemical is commonly used as a drinking-water
disinfectant?
A. Chlorine
B. Sand
C. Sodium chloride only
D. Calcium carbonate only
Correct answer: A. Chlorine.
Rationale: Chlorine and chlorine-based compounds are widely
used because they provide effective microbial control and can
maintain a residual.
9. What is chlorine demand?
A. The amount of chlorine consumed by reactions in the water
B. The total volume of water in a tank
C. The pressure required to pump water
D. The amount of sand in a filter
QUESTIONS AND CORRECT ANSWERS (VERIFED
ANSWERS) Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a water treatment system?
A. Increase water hardness
B. Remove or control contaminants so water is suitable for its
intended use
C. Add suspended solids
D. Reduce water pressure
Correct answer: B. Remove or control contaminants so water is
suitable for its intended use.
Rationale: Water treatment is designed to reduce physical,
chemical, and biological contaminants and produce water that
meets applicable quality requirements.
2. Which characteristic describes water that contains visible
particles suspended throughout it?
A. Turbidity
B. Alkalinity
C. Hardness
D. Conductivity
Correct answer: A. Turbidity.
,Rationale: Turbidity is caused by suspended particles that
scatter light and make water appear cloudy.
3. What is the main purpose of coagulation in conventional
water treatment?
A. Kill all microorganisms immediately
B. Convert dissolved oxygen into chlorine
C. Destabilize and aggregate small suspended particles
D. Increase water temperature
Correct answer: C. Destabilize and aggregate small suspended
particles.
Rationale: Coagulants destabilize colloidal particles so they can
combine into larger particles during flocculation.
4. What is flocculation?
A. Rapid heating of water
B. Gentle mixing that encourages particles to form larger flocs
C. Removal of chlorine
D. Measurement of pH
Correct answer: B. Gentle mixing that encourages particles to
form larger flocs.
Rationale: Flocculation follows coagulation and uses controlled
mixing to bring destabilized particles together.
,5. What is the purpose of sedimentation?
A. Allow heavier floc particles to settle
B. Add oxygen to water
C. Increase hardness
D. Sterilize filters
Correct answer: A. Allow heavier floc particles to settle.
Rationale: Sedimentation removes settleable solids by gravity
before the water proceeds to later treatment stages.
6. Which treatment process is primarily designed to remove
suspended particles by passing water through a porous
medium?
A. Filtration
B. Aeration
C. Chlorination
D. Fluoridation
Correct answer: A. Filtration.
Rationale: Filters physically retain particles and may also
provide biological or chemical removal depending on the filter
type.
7. What is the main purpose of disinfection?
, A. Increase turbidity
B. Control disease-causing microorganisms
C. Increase suspended solids
D. Remove all minerals
Correct answer: B. Control disease-causing microorganisms.
Rationale: Disinfection reduces pathogenic microorganisms to
protect public health.
8. Which chemical is commonly used as a drinking-water
disinfectant?
A. Chlorine
B. Sand
C. Sodium chloride only
D. Calcium carbonate only
Correct answer: A. Chlorine.
Rationale: Chlorine and chlorine-based compounds are widely
used because they provide effective microbial control and can
maintain a residual.
9. What is chlorine demand?
A. The amount of chlorine consumed by reactions in the water
B. The total volume of water in a tank
C. The pressure required to pump water
D. The amount of sand in a filter
