AWWA WATER TREATMENT OPERATOR
CERTIFICATION GRADE 1 EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS Q&A
2026 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of water treatment?
A. To make water taste better only
B. To remove impurities and make water safe for consumption
C. To increase water pressure
D. To color water blue
Rationale: Water treatment ensures water is safe, clean, and
free from harmful contaminants.
Correct Answer: B
2. Which process removes suspended solids by allowing them
to settle?
A. Filtration
B. Coagulation
C. Sedimentation
D. Chlorination
Rationale: Sedimentation allows heavier particles to settle at
the bottom of a tank.
Correct Answer: C
,3. What chemical is most commonly used for disinfection in
water treatment plants?
A. Fluoride
B. Chlorine
C. Oxygen
D. Nitrogen
Rationale: Chlorine is widely used to kill pathogens in water.
Correct Answer: B
4. Coagulation in water treatment refers to:
A. Heating water
B. Adding chemicals to clump particles together
C. Freezing water
D. Filtering water through sand only
Rationale: Coagulation destabilizes particles so they can form
larger clumps.
Correct Answer: B
5. The process that removes fine particles by passing water
through a medium is called:
A. Sedimentation
B. Aeration
C. Filtration
D. Flocculation
,Rationale: Filtration uses materials like sand or gravel to
remove particles.
Correct Answer: C
6. Flocculation is best described as:
A. Rapid mixing of chemicals
B. Slow mixing to form larger particles (floc)
C. Boiling water
D. Adding chlorine only
Rationale: Flocculation gently mixes water to form larger
particle clumps.
Correct Answer: B
7. What is turbidity in water?
A. Water temperature
B. Cloudiness caused by suspended particles
C. Water color
D. Water pressure
Rationale: Turbidity indicates how clear or cloudy water is.
Correct Answer: B
8. Which unit is commonly used to measure turbidity?
, A. ppm
B. NTU
C. mg/L
D. psi
Rationale: NTU (Nephelometric Turbidity Units) measures
water clarity.
Correct Answer: B
9. The main purpose of a sedimentation tank is to:
A. Add chlorine
B. Store clean water
C. Allow solids to settle out of water
D. Increase water flow
Rationale: It allows gravity to separate solids from water.
Correct Answer: C
10. What is the role of activated carbon in water treatment?
A. Increase hardness
B. Remove taste and odor
C. Add minerals
D. Increase turbidity
Rationale: Activated carbon absorbs organic compounds
affecting taste and smell.
Correct Answer: B
CERTIFICATION GRADE 1 EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS Q&A
2026 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of water treatment?
A. To make water taste better only
B. To remove impurities and make water safe for consumption
C. To increase water pressure
D. To color water blue
Rationale: Water treatment ensures water is safe, clean, and
free from harmful contaminants.
Correct Answer: B
2. Which process removes suspended solids by allowing them
to settle?
A. Filtration
B. Coagulation
C. Sedimentation
D. Chlorination
Rationale: Sedimentation allows heavier particles to settle at
the bottom of a tank.
Correct Answer: C
,3. What chemical is most commonly used for disinfection in
water treatment plants?
A. Fluoride
B. Chlorine
C. Oxygen
D. Nitrogen
Rationale: Chlorine is widely used to kill pathogens in water.
Correct Answer: B
4. Coagulation in water treatment refers to:
A. Heating water
B. Adding chemicals to clump particles together
C. Freezing water
D. Filtering water through sand only
Rationale: Coagulation destabilizes particles so they can form
larger clumps.
Correct Answer: B
5. The process that removes fine particles by passing water
through a medium is called:
A. Sedimentation
B. Aeration
C. Filtration
D. Flocculation
,Rationale: Filtration uses materials like sand or gravel to
remove particles.
Correct Answer: C
6. Flocculation is best described as:
A. Rapid mixing of chemicals
B. Slow mixing to form larger particles (floc)
C. Boiling water
D. Adding chlorine only
Rationale: Flocculation gently mixes water to form larger
particle clumps.
Correct Answer: B
7. What is turbidity in water?
A. Water temperature
B. Cloudiness caused by suspended particles
C. Water color
D. Water pressure
Rationale: Turbidity indicates how clear or cloudy water is.
Correct Answer: B
8. Which unit is commonly used to measure turbidity?
, A. ppm
B. NTU
C. mg/L
D. psi
Rationale: NTU (Nephelometric Turbidity Units) measures
water clarity.
Correct Answer: B
9. The main purpose of a sedimentation tank is to:
A. Add chlorine
B. Store clean water
C. Allow solids to settle out of water
D. Increase water flow
Rationale: It allows gravity to separate solids from water.
Correct Answer: C
10. What is the role of activated carbon in water treatment?
A. Increase hardness
B. Remove taste and odor
C. Add minerals
D. Increase turbidity
Rationale: Activated carbon absorbs organic compounds
affecting taste and smell.
Correct Answer: B
