AWWA WATER QUALITY ANALYST CERTIFICATION
EXAM QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS Q&A 2026 |INSTANT
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1. Which parameter is the best indicator of bacterial
contamination in drinking water?
A. pH
B. Turbidity
C. Total coliforms
D. Hardness
Rationale: Total coliforms are commonly used as indicator
organisms for microbial contamination in water systems.
Correct Answer: C. Total coliforms
2. What is the primary purpose of chlorination in water
treatment?
A. Remove turbidity
B. Kill or inactivate pathogens
C. Increase alkalinity
D. Remove hardness
,Rationale: Chlorine disinfects water by destroying disease-
causing microorganisms.
Correct Answer: B. Kill or inactivate pathogens
3. Which unit is used to measure turbidity?
A. mg/L
B. NTU
C. ppm
D. CFU
Rationale: Turbidity is measured in Nephelometric Turbidity
Units (NTU).
Correct Answer: B. NTU
4. What does pH measure in water?
A. Temperature
B. Acidity or alkalinity
C. Hardness
D. Dissolved oxygen
Rationale: pH indicates hydrogen ion concentration, showing
how acidic or basic water is.
Correct Answer: B. Acidity or alkalinity
5. Which gas is most important for aquatic life survival?
,A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Methane
Rationale: Dissolved oxygen is essential for fish and aerobic
organisms.
Correct Answer: B. Oxygen
6. What is the acceptable drinking water pH range
recommended by most standards?
A. 2.0 – 4.0
B. 4.0 – 5.5
C. 6.5 – 8.5
D. 9.5 – 12.0
Rationale: Safe drinking water is typically slightly neutral to
slightly alkaline.
Correct Answer: C. 6.5 – 8.5
7. What does turbidity in water indicate?
A. Dissolved salts
B. Clarity of water
C. Water hardness
D. Temperature
, Rationale: Turbidity measures how clear or cloudy water is due
to suspended particles.
Correct Answer: B. Clarity of water
8. Which process removes suspended solids from water?
A. Chlorination
B. Filtration
C. Fluoridation
D. Aeration
Rationale: Filtration physically removes particles from water.
Correct Answer: B. Filtration
9. What is the main purpose of coagulation in water
treatment?
A. Kill bacteria
B. Remove dissolved salts
C. Form larger particles for removal
D. Increase pH
Rationale: Coagulation helps small particles stick together to
form flocs.
Correct Answer: C. Form larger particles for removal
10. Which chemical is commonly used as a coagulant?
EXAM QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS Q&A 2026 |INSTANT
DOWNLOAD PDF
1. Which parameter is the best indicator of bacterial
contamination in drinking water?
A. pH
B. Turbidity
C. Total coliforms
D. Hardness
Rationale: Total coliforms are commonly used as indicator
organisms for microbial contamination in water systems.
Correct Answer: C. Total coliforms
2. What is the primary purpose of chlorination in water
treatment?
A. Remove turbidity
B. Kill or inactivate pathogens
C. Increase alkalinity
D. Remove hardness
,Rationale: Chlorine disinfects water by destroying disease-
causing microorganisms.
Correct Answer: B. Kill or inactivate pathogens
3. Which unit is used to measure turbidity?
A. mg/L
B. NTU
C. ppm
D. CFU
Rationale: Turbidity is measured in Nephelometric Turbidity
Units (NTU).
Correct Answer: B. NTU
4. What does pH measure in water?
A. Temperature
B. Acidity or alkalinity
C. Hardness
D. Dissolved oxygen
Rationale: pH indicates hydrogen ion concentration, showing
how acidic or basic water is.
Correct Answer: B. Acidity or alkalinity
5. Which gas is most important for aquatic life survival?
,A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Methane
Rationale: Dissolved oxygen is essential for fish and aerobic
organisms.
Correct Answer: B. Oxygen
6. What is the acceptable drinking water pH range
recommended by most standards?
A. 2.0 – 4.0
B. 4.0 – 5.5
C. 6.5 – 8.5
D. 9.5 – 12.0
Rationale: Safe drinking water is typically slightly neutral to
slightly alkaline.
Correct Answer: C. 6.5 – 8.5
7. What does turbidity in water indicate?
A. Dissolved salts
B. Clarity of water
C. Water hardness
D. Temperature
, Rationale: Turbidity measures how clear or cloudy water is due
to suspended particles.
Correct Answer: B. Clarity of water
8. Which process removes suspended solids from water?
A. Chlorination
B. Filtration
C. Fluoridation
D. Aeration
Rationale: Filtration physically removes particles from water.
Correct Answer: B. Filtration
9. What is the main purpose of coagulation in water
treatment?
A. Kill bacteria
B. Remove dissolved salts
C. Form larger particles for removal
D. Increase pH
Rationale: Coagulation helps small particles stick together to
form flocs.
Correct Answer: C. Form larger particles for removal
10. Which chemical is commonly used as a coagulant?
