ALBERTA WATER TREATMENT OPERATOR
CONTUINING COMPETENCY EXAM QUESTIONS
WITH CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A |INSTANT
DOWNLOAD PDF
1. What is the primary purpose of coagulation in water
treatment?
A. Filtration
B. Aggregation of small particles
C. Disinfection
D. pH adjustment
Rationale: Coagulation causes particles to clump for easier
removal.
2. Which chemical is most commonly used as a coagulant?
A. Sodium hypochlorite
B. Aluminum sulfate
C. Calcium carbonate
D. Hydrogen peroxide
Rationale: Aluminum sulfate destabilizes colloids.
,3. What is the typical pH range for optimal coagulation with
aluminum sulfate?
A. 2.0–4.0
B. 5.5–7.0
C. 7.5–9.0
D. >10.0
Rationale: Optimal pH improves floc formation.
4. Flocculation is primarily designed to:
A. Increase turbidity
B. Sterilize water
C. Bring particles into contact
D. Remove dissolved gases
Rationale: Gentle mixing promotes floc growth.
5. What process follows coagulation and flocculation?
A. Disinfection
B. Aeration
C. Sedimentation
D. Backwashing
Rationale: Sedimentation allows flocs to settle.
6. Sedimentation removes particles by:
,A. Filtration
B. Gravity settling
C. Chemical reaction
D. Osmosis
Rationale: Heavier particles settle out under gravity.
7. The primary purpose of filtration is to remove:
A. Dissolved oxygen
B. Suspended solids
C. CO₂
D. Hardness
Rationale: Filters trap solids that didn’t settle.
8. Which filter media is most common in water treatment?
A. Activated carbon
B. Sand
C. Latex
D. Sulfur
Rationale: Sand is standard in granular media filters.
9. Backwashing is necessary to:
A. Add coagulant
B. Clean filter media
C. Lower pH
, D. Increase chlorine residual
Rationale: Backwash reverses flow to remove trapped solids.
10. The term “CT value” refers to:
A. Temperature × turbidity
B. Concentration × time for disinfection
C. Coagulant × temperature
D. Chlorine × tap flow
Rationale: CT determines disinfection efficacy.
11. What is the most common disinfectant used in municipal
water systems?
A. UV light
B. Ozone
C. Chlorine
D. Hydrogen peroxide
Rationale: Chlorine provides residual protection.
12. Free chlorine residual is measured to ensure:
A. pH stability
B. Disinfection continues in the distribution system
C. Softening efficiency
D. Filtration rate
Rationale: Adequate residual prevents regrowth.
CONTUINING COMPETENCY EXAM QUESTIONS
WITH CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A |INSTANT
DOWNLOAD PDF
1. What is the primary purpose of coagulation in water
treatment?
A. Filtration
B. Aggregation of small particles
C. Disinfection
D. pH adjustment
Rationale: Coagulation causes particles to clump for easier
removal.
2. Which chemical is most commonly used as a coagulant?
A. Sodium hypochlorite
B. Aluminum sulfate
C. Calcium carbonate
D. Hydrogen peroxide
Rationale: Aluminum sulfate destabilizes colloids.
,3. What is the typical pH range for optimal coagulation with
aluminum sulfate?
A. 2.0–4.0
B. 5.5–7.0
C. 7.5–9.0
D. >10.0
Rationale: Optimal pH improves floc formation.
4. Flocculation is primarily designed to:
A. Increase turbidity
B. Sterilize water
C. Bring particles into contact
D. Remove dissolved gases
Rationale: Gentle mixing promotes floc growth.
5. What process follows coagulation and flocculation?
A. Disinfection
B. Aeration
C. Sedimentation
D. Backwashing
Rationale: Sedimentation allows flocs to settle.
6. Sedimentation removes particles by:
,A. Filtration
B. Gravity settling
C. Chemical reaction
D. Osmosis
Rationale: Heavier particles settle out under gravity.
7. The primary purpose of filtration is to remove:
A. Dissolved oxygen
B. Suspended solids
C. CO₂
D. Hardness
Rationale: Filters trap solids that didn’t settle.
8. Which filter media is most common in water treatment?
A. Activated carbon
B. Sand
C. Latex
D. Sulfur
Rationale: Sand is standard in granular media filters.
9. Backwashing is necessary to:
A. Add coagulant
B. Clean filter media
C. Lower pH
, D. Increase chlorine residual
Rationale: Backwash reverses flow to remove trapped solids.
10. The term “CT value” refers to:
A. Temperature × turbidity
B. Concentration × time for disinfection
C. Coagulant × temperature
D. Chlorine × tap flow
Rationale: CT determines disinfection efficacy.
11. What is the most common disinfectant used in municipal
water systems?
A. UV light
B. Ozone
C. Chlorine
D. Hydrogen peroxide
Rationale: Chlorine provides residual protection.
12. Free chlorine residual is measured to ensure:
A. pH stability
B. Disinfection continues in the distribution system
C. Softening efficiency
D. Filtration rate
Rationale: Adequate residual prevents regrowth.
