Wake county CPO QUESTIONS
WITH COMPLETE SOLUTIONS
Course
CPO
1. Pool Chemistry
Which chlorine measurement best indicates the sanitizer available to disinfect pool water?
A. Total Chlorine
B. Combined Chlorine
C. Free Available Chlorine (FAC)
D. Cyanuric Acid
Answer: C. Free Available Chlorine (FAC)
Rationale: Free Available Chlorine is the active sanitizer that kills bacteria, viruses, and algae.
2. pH
The recommended operating pH range for most swimming pools is:
A. 5.5–6.5
B. 6.8–7.0
C. 7.2–7.8
D. 8.5–9.0
Answer: C
Rationale: A pH between 7.2 and 7.8 provides effective chlorine activity while minimizing
corrosion and swimmer irritation.
3. Chlorine
If free chlorine is too low, the operator should:
A. Lower alkalinity
B. Add chlorine according to established operating procedures
C. Increase calcium hardness
,D. Lower water level
Answer: B
Rationale: Low free chlorine reduces disinfection effectiveness and should be corrected
promptly.
4. Combined Chlorine
Combined chlorine levels above approximately 0.2 ppm generally indicate:
A. Excellent water quality
B. Chloramines are accumulating and corrective action may be needed
C. Excess calcium
D. High alkalinity
Answer: B
Rationale: Chloramines reduce sanitizer effectiveness and may cause eye irritation and chlorine
odor.
5. Cyanuric Acid
The primary purpose of cyanuric acid in an outdoor pool is to:
A. Increase pH
B. Stabilize chlorine from sunlight degradation
C. Lower alkalinity
D. Raise calcium hardness
Answer: B
Rationale: Cyanuric acid protects chlorine from ultraviolet light.
6. Total Alkalinity
Total alkalinity primarily acts as:
A. A sanitizer
,B. A pH buffer
C. A disinfectant
D. A filter aid
Answer: B
Rationale: Proper alkalinity helps prevent rapid pH fluctuations.
7. Calcium Hardness
Low calcium hardness can contribute to:
A. Scale formation only
B. Corrosive water
C. Excess chlorine
D. High cyanuric acid
Answer: B
Rationale: Soft water can dissolve plaster, grout, and metal components.
8. Filtration
The primary function of a pool filter is to:
A. Kill bacteria
B. Remove suspended particles
C. Lower pH
D. Increase chlorine
Answer: B
Rationale: Filtration removes debris and fine particles, while disinfectants kill microorganisms.
9. Sand Filters
When should a sand filter normally be backwashed?
, A. Every day regardless of pressure
B. When pressure rises approximately 8–10 psi above clean starting pressure (or according to
manufacturer guidance)
C. Every hour
D. Only once per year
Answer: B
Rationale: Increased pressure indicates accumulated debris restricting flow.
10. Circulation
Proper circulation helps:
A. Evenly distribute chemicals
B. Remove contaminants
C. Improve filtration efficiency
D. All of the above
Answer: D
Rationale: Good circulation is essential for balanced water quality and effective sanitation.
11. Pool Safety
The first priority when responding to a drowning emergency is:
A. Close the concession stand
B. Activate the emergency action plan and begin rescue
C. Test chlorine
D. Vacuum the pool
Answer: B
Rationale: Immediate rescue and emergency response save lives.
WITH COMPLETE SOLUTIONS
Course
CPO
1. Pool Chemistry
Which chlorine measurement best indicates the sanitizer available to disinfect pool water?
A. Total Chlorine
B. Combined Chlorine
C. Free Available Chlorine (FAC)
D. Cyanuric Acid
Answer: C. Free Available Chlorine (FAC)
Rationale: Free Available Chlorine is the active sanitizer that kills bacteria, viruses, and algae.
2. pH
The recommended operating pH range for most swimming pools is:
A. 5.5–6.5
B. 6.8–7.0
C. 7.2–7.8
D. 8.5–9.0
Answer: C
Rationale: A pH between 7.2 and 7.8 provides effective chlorine activity while minimizing
corrosion and swimmer irritation.
3. Chlorine
If free chlorine is too low, the operator should:
A. Lower alkalinity
B. Add chlorine according to established operating procedures
C. Increase calcium hardness
,D. Lower water level
Answer: B
Rationale: Low free chlorine reduces disinfection effectiveness and should be corrected
promptly.
4. Combined Chlorine
Combined chlorine levels above approximately 0.2 ppm generally indicate:
A. Excellent water quality
B. Chloramines are accumulating and corrective action may be needed
C. Excess calcium
D. High alkalinity
Answer: B
Rationale: Chloramines reduce sanitizer effectiveness and may cause eye irritation and chlorine
odor.
5. Cyanuric Acid
The primary purpose of cyanuric acid in an outdoor pool is to:
A. Increase pH
B. Stabilize chlorine from sunlight degradation
C. Lower alkalinity
D. Raise calcium hardness
Answer: B
Rationale: Cyanuric acid protects chlorine from ultraviolet light.
6. Total Alkalinity
Total alkalinity primarily acts as:
A. A sanitizer
,B. A pH buffer
C. A disinfectant
D. A filter aid
Answer: B
Rationale: Proper alkalinity helps prevent rapid pH fluctuations.
7. Calcium Hardness
Low calcium hardness can contribute to:
A. Scale formation only
B. Corrosive water
C. Excess chlorine
D. High cyanuric acid
Answer: B
Rationale: Soft water can dissolve plaster, grout, and metal components.
8. Filtration
The primary function of a pool filter is to:
A. Kill bacteria
B. Remove suspended particles
C. Lower pH
D. Increase chlorine
Answer: B
Rationale: Filtration removes debris and fine particles, while disinfectants kill microorganisms.
9. Sand Filters
When should a sand filter normally be backwashed?
, A. Every day regardless of pressure
B. When pressure rises approximately 8–10 psi above clean starting pressure (or according to
manufacturer guidance)
C. Every hour
D. Only once per year
Answer: B
Rationale: Increased pressure indicates accumulated debris restricting flow.
10. Circulation
Proper circulation helps:
A. Evenly distribute chemicals
B. Remove contaminants
C. Improve filtration efficiency
D. All of the above
Answer: D
Rationale: Good circulation is essential for balanced water quality and effective sanitation.
11. Pool Safety
The first priority when responding to a drowning emergency is:
A. Close the concession stand
B. Activate the emergency action plan and begin rescue
C. Test chlorine
D. Vacuum the pool
Answer: B
Rationale: Immediate rescue and emergency response save lives.
