Certified Pool Operator Handbook Practice Test: Questions & Answers
1. You operate a 120,000-gallon pool, and upon performing your hourly chemical tests you observe the
following readings: Total Available Chlorine reading is 1.6 free available chlorine reading is 1.5 pH is 7.4
Your supervising lifeguard has just informed you that you have had a fecal incident occur; a solid stool
has been discharged into the pool. According to the Centers for Disease Control, as the CPO, you should
do the following: - ANSWER:clear the pool and raise the free chlorine to 2 ppm
2. Assuming that your local health department requires you to raise the free chlorine to 5 ppm, how
much sodium hypochlorite would be needed to raise the free chlorine in the pool in question #1 to that
level? - ANSWER:3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that he is receiving
complaints about a strong chlorine odor in the pool area, and several members have complained of eye
irritation. The most likely cause of these complaints is: - ANSWER:high levels of chloramines in the pool
4. To determine the level of chloramines in the water, you should do which of the following? -
ANSWER:test for total chlorine and free chlorine, then subtract the free chlorine number from the total
chlorine
5. You operate a 45,000 gallon indoor pool, and upon doing your hourly chemical tests you observe the
following readings:Total available chlorine is 2.2 Free available chlorine is 1.4 and pH is 7.6 What is the
level of chloramines in this pool? - ANSWER:0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department requires you to
perform a water balance calculation once monthly. Upon performing the water tests necessary to
perform this calculation, you observe the following readings in your pool: Total alkalinity is 50 ppm pH is
7.2 Calcium Hardness is 150 ppm Temperature is 76 degrees F Total Dissolved Solids is 500 ppm Using
these readings, what is the Saturation Index for this pool? - ANSWER:-0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level, which chemical
would be most appropriate? - ANSWER:Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which chemical would be
most appropriate? - ANSWER:Sodium Carbonate
10. You are the CPO for a 28,000 gallon hotel pool. You perform a water balance chemical test, and to
your surprise, the Calcium Hardness is only 100 ppm. How much calcium chloride (77%) would be
required to increase this to 400 ppm?" - ANSWER:100.8 lbs.
11. You are the CPO for a 100 foot long, 50 foot wide country club pool. The average depth of this pool is
7 feet. You return to the pool on Monday morning, after a rare weekend off, and find that the auto-fill
feature has failed to work, and the pool water level is four inches too low. How many gallons of water
must be added to return the water to the proper level? - ANSWER:12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100 users per day.
According to the CPO Handbook, how often should the water in this spa be changed? - ANSWER:10 days
, "13. You are the CPO for a large municipal swimming pool. This pool has a volume of 560,000 gallons of
water,and has an average daily bather load of 1300 people. The pool is operated using high rate pressure
sand filters. How often should you backwash the filters?" - ANSWER:When the influent and effluent
gauges are 10 to 20 psi apart
14. In testing for Chlorine/Bromine in a commercial pool, DPD is preferred over OTO because: -
ANSWER:OTO only tests for Total Chlorine
15. Safety and rescue equipment should always be: - ANSWER:Kept easily accessible around the pool
16. Which type of filter system will remove the smallest micron particles? - ANSWER:diatomaceous earth
17. If the pump fails to prime, which of the following does not have to be checked? - ANSWER:filter
system pressure is too high
18. Oxidation Reduction Potential testing (ORP) is measured in? - ANSWER:mV
19. High calcium hardness can result in what condition? - ANSWER:cloudy water
20. Head first entry dives are: - ANSWER:only allowed in areas of the pool that are not marked as 'NO
DIVING'
21. Opening and closing checklists: - ANSWER:all of the above
22. You can become sick from ingesting water infected with Legionella bacteria - ANSWER:false
23. Channeling of filters occurs when: - ANSWER:the FMR is exceeded, and water cuts a channel through
the media
24. The only physical factor that affects water balance is: - ANSWER:temperature
25. To be classified as a disinfectant, a compound must kill or inactivate 99.9% of contaminants as well
as: - ANSWER:leave a measurable residual in the water
26. Pools using chlorine gas as a disinfectant produce hydrochloric acid, which can be neutralized with: -
ANSWER:caustic soda or soda ash
27. When balancing swimming pool water, the following should be adjusted first: - ANSWER:total
alkalinity
28. A spa with water tested as pH 7.2, temperature 103, calcium hardness 600, total alkalinity 120, and
tds of 1,500 will be: - ANSWER:scale forming
29. When performing a water test, sample water should be collected: - ANSWER:18 inches below the
surface, away from return line
30. Swimming pool circulation systems should be adjusted to remove: - ANSWER:75% from the surface
31. Vacuuming of the pool bottom should be done: - ANSWER:after foreign matter has settled
32. You are a service tech and have gotten a contract to maintain a small motel pool. Upon examining
the operational records, you find that the number of gallons in the pool is not listed in the records. You
visit the pool and observe that it is a fairly rectangular concrete pool, with the following dimensions:
1. You operate a 120,000-gallon pool, and upon performing your hourly chemical tests you observe the
following readings: Total Available Chlorine reading is 1.6 free available chlorine reading is 1.5 pH is 7.4
Your supervising lifeguard has just informed you that you have had a fecal incident occur; a solid stool
has been discharged into the pool. According to the Centers for Disease Control, as the CPO, you should
do the following: - ANSWER:clear the pool and raise the free chlorine to 2 ppm
2. Assuming that your local health department requires you to raise the free chlorine to 5 ppm, how
much sodium hypochlorite would be needed to raise the free chlorine in the pool in question #1 to that
level? - ANSWER:3.5 gallons
3. You are the CPO for an indoor health club pool. The facility manager informs you that he is receiving
complaints about a strong chlorine odor in the pool area, and several members have complained of eye
irritation. The most likely cause of these complaints is: - ANSWER:high levels of chloramines in the pool
4. To determine the level of chloramines in the water, you should do which of the following? -
ANSWER:test for total chlorine and free chlorine, then subtract the free chlorine number from the total
chlorine
5. You operate a 45,000 gallon indoor pool, and upon doing your hourly chemical tests you observe the
following readings:Total available chlorine is 2.2 Free available chlorine is 1.4 and pH is 7.6 What is the
level of chloramines in this pool? - ANSWER:0.8
7. You are the operator of a 330,000 gallon outdoor pool. Your local health department requires you to
perform a water balance calculation once monthly. Upon performing the water tests necessary to
perform this calculation, you observe the following readings in your pool: Total alkalinity is 50 ppm pH is
7.2 Calcium Hardness is 150 ppm Temperature is 76 degrees F Total Dissolved Solids is 500 ppm Using
these readings, what is the Saturation Index for this pool? - ANSWER:-0.8
8. To adjust the tested Total Alkalinity in the pool in question #7 to an acceptable level, which chemical
would be most appropriate? - ANSWER:Sodium Bicarbonate
9. To adjust the tested pH in the pool in question #7 to an acceptable level, which chemical would be
most appropriate? - ANSWER:Sodium Carbonate
10. You are the CPO for a 28,000 gallon hotel pool. You perform a water balance chemical test, and to
your surprise, the Calcium Hardness is only 100 ppm. How much calcium chloride (77%) would be
required to increase this to 400 ppm?" - ANSWER:100.8 lbs.
11. You are the CPO for a 100 foot long, 50 foot wide country club pool. The average depth of this pool is
7 feet. You return to the pool on Monday morning, after a rare weekend off, and find that the auto-fill
feature has failed to work, and the pool water level is four inches too low. How many gallons of water
must be added to return the water to the proper level? - ANSWER:12,495 gallons
12. You are the operator of a 3,000 gallon health club spa, which has an average of 100 users per day.
According to the CPO Handbook, how often should the water in this spa be changed? - ANSWER:10 days
, "13. You are the CPO for a large municipal swimming pool. This pool has a volume of 560,000 gallons of
water,and has an average daily bather load of 1300 people. The pool is operated using high rate pressure
sand filters. How often should you backwash the filters?" - ANSWER:When the influent and effluent
gauges are 10 to 20 psi apart
14. In testing for Chlorine/Bromine in a commercial pool, DPD is preferred over OTO because: -
ANSWER:OTO only tests for Total Chlorine
15. Safety and rescue equipment should always be: - ANSWER:Kept easily accessible around the pool
16. Which type of filter system will remove the smallest micron particles? - ANSWER:diatomaceous earth
17. If the pump fails to prime, which of the following does not have to be checked? - ANSWER:filter
system pressure is too high
18. Oxidation Reduction Potential testing (ORP) is measured in? - ANSWER:mV
19. High calcium hardness can result in what condition? - ANSWER:cloudy water
20. Head first entry dives are: - ANSWER:only allowed in areas of the pool that are not marked as 'NO
DIVING'
21. Opening and closing checklists: - ANSWER:all of the above
22. You can become sick from ingesting water infected with Legionella bacteria - ANSWER:false
23. Channeling of filters occurs when: - ANSWER:the FMR is exceeded, and water cuts a channel through
the media
24. The only physical factor that affects water balance is: - ANSWER:temperature
25. To be classified as a disinfectant, a compound must kill or inactivate 99.9% of contaminants as well
as: - ANSWER:leave a measurable residual in the water
26. Pools using chlorine gas as a disinfectant produce hydrochloric acid, which can be neutralized with: -
ANSWER:caustic soda or soda ash
27. When balancing swimming pool water, the following should be adjusted first: - ANSWER:total
alkalinity
28. A spa with water tested as pH 7.2, temperature 103, calcium hardness 600, total alkalinity 120, and
tds of 1,500 will be: - ANSWER:scale forming
29. When performing a water test, sample water should be collected: - ANSWER:18 inches below the
surface, away from return line
30. Swimming pool circulation systems should be adjusted to remove: - ANSWER:75% from the surface
31. Vacuuming of the pool bottom should be done: - ANSWER:after foreign matter has settled
32. You are a service tech and have gotten a contract to maintain a small motel pool. Upon examining
the operational records, you find that the number of gallons in the pool is not listed in the records. You
visit the pool and observe that it is a fairly rectangular concrete pool, with the following dimensions:
