CPO Operation and Maintenance Test 2

Question 1

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 to that level?

Accepted Answer

3.5 gallons

Answer

To calculate the amount of sodium hypochlorite needed, one must know the pool's volume and the concentration of the chlorine product. Assuming a typical pool volume (e.g., around 40,000 gallons) and a common liquid chlorine concentration (e.g., 10-12.5%), approximately 3.5 gallons of sodium hypochlorite would be required to increase the free chlorine level by 5 ppm. This calculation ensures the correct dosage is applied to achieve the desired sanitation level.

Question 2

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:

Accepted Answer

high levels of chloramines in the pool

Answer

A strong chlorine odor and eye irritation in a pool are classic indicators of high levels of chloramines, not too much free chlorine. Chloramines are formed when free chlorine reacts with nitrogen-containing compounds from swimmer waste (sweat, urine, etc.). These compounds are ineffective disinfectants and are responsible for the unpleasant 'chlorine smell' and irritant effects, signaling poor water quality and the need for breakpoint chlorination or shocking.

Question 3

To adjust the tested Total Alkalinity in the pool to an acceptable level, which chemical would be most appropriate?

Accepted Answer

Sodium Bicarbonate

Answer

Total Alkalinity (TA) is a measure of the water's ability to resist changes in pH. If the TA is too low, the pH will fluctuate wildly, leading to water balance issues. Sodium Bicarbonate (baking soda) is the most appropriate chemical to increase Total Alkalinity in pool water without significantly impacting other parameters like pH or calcium hardness, effectively stabilizing the water's pH.

Question 4

To adjust the tested pH in the pool to an acceptable level, which chemical would be most appropriate?

Accepted Answer

Sodium Carbonate

Answer

Sodium Carbonate, commonly known as soda ash, is an alkaline chemical used to increase the pH level in pool water. If the tested pH is too low, adding sodium carbonate will raise it to the acceptable range (typically 7.4-7.6), which is crucial for bather comfort, sanitizer effectiveness, and preventing corrosion of pool equipment.

Question 5

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?

Accepted Answer

When the influent and effluent gauges are 10 to 20 psi apart

Answer

Filter backwashing is primarily triggered by a pressure differential, not a fixed time interval. As debris accumulates in the filter media, it restricts water flow, causing the pressure on the influent (incoming) side to rise and the effluent (outgoing) side to drop. A significant pressure difference, typically 10 to 20 psi above the clean filter pressure, indicates the filter is dirty and needs backwashing to restore proper flow and filtration efficiency.

Uncategorized Practice Test

Uncategorized Practice Test

CPO Operation and Maintenance Test 2