Public Water Supply
DRIVER OPERATOR/PUBLIC
Responsibilities
WATER SUPPLY
QUESTIONS AND CORRECT ANSWERS WITH
COMPLETE SOLUTION
1. Which of the following is NOT a chemical source of fluoride used in water treatment?
Fluorosilicic acid
Sodium fluoride
Silicafluoride
Calcium carbonate
2. Explain why hydrogen sulfide (H2S) is associated with the smell of rotten eggs and
discuss its implications for water quality.
It is a byproduct of chlorine reactions
It indicates the presence of organic matter
It is a result of bacterial activity in anaerobic conditions
It is a harmless compound
3. What is the maximum allowable concentration of chlorine residual in discharged
water after dichlorination?
1.0 mg/L
2.0 mg/L
5.0 mg/L
10.0 mg/L
4. Explain the significance of taking repeat samples after a positive microbiological
result in a water supply system. Why is this practice important?
To confirm the presence of contaminants
To reduce the workload of testing
, To comply with regulations
To improve water taste
5. Explain how fluoride contributes to dental health when added to drinking water.
, It strengthens tooth enamel and reduces the risk of cavities
It kills bacteria in the mouth
It whitens teeth
It replaces lost minerals in teeth
6. If a water treatment facility is currently using a 150-pound chlorine cylinder at a feed
rate of 50 pounds per day, what potential issues could arise from exceeding the
maximum feed rate?
Increased water safety
Risk of chlorine gas leaks
Enhanced water quality
Reduced operational costs
7. Which of the following is NOT one of the three types of aquifers?
Unconfined
Perched
Artesian (confined)
Saturated
8. Explain why the characteristics of chlorine gas, such as its color and odor, are
important for safety in public water supply systems.
They help in identifying leaks and potential hazards.
They determine the effectiveness of water treatment processes.
They indicate the presence of beneficial minerals.
They are irrelevant to water quality management.
9. The thermocline is the layer in a lake at which:
pollutants are trapped and held
the warm upper zone meets the cold lower zone
nutrient levels are the lowest
light no longer penetrates enough for photosynthesis to occur
, the oxygen level is the lowest
10. Samples collected for inorganic metals are preserved with:
dilute hydrochloric acid
concentrated hydrochloric acid
concentrated nitric acid
dilute nitric acid
11. Explain the rationale behind checking the residual chlorine levels after receiving a
chlorine odor complaint.
To determine the source of the odor
To ensure compliance with regulations
To assess the effectiveness of the disinfection process
To decide whether to add more chlorine
12. The fecal coliform membrane filter test is incubated at ___ degrees C and produces
blue or blue-green colonies.
35.0 °C
98.6 °C
44.5 °C
37.0 °C
13. Explain the significance of the MPN method in assessing water quality.
It measures the chemical composition of water.
It estimates the concentration of bacteria in a water sample.
It determines the physical properties of water.
It evaluates the presence of heavy metals in water.
14. What is the definition of a 'log removal' in the context of water treatment?
A measure of the volume of water treated
DRIVER OPERATOR/PUBLIC
Responsibilities
WATER SUPPLY
QUESTIONS AND CORRECT ANSWERS WITH
COMPLETE SOLUTION
1. Which of the following is NOT a chemical source of fluoride used in water treatment?
Fluorosilicic acid
Sodium fluoride
Silicafluoride
Calcium carbonate
2. Explain why hydrogen sulfide (H2S) is associated with the smell of rotten eggs and
discuss its implications for water quality.
It is a byproduct of chlorine reactions
It indicates the presence of organic matter
It is a result of bacterial activity in anaerobic conditions
It is a harmless compound
3. What is the maximum allowable concentration of chlorine residual in discharged
water after dichlorination?
1.0 mg/L
2.0 mg/L
5.0 mg/L
10.0 mg/L
4. Explain the significance of taking repeat samples after a positive microbiological
result in a water supply system. Why is this practice important?
To confirm the presence of contaminants
To reduce the workload of testing
, To comply with regulations
To improve water taste
5. Explain how fluoride contributes to dental health when added to drinking water.
, It strengthens tooth enamel and reduces the risk of cavities
It kills bacteria in the mouth
It whitens teeth
It replaces lost minerals in teeth
6. If a water treatment facility is currently using a 150-pound chlorine cylinder at a feed
rate of 50 pounds per day, what potential issues could arise from exceeding the
maximum feed rate?
Increased water safety
Risk of chlorine gas leaks
Enhanced water quality
Reduced operational costs
7. Which of the following is NOT one of the three types of aquifers?
Unconfined
Perched
Artesian (confined)
Saturated
8. Explain why the characteristics of chlorine gas, such as its color and odor, are
important for safety in public water supply systems.
They help in identifying leaks and potential hazards.
They determine the effectiveness of water treatment processes.
They indicate the presence of beneficial minerals.
They are irrelevant to water quality management.
9. The thermocline is the layer in a lake at which:
pollutants are trapped and held
the warm upper zone meets the cold lower zone
nutrient levels are the lowest
light no longer penetrates enough for photosynthesis to occur
, the oxygen level is the lowest
10. Samples collected for inorganic metals are preserved with:
dilute hydrochloric acid
concentrated hydrochloric acid
concentrated nitric acid
dilute nitric acid
11. Explain the rationale behind checking the residual chlorine levels after receiving a
chlorine odor complaint.
To determine the source of the odor
To ensure compliance with regulations
To assess the effectiveness of the disinfection process
To decide whether to add more chlorine
12. The fecal coliform membrane filter test is incubated at ___ degrees C and produces
blue or blue-green colonies.
35.0 °C
98.6 °C
44.5 °C
37.0 °C
13. Explain the significance of the MPN method in assessing water quality.
It measures the chemical composition of water.
It estimates the concentration of bacteria in a water sample.
It determines the physical properties of water.
It evaluates the presence of heavy metals in water.
14. What is the definition of a 'log removal' in the context of water treatment?
A measure of the volume of water treated
