Louisiana Water Treatment Technician Exam
Questions And Correct Answer with Rational
(100% verified answer) Q & A 2026 /
Instant download PDF
1. What is the primary purpose of a water treatment plant?
A. Generate electricity
B. Remove contaminants from raw water
C. Store wastewater
D. Increase water hardness
Correct Answer: B
Rationale: Water treatment plants are designed to remove physical, chemical, and
biological contaminants to make water safe for use.
2. Which process removes suspended particles using gravity?
A. Filtration
B. Sedimentation
C. Chlorination
D. Aeration
Correct Answer: B
Rationale: Sedimentation allows heavier particles to settle at the bottom due to
gravity.
,3. What chemical is most commonly used for disinfection in water treatment?
A. Sodium chloride
B. Chlorine
C. Ammonia
D. Calcium carbonate
Correct Answer: B
Rationale: Chlorine is widely used because it effectively kills pathogens.
4. What is turbidity in water?
A. Water temperature
B. Water hardness
C. Cloudiness caused by particles
D. Oxygen content
Correct Answer: C
Rationale: Turbidity measures how clear or cloudy water is due to suspended
solids.
5. Which unit measures flow rate in water systems?
A. PSI
B. Gallons per minute (GPM)
C. ppm
D. NTU
Correct Answer: B
Rationale: Flow rate is commonly measured in gallons per minute.
6. What is coagulation in water treatment?
,A. Heating water
B. Adding chemicals to form flocs
C. Freezing impurities
D. Removing chlorine
Correct Answer: B
Rationale: Coagulation involves adding chemicals to destabilize particles so they
clump together.
7. What is flocculation?
A. Breaking particles apart
B. Mixing water rapidly
C. Gentle mixing to form larger particles
D. Removing oxygen
Correct Answer: C
Rationale: Flocculation slowly mixes water to form larger flocs for easier removal.
8. What does pH measure?
A. Water pressure
B. Acidity or alkalinity
C. Hardness
D. Temperature
Correct Answer: B
Rationale: pH indicates how acidic or basic water is.
9. What is the safe drinking water pH range generally accepted?
A. 0–2
B. 3–4
, C. 6.5–8.5
D. 10–14
Correct Answer: C
Rationale: Drinking water is typically safe within pH 6.5–8.5.
10. What is filtration used for?
A. Adding oxygen
B. Removing suspended particles
C. Increasing hardness
D. Heating water
Correct Answer: B
Rationale: Filtration removes remaining solids after sedimentation.
11. Which gas is commonly produced by anaerobic bacteria in water systems?
A. Oxygen
B. Methane
C. Chlorine
D. Nitrogen
Correct Answer: B
Rationale: Anaerobic decomposition produces methane gas.
12. What does residual chlorine indicate?
A. No chlorine present
B. Chlorine completely used up
C. Remaining disinfectant in water
D. Hard water level
Questions And Correct Answer with Rational
(100% verified answer) Q & A 2026 /
Instant download PDF
1. What is the primary purpose of a water treatment plant?
A. Generate electricity
B. Remove contaminants from raw water
C. Store wastewater
D. Increase water hardness
Correct Answer: B
Rationale: Water treatment plants are designed to remove physical, chemical, and
biological contaminants to make water safe for use.
2. Which process removes suspended particles using gravity?
A. Filtration
B. Sedimentation
C. Chlorination
D. Aeration
Correct Answer: B
Rationale: Sedimentation allows heavier particles to settle at the bottom due to
gravity.
,3. What chemical is most commonly used for disinfection in water treatment?
A. Sodium chloride
B. Chlorine
C. Ammonia
D. Calcium carbonate
Correct Answer: B
Rationale: Chlorine is widely used because it effectively kills pathogens.
4. What is turbidity in water?
A. Water temperature
B. Water hardness
C. Cloudiness caused by particles
D. Oxygen content
Correct Answer: C
Rationale: Turbidity measures how clear or cloudy water is due to suspended
solids.
5. Which unit measures flow rate in water systems?
A. PSI
B. Gallons per minute (GPM)
C. ppm
D. NTU
Correct Answer: B
Rationale: Flow rate is commonly measured in gallons per minute.
6. What is coagulation in water treatment?
,A. Heating water
B. Adding chemicals to form flocs
C. Freezing impurities
D. Removing chlorine
Correct Answer: B
Rationale: Coagulation involves adding chemicals to destabilize particles so they
clump together.
7. What is flocculation?
A. Breaking particles apart
B. Mixing water rapidly
C. Gentle mixing to form larger particles
D. Removing oxygen
Correct Answer: C
Rationale: Flocculation slowly mixes water to form larger flocs for easier removal.
8. What does pH measure?
A. Water pressure
B. Acidity or alkalinity
C. Hardness
D. Temperature
Correct Answer: B
Rationale: pH indicates how acidic or basic water is.
9. What is the safe drinking water pH range generally accepted?
A. 0–2
B. 3–4
, C. 6.5–8.5
D. 10–14
Correct Answer: C
Rationale: Drinking water is typically safe within pH 6.5–8.5.
10. What is filtration used for?
A. Adding oxygen
B. Removing suspended particles
C. Increasing hardness
D. Heating water
Correct Answer: B
Rationale: Filtration removes remaining solids after sedimentation.
11. Which gas is commonly produced by anaerobic bacteria in water systems?
A. Oxygen
B. Methane
C. Chlorine
D. Nitrogen
Correct Answer: B
Rationale: Anaerobic decomposition produces methane gas.
12. What does residual chlorine indicate?
A. No chlorine present
B. Chlorine completely used up
C. Remaining disinfectant in water
D. Hard water level
