Michigan Water Treatment Operator Level
2 exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of coagulation in a conventional
water treatment process?
A. To disinfect microorganisms
B. To remove dissolved gases
C. To destabilize colloidal particles
D. To adjust pH for corrosion control
Answer: C
Rationale: Coagulation destabilizes colloidal particles by
neutralizing their electrical charges, allowing them to combine
into larger particles during flocculation for easier removal in
sedimentation and filtration.
2. Which chemical is most commonly used as a primary coagulant in
Michigan water treatment plants?
A. Sodium hypochlorite
B. Aluminum sulfate
C. Calcium carbonate
D. Potassium permanganate
Answer: B
Rationale: Aluminum sulfate (alum) is widely used as a primary
, coagulant because it effectively neutralizes negative charges on
suspended particles and forms floc that can settle or be filtered
out.
3. The process of gently mixing water to promote particle collision
and floc formation is known as:
A. Aeration
B. Sedimentation
C. Flocculation
D. Filtration
Answer: C
Rationale: Flocculation follows coagulation and involves gentle
mixing to encourage destabilized particles to collide and form
larger, settleable flocs.
4. What is the main objective of sedimentation?
A. Increase pH
B. Remove settleable solids
C. Add disinfectant
D. Improve taste
Answer: B
Rationale: Sedimentation allows gravity to remove settleable
solids formed during coagulation and flocculation, reducing the
load on filters.
5. Rapid sand filters primarily remove:
A. Dissolved minerals
B. Bacteria through chemical reaction
C. Suspended particles
D. Hardness
Answer: C
, Rationale: Rapid sand filters remove suspended particles through
physical straining, adsorption, and biological action.
6. The effectiveness of chlorination depends greatly on:
A. Water color only
B. Contact time and concentration
C. Pipe diameter
D. Pump speed
Answer: B
Rationale: Disinfection effectiveness is based on CT (concentration
× time). Adequate chlorine concentration and contact time are
necessary for pathogen inactivation.
7. Turbidity is measured in:
A. mg/L
B. NTU
C. ppm
D. psi
Answer: B
Rationale: Turbidity is measured in Nephelometric Turbidity Units
(NTU), indicating the clarity of water.
8. Backwashing a filter is performed to:
A. Add disinfectant
B. Remove accumulated solids
C. Increase alkalinity
D. Reduce hardness
Answer: B
Rationale: Backwashing reverses water flow to remove trapped
solids and restore filter capacity.
9. A jar test is used to determine:
A. Pump efficiency
2 exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of coagulation in a conventional
water treatment process?
A. To disinfect microorganisms
B. To remove dissolved gases
C. To destabilize colloidal particles
D. To adjust pH for corrosion control
Answer: C
Rationale: Coagulation destabilizes colloidal particles by
neutralizing their electrical charges, allowing them to combine
into larger particles during flocculation for easier removal in
sedimentation and filtration.
2. Which chemical is most commonly used as a primary coagulant in
Michigan water treatment plants?
A. Sodium hypochlorite
B. Aluminum sulfate
C. Calcium carbonate
D. Potassium permanganate
Answer: B
Rationale: Aluminum sulfate (alum) is widely used as a primary
, coagulant because it effectively neutralizes negative charges on
suspended particles and forms floc that can settle or be filtered
out.
3. The process of gently mixing water to promote particle collision
and floc formation is known as:
A. Aeration
B. Sedimentation
C. Flocculation
D. Filtration
Answer: C
Rationale: Flocculation follows coagulation and involves gentle
mixing to encourage destabilized particles to collide and form
larger, settleable flocs.
4. What is the main objective of sedimentation?
A. Increase pH
B. Remove settleable solids
C. Add disinfectant
D. Improve taste
Answer: B
Rationale: Sedimentation allows gravity to remove settleable
solids formed during coagulation and flocculation, reducing the
load on filters.
5. Rapid sand filters primarily remove:
A. Dissolved minerals
B. Bacteria through chemical reaction
C. Suspended particles
D. Hardness
Answer: C
, Rationale: Rapid sand filters remove suspended particles through
physical straining, adsorption, and biological action.
6. The effectiveness of chlorination depends greatly on:
A. Water color only
B. Contact time and concentration
C. Pipe diameter
D. Pump speed
Answer: B
Rationale: Disinfection effectiveness is based on CT (concentration
× time). Adequate chlorine concentration and contact time are
necessary for pathogen inactivation.
7. Turbidity is measured in:
A. mg/L
B. NTU
C. ppm
D. psi
Answer: B
Rationale: Turbidity is measured in Nephelometric Turbidity Units
(NTU), indicating the clarity of water.
8. Backwashing a filter is performed to:
A. Add disinfectant
B. Remove accumulated solids
C. Increase alkalinity
D. Reduce hardness
Answer: B
Rationale: Backwashing reverses water flow to remove trapped
solids and restore filter capacity.
9. A jar test is used to determine:
A. Pump efficiency
