Texas Industrial Water Treatment
Operator License Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
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1. What is the primary purpose of coagulation in water treatment?
A. Remove dissolved salts
B. Disinfect water
C. Destabilize suspended particles
D. Adjust pH
Coagulation involves adding chemicals to destabilize suspended
particles, allowing them to clump together for removal in subsequent
processes.
2. The Safe Drinking Water Act is primarily enforced by which agency?
A. U.S. Environmental Protection Agency (EPA)
B. Texas Commission on Environmental Quality (TCEQ)
, C. Occupational Safety and Health Administration (OSHA)
D. Texas Department of State Health Services
The EPA is the federal agency that enforces the Safe Drinking Water
Act, setting national standards for drinking water quality.
3. What is the most common chemical used for disinfection in water
treatment?
A. Ozone
B. Chloramines
C. Ultraviolet light
D. Chlorine
Chlorine is the most widely used disinfectant due to its effectiveness,
residual protection, and relatively low cost.
4. Which term describes water’s capacity to resist changes in pH?
A. Hardness
B. Alkalinity
C. Turbidity
D. Conductivity
Alkalinity measures the buffering capacity of water, which resists
changes in pH.
5. In a water treatment plant, what is the primary goal of sedimentation?
A. Remove dissolved solids
B. Kill pathogens
C. Allow heavier particles to settle out
, D. Reduce hardness
Sedimentation relies on gravity to allow suspended particles to settle
to the bottom before filtration.
6. What is the unit for measuring turbidity?
A. Nephelometric Turbidity Unit (NTU)
B. Parts per million (ppm)
C. Microns
D. Milligrams per liter (mg/L)
Turbidity is measured in NTU, indicating the cloudiness caused by
suspended particles.
7. Which component in a water treatment plant removes pathogens by
physical straining?
A. Sedimentation basin
B. Chemical feed system
C. Clearwell
D. Filter
Filters physically remove suspended particles, including many
pathogens, from the water.
8. The term “breakpoint chlorination” refers to:
A. Chlorine levels exceeding secondary standards
B. The point where chlorine demand is met and free chlorine remains
C. Maximum contaminant level for chlorine
D. Minimum disinfection level
, Breakpoint chlorination is when all chlorine demand is satisfied, and
free chlorine residual is established.
9. Which of the following is a primary standard regulated by the EPA?
A. Color
B. Odor
C. Lead
D. pH
Lead is regulated under primary drinking water standards because of
its health risks.
10. Which process uses semi-permeable membranes to remove
dissolved salts from water?
A. Reverse osmosis
B. Sedimentation
C. Coagulation
D. Aeration
Reverse osmosis forces water through a semi-permeable membrane
to remove salts and impurities.
11. What does “BOD” stand for in wastewater analysis?
A. Biological Oxidation Density
B. Biochemical Organic Deposition
C. Biological Oxidizing Demand
D. Biochemical Oxygen Demand
Operator License Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of coagulation in water treatment?
A. Remove dissolved salts
B. Disinfect water
C. Destabilize suspended particles
D. Adjust pH
Coagulation involves adding chemicals to destabilize suspended
particles, allowing them to clump together for removal in subsequent
processes.
2. The Safe Drinking Water Act is primarily enforced by which agency?
A. U.S. Environmental Protection Agency (EPA)
B. Texas Commission on Environmental Quality (TCEQ)
, C. Occupational Safety and Health Administration (OSHA)
D. Texas Department of State Health Services
The EPA is the federal agency that enforces the Safe Drinking Water
Act, setting national standards for drinking water quality.
3. What is the most common chemical used for disinfection in water
treatment?
A. Ozone
B. Chloramines
C. Ultraviolet light
D. Chlorine
Chlorine is the most widely used disinfectant due to its effectiveness,
residual protection, and relatively low cost.
4. Which term describes water’s capacity to resist changes in pH?
A. Hardness
B. Alkalinity
C. Turbidity
D. Conductivity
Alkalinity measures the buffering capacity of water, which resists
changes in pH.
5. In a water treatment plant, what is the primary goal of sedimentation?
A. Remove dissolved solids
B. Kill pathogens
C. Allow heavier particles to settle out
, D. Reduce hardness
Sedimentation relies on gravity to allow suspended particles to settle
to the bottom before filtration.
6. What is the unit for measuring turbidity?
A. Nephelometric Turbidity Unit (NTU)
B. Parts per million (ppm)
C. Microns
D. Milligrams per liter (mg/L)
Turbidity is measured in NTU, indicating the cloudiness caused by
suspended particles.
7. Which component in a water treatment plant removes pathogens by
physical straining?
A. Sedimentation basin
B. Chemical feed system
C. Clearwell
D. Filter
Filters physically remove suspended particles, including many
pathogens, from the water.
8. The term “breakpoint chlorination” refers to:
A. Chlorine levels exceeding secondary standards
B. The point where chlorine demand is met and free chlorine remains
C. Maximum contaminant level for chlorine
D. Minimum disinfection level
, Breakpoint chlorination is when all chlorine demand is satisfied, and
free chlorine residual is established.
9. Which of the following is a primary standard regulated by the EPA?
A. Color
B. Odor
C. Lead
D. pH
Lead is regulated under primary drinking water standards because of
its health risks.
10. Which process uses semi-permeable membranes to remove
dissolved salts from water?
A. Reverse osmosis
B. Sedimentation
C. Coagulation
D. Aeration
Reverse osmosis forces water through a semi-permeable membrane
to remove salts and impurities.
11. What does “BOD” stand for in wastewater analysis?
A. Biological Oxidation Density
B. Biochemical Organic Deposition
C. Biological Oxidizing Demand
D. Biochemical Oxygen Demand
