TCEQ SURFACE WATER B LICENSE TEST EXAM | ALL
PRACTICE Q&A 2026/2027 | A+ GRADED |
COMPREHENSIVE EXAM GUIDE 2026&2027
1. Which statement best describes the primary responsibility of a Class B Surface Water
Treatment Operator?
A. Maintaining only the distribution system
B. Operating and controlling treatment processes so finished water meets applicable
requirements ✔
C. Performing only administrative duties
D. Inspecting private plumbing systems
The operator is responsible for controlling treatment processes, monitoring performance,
responding to process changes, and helping ensure finished water complies with applicable
drinking-water requirements.
2. A raw-water turbidity reading begins increasing rapidly after a storm. What should the
operator evaluate first?
A. The condition of the raw-water source and treatment response ✔
B. The color of the finished-water storage tank
C. The billing records for customers
D. The age of the distribution piping
A storm can introduce increased suspended solids and organic material into the source. The
operator should assess source conditions and determine whether coagulation, filtration, and
other treatment processes require adjustment.
3. Which treatment objective is most directly associated with coagulation?
A. Increasing finished-water hardness
B. Destroying all microorganisms
C. Destabilizing suspended and colloidal particles so they can form larger flocs ✔
D. Increasing water temperature
Coagulation reduces particle stability and promotes aggregation. Properly destabilized
particles can then form floc that is more readily removed by subsequent treatment processes.
4. During a jar test, an operator observes that a slightly lower coagulant dose produces
stronger, larger floc than the current dose. What is the most appropriate next step?
A. Immediately double the plant dosage
B. Stop coagulation completely
C. Ignore the jar-test results
D. Evaluate the test conditions and consider an appropriately controlled process adjustment ✔
,Jar testing is a process-control tool. Results should be evaluated against plant conditions
before making a controlled adjustment rather than blindly changing the chemical feed rate.
5. Why is rapid mixing important immediately after coagulant addition?
A. It rapidly distributes the chemical throughout the water ✔
B. It removes settled sludge
C. It increases filter-bed depth
D. It disinfects the distribution system
Rapid mixing promotes uniform dispersion of the coagulant and allows the chemical to
interact effectively with particles before the water enters the flocculation stage.
6. A flocculation basin is producing small, fragile floc. Which condition should the operator
investigate?
A. Customer meter accuracy
B. Excessive or insufficient mixing energy ✔
C. Finished-water billing
D. Distribution pressure only
Flocculation requires controlled mixing. Excessive shear can break floc apart, while
inadequate mixing may prevent particles from colliding and forming strong floc.
7. What is the primary purpose of sedimentation following flocculation?
A. Increase chlorine concentration
B. Remove formed floc by gravity settling ✔
C. Raise alkalinity
D. Add oxygen to the water
Sedimentation provides relatively quiescent conditions that allow heavier floc particles to
settle from the water before filtration.
8. An operator notices that settled-water turbidity is increasing while sludge accumulation
is unusually high. What should be investigated?
A. Whether solids removal and sludge-management practices are adequate ✔
B. Whether customer bills are correct
C. Whether hydrants are painted
D. Whether distribution meters are calibrated
Excessive sludge accumulation can interfere with basin performance and may contribute to
solids carryover. Proper sludge removal and basin operation are essential for stable
treatment.
9. What is the principal purpose of filtration in a conventional surface-water treatment
process?
A. Remove remaining particulate matter and other contaminants after clarification ✔
,B. Increase raw-water flow
C. Add coagulant to the source
D. Replace all disinfection requirements
Filtration provides an important physical barrier for removing remaining particles and can
contribute significantly to microbial removal when properly operated.
10. A filter begins showing an unusually rapid increase in head loss shortly after being
placed in service. What should the operator investigate?
A. Potential solids loading, media condition, or filtration-rate problems ✔
B. Customer complaints about billing
C. Chlorine cylinder labels only
D. Distribution-system maps
Rapid head-loss development can indicate excessive particulate loading, media problems,
inappropriate filtration conditions, or other operational issues requiring investigation.
11. What does filter breakthrough generally indicate?
A. Improved particle removal
B. Loss of effective particle-removal performance ✔
C. Increased source-water alkalinity
D. Successful chemical storage
Filter breakthrough means particles or turbidity are passing through the filter at unacceptable
or increasing levels, indicating that filtration performance requires attention.
12. A filter effluent turbidity suddenly increases while other filters remain stable. What is
the most appropriate initial response?
A. Assume the laboratory result is wrong
B. Investigate the individual filter and verify the measurement ✔
C. Increase plant flow immediately
D. Shut down the entire distribution system without investigation
The operator should first verify the measurement and investigate the affected filter for
operational or mechanical causes before making broader plant decisions.
13. Why is backwashing performed on granular-media filters?
A. To remove accumulated solids and restore filter performance ✔
B. To increase coagulant concentration
C. To disinfect the raw-water intake
D. To increase finished-water hardness
Backwashing reverses flow through the filter bed to expand and clean the media, removing
accumulated solids and restoring hydraulic performance.
, 14. During backwash, excessive media loss is observed. What should the operator
investigate?
A. Backwash rate and bed expansion conditions ✔
B. Customer billing records
C. Fluoride taste complaints only
D. Distribution-pipe age
Excessive media loss can result when backwash flow is too high or when other filter-bed
conditions are abnormal. The operator should verify the backwash rate and bed behavior.
15. Which factor is especially important when evaluating chlorine disinfection
effectiveness?
A. Contact time and disinfectant concentration ✔
B. Pipe color
C. Employee uniform type
D. Customer account number
Disinfection effectiveness depends on factors including disinfectant concentration, contact
time, temperature, pH, and water quality.
16. Why does increasing water temperature generally affect chlorine disinfection?
A. Temperature can influence reaction rates and disinfection effectiveness ✔
B. Temperature has no relationship to disinfection
C. Temperature eliminates the need for chlorine
D. Temperature determines filter-media size
Temperature influences chemical reactions and microbial inactivation. Operators must
consider temperature along with concentration, contact time, pH, and other conditions.
17. A chlorine residual is unexpectedly low leaving the treatment process. What should the
operator check first?
A. Chemical feed, chlorine supply, analyzer performance, and process conditions ✔
B. Customer meter serial numbers
C. Distribution hydrant paint
D. Office lighting
A low residual can result from feed-system problems, depleted chemical supply, analyzer
errors, increased chlorine demand, or other treatment conditions. Systematic troubleshooting
is required.
18. What is chlorine demand?
A. The amount of chlorine consumed by reactions with substances in the water before the desired
residual remains ✔
B. The amount of water entering the plant
PRACTICE Q&A 2026/2027 | A+ GRADED |
COMPREHENSIVE EXAM GUIDE 2026&2027
1. Which statement best describes the primary responsibility of a Class B Surface Water
Treatment Operator?
A. Maintaining only the distribution system
B. Operating and controlling treatment processes so finished water meets applicable
requirements ✔
C. Performing only administrative duties
D. Inspecting private plumbing systems
The operator is responsible for controlling treatment processes, monitoring performance,
responding to process changes, and helping ensure finished water complies with applicable
drinking-water requirements.
2. A raw-water turbidity reading begins increasing rapidly after a storm. What should the
operator evaluate first?
A. The condition of the raw-water source and treatment response ✔
B. The color of the finished-water storage tank
C. The billing records for customers
D. The age of the distribution piping
A storm can introduce increased suspended solids and organic material into the source. The
operator should assess source conditions and determine whether coagulation, filtration, and
other treatment processes require adjustment.
3. Which treatment objective is most directly associated with coagulation?
A. Increasing finished-water hardness
B. Destroying all microorganisms
C. Destabilizing suspended and colloidal particles so they can form larger flocs ✔
D. Increasing water temperature
Coagulation reduces particle stability and promotes aggregation. Properly destabilized
particles can then form floc that is more readily removed by subsequent treatment processes.
4. During a jar test, an operator observes that a slightly lower coagulant dose produces
stronger, larger floc than the current dose. What is the most appropriate next step?
A. Immediately double the plant dosage
B. Stop coagulation completely
C. Ignore the jar-test results
D. Evaluate the test conditions and consider an appropriately controlled process adjustment ✔
,Jar testing is a process-control tool. Results should be evaluated against plant conditions
before making a controlled adjustment rather than blindly changing the chemical feed rate.
5. Why is rapid mixing important immediately after coagulant addition?
A. It rapidly distributes the chemical throughout the water ✔
B. It removes settled sludge
C. It increases filter-bed depth
D. It disinfects the distribution system
Rapid mixing promotes uniform dispersion of the coagulant and allows the chemical to
interact effectively with particles before the water enters the flocculation stage.
6. A flocculation basin is producing small, fragile floc. Which condition should the operator
investigate?
A. Customer meter accuracy
B. Excessive or insufficient mixing energy ✔
C. Finished-water billing
D. Distribution pressure only
Flocculation requires controlled mixing. Excessive shear can break floc apart, while
inadequate mixing may prevent particles from colliding and forming strong floc.
7. What is the primary purpose of sedimentation following flocculation?
A. Increase chlorine concentration
B. Remove formed floc by gravity settling ✔
C. Raise alkalinity
D. Add oxygen to the water
Sedimentation provides relatively quiescent conditions that allow heavier floc particles to
settle from the water before filtration.
8. An operator notices that settled-water turbidity is increasing while sludge accumulation
is unusually high. What should be investigated?
A. Whether solids removal and sludge-management practices are adequate ✔
B. Whether customer bills are correct
C. Whether hydrants are painted
D. Whether distribution meters are calibrated
Excessive sludge accumulation can interfere with basin performance and may contribute to
solids carryover. Proper sludge removal and basin operation are essential for stable
treatment.
9. What is the principal purpose of filtration in a conventional surface-water treatment
process?
A. Remove remaining particulate matter and other contaminants after clarification ✔
,B. Increase raw-water flow
C. Add coagulant to the source
D. Replace all disinfection requirements
Filtration provides an important physical barrier for removing remaining particles and can
contribute significantly to microbial removal when properly operated.
10. A filter begins showing an unusually rapid increase in head loss shortly after being
placed in service. What should the operator investigate?
A. Potential solids loading, media condition, or filtration-rate problems ✔
B. Customer complaints about billing
C. Chlorine cylinder labels only
D. Distribution-system maps
Rapid head-loss development can indicate excessive particulate loading, media problems,
inappropriate filtration conditions, or other operational issues requiring investigation.
11. What does filter breakthrough generally indicate?
A. Improved particle removal
B. Loss of effective particle-removal performance ✔
C. Increased source-water alkalinity
D. Successful chemical storage
Filter breakthrough means particles or turbidity are passing through the filter at unacceptable
or increasing levels, indicating that filtration performance requires attention.
12. A filter effluent turbidity suddenly increases while other filters remain stable. What is
the most appropriate initial response?
A. Assume the laboratory result is wrong
B. Investigate the individual filter and verify the measurement ✔
C. Increase plant flow immediately
D. Shut down the entire distribution system without investigation
The operator should first verify the measurement and investigate the affected filter for
operational or mechanical causes before making broader plant decisions.
13. Why is backwashing performed on granular-media filters?
A. To remove accumulated solids and restore filter performance ✔
B. To increase coagulant concentration
C. To disinfect the raw-water intake
D. To increase finished-water hardness
Backwashing reverses flow through the filter bed to expand and clean the media, removing
accumulated solids and restoring hydraulic performance.
, 14. During backwash, excessive media loss is observed. What should the operator
investigate?
A. Backwash rate and bed expansion conditions ✔
B. Customer billing records
C. Fluoride taste complaints only
D. Distribution-pipe age
Excessive media loss can result when backwash flow is too high or when other filter-bed
conditions are abnormal. The operator should verify the backwash rate and bed behavior.
15. Which factor is especially important when evaluating chlorine disinfection
effectiveness?
A. Contact time and disinfectant concentration ✔
B. Pipe color
C. Employee uniform type
D. Customer account number
Disinfection effectiveness depends on factors including disinfectant concentration, contact
time, temperature, pH, and water quality.
16. Why does increasing water temperature generally affect chlorine disinfection?
A. Temperature can influence reaction rates and disinfection effectiveness ✔
B. Temperature has no relationship to disinfection
C. Temperature eliminates the need for chlorine
D. Temperature determines filter-media size
Temperature influences chemical reactions and microbial inactivation. Operators must
consider temperature along with concentration, contact time, pH, and other conditions.
17. A chlorine residual is unexpectedly low leaving the treatment process. What should the
operator check first?
A. Chemical feed, chlorine supply, analyzer performance, and process conditions ✔
B. Customer meter serial numbers
C. Distribution hydrant paint
D. Office lighting
A low residual can result from feed-system problems, depleted chemical supply, analyzer
errors, increased chlorine demand, or other treatment conditions. Systematic troubleshooting
is required.
18. What is chlorine demand?
A. The amount of chlorine consumed by reactions with substances in the water before the desired
residual remains ✔
B. The amount of water entering the plant
