Accurate Exam Coverage Area (High-Yield Recent Topics)
1. Coagulation, Flocculation & Sedimentation – Jar testing, coagulant
dose calculations, pH optimization for alum, floc formation
troubleshooting, sedimentation basin hydraulics.
2. Filtration – Head loss monitoring, backwash rates, filter production
calculations, media types, turbidity breakthrough causes.
3. Disinfection & CT Values – Chlorine chemistry, breakpoint
chlorination, CT calculations, chloramine formation, DBP reduction,
disinfectant selection.
4. Water Quality Regulations (Title 22) – MCLs for TTHM/HAA5, total
coliform rule, turbidity limits, reporting requirements.
5. Corrosion Control & Stability – pH adjustment, alkalinity relationships,
lead/copper corrosion indicators, inhibitor feed.
, 6. Chemical Feed & Laboratory – Dilution calculations, feeder
calibration, reagent preparation, chlorine residual analysis, turbidity
measurement.
7. Pumps, Motors & Instrumentation – Pump installation, SCADA normal
operation, online analyzer components, pressure gauge replacement.
8. Source Water & Hydrology – Reservoir intake level effects, seasonal
water quality changes, algae impacts.
9. Safety & Emergency Response – Chemical handling compatibility,
chlorine gas emergency procedures, confined space basics.
10. Math & Calculations – Pounds formula, detention time, filter rate,
chemical dosage, CT value, dilution factors.
California Water System/Treatment Operator Grade 2 (T2) Exam
250 Multiple-Choice Questions with Answers and Rationales
,1. A water treatment operator observes that settled water turbidity has
increased sharply while raw water quality remains stable. Which of the
following is the most likely operational cause that should be
investigated first?
A. The sedimentation basin sludge collector is running continuously
B. The coagulant feed pump has lost calibration and is underfeeding
C. The filter backwash cycle was completed earlier than usual
D. The finished water storage tank level is unusually high
Answer: B
Rationale: Stable raw water with worsening settled turbidity points to a
treatment process failure, most commonly coagulant underfeed due to
pump calibration drift, which directly reduces particle destabilization
and floc formation.
2. When performing a jar test to optimize coagulation for a surface
water source with high turbidity and low alkalinity, which parameter
, should the operator adjust across the test jars to determine the most
effective dose?
A. The rapid mix speed only
B. The coagulant dose while maintaining consistent mixing
C. The filter loading rate
D. The clearwell chlorine residual
Answer: B
Rationale: Jar tests systematically vary coagulant dose while holding
mixing intensity and time constant, allowing the operator to identify the
dose producing the lowest settled turbidity and best floc characteristics.
3. A filter has been in service for 68 hours and the head loss has
reached 9.5 feet, which exceeds the plant’s terminal head loss limit of
8 feet. What is the correct operational response?
A. Increase the filtration rate to push water through the media
B. Continue running until turbidity breakthrough occurs
1. Coagulation, Flocculation & Sedimentation – Jar testing, coagulant
dose calculations, pH optimization for alum, floc formation
troubleshooting, sedimentation basin hydraulics.
2. Filtration – Head loss monitoring, backwash rates, filter production
calculations, media types, turbidity breakthrough causes.
3. Disinfection & CT Values – Chlorine chemistry, breakpoint
chlorination, CT calculations, chloramine formation, DBP reduction,
disinfectant selection.
4. Water Quality Regulations (Title 22) – MCLs for TTHM/HAA5, total
coliform rule, turbidity limits, reporting requirements.
5. Corrosion Control & Stability – pH adjustment, alkalinity relationships,
lead/copper corrosion indicators, inhibitor feed.
, 6. Chemical Feed & Laboratory – Dilution calculations, feeder
calibration, reagent preparation, chlorine residual analysis, turbidity
measurement.
7. Pumps, Motors & Instrumentation – Pump installation, SCADA normal
operation, online analyzer components, pressure gauge replacement.
8. Source Water & Hydrology – Reservoir intake level effects, seasonal
water quality changes, algae impacts.
9. Safety & Emergency Response – Chemical handling compatibility,
chlorine gas emergency procedures, confined space basics.
10. Math & Calculations – Pounds formula, detention time, filter rate,
chemical dosage, CT value, dilution factors.
California Water System/Treatment Operator Grade 2 (T2) Exam
250 Multiple-Choice Questions with Answers and Rationales
,1. A water treatment operator observes that settled water turbidity has
increased sharply while raw water quality remains stable. Which of the
following is the most likely operational cause that should be
investigated first?
A. The sedimentation basin sludge collector is running continuously
B. The coagulant feed pump has lost calibration and is underfeeding
C. The filter backwash cycle was completed earlier than usual
D. The finished water storage tank level is unusually high
Answer: B
Rationale: Stable raw water with worsening settled turbidity points to a
treatment process failure, most commonly coagulant underfeed due to
pump calibration drift, which directly reduces particle destabilization
and floc formation.
2. When performing a jar test to optimize coagulation for a surface
water source with high turbidity and low alkalinity, which parameter
, should the operator adjust across the test jars to determine the most
effective dose?
A. The rapid mix speed only
B. The coagulant dose while maintaining consistent mixing
C. The filter loading rate
D. The clearwell chlorine residual
Answer: B
Rationale: Jar tests systematically vary coagulant dose while holding
mixing intensity and time constant, allowing the operator to identify the
dose producing the lowest settled turbidity and best floc characteristics.
3. A filter has been in service for 68 hours and the head loss has
reached 9.5 feet, which exceeds the plant’s terminal head loss limit of
8 feet. What is the correct operational response?
A. Increase the filtration rate to push water through the media
B. Continue running until turbidity breakthrough occurs
