Waste Water Operator class C exam
2024/2025 Review Questions and Answers
correct verified
When Chlorine is combined with water what type of pipe should be used?
A. Ductile iron
B. Asbestos concrete
C. PVC
D. Carbon Steel
C. PVC
A good settling sludge would consist of what type of protozoa?
A. Rotifers and nematodes
B. Amoebas and Flagellates
C. Stalked ciliates and mastagoria
D. Free swimmers and stalk ciliates
D. Free swimmers and stalk ciliates
What is Phenolphylein used for in titration
A. Oxidizer
B. Indicator
C. Acid reducer to lower pH
D. Applicator
B. Indicator
Your plant has an influent of 220 BOD and 163 TSS, and an effluent of 10 BOD, and 6 TSS. What is the
BOD removal efficiency in your plant?
A. 92%
B. 94%
C. 95%
D. 96%
C. 95%
You suspect your anaerobic digester is going sour. What is the best way to verify its condition?
A. pH
B. Foam type
C. VA/ALK ratio
D. DO
C. VA/ALK ratio
Before operating any piece of equipment what should be done?
A. Lock out Tag out (remember, safety first!)
B. Read O & M manual
C. Read manufacturers manual
D. Notify supervisor
,C. Read manufacturers manual
Detritus is noticed in your grit channel. What is the problem?
A. Velocity too fast with short D/T
B. Velocity too low with long D/T
C. Short circuiting
D. Density currents
B. Velocity too low with long D/T
What is considered normal operation of an aerobic digester?
A. Fill react
B. Skim off foam when needed
C. Settle and Decant as needed
D. Feed only during low flow or constant when the sun is out
C. Settle and Decant as needed
A plant with a flow of 1 MGD should be monitored
A. Continuously
B. Intermittently
C. Daily
D. Every four hours depending on surface load
A. Continuously
What do total solids consist of?
A. Dissolved and settleable
B. Floatable and settlable
C. Suspended and dissolved
D. Settlable and nonsettleable
C. Suspended and dissolved
What would cause excessive wear on bearing?
A. Misalignment
B. Reduced Oil due to low viscosity
C. Blow seal
D. Over tubercation
A. Misalignment
Amperometric titration is used to measure
A. Dissolved solids
B. Chlorine residual
C. Colloids
D. Emulsions
B. Chlorine residual
, What growth phase is an aerobic digester operated in.
A. Log
B. Lag
C. Endogenous respiration
D. Declining phase
C. Endogenous respiration
If excessive pressure builds up in a chlorine tank due to excessive heat. What will prevent explosions?
A. Valve seat adjustments
B. Heat reducing valve
C. Fusible plug
D. Check valve
C. Fusible plug
You notice that your bearings are excessively hot on a pump, why?
A. Ambient temperature too high
B. Over lubrication
C. Oil seal blown
D. Discharge rate too low
B. Over lubrication
Where can you gain access for collection system maintenance?
A. Lift station
B. Force main
C. Man hole
D. Gravity main
C. Man hole
Low DO and nutrient deficiency will promote the growth of what?
A. Rotifers
B. Filamentous bacteria
C. Spirillium
D. Amoebas
B. Filamentous bacteria
When charging a lead-acid type battery for a composite sampler, what dangerous gas could be
produced?
A. Hydrogen
B. Oxygen
C. Hydrogen sulfide
D. Cyanide
A. Hydrogen
What is the best method in dealing with a chemical spill?
2024/2025 Review Questions and Answers
correct verified
When Chlorine is combined with water what type of pipe should be used?
A. Ductile iron
B. Asbestos concrete
C. PVC
D. Carbon Steel
C. PVC
A good settling sludge would consist of what type of protozoa?
A. Rotifers and nematodes
B. Amoebas and Flagellates
C. Stalked ciliates and mastagoria
D. Free swimmers and stalk ciliates
D. Free swimmers and stalk ciliates
What is Phenolphylein used for in titration
A. Oxidizer
B. Indicator
C. Acid reducer to lower pH
D. Applicator
B. Indicator
Your plant has an influent of 220 BOD and 163 TSS, and an effluent of 10 BOD, and 6 TSS. What is the
BOD removal efficiency in your plant?
A. 92%
B. 94%
C. 95%
D. 96%
C. 95%
You suspect your anaerobic digester is going sour. What is the best way to verify its condition?
A. pH
B. Foam type
C. VA/ALK ratio
D. DO
C. VA/ALK ratio
Before operating any piece of equipment what should be done?
A. Lock out Tag out (remember, safety first!)
B. Read O & M manual
C. Read manufacturers manual
D. Notify supervisor
,C. Read manufacturers manual
Detritus is noticed in your grit channel. What is the problem?
A. Velocity too fast with short D/T
B. Velocity too low with long D/T
C. Short circuiting
D. Density currents
B. Velocity too low with long D/T
What is considered normal operation of an aerobic digester?
A. Fill react
B. Skim off foam when needed
C. Settle and Decant as needed
D. Feed only during low flow or constant when the sun is out
C. Settle and Decant as needed
A plant with a flow of 1 MGD should be monitored
A. Continuously
B. Intermittently
C. Daily
D. Every four hours depending on surface load
A. Continuously
What do total solids consist of?
A. Dissolved and settleable
B. Floatable and settlable
C. Suspended and dissolved
D. Settlable and nonsettleable
C. Suspended and dissolved
What would cause excessive wear on bearing?
A. Misalignment
B. Reduced Oil due to low viscosity
C. Blow seal
D. Over tubercation
A. Misalignment
Amperometric titration is used to measure
A. Dissolved solids
B. Chlorine residual
C. Colloids
D. Emulsions
B. Chlorine residual
, What growth phase is an aerobic digester operated in.
A. Log
B. Lag
C. Endogenous respiration
D. Declining phase
C. Endogenous respiration
If excessive pressure builds up in a chlorine tank due to excessive heat. What will prevent explosions?
A. Valve seat adjustments
B. Heat reducing valve
C. Fusible plug
D. Check valve
C. Fusible plug
You notice that your bearings are excessively hot on a pump, why?
A. Ambient temperature too high
B. Over lubrication
C. Oil seal blown
D. Discharge rate too low
B. Over lubrication
Where can you gain access for collection system maintenance?
A. Lift station
B. Force main
C. Man hole
D. Gravity main
C. Man hole
Low DO and nutrient deficiency will promote the growth of what?
A. Rotifers
B. Filamentous bacteria
C. Spirillium
D. Amoebas
B. Filamentous bacteria
When charging a lead-acid type battery for a composite sampler, what dangerous gas could be
produced?
A. Hydrogen
B. Oxygen
C. Hydrogen sulfide
D. Cyanide
A. Hydrogen
What is the best method in dealing with a chemical spill?
