WasteWater Operator class C Exam

WasteWater Operator class C Exam Practice Review Questions with Correct Answers 2023/2024 When Chlorine is combined with water what type of pipe should be used?

• Ductile iron
• Asbestos concrete

C. PVC

• Carbon Steel - Correct Answer C. PVC

A good settling sludge would consist of what type of protozoa?

• Rotifers and nematodes
• Amoebas and Flagellates
• Stalked ciliates and mastagoria
• Free swimmers and stalk ciliates - Correct Answer D. Free swimmers and stalk

ciliates What is Phenolphylein used for in titration

• Oxidizer
• Indicator
• Acid reducer to lower pH
• Applicator - Correct Answer 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%

• 96% - Correct Answer C. 95%

You suspect your anaerobic digester is going sour. What is the best way to verify its condition?

• pH
• Foam type
• VA/ALK ratio
• DO - Correct Answer C. VA/ALK ratio

Before operating any piece of equipment what should be done? 1 / 3

• Lock out Tag out (remember, safety first!)
• Read O & M manual
• Read manufacturers manual
• Notify supervisor - Correct Answer C. Read manufacturers manual

Detritus is noticed in your grit channel. What is the problem?

• Velocity too fast with short D/T
• Velocity too low with long D/T
• Short circuiting
• Density currents - Correct Answer B. Velocity too low with long D/T

What is considered normal operation of an aerobic digester?

• Fill react
• Skim off foam when needed
• Settle and Decant as needed
• Feed only during low flow or constant when the sun is out - Correct Answer C. Settle

and Decant as needed A plant with a flow of 1 MGD should be monitored

• Continuously
• Intermittently
• Daily
• Every four hours depending on surface load - Correct Answer A. Continuously

What do total solids consist of?

• Dissolved and settleable
• Floatable and settlable
• Suspended and dissolved
• Settlable and nonsettleable - Correct Answer C. Suspended and dissolved

What would cause excessive wear on bearing?

• Misalignment
• Reduced Oil due to low viscosity
• Blow seal
• Over tubercation - Correct Answer A. Misalignment

Amperometric titration is used to measure

• Dissolved solids
• Chlorine residual
• Colloids 2 / 3

• Emulsions - Correct Answer B. Chlorine residual

What growth phase is an aerobic digester operated in.

• Log
• Lag
• Endogenous respiration
• Declining phase - Correct Answer C. Endogenous respiration

If excessive pressure builds up in a chlorine tank due to excessive heat. What will prevent explosions?

• Valve seat adjustments
• Heat reducing valve
• Fusible plug
• Check valve - Correct Answer C. Fusible plug

You notice that your bearings are excessively hot on a pump, why?

• Ambient temperature too high
• Over lubrication
• Oil seal blown
• Discharge rate too low - Correct Answer B. Over lubrication

Where can you gain access for collection system maintenance?

• Lift station
• Force main
• Man hole
• Gravity main - Correct Answer C. Man hole

Low DO and nutrient deficiency will promote the growth of what?

• Rotifers
• Filamentous bacteria
• Spirillium
• Amoebas - Correct Answer B. Filamentous bacteria

When charging a lead-acid type battery for a composite sampler, what dangerous gas could be produced?

• Hydrogen
• Oxygen
• Hydrogen sulfide
• Cyanide - Correct Answer A. Hydrogen
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