Level 2 · Intermediate sample questions

Grit Removal Practice Questions for Level 2 · Intermediate

4 free sample questions on grit removal for the Level 2 · Intermediate wastewater treatment operator exam. Try each one, then open the answer to check your work.

Question 1
Washed grit contains more organic matter than normal. What should the operator review?
1. Classifier washing and separation
2. Grit discharge-chute alignment
3. Classifier motor operating hours
4. Grit-container level and pickup schedule
Show the answer
Answer: A. Classifier washing and separation
Classifier washing helps separate lighter organic matter from the denser grit, so excess organics in the washed grit point back to that step.
Question 2
A grit pump's discharge flow falls while suction vacuum and hopper level both rise. What should the operator inspect first?
1. Discharge valve, check valve, and downstream classifier inlet.
2. Pump speed, motor current, and operating timer.
3. Hopper washwater, fluidization air, and level sensor.
4. Suction line, inlet valve, and possible obstruction.
Show the answer
Answer: D. Suction line, inlet valve, and possible obstruction.
Rising suction vacuum with falling discharge indicates restricted flow into the pump.
Question 3
A vortex grit unit captures less grit, and downstream mineral deposits increase. Collected grit remains low in organics, and influent flow is steady at 2.0 MGD. The motor controller commands 45 rpm, a tachometer at the motor shaft reads 45 rpm, and a second tachometer on the chamber mechanism reads 32 rpm. What should the operator inspect first?
1. Inspect the classifier wash header
2. Inspect the chamber drive train
3. Inspect the grit-pump suction line
4. Inspect the inlet-gate position feedback
Show the answer
Answer: B. Inspect the chamber drive train
The motor shaft turns at the commanded 45 rpm while the chamber mechanism turns at 32 rpm, so the chamber drive train should be checked for lost motion or slip. A checks grit washing after capture, C checks grit removal from the chamber, and D checks inlet hydraulics; all are nearby causes, but they do not explain the speed loss between the motor shaft and chamber mechanism.
Question 4
A vortex grit chamber carries mineral solids downstream. The drive and grit pump pass checks, but a manual depth reading is lower than the level transmitter, causing the inlet gate to hold excess depth. What should be checked first?
1. Increase the grit-pump run time
2. Check the level-sensing system
3. Reduce the classifier wash flow
4. Raise the downstream channel gate
Show the answer
Answer: B. Check the level-sensing system
Checking the level-sensing system targets the verified disagreement that is driving the gate to an excessive depth. A changes a pump that passed checks, C changes washing after capture, and D changes hydraulics without correcting the false signal.

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Operator Master has 4 Level 2 · Intermediate grit removal questions, free.

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Wastewater Math Formulas

Question 1

Washed grit contains more organic matter than normal. What should the operator review?

Classifier washing and separation

Grit discharge-chute alignment

Classifier motor operating hours

Grit-container level and pickup schedule

Show the answer

Answer: A. Classifier washing and separation

Classifier washing helps separate lighter organic matter from the denser grit, so excess organics in the washed grit point back to that step.

Question 2

A grit pump's discharge flow falls while suction vacuum and hopper level both rise. What should the operator inspect first?

Discharge valve, check valve, and downstream classifier inlet.

Pump speed, motor current, and operating timer.

Hopper washwater, fluidization air, and level sensor.

Suction line, inlet valve, and possible obstruction.

Show the answer

Answer: D. Suction line, inlet valve, and possible obstruction.

Rising suction vacuum with falling discharge indicates restricted flow into the pump.

Question 3

A vortex grit unit captures less grit, and downstream mineral deposits increase. Collected grit remains low in organics, and influent flow is steady at 2.0 MGD. The motor controller commands 45 rpm, a tachometer at the motor shaft reads 45 rpm, and a second tachometer on the chamber mechanism reads 32 rpm. What should the operator inspect first?

Inspect the classifier wash header

Inspect the chamber drive train

Inspect the grit-pump suction line

Inspect the inlet-gate position feedback

Show the answer

Answer: B. Inspect the chamber drive train

The motor shaft turns at the commanded 45 rpm while the chamber mechanism turns at 32 rpm, so the chamber drive train should be checked for lost motion or slip. A checks grit washing after capture, C checks grit removal from the chamber, and D checks inlet hydraulics; all are nearby causes, but they do not explain the speed loss between the motor shaft and chamber mechanism.

Question 4

A vortex grit chamber carries mineral solids downstream. The drive and grit pump pass checks, but a manual depth reading is lower than the level transmitter, causing the inlet gate to hold excess depth. What should be checked first?

Increase the grit-pump run time

Check the level-sensing system

Reduce the classifier wash flow

Raise the downstream channel gate

Show the answer

Answer: B. Check the level-sensing system

Checking the level-sensing system targets the verified disagreement that is driving the gate to an excessive depth. A changes a pump that passed checks, C changes washing after capture, and D changes hydraulics without correcting the false signal.