CWEA MECHANICAL
TECHNOLOGIST GRADE 3
CERTIFICATION EXAM 2026
TECHNOLOGIST SCRIPT SOLVED
QUESTIONS VERIFIED ANSWERS A+
◉ Mechanical seal failure.
Answer: A failure that can occur due to overheating, excessive vibration,
and low flow rates.
◉ Air blower.
Answer: A device used to supply oxygen to aerobic processes in
wastewater treatment.
◉ Motor maintenance checks.
Answer: Routine checks that include lubrication of bearings, voltage and
current levels, and alignment with the drive shaft.
◉ Corrosion prevention in mechanical components.
Answer: Typically achieved using stainless steel due to its resistance to
corrosion.
◉ Pump not priming troubleshooting.
Answer: Checking the pump's discharge valve to ensure it's fully open.
,◉ Cleaning a clogged pump impeller.
Answer: Recommended to remove and manually clean the impeller with
a brush.
◉ Safety precautions with electrical motors.
Answer: Ensuring the motor is properly grounded to prevent electrical
shock.
◉ Mechanical strainer function.
Answer: To filter out solids from liquids in wastewater treatment.
◉ Mechanical strainers.
Answer: Mechanical strainers are used to remove large solids and debris
from wastewater before it enters treatment systems, preventing damage
to equipment and ensuring smoother operation.
◉ Oil change interval for gear reducers.
Answer: Gear reducers should be serviced according to the
manufacturer's guidelines, which often specify an interval for oil
changes, typically between 6 months and 2 years depending on usage.
◉ Check valve.
Answer: Check valves allow flow in one direction and automatically
close to prevent backflow, protecting pumps and other equipment from
damage.
,◉ Cavitation in pumps.
Answer: Cavitation occurs when vapor bubbles form in the pump due to
low pressure and then collapse, causing noise, vibration, and potential
damage to the pump.
◉ Replacing bearings in a pump motor.
Answer: It is crucial to replace bearings with those that match the
original specifications to maintain proper motor function and extend
service life.
◉ First check if a pump motor is not starting.
Answer: If a pump motor is not starting, the first step should be to check
the power supply and ensure electrical connections are intact and
functioning.
◉ Variable frequency drive (VFD).
Answer: A VFD allows for variable speed operation of pumps, which
helps optimize energy usage based on system demand, reducing
electricity costs.
◉ Cast iron.
Answer: Cast iron is commonly used for pump impellers due to its
strength, wear resistance, and ability to withstand harsh wastewater
conditions.
, ◉ Sludge conveyor system.
Answer: Sludge conveyors are used to move accumulated sludge from
various treatment processes to the dewatering area or disposal site.
◉ Running a pump dry.
Answer: Running a pump dry can cause severe damage to the pump
components (like the seals and bearings), so it should be turned off as
soon as possible.
◉ Expansion joint.
Answer: Expansion joints are used to absorb the stresses caused by
thermal expansion or contraction in piping systems, preventing pipe
damage or breakage.
◉ Stainless steel.
Answer: Stainless steel is commonly used for pump shafts due to its
resistance to corrosion and wear in wastewater environments.
◉ Pressure relief valve set point.
Answer: The set point for a pressure relief valve should be adjusted
based on the maximum allowable discharge pressure to ensure safe
operation and prevent system overpressure.
◉ Screw conveyor.
Answer: Screw conveyors are designed to transport thick or wet
materials, such as sludge, and are less likely to clog over long distances.
TECHNOLOGIST GRADE 3
CERTIFICATION EXAM 2026
TECHNOLOGIST SCRIPT SOLVED
QUESTIONS VERIFIED ANSWERS A+
◉ Mechanical seal failure.
Answer: A failure that can occur due to overheating, excessive vibration,
and low flow rates.
◉ Air blower.
Answer: A device used to supply oxygen to aerobic processes in
wastewater treatment.
◉ Motor maintenance checks.
Answer: Routine checks that include lubrication of bearings, voltage and
current levels, and alignment with the drive shaft.
◉ Corrosion prevention in mechanical components.
Answer: Typically achieved using stainless steel due to its resistance to
corrosion.
◉ Pump not priming troubleshooting.
Answer: Checking the pump's discharge valve to ensure it's fully open.
,◉ Cleaning a clogged pump impeller.
Answer: Recommended to remove and manually clean the impeller with
a brush.
◉ Safety precautions with electrical motors.
Answer: Ensuring the motor is properly grounded to prevent electrical
shock.
◉ Mechanical strainer function.
Answer: To filter out solids from liquids in wastewater treatment.
◉ Mechanical strainers.
Answer: Mechanical strainers are used to remove large solids and debris
from wastewater before it enters treatment systems, preventing damage
to equipment and ensuring smoother operation.
◉ Oil change interval for gear reducers.
Answer: Gear reducers should be serviced according to the
manufacturer's guidelines, which often specify an interval for oil
changes, typically between 6 months and 2 years depending on usage.
◉ Check valve.
Answer: Check valves allow flow in one direction and automatically
close to prevent backflow, protecting pumps and other equipment from
damage.
,◉ Cavitation in pumps.
Answer: Cavitation occurs when vapor bubbles form in the pump due to
low pressure and then collapse, causing noise, vibration, and potential
damage to the pump.
◉ Replacing bearings in a pump motor.
Answer: It is crucial to replace bearings with those that match the
original specifications to maintain proper motor function and extend
service life.
◉ First check if a pump motor is not starting.
Answer: If a pump motor is not starting, the first step should be to check
the power supply and ensure electrical connections are intact and
functioning.
◉ Variable frequency drive (VFD).
Answer: A VFD allows for variable speed operation of pumps, which
helps optimize energy usage based on system demand, reducing
electricity costs.
◉ Cast iron.
Answer: Cast iron is commonly used for pump impellers due to its
strength, wear resistance, and ability to withstand harsh wastewater
conditions.
, ◉ Sludge conveyor system.
Answer: Sludge conveyors are used to move accumulated sludge from
various treatment processes to the dewatering area or disposal site.
◉ Running a pump dry.
Answer: Running a pump dry can cause severe damage to the pump
components (like the seals and bearings), so it should be turned off as
soon as possible.
◉ Expansion joint.
Answer: Expansion joints are used to absorb the stresses caused by
thermal expansion or contraction in piping systems, preventing pipe
damage or breakage.
◉ Stainless steel.
Answer: Stainless steel is commonly used for pump shafts due to its
resistance to corrosion and wear in wastewater environments.
◉ Pressure relief valve set point.
Answer: The set point for a pressure relief valve should be adjusted
based on the maximum allowable discharge pressure to ensure safe
operation and prevent system overpressure.
◉ Screw conveyor.
Answer: Screw conveyors are designed to transport thick or wet
materials, such as sludge, and are less likely to clog over long distances.
