Which of the following is not likely to develop if wastewater remains int eh collection system
too long? - ANSWER Algae
A high sewage pH can result int production of toxic gases due to : - ANSWER Ammonia
What problems do septic conditions in the collection system cause at the treatment plant? -
ANSWER Odor and oxygen demand
If a lift station pump will not start what do you check? - ANSWER Broken and loose termi-
nal connections
Shaft binding or sticking
Motor shorted or burned out
The amount of iron salts fed to the collection system should be increased whenever the: -
ANSWER Hydrogen sulfide level increases
Where should the flow meter sensor be located at the parshall flume? - ANSWER At a
specified location in the convergence of the flume
What/where is the palmer bowlus flume used in wastewater? - ANSWER Primary applica-
tion: pipelines, round bottom channels, manholes where it is often preferred because the
cost and ease of installation that can minimize construction expense
Which of the following statements is not true concerning the operation of a magnetic flow
meter? - ANSWER It operates partially full
1
,What methods can be used to check the performance of a flow meter? - ANSWER Meas-
ure area and velocity in an open channel
Measure how long it takes to fill a 55 gallon drum
Measure how long it takes to fill a tank
On what type of treatment process do hydraulic flow variations have the greatest impact? -
ANSWER Activated sludge
What is important to understand about the impact of high flow on treatment units? - AN-
SWER As flow increases, detention time decreases
What is the first indication that a strong toxic industrial substance has entered the activated
sludge plant? - ANSWER Increase in oxygen concentration in the aeration basin
Which type of cave in protection provides the best and most practical way to protect work-
ers in deep excavations? - ANSWER Drag shields and shoring
How do manholes, lift stations, and other features associated with collections/treatment
systems would be viewed from a risk assessment point of view? - ANSWER Vulnerabilities
Which of the following is an offensive smelling gas found in wastewater treatment plants? -
ANSWER Mercaptan
Workers in a sludge composting operation should wear respiratory protection because the
compost can give off: - ANSWER Airborne sludge particles
What safety equipment should an operator use in areas containing gaseous and particulate
contaminants? - ANSWER Supplied air respirator
Which type of fire extinguisher should be used for an electrical fire? - ANSWER Class C
2
,An accident prevention program in generate involves which of the following sets of steps? -
ANSWER Recognition of hazards, evaluation of hazards, and control of hazards
How often should fire extinguisher be recharged? - ANSWER After every use
Which of the following can poison the atmosphere in a room and should always be handled
with special care? - ANSWER Mercury
What is the danger level as defined by federal refs, to individuals whose normal noise expo-
sure might equal or exceed this dangerous level - ANSWER 8 hour (TWA) of 85 decibels
Widely fluctuating hydraulic flows may require which of the following? - ANSWER Flow
equalization
If you noticed poor solids settling in the clarifier and solids overflow into the chlorine contact
chamber, what would you do if the dilated settleometer showed improved settling?? - AN-
SWER Increase sludge wasting
As temperature decreases under normal conditions which are the following effect - AN-
SWER Biological activity slows down, viscosity of the H2O increases, solids settle slow
How does a water temperature decrease affect aerobic biological processes? - ANSWER
Decrease in solids settling efficiency
More oxygen in the solution
Fine screens typically consist of wedge wire, perforated plate, or closely spaced bars with
openings in what range? - ANSWER 0.06 - 0.25 inches
3
, One advantage of rotating screens over stationary screens is that rotating screens generally -
ANSWER Do not dam the flow
What is the purpose of injecting diffused air into aerated grit chambers? - ANSWER To
lower the specific gravity of water
What is accomplished by an aerated grit chamber? - ANSWER Grit is removed
Grit is washed
Wastewater is freshened
When using cyclones at the end of a grit removal process what will cause a decrease in grit
removal efficiency in the cyclone? - ANSWER Cyclone inlet pressure too low.
Increase the inlet pressure by adjusting the grit pump discharge
What should an operator do if the communicator is not operating properly? - ANSWER
Check the motor and look for blockage
Cut off the electricity
Lock out and tag the breaker
Place the bar screen into service
How often should communicators be operated? - ANSWER Continuously
How can you control the velocity in a grit channel in order to achieve velocities within a
range of 0.7 to 1.4 ft/ sec? - ANSWER Line the sides with bricks or blocks to change the
cross-sectional area
Use proportional weirs
Vary the number of channels in service in a multiple channel installation
What is primary clarifiers designed to remove? - ANSWER Settleable solids
4
too long? - ANSWER Algae
A high sewage pH can result int production of toxic gases due to : - ANSWER Ammonia
What problems do septic conditions in the collection system cause at the treatment plant? -
ANSWER Odor and oxygen demand
If a lift station pump will not start what do you check? - ANSWER Broken and loose termi-
nal connections
Shaft binding or sticking
Motor shorted or burned out
The amount of iron salts fed to the collection system should be increased whenever the: -
ANSWER Hydrogen sulfide level increases
Where should the flow meter sensor be located at the parshall flume? - ANSWER At a
specified location in the convergence of the flume
What/where is the palmer bowlus flume used in wastewater? - ANSWER Primary applica-
tion: pipelines, round bottom channels, manholes where it is often preferred because the
cost and ease of installation that can minimize construction expense
Which of the following statements is not true concerning the operation of a magnetic flow
meter? - ANSWER It operates partially full
1
,What methods can be used to check the performance of a flow meter? - ANSWER Meas-
ure area and velocity in an open channel
Measure how long it takes to fill a 55 gallon drum
Measure how long it takes to fill a tank
On what type of treatment process do hydraulic flow variations have the greatest impact? -
ANSWER Activated sludge
What is important to understand about the impact of high flow on treatment units? - AN-
SWER As flow increases, detention time decreases
What is the first indication that a strong toxic industrial substance has entered the activated
sludge plant? - ANSWER Increase in oxygen concentration in the aeration basin
Which type of cave in protection provides the best and most practical way to protect work-
ers in deep excavations? - ANSWER Drag shields and shoring
How do manholes, lift stations, and other features associated with collections/treatment
systems would be viewed from a risk assessment point of view? - ANSWER Vulnerabilities
Which of the following is an offensive smelling gas found in wastewater treatment plants? -
ANSWER Mercaptan
Workers in a sludge composting operation should wear respiratory protection because the
compost can give off: - ANSWER Airborne sludge particles
What safety equipment should an operator use in areas containing gaseous and particulate
contaminants? - ANSWER Supplied air respirator
Which type of fire extinguisher should be used for an electrical fire? - ANSWER Class C
2
,An accident prevention program in generate involves which of the following sets of steps? -
ANSWER Recognition of hazards, evaluation of hazards, and control of hazards
How often should fire extinguisher be recharged? - ANSWER After every use
Which of the following can poison the atmosphere in a room and should always be handled
with special care? - ANSWER Mercury
What is the danger level as defined by federal refs, to individuals whose normal noise expo-
sure might equal or exceed this dangerous level - ANSWER 8 hour (TWA) of 85 decibels
Widely fluctuating hydraulic flows may require which of the following? - ANSWER Flow
equalization
If you noticed poor solids settling in the clarifier and solids overflow into the chlorine contact
chamber, what would you do if the dilated settleometer showed improved settling?? - AN-
SWER Increase sludge wasting
As temperature decreases under normal conditions which are the following effect - AN-
SWER Biological activity slows down, viscosity of the H2O increases, solids settle slow
How does a water temperature decrease affect aerobic biological processes? - ANSWER
Decrease in solids settling efficiency
More oxygen in the solution
Fine screens typically consist of wedge wire, perforated plate, or closely spaced bars with
openings in what range? - ANSWER 0.06 - 0.25 inches
3
, One advantage of rotating screens over stationary screens is that rotating screens generally -
ANSWER Do not dam the flow
What is the purpose of injecting diffused air into aerated grit chambers? - ANSWER To
lower the specific gravity of water
What is accomplished by an aerated grit chamber? - ANSWER Grit is removed
Grit is washed
Wastewater is freshened
When using cyclones at the end of a grit removal process what will cause a decrease in grit
removal efficiency in the cyclone? - ANSWER Cyclone inlet pressure too low.
Increase the inlet pressure by adjusting the grit pump discharge
What should an operator do if the communicator is not operating properly? - ANSWER
Check the motor and look for blockage
Cut off the electricity
Lock out and tag the breaker
Place the bar screen into service
How often should communicators be operated? - ANSWER Continuously
How can you control the velocity in a grit channel in order to achieve velocities within a
range of 0.7 to 1.4 ft/ sec? - ANSWER Line the sides with bricks or blocks to change the
cross-sectional area
Use proportional weirs
Vary the number of channels in service in a multiple channel installation
What is primary clarifiers designed to remove? - ANSWER Settleable solids
4
