24 COLLECTION SYSTEM
MAINTENANCE GRADE 4 EXAM
QUESTIONS AND ANSWERS PLUS
RATIONALES
What do you do if a sewer line is plugged? - Answer-Look for a manhole with reduced
or no flow when the manhole upstream is flowing full
The first action taken when discovering gasoline when you open a manhole is? -
Answer-Call the police and fire departments
When do you wear splash goggles? - Answer-When pouring chemicals
When is the DO the highest in stabilization ponds? - Answer-Mid-afternoon
When do you do if a stabalization pond is going "septic"? - Answer-Raise the level (the
oxygen level is raised by the additional water volume)
An operators license is subject to? - Answer-Revocation, fine and imprisonment
How long are BOD tests incubated for? - Answer-5 days at 20* celcius
When do operators raise lagoon levels? - Answer-Fall
When do operators lower lagoon levels? - Answer-Spring
Where should you dig for a sewer line? - Answer-18 inches above where it is shown on
the pans
Corrosion in manholes is caused by? - Answer-hygrogen sulfide gas
What should you check before entering a manhole? - Answer-lower explosive limits
both before and after
How is TSS measured? - Answer-filtering though a gooch crucible
What is the greatest task for intermittent sand filters? - Answer-cleaning of the sand
An automatic vent fan that runs during the time the door is open is considered? -
Answer-ventilation in a lift station
Trickling filter treatment does not follow? - Answer-Lagoons
, What is heavier chlorine or air? - Answer-Chlorine
In an intermittent sand filter what is the top 1-3 inches of sand? - Answer-The portion
replaced during normal operation
With ponds or lagoons the term "freeboard" refers to? - Answer-The working area
remaining above the water surface
A D.O. meter needle fluctuates when? - Answer-The membrane in the probe needs
attention
Operations records are kept to help operators with? - Answer-Process control
How long do discharge monitoring reports (DMRs) have to be kept? - Answer-3 years
When does renewal info for NPDES permit that is expiring have to be submitted? -
Answer-180 days before expiration
A sample with a pH of 8.5 is considered? - Answer-Alkaline
One purpose of closing intermittent sand filters at intervals is for? - Answer-Better
treatment of the wastewater
Fresh wastewater has a characteristic color of? - Answer-Grey
How deep are faculative lagoons? - Answer-3-6 feet
Aerobic lagoons are how deep? - Answer-3-4 feet
Performance of a stabilization pond is a function of? - Answer-surface area
Inorganic waste is a material that has a? - Answer-Mineral Origin
Septic refers to wastewater that has? - Answer-Little or no DO
Gaseous chlorine is approximately how much heavier than air? - Answer-2.5 times
Cyclone is not what? - Answer-a type of pump
Wastewater in which solids have decomposed to inert solids is referred to as? - Answer-
stable
How far apart are the bars in a BOR screen? - Answer-1/4 to 2 inches
MAINTENANCE GRADE 4 EXAM
QUESTIONS AND ANSWERS PLUS
RATIONALES
What do you do if a sewer line is plugged? - Answer-Look for a manhole with reduced
or no flow when the manhole upstream is flowing full
The first action taken when discovering gasoline when you open a manhole is? -
Answer-Call the police and fire departments
When do you wear splash goggles? - Answer-When pouring chemicals
When is the DO the highest in stabilization ponds? - Answer-Mid-afternoon
When do you do if a stabalization pond is going "septic"? - Answer-Raise the level (the
oxygen level is raised by the additional water volume)
An operators license is subject to? - Answer-Revocation, fine and imprisonment
How long are BOD tests incubated for? - Answer-5 days at 20* celcius
When do operators raise lagoon levels? - Answer-Fall
When do operators lower lagoon levels? - Answer-Spring
Where should you dig for a sewer line? - Answer-18 inches above where it is shown on
the pans
Corrosion in manholes is caused by? - Answer-hygrogen sulfide gas
What should you check before entering a manhole? - Answer-lower explosive limits
both before and after
How is TSS measured? - Answer-filtering though a gooch crucible
What is the greatest task for intermittent sand filters? - Answer-cleaning of the sand
An automatic vent fan that runs during the time the door is open is considered? -
Answer-ventilation in a lift station
Trickling filter treatment does not follow? - Answer-Lagoons
, What is heavier chlorine or air? - Answer-Chlorine
In an intermittent sand filter what is the top 1-3 inches of sand? - Answer-The portion
replaced during normal operation
With ponds or lagoons the term "freeboard" refers to? - Answer-The working area
remaining above the water surface
A D.O. meter needle fluctuates when? - Answer-The membrane in the probe needs
attention
Operations records are kept to help operators with? - Answer-Process control
How long do discharge monitoring reports (DMRs) have to be kept? - Answer-3 years
When does renewal info for NPDES permit that is expiring have to be submitted? -
Answer-180 days before expiration
A sample with a pH of 8.5 is considered? - Answer-Alkaline
One purpose of closing intermittent sand filters at intervals is for? - Answer-Better
treatment of the wastewater
Fresh wastewater has a characteristic color of? - Answer-Grey
How deep are faculative lagoons? - Answer-3-6 feet
Aerobic lagoons are how deep? - Answer-3-4 feet
Performance of a stabilization pond is a function of? - Answer-surface area
Inorganic waste is a material that has a? - Answer-Mineral Origin
Septic refers to wastewater that has? - Answer-Little or no DO
Gaseous chlorine is approximately how much heavier than air? - Answer-2.5 times
Cyclone is not what? - Answer-a type of pump
Wastewater in which solids have decomposed to inert solids is referred to as? - Answer-
stable
How far apart are the bars in a BOR screen? - Answer-1/4 to 2 inches
