Alabama Wastewater Collection
Grade 4 C Exam (2025/2026)
UPDATE Verified Questions
And Answers
A flow of 60 gph is equal to?
a. 1 mgd
b. 1mg/L
c. 10 gpm
d. 1 gpm
d. 1 gpm (60 gph / 60 min/hr )
A flow of 1,000,000 gpd is approximately
a. 500 gpm
b. 700 gpm
c. 1000 gpm
d. 60,000 gph
b. 700 gpm
( 60 min/hr * 24 hrs = 1440 min)
1,000,000 gpd / 1440 = 694
( which is approximately 700 gpm)
Of the following abbreviations listed, which is not used in computing or expressing flow rates?
a. ft/sec
b. gpm
c. mgd
d. psi
d. psi
The slope of a sewer is measured by
a. The difference from the crown to the invert
b. The difference in invert elevations over the length
of the pipe
c. Using the diameter of the pipe
d. Only entering the manhole
b. The difference in invert elevation over the length
of the pipe
An air gap can be used to
,a. Clean sewer blockages caused by grease
b. Let air into manholes
c. Prevent backflow of wastewater into a drinking
water supply
d. Test for oxygen deficiency in manholes
c. Prevent backflow of wastewater into a drinking
water supply.
A cross connection is
a. Cast Iron pipe connected to concrete pipe
b. Steel pipe connected to asbestos pipe
c. Potable (Drinkable) water pipe connected to a supply
of questionable origin
d. Lateral line connected to an interceptor
c. Potable (Drinkable) water pipe connected to a
supply of questionable origin
Wastewater carried in a collection system may come from
a. Digester supernatant
b. Exfiltration
c. Primary settling tank
d. Inflow
d. Inflow
When using any hydraulic sewer cleaning method, care must be taken by the operator
a. To always plug the downstream manhole
b. Not to cause flooding in homes and businesses
c. To prevent any air gap from occurring
d. To throttle flows from the hydrants by using
the hydrant valve only
b. Not to cause flooding in homes and businesses
Disease producing bacteria are called
a. Saprophytic
b. Facultative
c. Pathogenic
d. Parasitic
c. Pathogenic
A manhole with a center grating is normally used for
a. Venting
b. Storm sewers
c. Sanitary sewers
d. None of the above
b. Storm sewers
A pig would be used as ________________in a force
main.
a. A reamer
,b. A stopper
c. A Float
d. A tell tale
a. A reamer
A minimum scouring velocity of 2 ft/sec in sewers is
necessary so that
a. Flow velocities can be estimated between manholes
b. Roots won't grow in sewers
c. Sewer pipes won't become eroded on the bottom
d. Solids won't build up in a sewer and
reduce flow capacity
d. Solids won't build up in a sewer and reduce flow capacity
A cross connection is best defined as
a. Ground water entering a gravity sewer through
cracks in the piping
b. A lateral line connected to the main illegally
c. Storm drainage piped into a domestic
collection system
d. A potable water supply connected to a potential source
of pollution.
d. A potable water supply connected to a potential
source of pollution.
When dealing with collection systems, I & I refers to
a. Inflow and inspection
b. inspection and information
c. infiltration and inflow
d. None of the above
c. infiltration and inflow
Corrosion of sewer pipes may be caused by
a. Laminar flow through them
b. Oils in wastewater
c. Fungi
d. Acids in water
d. Acids in water
In a collection system, wastewater that contains no "free" of dissolved oxygen is referred to as
a. Aerobic
b. Anaerobic
c. Ambient
d. Debris
b. Anaerobic
The primary reason why it is important not to have cross-connections of sewers with water supplies systems is
a. Possible overloading of water systems
b. Possible loss of drinking water pressure
, c. Possible drinking water contamination
d. Low of wastewater from the sewerage system
c. Possible drinking water contamination
A pig would likely be used for cleaning of a
a. Gravity sewer
b. Storm sewer
c. Force main
d. House or building sewer
c. Force main
Flow rates can be expressed in which of the following units
a. in³
b. gal/lb
c. mgd
d. Lb/mil
c. mgd
A sewer manhole is
a. The lowest point in the channel
b. a gate that opens or closes swinging around a
set of hinges
c. An opening in a sewer provided for the purpose
of access
d. A small hole in a sewer where a wastewater service
line connects
c. An opening in a sewer provided for the
purpose of access
The crown of a sewer pipe is the
a. Bottom
b. Top
c. Flow line
d. Outside at the grade line
b. Top
The primary purpose of wastewater disinfection is
a. Reduction of suspended solids
b. Destruction of algae
c. Prevention of receiving water contamination
d. Oxidation of effluent
c. Prevention of receiving water contamination
What should be considered as the scoring velocity of sanitary sewers?
a. 1 ft/sec
b. 2 ft/sec
c. 4 ft/sec
d. 4.5 ft/sec
Grade 4 C Exam (2025/2026)
UPDATE Verified Questions
And Answers
A flow of 60 gph is equal to?
a. 1 mgd
b. 1mg/L
c. 10 gpm
d. 1 gpm
d. 1 gpm (60 gph / 60 min/hr )
A flow of 1,000,000 gpd is approximately
a. 500 gpm
b. 700 gpm
c. 1000 gpm
d. 60,000 gph
b. 700 gpm
( 60 min/hr * 24 hrs = 1440 min)
1,000,000 gpd / 1440 = 694
( which is approximately 700 gpm)
Of the following abbreviations listed, which is not used in computing or expressing flow rates?
a. ft/sec
b. gpm
c. mgd
d. psi
d. psi
The slope of a sewer is measured by
a. The difference from the crown to the invert
b. The difference in invert elevations over the length
of the pipe
c. Using the diameter of the pipe
d. Only entering the manhole
b. The difference in invert elevation over the length
of the pipe
An air gap can be used to
,a. Clean sewer blockages caused by grease
b. Let air into manholes
c. Prevent backflow of wastewater into a drinking
water supply
d. Test for oxygen deficiency in manholes
c. Prevent backflow of wastewater into a drinking
water supply.
A cross connection is
a. Cast Iron pipe connected to concrete pipe
b. Steel pipe connected to asbestos pipe
c. Potable (Drinkable) water pipe connected to a supply
of questionable origin
d. Lateral line connected to an interceptor
c. Potable (Drinkable) water pipe connected to a
supply of questionable origin
Wastewater carried in a collection system may come from
a. Digester supernatant
b. Exfiltration
c. Primary settling tank
d. Inflow
d. Inflow
When using any hydraulic sewer cleaning method, care must be taken by the operator
a. To always plug the downstream manhole
b. Not to cause flooding in homes and businesses
c. To prevent any air gap from occurring
d. To throttle flows from the hydrants by using
the hydrant valve only
b. Not to cause flooding in homes and businesses
Disease producing bacteria are called
a. Saprophytic
b. Facultative
c. Pathogenic
d. Parasitic
c. Pathogenic
A manhole with a center grating is normally used for
a. Venting
b. Storm sewers
c. Sanitary sewers
d. None of the above
b. Storm sewers
A pig would be used as ________________in a force
main.
a. A reamer
,b. A stopper
c. A Float
d. A tell tale
a. A reamer
A minimum scouring velocity of 2 ft/sec in sewers is
necessary so that
a. Flow velocities can be estimated between manholes
b. Roots won't grow in sewers
c. Sewer pipes won't become eroded on the bottom
d. Solids won't build up in a sewer and
reduce flow capacity
d. Solids won't build up in a sewer and reduce flow capacity
A cross connection is best defined as
a. Ground water entering a gravity sewer through
cracks in the piping
b. A lateral line connected to the main illegally
c. Storm drainage piped into a domestic
collection system
d. A potable water supply connected to a potential source
of pollution.
d. A potable water supply connected to a potential
source of pollution.
When dealing with collection systems, I & I refers to
a. Inflow and inspection
b. inspection and information
c. infiltration and inflow
d. None of the above
c. infiltration and inflow
Corrosion of sewer pipes may be caused by
a. Laminar flow through them
b. Oils in wastewater
c. Fungi
d. Acids in water
d. Acids in water
In a collection system, wastewater that contains no "free" of dissolved oxygen is referred to as
a. Aerobic
b. Anaerobic
c. Ambient
d. Debris
b. Anaerobic
The primary reason why it is important not to have cross-connections of sewers with water supplies systems is
a. Possible overloading of water systems
b. Possible loss of drinking water pressure
, c. Possible drinking water contamination
d. Low of wastewater from the sewerage system
c. Possible drinking water contamination
A pig would likely be used for cleaning of a
a. Gravity sewer
b. Storm sewer
c. Force main
d. House or building sewer
c. Force main
Flow rates can be expressed in which of the following units
a. in³
b. gal/lb
c. mgd
d. Lb/mil
c. mgd
A sewer manhole is
a. The lowest point in the channel
b. a gate that opens or closes swinging around a
set of hinges
c. An opening in a sewer provided for the purpose
of access
d. A small hole in a sewer where a wastewater service
line connects
c. An opening in a sewer provided for the
purpose of access
The crown of a sewer pipe is the
a. Bottom
b. Top
c. Flow line
d. Outside at the grade line
b. Top
The primary purpose of wastewater disinfection is
a. Reduction of suspended solids
b. Destruction of algae
c. Prevention of receiving water contamination
d. Oxidation of effluent
c. Prevention of receiving water contamination
What should be considered as the scoring velocity of sanitary sewers?
a. 1 ft/sec
b. 2 ft/sec
c. 4 ft/sec
d. 4.5 ft/sec
