1 Exampromax - Stuvia US 2025/2026
Operation of Wastewater Treatment Plants
(Levels 1-2 Exam Prep) Questions and Answers
(100% Correct Answers) Already Graded A+
Quiz: An Imhoff cone is used to measure________solids.
A. suspended
B. colloidal
C. volatile
© 2025 Assignment Expert
D. settleable⼀Answer: D. settleable
Exampromax - Stuvia US
(Operation of Wastewater Treatment Plants, Volume 1
by Kenneth D. Kerri)
Quiz: A _____ flume is widely used for measuring wastewater flow.⼀
Answer: Parshall
(Operation of Wastewater Treatment Plants, Volume 1
by Kenneth D. Kerri)
Quiz: Velocity of flow in a grit channel must be reduced to a range of
____ to _____ fps in order for grit to properly settle.⼀Answer: .7 to 1.4 fps
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
by Kenneth D. Kerri)
, 2 Exampromax - Stuvia US 2025/2026
Quiz: With respect to grit removal systems, grit is traditionally defined as
particles larger than 0.21mm (0.008 in) (65 mesh) and with a specific gravity
of greater than ______.⼀Answer: specific gravity of grit is 2.65 or greater
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Quiz: Mechanically cleaned bar screens feature bars set at _____ to _____
degrees from vertical.⼀Answer: Bars set at 0 to 30 degrees from vertical.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
© 2025 Assignment Expert
Exampromax - Stuvia US
Quiz: Manually cleaned bar screens feature bars set at _____ to _____
degrees from vertical to facilitate cleaning.⼀Answer: Bars set at 30 to 45
degrees from vertical to facilitate cleaning. Primarily used in older or
smaller treatment facilities, or in bypass channels.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Quiz: The BOD test measures the amount of oxygen that is consumed
while a sample of wastewater is incubated in the dark at a temperature of
_____ °C for _____ days (± _____ hours)⼀Answer: The BOD test
measures the amount of oxygen that is consumed while a sample of
wastewater is incubated in the dark at a temperature of 20 °C for 5 days (± 3
hours)
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
Quiz: What do we mean by Total Dissolved Solids (TDS) in wastewater?
⼀Answer: All the solids that cannot be filtered out of the water
, 3 Exampromax - Stuvia US 2025/2026
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: What do we mean by Total Suspended Solids (TSS) in wastewater?
⼀Answer: All the solids that can be filtered out including: settleable solids
and non-settleable solids (colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: The wastewater in a sewer line should move at a speed that will
prevent the deposition and buildup of solids in the sewer; this is called a
"scouring velocity". A minimum velocity of _____ fps provides this scouring
© 2025 Assignment Expert
or self-cleaning velocity.⼀Answer: The wastewater in a sewer line should
Exampromax - Stuvia US
move at a speed that will prevent the deposition and buildup of solids in the
sewer; this is called a "scouring velocity". A minimum velocity of 2 fps
provides this scouring or self-cleaning velocity.
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Wastewater treatment ponds: Facultative ponds are _____ feet
deep⼀Answer: Facultative ponds are 4-8 feet deep
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Wastewater treatment ponds: Anaerobic ponds are _____ feet deep
⼀Answer: Anaerobic ponds are >14 feet in depth
(New Mexico Wastewater Systems Operator Certification Study Manual)
, 4 Exampromax - Stuvia US 2025/2026
Quiz: Typical Primary Clarifier Efficiencies: Settleable Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Settleable Solids expected removal efficiency 95% to 99%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Typical Primary Clarifier Efficiencies: Suspended Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Suspended Solids expected removal efficiency 40% to 60%
© 2025 Assignment Expert
(New Mexico Wastewater Systems Operator Certification Study Manual)
Exampromax - Stuvia US
Quiz: Typical Primary Clarifier Efficiencies: Total Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Total Solids expected removal efficiency 10% to 15%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Typical Primary Clarifier Efficiencies: Biochemical Oxygen
Demand (BOD) expected removal efficiency _____% to _____%⼀Answer:
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand
(BOD) expected removal efficiency 20% to 50%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Sludge septicity in the primary clarifier can be recognized when:
A. sludge gasification causes large clumps of sludge to float on the water
surface.
Operation of Wastewater Treatment Plants
(Levels 1-2 Exam Prep) Questions and Answers
(100% Correct Answers) Already Graded A+
Quiz: An Imhoff cone is used to measure________solids.
A. suspended
B. colloidal
C. volatile
© 2025 Assignment Expert
D. settleable⼀Answer: D. settleable
Exampromax - Stuvia US
(Operation of Wastewater Treatment Plants, Volume 1
by Kenneth D. Kerri)
Quiz: A _____ flume is widely used for measuring wastewater flow.⼀
Answer: Parshall
(Operation of Wastewater Treatment Plants, Volume 1
by Kenneth D. Kerri)
Quiz: Velocity of flow in a grit channel must be reduced to a range of
____ to _____ fps in order for grit to properly settle.⼀Answer: .7 to 1.4 fps
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
by Kenneth D. Kerri)
, 2 Exampromax - Stuvia US 2025/2026
Quiz: With respect to grit removal systems, grit is traditionally defined as
particles larger than 0.21mm (0.008 in) (65 mesh) and with a specific gravity
of greater than ______.⼀Answer: specific gravity of grit is 2.65 or greater
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Quiz: Mechanically cleaned bar screens feature bars set at _____ to _____
degrees from vertical.⼀Answer: Bars set at 0 to 30 degrees from vertical.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
© 2025 Assignment Expert
Exampromax - Stuvia US
Quiz: Manually cleaned bar screens feature bars set at _____ to _____
degrees from vertical to facilitate cleaning.⼀Answer: Bars set at 30 to 45
degrees from vertical to facilitate cleaning. Primarily used in older or
smaller treatment facilities, or in bypass channels.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Quiz: The BOD test measures the amount of oxygen that is consumed
while a sample of wastewater is incubated in the dark at a temperature of
_____ °C for _____ days (± _____ hours)⼀Answer: The BOD test
measures the amount of oxygen that is consumed while a sample of
wastewater is incubated in the dark at a temperature of 20 °C for 5 days (± 3
hours)
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
Quiz: What do we mean by Total Dissolved Solids (TDS) in wastewater?
⼀Answer: All the solids that cannot be filtered out of the water
, 3 Exampromax - Stuvia US 2025/2026
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: What do we mean by Total Suspended Solids (TSS) in wastewater?
⼀Answer: All the solids that can be filtered out including: settleable solids
and non-settleable solids (colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: The wastewater in a sewer line should move at a speed that will
prevent the deposition and buildup of solids in the sewer; this is called a
"scouring velocity". A minimum velocity of _____ fps provides this scouring
© 2025 Assignment Expert
or self-cleaning velocity.⼀Answer: The wastewater in a sewer line should
Exampromax - Stuvia US
move at a speed that will prevent the deposition and buildup of solids in the
sewer; this is called a "scouring velocity". A minimum velocity of 2 fps
provides this scouring or self-cleaning velocity.
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Wastewater treatment ponds: Facultative ponds are _____ feet
deep⼀Answer: Facultative ponds are 4-8 feet deep
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Wastewater treatment ponds: Anaerobic ponds are _____ feet deep
⼀Answer: Anaerobic ponds are >14 feet in depth
(New Mexico Wastewater Systems Operator Certification Study Manual)
, 4 Exampromax - Stuvia US 2025/2026
Quiz: Typical Primary Clarifier Efficiencies: Settleable Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Settleable Solids expected removal efficiency 95% to 99%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Typical Primary Clarifier Efficiencies: Suspended Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Suspended Solids expected removal efficiency 40% to 60%
© 2025 Assignment Expert
(New Mexico Wastewater Systems Operator Certification Study Manual)
Exampromax - Stuvia US
Quiz: Typical Primary Clarifier Efficiencies: Total Solids expected
removal efficiency _____% to _____%⼀Answer: Typical Primary Clarifier
Efficiencies: Total Solids expected removal efficiency 10% to 15%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Typical Primary Clarifier Efficiencies: Biochemical Oxygen
Demand (BOD) expected removal efficiency _____% to _____%⼀Answer:
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand
(BOD) expected removal efficiency 20% to 50%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Quiz: Sludge septicity in the primary clarifier can be recognized when:
A. sludge gasification causes large clumps of sludge to float on the water
surface.
