1 for specific request mail
Operation of Wastewater Treatment Plants (Levels 1-
2 Exam Prep) Questions and Correct Answers | Latest
Update
An Imhoff cone is used to measure________solids.
A. suspended
B. colloidal
C. volatile
Assignment Expert
D. settleable Ans: D. settleable
(Operation of Wastewater Treatment Plants, Volume 1
Guru01 - Stuvia
by Kenneth D. Kerri)
A _____ flume is widely used for measuring wastewater flow. Ans:
Parshall
2026
(Operation of Wastewater Treatment Plants, Volume 1
©
by Kenneth D. Kerri)
Velocity of flow in a grit channel must be reduced to a range of ____ to
_____ fps in order for grit to properly settle. Ans: .7 to 1.4 fps
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
by Kenneth D. Kerri)
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 ______. Ans: specific gravity of grit is 2.65 or
greater
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
, 2 for specific request mail
Mechanically cleaned bar screens feature bars set at _____ to _____
degrees from vertical. Ans: Bars set at 0 to 30 degrees from vertical.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Manually cleaned bar screens feature bars set at _____ to _____ degrees
from vertical to facilitate cleaning. Ans: 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)
Assignment Expert
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) Ans: The BOD test measures the amount
Guru01 - Stuvia
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)
2026
What do we mean by Total Dissolved Solids (TDS) in wastewater? Ans: All
©
the solids that cannot be filtered out of the water
(New Mexico Wastewater Systems Operator Certification Study Manual)
What do we mean by Total Suspended Solids (TSS) in wastewater? Ans: All
the solids that can be filtered out including: settleable solids and non-
settleable solids (colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
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 or self-cleaning velocity. Ans: The wastewater in a sewer line
should move at a speed that will prevent the deposition and buildup of
, 3 for specific request mail
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)
Wastewater treatment ponds: Facultative ponds are _____ feet deep Ans:
Facultative ponds are 4-8 feet deep
(New Mexico Wastewater Systems Operator Certification Study Manual)
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep Ans:
Anaerobic ponds are >14 feet in depth
Assignment Expert
(New Mexico Wastewater Systems Operator Certification Study Manual)
Guru01 - Stuvia
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Settleable Solids expected removal efficiency 95% to 99%
(New Mexico Wastewater Systems Operator Certification Study Manual)
2026
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal
©
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Suspended Solids expected removal efficiency 40% to 60%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Typical Primary Clarifier Efficiencies: Total Solids expected removal
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Total Solids expected removal efficiency 10% to 15%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD)
expected removal efficiency _____% to _____% Ans: Typical Primary
Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected
removal efficiency 20% to 50%
Operation of Wastewater Treatment Plants (Levels 1-
2 Exam Prep) Questions and Correct Answers | Latest
Update
An Imhoff cone is used to measure________solids.
A. suspended
B. colloidal
C. volatile
Assignment Expert
D. settleable Ans: D. settleable
(Operation of Wastewater Treatment Plants, Volume 1
Guru01 - Stuvia
by Kenneth D. Kerri)
A _____ flume is widely used for measuring wastewater flow. Ans:
Parshall
2026
(Operation of Wastewater Treatment Plants, Volume 1
©
by Kenneth D. Kerri)
Velocity of flow in a grit channel must be reduced to a range of ____ to
_____ fps in order for grit to properly settle. Ans: .7 to 1.4 fps
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
by Kenneth D. Kerri)
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 ______. Ans: specific gravity of grit is 2.65 or
greater
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
, 2 for specific request mail
Mechanically cleaned bar screens feature bars set at _____ to _____
degrees from vertical. Ans: Bars set at 0 to 30 degrees from vertical.
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
Manually cleaned bar screens feature bars set at _____ to _____ degrees
from vertical to facilitate cleaning. Ans: 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)
Assignment Expert
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) Ans: The BOD test measures the amount
Guru01 - Stuvia
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)
2026
What do we mean by Total Dissolved Solids (TDS) in wastewater? Ans: All
©
the solids that cannot be filtered out of the water
(New Mexico Wastewater Systems Operator Certification Study Manual)
What do we mean by Total Suspended Solids (TSS) in wastewater? Ans: All
the solids that can be filtered out including: settleable solids and non-
settleable solids (colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
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 or self-cleaning velocity. Ans: The wastewater in a sewer line
should move at a speed that will prevent the deposition and buildup of
, 3 for specific request mail
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)
Wastewater treatment ponds: Facultative ponds are _____ feet deep Ans:
Facultative ponds are 4-8 feet deep
(New Mexico Wastewater Systems Operator Certification Study Manual)
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep Ans:
Anaerobic ponds are >14 feet in depth
Assignment Expert
(New Mexico Wastewater Systems Operator Certification Study Manual)
Guru01 - Stuvia
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Settleable Solids expected removal efficiency 95% to 99%
(New Mexico Wastewater Systems Operator Certification Study Manual)
2026
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal
©
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Suspended Solids expected removal efficiency 40% to 60%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Typical Primary Clarifier Efficiencies: Total Solids expected removal
efficiency _____% to _____% Ans: Typical Primary Clarifier Efficiencies:
Total Solids expected removal efficiency 10% to 15%
(New Mexico Wastewater Systems Operator Certification Study Manual)
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD)
expected removal efficiency _____% to _____% Ans: Typical Primary
Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected
removal efficiency 20% to 50%
