CA GRADE 2 WASTEWATER
TREATMENT OPERATOR PRACTICE
EXAM 1 QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
What is the methane content in a properly operating anaerobic digester? - ANS 65 to 70% by
volume
What will the addition of chlorine gas do to the pH of wastewater? - ANS decrease the pH
What is the purpose of a Parshall Flume? - ANS Measure the flow rate
What is the typical removal efficency of settleable solids in a primary clarifier? - ANS 95 to
99%
Which of the follwing is true about pumoing scum from a primary clarifier? - ANS scum
causes more piping problems than other substances pumped at a wastewater treatment plant
What might cause thick billows of white sudsy foam in the aeration tank? - ANS MLSS is too
low
What does the M in F/M ratio represent? - ANS The mixed liquor volatile suspended solids in
the aeration tank
1 @COPYRIGHT 2026 ALLRIGHTS RESERVED.
, In general, how will warmer temp affect the settling rate of solids in a clarifer? - ANS Increase
the settling rate
What could happen if the digester gas is mixed with air(85 to 95% by volume)? - ANS Cause
an explosion
How will algae impact the chlorine demand in the pond effluent? - ANS increase the chlorine
demand
Which of the following is true about a positive displacement pump? - ANS it must never be
started with the discharge valve closed
What is true about the F/M ratio? - ANS the volume of the secondary clarifier is not needed
to determine the f/m ratio
Which of the following is one of the basic rules of lab work? - ANS never pipet hazardous
material with your mouth, even if the pipet has been sterialized
What is the recirculation ratio for a trickling filter? - ANS Qr/Q
Which of the following is true about COD and BOD? - ANS they are indirect measurements of
the organic content in the influent
What is the purpose of the grit channel? - ANS remove heavy inorganic waste
Which of the following is true about the extended aeration process? - ANS it does not
produce as much waste sludge as other processes
What is the correct formula for solids in raw wastewater? - ANS Non settleable solids +
settleable solids = total suspended solids
2 @COPYRIGHT 2026 ALLRIGHTS RESERVED.
TREATMENT OPERATOR PRACTICE
EXAM 1 QUESTIONS AND ANSWERS
GRADED A+ 2025/2026
What is the methane content in a properly operating anaerobic digester? - ANS 65 to 70% by
volume
What will the addition of chlorine gas do to the pH of wastewater? - ANS decrease the pH
What is the purpose of a Parshall Flume? - ANS Measure the flow rate
What is the typical removal efficency of settleable solids in a primary clarifier? - ANS 95 to
99%
Which of the follwing is true about pumoing scum from a primary clarifier? - ANS scum
causes more piping problems than other substances pumped at a wastewater treatment plant
What might cause thick billows of white sudsy foam in the aeration tank? - ANS MLSS is too
low
What does the M in F/M ratio represent? - ANS The mixed liquor volatile suspended solids in
the aeration tank
1 @COPYRIGHT 2026 ALLRIGHTS RESERVED.
, In general, how will warmer temp affect the settling rate of solids in a clarifer? - ANS Increase
the settling rate
What could happen if the digester gas is mixed with air(85 to 95% by volume)? - ANS Cause
an explosion
How will algae impact the chlorine demand in the pond effluent? - ANS increase the chlorine
demand
Which of the following is true about a positive displacement pump? - ANS it must never be
started with the discharge valve closed
What is true about the F/M ratio? - ANS the volume of the secondary clarifier is not needed
to determine the f/m ratio
Which of the following is one of the basic rules of lab work? - ANS never pipet hazardous
material with your mouth, even if the pipet has been sterialized
What is the recirculation ratio for a trickling filter? - ANS Qr/Q
Which of the following is true about COD and BOD? - ANS they are indirect measurements of
the organic content in the influent
What is the purpose of the grit channel? - ANS remove heavy inorganic waste
Which of the following is true about the extended aeration process? - ANS it does not
produce as much waste sludge as other processes
What is the correct formula for solids in raw wastewater? - ANS Non settleable solids +
settleable solids = total suspended solids
2 @COPYRIGHT 2026 ALLRIGHTS RESERVED.
