Ca Grade 2 Wastewater Treatment Operator Practice Exam 1| | Questions and Answers | 2026 Update | Graded +.
What is the methane content in a properly operating anaerobic digester? ✔️65 to 70% by volume
What will the addition of chlorine gas do to the pH of wastewater? ✔️decrease the pH
What is the purpose of a Parshall Flume? ✔️Measure the flow rate
What is the typical removal efficency of settleable solids in a primary clarifier? ✔️95 to 99%
Which of the follwing is true about pumoing scum from a primary clarifier? ✔️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? ✔️MLSS is too low
What does the M in F/M ratio represent? ✔️The mixed liquor volatile suspended solids in the aeration tank
In general, how will warmer temp affect the settling rate of solids in a clarifer? ✔️Increase the settling rate
What could happen if the digester gas is mixed with air(85 to 95% by volume)? ✔️Cause an explosion
How will algae impact the chlorine demand in the pond effluent? ✔️increase the chlorine demand
Which of the following is true about a positive displacement pump? ✔️it must never be started with the discharge valve closed
What is true about the F/M ratio? ✔️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? ✔️never pipet hazardous material with your mouth, even if the pipet has been
sterialized
What is the recirculation ratio for a trickling filter? ✔️Qr/Q
Which of the following is true about COD and BOD? ✔️they are indirect measurements of the organic content in the influent
What is the purpose of the grit channel? ✔️remove heavy inorganic waste
Which of the following is true about the extended aeration process? ✔️it does not produce as much waste sludge as other processes
What is the correct formula for solids in raw wastewater? ✔️Non settleable solids + settleable solids = total suspended solids
What is freeboard in a waste stabilization pond? ✔️the vertical distance from normal water surface to the top of the levee
What is one of the requirements for a BOD test? ✔️The BOD bottle should be completely filled to the top
What should be scheduled every 3 months for a flamer arrester in an anaerobic digester? ✔️maintenance
What is common practice in an activated sludge process? ✔️recirculate activated sludge
Prior to entering a permit-required confined space, what should you verify? ✔️a standby person should be located outside the entrance to the
confined space, while another person should be within sight or call of the standby person
What is a common way to determine the organic strength of wastes in the influent? ✔️test for the biochemical oxygen demand
What should you do if you are mildly exposed to chlorine gas? ✔️immediately evacuate the contaminated area, remian calm, keep warm. breath
lightly, avoid coughing
What are the main sources of domestic sewage in the collection system? ✔️household and commercial establishments
Why is it important to maintain a horizontal weir in a clarifier? ✔️to prevent short circuiting
What are mostly removed in the grit channel? ✔️sand, eggshells, cinders, and heavier particulate matter
How often should an anaerobic digester be fed? ✔️several times a day
What is the health effect of carbon dioxide? ✔️could lead to asphyxiation
What is the methane content in a properly operating anaerobic digester? ✔️65 to 70% by volume
What will the addition of chlorine gas do to the pH of wastewater? ✔️decrease the pH
What is the purpose of a Parshall Flume? ✔️Measure the flow rate
What is the typical removal efficency of settleable solids in a primary clarifier? ✔️95 to 99%
Which of the follwing is true about pumoing scum from a primary clarifier? ✔️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? ✔️MLSS is too low
What does the M in F/M ratio represent? ✔️The mixed liquor volatile suspended solids in the aeration tank
In general, how will warmer temp affect the settling rate of solids in a clarifer? ✔️Increase the settling rate
What could happen if the digester gas is mixed with air(85 to 95% by volume)? ✔️Cause an explosion
How will algae impact the chlorine demand in the pond effluent? ✔️increase the chlorine demand
Which of the following is true about a positive displacement pump? ✔️it must never be started with the discharge valve closed
What is true about the F/M ratio? ✔️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? ✔️never pipet hazardous material with your mouth, even if the pipet has been
sterialized
What is the recirculation ratio for a trickling filter? ✔️Qr/Q
Which of the following is true about COD and BOD? ✔️they are indirect measurements of the organic content in the influent
What is the purpose of the grit channel? ✔️remove heavy inorganic waste
Which of the following is true about the extended aeration process? ✔️it does not produce as much waste sludge as other processes
What is the correct formula for solids in raw wastewater? ✔️Non settleable solids + settleable solids = total suspended solids
What is freeboard in a waste stabilization pond? ✔️the vertical distance from normal water surface to the top of the levee
What is one of the requirements for a BOD test? ✔️The BOD bottle should be completely filled to the top
What should be scheduled every 3 months for a flamer arrester in an anaerobic digester? ✔️maintenance
What is common practice in an activated sludge process? ✔️recirculate activated sludge
Prior to entering a permit-required confined space, what should you verify? ✔️a standby person should be located outside the entrance to the
confined space, while another person should be within sight or call of the standby person
What is a common way to determine the organic strength of wastes in the influent? ✔️test for the biochemical oxygen demand
What should you do if you are mildly exposed to chlorine gas? ✔️immediately evacuate the contaminated area, remian calm, keep warm. breath
lightly, avoid coughing
What are the main sources of domestic sewage in the collection system? ✔️household and commercial establishments
Why is it important to maintain a horizontal weir in a clarifier? ✔️to prevent short circuiting
What are mostly removed in the grit channel? ✔️sand, eggshells, cinders, and heavier particulate matter
How often should an anaerobic digester be fed? ✔️several times a day
What is the health effect of carbon dioxide? ✔️could lead to asphyxiation
