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WASTEWATER CLASS B TEXAS 2025/
2026 BRAND NEW QUESTIONS WITH
ANSWERS| ACE YOUR GRADES!
1. In the activated sludge process, Dissolved Oxygen levels
throughout the aeration basins are measured using a portable
DO meter. The operator should keep DO levels between
______ and _______. - correct answer -2 mg/L and 4.0 mg/L
2. In the activated sludge process, "Classic Bulking" is a common
problem typically caused by - correct answer -Low density
sludge
3. In the activated sludge process, Sludge Rising differs from
"Sludge Bulking" and "Sludge Rising" is typically associated -
correct answer -Nitrification - De-nitrification process
4. In the activated sludge process, techniques used to reduce
"Frothing & Foaming" typically include - correct answer -
Adjusting sludge age, Reducing the amount of air, Spraying the
frothing area with water, Applying de-foaming agents
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5. In the activated sludge process, floc is very important to the
settling process. Floc is composed primarily of - correct answer
-Bacteria, Protozoa, Microscopic Animals, & Fungi
6. In the activated sludge plants, the operator will experience
problems. Some of the common Treatment plant problems
include - correct answer -Insufficent capacity, Equipment
failures, Design inadequacies, Poor maintenance, & Inflow
rates exceed plant capacities.
7. In the activated sludge plants the operator will experience
problems. Some of the common Influent problems include -
correct answer -Septic inflow, Organic overloading, and under
loading, Hydraulic overloading, Solids washout during storm
inflow, Toxic substances, Shock loads, & Nutrient deficiencies
8. In the activated sludge plants, the operator will experience
problems. Some common Operational problems include -
correct answer -Sludge quality, foaming, improper operating
techniques
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9. In the activated sludge plants, the operator will experience
problems. Some common Environmental problems include. -
correct answer -Low temperatures, System pH out of range, &
Excessive algae growth
10. In the activated sludge plants, to properly set the clarifier
return rate the operator must know three things - correct
answer -Return activated sludge rate, Sludge blanket
thickness, & the Solids concentration of the return flow
11. The typical sludge age for extended aeration plants is -
correct answer -20 to 40 days
12. In the activated sludge plant, good quality sludge will settle
_________& _______ over _________ minute period. - correct
answer -Gently & Uniformly over 15 to 20 minutes
13. In the activated sludge plant, old sludge quality will settle
________& _________ over ________ minute period. - correct
answer -Rapidly and ragged over 5 minutes.
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14. In the activated sludge plant, there are (5) important nitroen
transformation processes that occur by microorganisms. They
are- - correct answer -Assumilation, Ammonification,
Nitrification, Denitrification, & Nitrogen fixation.
15. __________in the effluent from an activated sludge process
is a pollutant and may create toxic conditions for aquatic life in
the receiving stream - correct answer -Nitrogen
16. Denitrification occurs in an activated sludge system when
there is __________ to maintain the aerobic metabolism of the
carbon stabilizing bacteria. - correct answer -Insufficient
Dissolved Oxygen
17. The lack of _________ triggers the facuitative bacteria to
change from aerobic and anaerobic - correct answer -Dissolved
Oxygen
18. In the activated sludge system, "Hydraulic Wash Out" is -
correct answer -When the upward movement of the water in
the clarifier exceeds the downward settling velocity
WASTEWATER CLASS B TEXAS 2025/
2026 BRAND NEW QUESTIONS WITH
ANSWERS| ACE YOUR GRADES!
1. In the activated sludge process, Dissolved Oxygen levels
throughout the aeration basins are measured using a portable
DO meter. The operator should keep DO levels between
______ and _______. - correct answer -2 mg/L and 4.0 mg/L
2. In the activated sludge process, "Classic Bulking" is a common
problem typically caused by - correct answer -Low density
sludge
3. In the activated sludge process, Sludge Rising differs from
"Sludge Bulking" and "Sludge Rising" is typically associated -
correct answer -Nitrification - De-nitrification process
4. In the activated sludge process, techniques used to reduce
"Frothing & Foaming" typically include - correct answer -
Adjusting sludge age, Reducing the amount of air, Spraying the
frothing area with water, Applying de-foaming agents
, Page | 2
5. In the activated sludge process, floc is very important to the
settling process. Floc is composed primarily of - correct answer
-Bacteria, Protozoa, Microscopic Animals, & Fungi
6. In the activated sludge plants, the operator will experience
problems. Some of the common Treatment plant problems
include - correct answer -Insufficent capacity, Equipment
failures, Design inadequacies, Poor maintenance, & Inflow
rates exceed plant capacities.
7. In the activated sludge plants the operator will experience
problems. Some of the common Influent problems include -
correct answer -Septic inflow, Organic overloading, and under
loading, Hydraulic overloading, Solids washout during storm
inflow, Toxic substances, Shock loads, & Nutrient deficiencies
8. In the activated sludge plants, the operator will experience
problems. Some common Operational problems include -
correct answer -Sludge quality, foaming, improper operating
techniques
, Page | 3
9. In the activated sludge plants, the operator will experience
problems. Some common Environmental problems include. -
correct answer -Low temperatures, System pH out of range, &
Excessive algae growth
10. In the activated sludge plants, to properly set the clarifier
return rate the operator must know three things - correct
answer -Return activated sludge rate, Sludge blanket
thickness, & the Solids concentration of the return flow
11. The typical sludge age for extended aeration plants is -
correct answer -20 to 40 days
12. In the activated sludge plant, good quality sludge will settle
_________& _______ over _________ minute period. - correct
answer -Gently & Uniformly over 15 to 20 minutes
13. In the activated sludge plant, old sludge quality will settle
________& _________ over ________ minute period. - correct
answer -Rapidly and ragged over 5 minutes.
, Page | 4
14. In the activated sludge plant, there are (5) important nitroen
transformation processes that occur by microorganisms. They
are- - correct answer -Assumilation, Ammonification,
Nitrification, Denitrification, & Nitrogen fixation.
15. __________in the effluent from an activated sludge process
is a pollutant and may create toxic conditions for aquatic life in
the receiving stream - correct answer -Nitrogen
16. Denitrification occurs in an activated sludge system when
there is __________ to maintain the aerobic metabolism of the
carbon stabilizing bacteria. - correct answer -Insufficient
Dissolved Oxygen
17. The lack of _________ triggers the facuitative bacteria to
change from aerobic and anaerobic - correct answer -Dissolved
Oxygen
18. In the activated sludge system, "Hydraulic Wash Out" is -
correct answer -When the upward movement of the water in
the clarifier exceeds the downward settling velocity
