WASTEWATER B TEST EXAM
QUESTIONS AND ANSWERS 2026
Percent of volatile solids normally in sludge - ANSWERS70-80%
D.O. levels in a primary clarifier - ANSWERS0.5-1.0 MG/L
Why are precautionary measures needed around an aeration basin? -
ANSWERSundertow and turbulence
O.S.H.A. approved trench - ANSWERSnarrow excavation in which the depth is greater
than the width; the width must be less than 15 feet
What causes bulking? - ANSWERS1. Excessive hydraulic loading,
2. Solids not promptly removed from clarifier
3. Inadequate weir length
4. Improper ratio of depth to surface area of the final clarifier
What are the 5 elements of a trickling filter? - ANSWERS1. Floor
2. under drain
3. Wall containing the filter bed
4. media
5. filter distribution arm
When and where are monthly reports submitted? - ANSWERSby the 20th of the
following month; submitted to Austin
How and when do you report a bypass? - ANSWERSas soon as possible by phone
within 24 hours; followed by in writing within 5 working days
What are the 5 events of stream purification? - ANSWERS1. Pollution
2. Degradation
3. Decomposition
4. Recovery
5. Clear
What are the 2 methods for measuring D.O.? - ANSWERS1. Winkler method
2. meter
What is needed for good communication? - ANSWERSgood listening
How much chlorine gas comes from one part liquid chlorine? - ANSWERS450
, What does the "F and M" stand for in the F:M Ratio? - ANSWERSFood to
Microorganism
What feeds the nitrification organisms? - ANSWERSfatty volatile acids
An explosive atmosphere contains what 2 things? - ANSWERS1. Oxygen
2. flammable gas vapor or dust
How deep should the drying bed sludge be? - ANSWERS8-12 inches
Why is a low flow rated important when filling a drying bed? - ANSWERSto prevent
undigested sludge from breaking through the ripe sludge blanket in the digester
Under a microscope what 2 organizms should be predominant? - ANSWERS1. SILIATE
2. rotifers
The detention time in a contact stabilization plant is more or less than other extended
aeration plants? - ANSWERSLess
What 2 things are chlorine used for? - ANSWERS1. disinfection
2. odor control
What will a leaking chlorine container do? - ANSWERSfreeze up
How are plant goals best accomplished? - ANSWERSplanning, PM, records, analysis
What is the function of the bottom float in a lift station? - ANSWERSturns the pump off
What must be used when connecting a potable water supply to a lift station? -
ANSWERSan air gap between the pump and the water line twice the diameter of the
water line or at least 1", whichever is greater
What is the problem if the supernatant in the settleometer is clear but the effluent is not?
- ANSWERS1. Bulking
2. An equipment malfuntion such as a plugged R.A.S. or W.A.S. line
3. problem in secondary clarifier
Why does flow through a clarifier move up slowly? - ANSWERSto keep floc particles
from coming over the wiers
when should a manhole be placed? - ANSWERSat least every 500 feet or whenever
necessary
Where should the sludge in the clarifier be kept in the activated sludge process? -
ANSWERSbottom quarter
QUESTIONS AND ANSWERS 2026
Percent of volatile solids normally in sludge - ANSWERS70-80%
D.O. levels in a primary clarifier - ANSWERS0.5-1.0 MG/L
Why are precautionary measures needed around an aeration basin? -
ANSWERSundertow and turbulence
O.S.H.A. approved trench - ANSWERSnarrow excavation in which the depth is greater
than the width; the width must be less than 15 feet
What causes bulking? - ANSWERS1. Excessive hydraulic loading,
2. Solids not promptly removed from clarifier
3. Inadequate weir length
4. Improper ratio of depth to surface area of the final clarifier
What are the 5 elements of a trickling filter? - ANSWERS1. Floor
2. under drain
3. Wall containing the filter bed
4. media
5. filter distribution arm
When and where are monthly reports submitted? - ANSWERSby the 20th of the
following month; submitted to Austin
How and when do you report a bypass? - ANSWERSas soon as possible by phone
within 24 hours; followed by in writing within 5 working days
What are the 5 events of stream purification? - ANSWERS1. Pollution
2. Degradation
3. Decomposition
4. Recovery
5. Clear
What are the 2 methods for measuring D.O.? - ANSWERS1. Winkler method
2. meter
What is needed for good communication? - ANSWERSgood listening
How much chlorine gas comes from one part liquid chlorine? - ANSWERS450
, What does the "F and M" stand for in the F:M Ratio? - ANSWERSFood to
Microorganism
What feeds the nitrification organisms? - ANSWERSfatty volatile acids
An explosive atmosphere contains what 2 things? - ANSWERS1. Oxygen
2. flammable gas vapor or dust
How deep should the drying bed sludge be? - ANSWERS8-12 inches
Why is a low flow rated important when filling a drying bed? - ANSWERSto prevent
undigested sludge from breaking through the ripe sludge blanket in the digester
Under a microscope what 2 organizms should be predominant? - ANSWERS1. SILIATE
2. rotifers
The detention time in a contact stabilization plant is more or less than other extended
aeration plants? - ANSWERSLess
What 2 things are chlorine used for? - ANSWERS1. disinfection
2. odor control
What will a leaking chlorine container do? - ANSWERSfreeze up
How are plant goals best accomplished? - ANSWERSplanning, PM, records, analysis
What is the function of the bottom float in a lift station? - ANSWERSturns the pump off
What must be used when connecting a potable water supply to a lift station? -
ANSWERSan air gap between the pump and the water line twice the diameter of the
water line or at least 1", whichever is greater
What is the problem if the supernatant in the settleometer is clear but the effluent is not?
- ANSWERS1. Bulking
2. An equipment malfuntion such as a plugged R.A.S. or W.A.S. line
3. problem in secondary clarifier
Why does flow through a clarifier move up slowly? - ANSWERSto keep floc particles
from coming over the wiers
when should a manhole be placed? - ANSWERSat least every 500 feet or whenever
necessary
Where should the sludge in the clarifier be kept in the activated sludge process? -
ANSWERSbottom quarter
