1|Page
TEXAS WASTEWATER CLASS B EXAM 2025 | ALL
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) | LATEST VERSION | ALREADY GRADED
A+
The name of the State Agency responsible for enforcing pollution control laws in
Texas - (ANSWER)Texas Commission of Environmental Quality
The term pathogenic means - (ANSWER)Capable of causing disease
The minimum separation between sewer lines and potable water lines is -
(ANSWER)9 feet
A licensed wastewater operator is a professional - (ANSWER)consistently does
best job possible, practices personal safety, strives to improve job knowledge,
strives to keep the plant and collection system in the best appearance and
working order
An important step in testing a sample for Total Suspended Solids is -
(ANSWER)Filtering a sample
The Biochemical oxygen Demand (BOD) of a sample is based on -
(ANSWER)Measuring the dissolved oxygen (DO) used
The results of Biochemical Oxygen Demand (BOD) sample taken at a treatment
plant tells the operator - (ANSWER)How the plant was operating 5 days ago
,2|Page
Which of the following are dangerous gasses that are likely to be present in lift
stations and manholes? - (ANSWER)Natural gas, gasoline fumes, hydrogen sulfide
and carbon dioxide
A preferred hydraulic method of cleaning sewer lines is - (ANSWER)Hydro Jet
Cleaner
Ways to reduce bad odors coming from a collection system - (ANSWER)routinely
cleaning slow running or low flow lines, adding chlorine or hydrogen peroxide to
the collection system
Types of pipe that are commonly used in wastewater collection system -
(ANSWER)ductile iron, Poly Vinyl Chloride (PVC)
Before entering a confined space a worker should - (ANSWER)Use approved
monitoring device and check for the presence of dangerous gasses, ventilate the
space with a blower, wear a safety harness and attach a life line
A properly designed and operated primary sedimentation tank should remove
_____ percent of incoming BOD - (ANSWER)30-40%
Devices that may be used to determine the level of sewage in a lift station -
(ANSWER)air bubbler, floats, electrodes, Acoustic (sonic)
, 3|Page
What is the most important role of aerobic bacteria in the treatment of
wastewater? - (ANSWER)decompose organic matter
The hydraulic loading of a trickling filter may be determined by - (ANSWER)flow
rate and filter area
These can be used to dewater sludge - (ANSWER)belt press, drying beds, solid
bowl centrifuge, gravity thickener
Most important to providing adequate sewage treatment in a stabilization pond -
(ANSWER)sunlight, algae, bacteria and time
Offensive and objectionable odors which sometimes occur in trickling filters
usually indicate - (ANSWER)septic conditions are present
Dissolved Oxygen (DO) in aeration tank of an activated sludge plant should be
maintained at or about - (ANSWER)2 to 4 mg/L
Contributes to the infiltration in a collection system - (ANSWER)breaks in the
main lines, high ground water levels, heavy rains, hydro jet cleaning plugged
mains
When a centrifuge pump loses prime the - (ANSWER)pump is no longer moving
liquid
TEXAS WASTEWATER CLASS B EXAM 2025 | ALL
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) | LATEST VERSION | ALREADY GRADED
A+
The name of the State Agency responsible for enforcing pollution control laws in
Texas - (ANSWER)Texas Commission of Environmental Quality
The term pathogenic means - (ANSWER)Capable of causing disease
The minimum separation between sewer lines and potable water lines is -
(ANSWER)9 feet
A licensed wastewater operator is a professional - (ANSWER)consistently does
best job possible, practices personal safety, strives to improve job knowledge,
strives to keep the plant and collection system in the best appearance and
working order
An important step in testing a sample for Total Suspended Solids is -
(ANSWER)Filtering a sample
The Biochemical oxygen Demand (BOD) of a sample is based on -
(ANSWER)Measuring the dissolved oxygen (DO) used
The results of Biochemical Oxygen Demand (BOD) sample taken at a treatment
plant tells the operator - (ANSWER)How the plant was operating 5 days ago
,2|Page
Which of the following are dangerous gasses that are likely to be present in lift
stations and manholes? - (ANSWER)Natural gas, gasoline fumes, hydrogen sulfide
and carbon dioxide
A preferred hydraulic method of cleaning sewer lines is - (ANSWER)Hydro Jet
Cleaner
Ways to reduce bad odors coming from a collection system - (ANSWER)routinely
cleaning slow running or low flow lines, adding chlorine or hydrogen peroxide to
the collection system
Types of pipe that are commonly used in wastewater collection system -
(ANSWER)ductile iron, Poly Vinyl Chloride (PVC)
Before entering a confined space a worker should - (ANSWER)Use approved
monitoring device and check for the presence of dangerous gasses, ventilate the
space with a blower, wear a safety harness and attach a life line
A properly designed and operated primary sedimentation tank should remove
_____ percent of incoming BOD - (ANSWER)30-40%
Devices that may be used to determine the level of sewage in a lift station -
(ANSWER)air bubbler, floats, electrodes, Acoustic (sonic)
, 3|Page
What is the most important role of aerobic bacteria in the treatment of
wastewater? - (ANSWER)decompose organic matter
The hydraulic loading of a trickling filter may be determined by - (ANSWER)flow
rate and filter area
These can be used to dewater sludge - (ANSWER)belt press, drying beds, solid
bowl centrifuge, gravity thickener
Most important to providing adequate sewage treatment in a stabilization pond -
(ANSWER)sunlight, algae, bacteria and time
Offensive and objectionable odors which sometimes occur in trickling filters
usually indicate - (ANSWER)septic conditions are present
Dissolved Oxygen (DO) in aeration tank of an activated sludge plant should be
maintained at or about - (ANSWER)2 to 4 mg/L
Contributes to the infiltration in a collection system - (ANSWER)breaks in the
main lines, high ground water levels, heavy rains, hydro jet cleaning plugged
mains
When a centrifuge pump loses prime the - (ANSWER)pump is no longer moving
liquid
