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Texas Wastewater Collection System Operator
Class II Exam (TCEQ) QUESTIONS AND VERIFIED
ANSWERS WITH RATIONALES JUST RELEASED
Texas Wastewater Collection System Operator Class II Exam (TCEQ)
Content areas (summarized, short point-form)
• Hydraulics & Pumping (flow, velocity, pressure, head, friction loss, pump curves, NPSH)
• Collection System Components (pipes – gravity & force main, manholes, lift stations, wet wells,
valves, air release valves, cleanouts)
• Pumps & Motors (centrifugal, submersible, screw pumps, impellers, seals, bearings, VFDs)
• Safety (confined space entry, lockout/tagout, PPE, gas detection (H₂S, CH₄, O₂), traffic control,
slip/trip hazards)
• Operation & Maintenance (preventive maintenance schedules, troubleshooting, cleaning
methods (rodding, jetting, bucket machine), CCTV inspection)
• Pipeline Rehabilitation (CIPP, slip lining, pipe bursting, spot repairs)
• Lift Station Maintenance (level controls, pump replacement, valve exercising, wet well cleaning)
• Troubleshooting & Odor Control (H₂S, corrosion, odor control systems (chemical injection,
carbon filters, biofilters))
• Regulatory Compliance (TCEQ rules – 30 TAC Chapter 317, 30 TAC Chapter 319, reporting,
overflow notification)
• Safety & Health (H₂S toxicity, oxygen deficiency, explosive limits, gas testing procedures)
• Flow Monitoring (weirs, flumes, meters, data logging)
• Environmental Protection (sanitary sewer overflows (SSOs), bypass procedures, spill response,
reporting)
1. What is the most common type of pipe used for gravity sewer collection systems in Texas?
A) Ductile iron pipe (DIP)
B) Polyvinyl chloride (PVC)
C) Clay pipe (VCP)
D) High-density polyethylene (HDPE)
Answer: B
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Rationale: PVC pipe is widely used due to its corrosion resistance, light weight, and ease of installation .
2. The minimum velocity required in a gravity sewer to prevent solids deposition (self-cleaning) is
typically:
A) 1.0 feet per second (fps)
B) 2.0 feet per second (fps)
C) 3.0 feet per second (fps)
D) 5.0 feet per second (fps)
Answer: B
Rationale: A minimum velocity of 2 fps is required to keep solids suspended and prevent settling .
3. A lift station wet well that has a rotten egg odor indicates the presence of:
A) Methane gas (CH₄)
B) Carbon dioxide (CO₂)
C) Hydrogen sulfide (H₂S)
D) Ammonia (NH₃)
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Answer: C
Rationale: Hydrogen sulfide (H₂S) is produced by anaerobic bacteria and smells like rotten eggs; it is
toxic and corrosive .
4. When entering a manhole, what is the first step in confined space entry?
A) Put on a harness
B) Test the atmosphere (O₂, H₂S, CO, LEL)
C) Open the manhole cover
D) Call a standby person
Answer: B
Rationale: Atmospheric testing must be performed (with calibrated equipment) before any entry to
ensure oxygen levels are sufficient and toxic/explosive gases are within safe limits .
5. What is the maximum allowable H₂S exposure limit (ceiling) for an 8-hour work shift according to
OSHA?
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A) 1 ppm
B) 5 ppm
C) 10 ppm
D) 20 ppm
Answer: C
Rationale: OSHA PEL for H₂S is 10 ppm (ceiling) for an 8-hour shift; levels above 100 ppm are
immediately dangerous to life and health .
6. What is the primary purpose of a manhole in a sewer collection system?
A) To allow access for inspection and cleaning
B) To increase flow velocity
C) To add chlorine to wastewater
D) To measure flow rates
Answer: A
Texas Wastewater Collection System Operator
Class II Exam (TCEQ) QUESTIONS AND VERIFIED
ANSWERS WITH RATIONALES JUST RELEASED
Texas Wastewater Collection System Operator Class II Exam (TCEQ)
Content areas (summarized, short point-form)
• Hydraulics & Pumping (flow, velocity, pressure, head, friction loss, pump curves, NPSH)
• Collection System Components (pipes – gravity & force main, manholes, lift stations, wet wells,
valves, air release valves, cleanouts)
• Pumps & Motors (centrifugal, submersible, screw pumps, impellers, seals, bearings, VFDs)
• Safety (confined space entry, lockout/tagout, PPE, gas detection (H₂S, CH₄, O₂), traffic control,
slip/trip hazards)
• Operation & Maintenance (preventive maintenance schedules, troubleshooting, cleaning
methods (rodding, jetting, bucket machine), CCTV inspection)
• Pipeline Rehabilitation (CIPP, slip lining, pipe bursting, spot repairs)
• Lift Station Maintenance (level controls, pump replacement, valve exercising, wet well cleaning)
• Troubleshooting & Odor Control (H₂S, corrosion, odor control systems (chemical injection,
carbon filters, biofilters))
• Regulatory Compliance (TCEQ rules – 30 TAC Chapter 317, 30 TAC Chapter 319, reporting,
overflow notification)
• Safety & Health (H₂S toxicity, oxygen deficiency, explosive limits, gas testing procedures)
• Flow Monitoring (weirs, flumes, meters, data logging)
• Environmental Protection (sanitary sewer overflows (SSOs), bypass procedures, spill response,
reporting)
1. What is the most common type of pipe used for gravity sewer collection systems in Texas?
A) Ductile iron pipe (DIP)
B) Polyvinyl chloride (PVC)
C) Clay pipe (VCP)
D) High-density polyethylene (HDPE)
Answer: B
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Rationale: PVC pipe is widely used due to its corrosion resistance, light weight, and ease of installation .
2. The minimum velocity required in a gravity sewer to prevent solids deposition (self-cleaning) is
typically:
A) 1.0 feet per second (fps)
B) 2.0 feet per second (fps)
C) 3.0 feet per second (fps)
D) 5.0 feet per second (fps)
Answer: B
Rationale: A minimum velocity of 2 fps is required to keep solids suspended and prevent settling .
3. A lift station wet well that has a rotten egg odor indicates the presence of:
A) Methane gas (CH₄)
B) Carbon dioxide (CO₂)
C) Hydrogen sulfide (H₂S)
D) Ammonia (NH₃)
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Answer: C
Rationale: Hydrogen sulfide (H₂S) is produced by anaerobic bacteria and smells like rotten eggs; it is
toxic and corrosive .
4. When entering a manhole, what is the first step in confined space entry?
A) Put on a harness
B) Test the atmosphere (O₂, H₂S, CO, LEL)
C) Open the manhole cover
D) Call a standby person
Answer: B
Rationale: Atmospheric testing must be performed (with calibrated equipment) before any entry to
ensure oxygen levels are sufficient and toxic/explosive gases are within safe limits .
5. What is the maximum allowable H₂S exposure limit (ceiling) for an 8-hour work shift according to
OSHA?
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A) 1 ppm
B) 5 ppm
C) 10 ppm
D) 20 ppm
Answer: C
Rationale: OSHA PEL for H₂S is 10 ppm (ceiling) for an 8-hour shift; levels above 100 ppm are
immediately dangerous to life and health .
6. What is the primary purpose of a manhole in a sewer collection system?
A) To allow access for inspection and cleaning
B) To increase flow velocity
C) To add chlorine to wastewater
D) To measure flow rates
Answer: A
