Texas Wastewater Class C – 2024–2025 Updated Study
Guide & Practice Concepts Focus: wastewater operations,
safety, regulations, treatment processes.
Safety (Questions 1-15)
1. What is the primary purpose of a Confined Space Entry Permit?
a) To authorize overtime pay
b) To document that all safety hazards have been assessed and controlled ✓
c) To order necessary equipment
d) To schedule maintenance
2. The "Danger" safety tag on an electrical panel signifies what?
a) A non-critical maintenance note
b) A potential hazard that must be avoided ✓
c) Instructions for operation
d) A reminder for future work
3. What is the most immediate danger when entering a wastewater wet well?
a) Slippery surfaces
b) Oxygen deficiency or toxic gases ✓
c) Noise exposure
d) Cold temperatures
4. What type of fire extinguisher is used for electrical fires?
a) Class A
b) Class B
c) Class C ✓
d) Class D
5. The acronym "LOTO" stands for:
a) Log Out, Tag Out
b) Lock Out, Test Out
c) Lock Out, Tag Out ✓
d) Log On, Tag On
6. A permit-required confined space has the potential for which of the following?
a) Hazardous atmosphere
b) Engulfment
,c) Configuration that could trap or asphyxiate
d) All of the above ✓
7. What is the minimum oxygen level for safe entry into a confined space without an SCBA?
a) 15.0%
b) 19.5% ✓
c) 21.0%
d) 23.5%
8. Hydrogen Sulfide (H₂S) gas is characterized by what smell at low concentrations?
a) No smell
b) Rotten eggs ✓
c) Sweet aroma
d) Sharp, pungent odor
9. Why is it dangerous to rely on your sense of smell for H₂S detection?
a) It smells like flowers
b) It rapidly deadens your sense of smell at high concentrations ✓
c) It has no odor
d) It only smells in cold weather
10. The primary health effect of high concentrations of H₂S is:
a) Skin irritation
b) Immediate unconsciousness and respiratory paralysis ✓
c) Long-term lung cancer
d) Headaches only
11. What Personal Protective Equipment (PPE) is essential for handling chemicals like
chlorine?
a) Just gloves
b) Safety glasses, gloves, and a chemical-resistant apron ✓
c) Hard hat and steel-toed boots only
d) Hearing protection
12. The safest way to descend a vertical ladder into a confined space is to:
a) Jump down quickly
b) Use a safety harness and retrieval system ✓
c) Slide down the rails
d) Have a coworker spot you from below
,13. If a coworker collapses in a confined space, your first action should be to:
a) Immediately jump in to rescue them
b) Shut down the nearest pump
c) Activate the emergency response plan and call for help without entering ✓
d) Try to wake them up by shouting
14. Chlorine gas is what color?
a) Invisible
b) Greenish-yellow ✓
c) Blue
d) Reddish-brown
15. Sodium Hypochlorite (bleach) can react with which common substance to release toxic
chlorine gas?
a) Water
b) Ammonia ✓
c) Sand
d) Grease
Regulations & Administration (Questions 16-30)
16. The state agency responsible for administering the wastewater operator licensing program
in Texas is the:
a) Texas Commission on Environmental Quality (TCEQ) ✓
b) Environmental Protection Agency (EPA)
c) Texas Department of Water Resources
d) Occupational Safety and Health Administration (OSHA)
17. The National Pollutant Discharge Elimination System (NPDES) permit program is
authorized by the:
a) Safe Drinking Water Act
b) Clean Water Act ✓
c) Resource Conservation and Recovery Act
d) Clean Air Act
18. What is the primary purpose of an NPDES permit?
a) To regulate air emissions from the plant
b) To set limits on what can be discharged to a receiving stream ✓
, c) To govern the disposal of sewage sludge
d) To set drinking water standards
19. A "bypass" of untreated wastewater is:
a) Always allowed to prevent plant overload
b) Only permitted in accordance with specific NPDES permit conditions ✓
c) A standard operating procedure
d) Not regulated
20. The TCEQ requires operators to report any noncompliance that could affect health or the
environment within:
a) 30 days
b) 24 hours ✓
c) 1 week
d) The next monthly report
21. The recommended pH range for discharge in a typical NPDES permit is:
a) 5.0 to 8.0
b) 4.0 to 10.0
c) 6.0 to 9.0 ✓
d) 7.0 to 8.5
22. What is the primary record kept by a wastewater treatment plant to demonstrate
compliance?
a) Employee time sheets
b) The Plant's Operational Log (or Discharge Monitoring Report) ✓
c) Equipment purchase orders
d) Safety meeting minutes
23. A Class C operator can typically:
a) Supervise a Class IV plant
b) Perform process control duties under direct supervision ✓
c) Sign DMRs independently
d) Bypass treatment units without approval
24. Falsifying a Discharge Monitoring Report (DMR) is:
a) A minor clerical error
b) A serious federal offense with criminal penalties ✓
c) Only a problem if the discharge limits are exceeded
d) Approved if it saves the plant money
Guide & Practice Concepts Focus: wastewater operations,
safety, regulations, treatment processes.
Safety (Questions 1-15)
1. What is the primary purpose of a Confined Space Entry Permit?
a) To authorize overtime pay
b) To document that all safety hazards have been assessed and controlled ✓
c) To order necessary equipment
d) To schedule maintenance
2. The "Danger" safety tag on an electrical panel signifies what?
a) A non-critical maintenance note
b) A potential hazard that must be avoided ✓
c) Instructions for operation
d) A reminder for future work
3. What is the most immediate danger when entering a wastewater wet well?
a) Slippery surfaces
b) Oxygen deficiency or toxic gases ✓
c) Noise exposure
d) Cold temperatures
4. What type of fire extinguisher is used for electrical fires?
a) Class A
b) Class B
c) Class C ✓
d) Class D
5. The acronym "LOTO" stands for:
a) Log Out, Tag Out
b) Lock Out, Test Out
c) Lock Out, Tag Out ✓
d) Log On, Tag On
6. A permit-required confined space has the potential for which of the following?
a) Hazardous atmosphere
b) Engulfment
,c) Configuration that could trap or asphyxiate
d) All of the above ✓
7. What is the minimum oxygen level for safe entry into a confined space without an SCBA?
a) 15.0%
b) 19.5% ✓
c) 21.0%
d) 23.5%
8. Hydrogen Sulfide (H₂S) gas is characterized by what smell at low concentrations?
a) No smell
b) Rotten eggs ✓
c) Sweet aroma
d) Sharp, pungent odor
9. Why is it dangerous to rely on your sense of smell for H₂S detection?
a) It smells like flowers
b) It rapidly deadens your sense of smell at high concentrations ✓
c) It has no odor
d) It only smells in cold weather
10. The primary health effect of high concentrations of H₂S is:
a) Skin irritation
b) Immediate unconsciousness and respiratory paralysis ✓
c) Long-term lung cancer
d) Headaches only
11. What Personal Protective Equipment (PPE) is essential for handling chemicals like
chlorine?
a) Just gloves
b) Safety glasses, gloves, and a chemical-resistant apron ✓
c) Hard hat and steel-toed boots only
d) Hearing protection
12. The safest way to descend a vertical ladder into a confined space is to:
a) Jump down quickly
b) Use a safety harness and retrieval system ✓
c) Slide down the rails
d) Have a coworker spot you from below
,13. If a coworker collapses in a confined space, your first action should be to:
a) Immediately jump in to rescue them
b) Shut down the nearest pump
c) Activate the emergency response plan and call for help without entering ✓
d) Try to wake them up by shouting
14. Chlorine gas is what color?
a) Invisible
b) Greenish-yellow ✓
c) Blue
d) Reddish-brown
15. Sodium Hypochlorite (bleach) can react with which common substance to release toxic
chlorine gas?
a) Water
b) Ammonia ✓
c) Sand
d) Grease
Regulations & Administration (Questions 16-30)
16. The state agency responsible for administering the wastewater operator licensing program
in Texas is the:
a) Texas Commission on Environmental Quality (TCEQ) ✓
b) Environmental Protection Agency (EPA)
c) Texas Department of Water Resources
d) Occupational Safety and Health Administration (OSHA)
17. The National Pollutant Discharge Elimination System (NPDES) permit program is
authorized by the:
a) Safe Drinking Water Act
b) Clean Water Act ✓
c) Resource Conservation and Recovery Act
d) Clean Air Act
18. What is the primary purpose of an NPDES permit?
a) To regulate air emissions from the plant
b) To set limits on what can be discharged to a receiving stream ✓
, c) To govern the disposal of sewage sludge
d) To set drinking water standards
19. A "bypass" of untreated wastewater is:
a) Always allowed to prevent plant overload
b) Only permitted in accordance with specific NPDES permit conditions ✓
c) A standard operating procedure
d) Not regulated
20. The TCEQ requires operators to report any noncompliance that could affect health or the
environment within:
a) 30 days
b) 24 hours ✓
c) 1 week
d) The next monthly report
21. The recommended pH range for discharge in a typical NPDES permit is:
a) 5.0 to 8.0
b) 4.0 to 10.0
c) 6.0 to 9.0 ✓
d) 7.0 to 8.5
22. What is the primary record kept by a wastewater treatment plant to demonstrate
compliance?
a) Employee time sheets
b) The Plant's Operational Log (or Discharge Monitoring Report) ✓
c) Equipment purchase orders
d) Safety meeting minutes
23. A Class C operator can typically:
a) Supervise a Class IV plant
b) Perform process control duties under direct supervision ✓
c) Sign DMRs independently
d) Bypass treatment units without approval
24. Falsifying a Discharge Monitoring Report (DMR) is:
a) A minor clerical error
b) A serious federal offense with criminal penalties ✓
c) Only a problem if the discharge limits are exceeded
d) Approved if it saves the plant money
