TEXAS WASTEWATER CLASS A 2026/2027 EXAM VERIFIED CURRENTLY
TESTING QUESTIONS WITH COMPLETE SOLUTIONS
SECTION 1: REGULATIONS & SAFETY (Questions 1-30)
QUESTION 1
The Texas Commission on Environmental Quality (TCEQ) regulates wastewater
treatment facilities under which chapter of the Texas Water Code?
A) Chapter 5
B) Chapter 26
C) Chapter 7
D) Chapter 11
Correct Answer: B
Rationale: TCEQ regulates water quality under Chapter 26 of the Texas Water
Code, which provides authority for the Texas Pollutant Discharge Elimination
System (TPDES). Chapter 5 covers general powers, Chapter 7 addresses
enforcement, and Chapter 11 covers water rights.
QUESTION 2
What is the maximum allowable fecal coliform concentration for a Class A
wastewater effluent used for unrestricted public access irrigation (Type I)?
A) 200 CFU/100 mL
B) 400 CFU/100 mL
C) 20 CFU/100 mL
D) 50 CFU/100 mL
Correct Answer: C
Rationale: Type I uses (unrestricted public access) require fecal coliform
geometric mean of 20 CFU/100 mL, with no single sample exceeding 75 CFU/100
mL. Type II (restricted public access) allows 200 CFU/100 mL. Type III (agricultural)
allows 400 CFU/100 mL.
QUESTION 3
A wastewater operator notices a chlorine gas leak in the disinfection building.
What is the FIRST action the operator should take?
A) Attempt to repair the leak immediately
B) Evacuate the area and alert others, then call emergency response
1
,C) Turn off the chlorine feed and then investigate
D) Put on a respirator and locate the source
Correct Answer: B
Rationale: Safety first: immediately evacuate the area, warn others, and call
emergency services (or follow the facility's emergency response plan). Do not
attempt repairs without proper equipment and training; a chlorine leak can be
rapidly fatal.
QUESTION 4
Under TCEQ rules, an operator of a Class A wastewater treatment plant must hold
a license at what minimum level?
A) Class D
B) Class C
C) Class B
D) Class A
Correct Answer: D
Rationale: A Class A plant requires a Class A operator (the highest level) to be
responsible for the facility. While Class B or C operators may work under
supervision, the designated responsible operator must hold a Class A license.
QUESTION 5
What is the permissible exposure limit (PEL) for hydrogen sulfide (H2S) in the
workplace as set by OSHA?
A) 10 ppm (8-hour TWA)
B) 20 ppm (8-hour TWA)
C) 50 ppm (8-hour TWA)
D) 100 ppm (8-hour TWA)
Correct Answer: B (for general industry; 10 ppm for construction)
Rationale: OSHA's PEL for H2S is 20 ppm as an 8-hour time-weighted average,
with a ceiling of 50 ppm for 10 minutes. However, many facilities use the more
stringent ACGIH TLV of 10 ppm. The question tests the OSHA standard.
QUESTION 6
The Texas Pollutant Discharge Elimination System (TPDES) permit requires a
wastewater treatment plant to monitor and report which of the following?
2
,A) Effluent flow only
B) Influent flow only
C) Effluent flow, pollutant concentrations, and receiving water impacts
D) Only pH and temperature
Correct Answer: C
Rationale: TPDES permits require monitoring of effluent flow, pollutant levels
(BOD, TSS, nutrients, etc.), and compliance with water quality standards that
protect the receiving waterbody. Self-monitoring reports are submitted to TCEQ.
QUESTION 7
A confined space entry permit is required when:
A) The space has limited access and is not designed for continuous occupancy
B) The space contains a hazardous atmosphere, engulfment hazard, or other
serious
safety risks
C) The space is larger than 500 cubic feet
D) Both A and B
Correct Answer: D
Rationale: A permit-required confined space (permit space) must have both
limited access AND one or more hazards (atmospheric, engulfment, configuration,
etc.). The permit ensures all safety measures are in place before entry.
QUESTION 8
What is the minimum free chlorine residual required for wastewater disinfection
in most TPDES permits?
A) 0.5 mg/L after 30 minutes contact time
B) 1.0 mg/L after 15 minutes contact time
C) 2.0 mg/L after 15 minutes contact time
D) 0.2 mg/L after 60 minutes contact time
Correct Answer: A
Rationale: Typical permits require a free chlorine residual of at least 0.5 mg/L
after a minimum 30-minute contact time (at peak flow) to ensure effective
disinfection and meet fecal coliform limits.
QUESTION 9
3
, Which federal agency is responsible for setting national wastewater discharge
standards under the Clean Water Act?
A) TCEQ
B) EPA
C) OSHA
D) FEMA
Correct Answer: B
Rationale: The U.S. Environmental Protection Agency (EPA) sets national effluent
guidelines and water quality criteria under the Clean Water Act. TCEQ implements
these standards in Texas through the TPDES program.
QUESTION 10
A wastewater treatment plant experiences a chlorine gas release. What is the
immediate health concern for workers?
A) Skin irritation
B) Respiratory distress and pulmonary edema
C) Liver damage
D) Hearing loss
Correct Answer: B
Rationale: Chlorine gas is a potent respiratory irritant that can cause coughing,
chest pain, pulmonary edema, and asphyxiation. It is heavier than air and
accumulates in low areas.
QUESTION 11
Under TCEQ rules, a facility must submit its Discharge Monitoring Report (DMR)
by what date?
A) The 10th of the month following the reporting period
B) The 15th of the month following the reporting period
C) The last day of the month following the reporting period
D) Quarterly only
Correct Answer: B
Rationale: DMRs are typically due by the 15th day of the month following the
reporting period (monthly or quarterly, as specified in the permit). Late
submissions can result in enforcement action.
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TESTING QUESTIONS WITH COMPLETE SOLUTIONS
SECTION 1: REGULATIONS & SAFETY (Questions 1-30)
QUESTION 1
The Texas Commission on Environmental Quality (TCEQ) regulates wastewater
treatment facilities under which chapter of the Texas Water Code?
A) Chapter 5
B) Chapter 26
C) Chapter 7
D) Chapter 11
Correct Answer: B
Rationale: TCEQ regulates water quality under Chapter 26 of the Texas Water
Code, which provides authority for the Texas Pollutant Discharge Elimination
System (TPDES). Chapter 5 covers general powers, Chapter 7 addresses
enforcement, and Chapter 11 covers water rights.
QUESTION 2
What is the maximum allowable fecal coliform concentration for a Class A
wastewater effluent used for unrestricted public access irrigation (Type I)?
A) 200 CFU/100 mL
B) 400 CFU/100 mL
C) 20 CFU/100 mL
D) 50 CFU/100 mL
Correct Answer: C
Rationale: Type I uses (unrestricted public access) require fecal coliform
geometric mean of 20 CFU/100 mL, with no single sample exceeding 75 CFU/100
mL. Type II (restricted public access) allows 200 CFU/100 mL. Type III (agricultural)
allows 400 CFU/100 mL.
QUESTION 3
A wastewater operator notices a chlorine gas leak in the disinfection building.
What is the FIRST action the operator should take?
A) Attempt to repair the leak immediately
B) Evacuate the area and alert others, then call emergency response
1
,C) Turn off the chlorine feed and then investigate
D) Put on a respirator and locate the source
Correct Answer: B
Rationale: Safety first: immediately evacuate the area, warn others, and call
emergency services (or follow the facility's emergency response plan). Do not
attempt repairs without proper equipment and training; a chlorine leak can be
rapidly fatal.
QUESTION 4
Under TCEQ rules, an operator of a Class A wastewater treatment plant must hold
a license at what minimum level?
A) Class D
B) Class C
C) Class B
D) Class A
Correct Answer: D
Rationale: A Class A plant requires a Class A operator (the highest level) to be
responsible for the facility. While Class B or C operators may work under
supervision, the designated responsible operator must hold a Class A license.
QUESTION 5
What is the permissible exposure limit (PEL) for hydrogen sulfide (H2S) in the
workplace as set by OSHA?
A) 10 ppm (8-hour TWA)
B) 20 ppm (8-hour TWA)
C) 50 ppm (8-hour TWA)
D) 100 ppm (8-hour TWA)
Correct Answer: B (for general industry; 10 ppm for construction)
Rationale: OSHA's PEL for H2S is 20 ppm as an 8-hour time-weighted average,
with a ceiling of 50 ppm for 10 minutes. However, many facilities use the more
stringent ACGIH TLV of 10 ppm. The question tests the OSHA standard.
QUESTION 6
The Texas Pollutant Discharge Elimination System (TPDES) permit requires a
wastewater treatment plant to monitor and report which of the following?
2
,A) Effluent flow only
B) Influent flow only
C) Effluent flow, pollutant concentrations, and receiving water impacts
D) Only pH and temperature
Correct Answer: C
Rationale: TPDES permits require monitoring of effluent flow, pollutant levels
(BOD, TSS, nutrients, etc.), and compliance with water quality standards that
protect the receiving waterbody. Self-monitoring reports are submitted to TCEQ.
QUESTION 7
A confined space entry permit is required when:
A) The space has limited access and is not designed for continuous occupancy
B) The space contains a hazardous atmosphere, engulfment hazard, or other
serious
safety risks
C) The space is larger than 500 cubic feet
D) Both A and B
Correct Answer: D
Rationale: A permit-required confined space (permit space) must have both
limited access AND one or more hazards (atmospheric, engulfment, configuration,
etc.). The permit ensures all safety measures are in place before entry.
QUESTION 8
What is the minimum free chlorine residual required for wastewater disinfection
in most TPDES permits?
A) 0.5 mg/L after 30 minutes contact time
B) 1.0 mg/L after 15 minutes contact time
C) 2.0 mg/L after 15 minutes contact time
D) 0.2 mg/L after 60 minutes contact time
Correct Answer: A
Rationale: Typical permits require a free chlorine residual of at least 0.5 mg/L
after a minimum 30-minute contact time (at peak flow) to ensure effective
disinfection and meet fecal coliform limits.
QUESTION 9
3
, Which federal agency is responsible for setting national wastewater discharge
standards under the Clean Water Act?
A) TCEQ
B) EPA
C) OSHA
D) FEMA
Correct Answer: B
Rationale: The U.S. Environmental Protection Agency (EPA) sets national effluent
guidelines and water quality criteria under the Clean Water Act. TCEQ implements
these standards in Texas through the TPDES program.
QUESTION 10
A wastewater treatment plant experiences a chlorine gas release. What is the
immediate health concern for workers?
A) Skin irritation
B) Respiratory distress and pulmonary edema
C) Liver damage
D) Hearing loss
Correct Answer: B
Rationale: Chlorine gas is a potent respiratory irritant that can cause coughing,
chest pain, pulmonary edema, and asphyxiation. It is heavier than air and
accumulates in low areas.
QUESTION 11
Under TCEQ rules, a facility must submit its Discharge Monitoring Report (DMR)
by what date?
A) The 10th of the month following the reporting period
B) The 15th of the month following the reporting period
C) The last day of the month following the reporting period
D) Quarterly only
Correct Answer: B
Rationale: DMRs are typically due by the 15th day of the month following the
reporting period (monthly or quarterly, as specified in the permit). Late
submissions can result in enforcement action.
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