TEXAS WASTEWATER CLASS A EXAM
High-Yield Questions and Answers with
Rationales 2026/2027 Edition
Section 1: Regulations, Administration, and Safety
Question 1
What is the Texas Commission on Environmental Quality (TCEQ)
primary method for controlling point-source pollution discharges into
state waterways?
A. Issuing water allocation rights
B. Permitting of domestic and industrial wastewater treatment plants
C. Managing municipal solid waste landfills
D. Enforcing ambient air quality standards
Correct Answer: B. Permitting of domestic and industrial
wastewater treatment plants
Rationale: Under the Texas Water Code and TCEQ regulations, point-
source discharges require a Texas Pollutant Discharge Elimination
System (TPDES) permit. These permits establish specific effluent limits,
monitoring requirements, and operational standards to protect state water
quality.
Question 2
When must a utility notify the TCEQ regarding major expansions or
alterations of an existing wastewater treatment facility?
A. Within 30 days after construction is completed
B. Annually during the renewal of the TPDES permit
, C. Before construction begins
D. Only if the hydraulic capacity increases by more than 50 percent
Correct Answer: C. Before construction begins
Rationale: TCEQ design criteria and rules require engineering plans and
specifications to be submitted and formally approved prior to the
commencement of any construction or expansion of treatment facilities
to ensure compliance with state criteria.
Question 3
As the complexity, size, and regulatory burden of a wastewater utility
organization increase, which management function becomes the most
critical for an operator or manager?
A. Direct supervision of daily manual labor
B. Planning
C. Equipment purchasing
D. Public relations
Correct Answer: B. Planning
Rationale: In complex utility organizations, proactive planning—
covering long-term capital improvements, regulatory compliance
scheduling, emergency response, and budgeting—prevents system
failures and ensures resources align with operational demands.
Question 4
What type of fire extinguisher is appropriate for use on an energized
electrical control panel?
A. Class A water extinguisher
, B. Class B foam extinguisher
C. Class C carbon dioxide or dry chemical extinguisher
D. Class D metal powder extinguisher
Correct Answer: C. Class C carbon dioxide or dry chemical
extinguisher
Rationale: Class C fire extinguishers use non-conductive agents (like
CO2 or dry chemicals) safe for use on energized electrical equipment.
Using water (Class A) on electrical panels risks severe electrical shock
to the operator.
Section 2: Collection Systems and Hydraulics
Question 5
What are the standard design requirements for gravity wastewater
collection lines under normal operating conditions?
A. Designed to flow completely full at a minimum velocity of 1 fps
B. Designed to flow half-full at a minimum velocity of 2 fps and a
maximum of 10 fps
C. Designed to flow at a constant velocity of 15 fps to prevent any
settling
D. Designed with no minimum velocity requirement if slopes exceed
2 percent
Correct Answer: B. Designed to flow half-full at a minimum velocity
of 2 fps and a maximum of 10 fps
Rationale: Gravity sewers are designed to maintain a self-cleansing
velocity of at least 2.0 feet per second (fps) at peak or normal flow to
, prevent the deposition of solids, while capping velocities at 10 fps to
prevent excessive structural abrasion of the pipe invert.
Question 6
According to Texas design criteria, what are the minimum dimensions
for a wastewater manhole access opening and its interior diameter?
A. 18-inch opening and 36-inch interior diameter
B. 24-inch opening and 48-inch interior diameter
C. 30-inch opening and 60-inch interior diameter
D. 36-inch opening and 72-inch interior diameter
Correct Answer: B. 24-inch opening and 48-inch interior diameter
Rationale: Manholes must provide safe physical and equipment entry
for operators. A minimum 24-inch clear opening and a 48-inch (4-foot)
interior base diameter are required to allow working room and basket
retrieval during emergencies.
Question 7
What is the mandatory minimum working pressure rating and minimum
diameter for wastewater force mains?
A. 50 psi rating and 2-inch diameter
B. 100 psi rating and 3-inch diameter
C. 150 psi rating and 4-inch diameter
D. 200 psi rating and 6-inch diameter
Correct Answer: C. 150 psi rating and 4-inch diameter
High-Yield Questions and Answers with
Rationales 2026/2027 Edition
Section 1: Regulations, Administration, and Safety
Question 1
What is the Texas Commission on Environmental Quality (TCEQ)
primary method for controlling point-source pollution discharges into
state waterways?
A. Issuing water allocation rights
B. Permitting of domestic and industrial wastewater treatment plants
C. Managing municipal solid waste landfills
D. Enforcing ambient air quality standards
Correct Answer: B. Permitting of domestic and industrial
wastewater treatment plants
Rationale: Under the Texas Water Code and TCEQ regulations, point-
source discharges require a Texas Pollutant Discharge Elimination
System (TPDES) permit. These permits establish specific effluent limits,
monitoring requirements, and operational standards to protect state water
quality.
Question 2
When must a utility notify the TCEQ regarding major expansions or
alterations of an existing wastewater treatment facility?
A. Within 30 days after construction is completed
B. Annually during the renewal of the TPDES permit
, C. Before construction begins
D. Only if the hydraulic capacity increases by more than 50 percent
Correct Answer: C. Before construction begins
Rationale: TCEQ design criteria and rules require engineering plans and
specifications to be submitted and formally approved prior to the
commencement of any construction or expansion of treatment facilities
to ensure compliance with state criteria.
Question 3
As the complexity, size, and regulatory burden of a wastewater utility
organization increase, which management function becomes the most
critical for an operator or manager?
A. Direct supervision of daily manual labor
B. Planning
C. Equipment purchasing
D. Public relations
Correct Answer: B. Planning
Rationale: In complex utility organizations, proactive planning—
covering long-term capital improvements, regulatory compliance
scheduling, emergency response, and budgeting—prevents system
failures and ensures resources align with operational demands.
Question 4
What type of fire extinguisher is appropriate for use on an energized
electrical control panel?
A. Class A water extinguisher
, B. Class B foam extinguisher
C. Class C carbon dioxide or dry chemical extinguisher
D. Class D metal powder extinguisher
Correct Answer: C. Class C carbon dioxide or dry chemical
extinguisher
Rationale: Class C fire extinguishers use non-conductive agents (like
CO2 or dry chemicals) safe for use on energized electrical equipment.
Using water (Class A) on electrical panels risks severe electrical shock
to the operator.
Section 2: Collection Systems and Hydraulics
Question 5
What are the standard design requirements for gravity wastewater
collection lines under normal operating conditions?
A. Designed to flow completely full at a minimum velocity of 1 fps
B. Designed to flow half-full at a minimum velocity of 2 fps and a
maximum of 10 fps
C. Designed to flow at a constant velocity of 15 fps to prevent any
settling
D. Designed with no minimum velocity requirement if slopes exceed
2 percent
Correct Answer: B. Designed to flow half-full at a minimum velocity
of 2 fps and a maximum of 10 fps
Rationale: Gravity sewers are designed to maintain a self-cleansing
velocity of at least 2.0 feet per second (fps) at peak or normal flow to
, prevent the deposition of solids, while capping velocities at 10 fps to
prevent excessive structural abrasion of the pipe invert.
Question 6
According to Texas design criteria, what are the minimum dimensions
for a wastewater manhole access opening and its interior diameter?
A. 18-inch opening and 36-inch interior diameter
B. 24-inch opening and 48-inch interior diameter
C. 30-inch opening and 60-inch interior diameter
D. 36-inch opening and 72-inch interior diameter
Correct Answer: B. 24-inch opening and 48-inch interior diameter
Rationale: Manholes must provide safe physical and equipment entry
for operators. A minimum 24-inch clear opening and a 48-inch (4-foot)
interior base diameter are required to allow working room and basket
retrieval during emergencies.
Question 7
What is the mandatory minimum working pressure rating and minimum
diameter for wastewater force mains?
A. 50 psi rating and 2-inch diameter
B. 100 psi rating and 3-inch diameter
C. 150 psi rating and 4-inch diameter
D. 200 psi rating and 6-inch diameter
Correct Answer: C. 150 psi rating and 4-inch diameter
