Texas Class D Water License Exam 2026/2027 –
Complete Study Guide & Test Bank | 300+
Practice Questions with Verified Answers | TCEQ
Class D Water Operator Certification
Question 1
The most important federal law impacting the water utility industry is the:
A) Water Resources Development Act
B) Federal Water Pollution Control Act
C) Hazard Communication Act
D) Safe Drinking Water Act
Answer: D) Safe Drinking Water Act
Rationale: The Safe Drinking Water Act (SDWA) is the primary federal law that
establishes national safety and quality standards for drinking water. It authorizes the EPA
to set Maximum Contaminant Levels (MCLs) for drinking water contaminants .
Question 2
The state agency that regulates drinking water in Texas and administers the federal Safe
Drinking Water Act is the:
A) Texas Department of Health (TDH)
B) Texas Commission on Environmental Quality (TCEQ)
C) Texas Department of Public Safety (DPS)
D) Public Utility Commission (PUC)
Answer: B) Texas Commission on Environmental Quality (TCEQ)
Rationale: TCEQ has primacy over the SDWA in Texas, meaning it is the state agency
responsible for enforcing federal drinking water standards. Primacy was initially granted
to TDH in 1978 before being transferred to TCEQ .
,Question 3
True or False: Operators have a responsibility to provide drinking water that meets
Federal and State Standards.
Answer: True
Rationale: Licensed water operators are responsible for ensuring that the water they
produce meets all federal and state drinking water standards, including EPA Maximum
Contaminant Levels (MCLs) and TCEQ regulations .
Question 4
The 4 national safety and quality standards for drinking water covered in the Safe
Drinking Water Act are physical, chemical, _____, and radiological.
A) Mineral
B) Thermal
C) Bacteriological
D) Mathematical
Answer: C) Bacteriological
Rationale: The SDWA establishes standards for physical, chemical, bacteriological, and
radiological contaminants. Bacteriological standards are particularly important because
they address waterborne pathogens that can cause immediate health effects .
Question 5
True or False: A public water system provides the public with piped water for human
consumption, serves at least 15 service connections, and regularly serves at least 25
individuals daily at least 60 days out of the year.
Answer: True
Rationale: This is the official definition of a public water system (PWS) under both
federal and Texas regulations. Systems meeting these criteria are subject to SDWA and
TCEQ regulation .
,Question 6
Which Texas agency originally assumed primacy over the Safe Drinking Water Act from
the EPA in 1978?
A) Texas Water Commission
B) Texas Department of Health (TDH)
C) Texas Railroad Commission
D) Texas Parks and Wildlife
Answer: B) Texas Department of Health (TDH)
Rationale: Primacy over the SDWA was initially granted to the Texas Department of
Health (TDH). This authority was later transferred to TCEQ, which currently administers
the program .
Question 7
True or False: The state requires bacteriological sample results to be kept for 2 years.
Answer: False
Rationale: TCEQ requires bacteriological sample results to be kept for 5 years, not 2
years. Longer retention periods are required for chemical analysis records .
Question 8
The state requires chemical analysis records to be kept at least _____ years.
A) 5
B) 7
C) 10
D) 15
Answer: C) 10 years
, Rationale: TCEQ requires chemical analysis records to be retained for at least 10 years.
This ensures that historical water quality data is available for regulatory review and
public health monitoring .
Question 9
The EPA requires a water system to keep a copy of each Consumer Confidence Report
for at least:
A) 1 year
B) 3 years
C) 5 years
D) 10 years
Answer: C) 5 years
Rationale: Consumer Confidence Reports (CCRs), which inform customers about water
quality and contaminant levels, must be retained for at least 5 years per EPA
requirements .
Question 10
Which Texas Administrative Code (TAC) chapter covers Drinking Water Standards?
A) 30 TAC Chapter 30, Subchapter F
B) 30 TAC Chapter 290, Subchapter F
C) 30 TAC Chapter 217
D) 30 TAC Chapter 290, Subchapter D
Answer: B) 30 TAC Chapter 290, Subchapter F
Rationale: 30 TAC Chapter 290 covers the rules and regulations for public water
systems. Subchapter F specifically addresses Drinking Water Standards, including
Maximum Contaminant Levels (MCLs) and monitoring requirements .
Question 11
Complete Study Guide & Test Bank | 300+
Practice Questions with Verified Answers | TCEQ
Class D Water Operator Certification
Question 1
The most important federal law impacting the water utility industry is the:
A) Water Resources Development Act
B) Federal Water Pollution Control Act
C) Hazard Communication Act
D) Safe Drinking Water Act
Answer: D) Safe Drinking Water Act
Rationale: The Safe Drinking Water Act (SDWA) is the primary federal law that
establishes national safety and quality standards for drinking water. It authorizes the EPA
to set Maximum Contaminant Levels (MCLs) for drinking water contaminants .
Question 2
The state agency that regulates drinking water in Texas and administers the federal Safe
Drinking Water Act is the:
A) Texas Department of Health (TDH)
B) Texas Commission on Environmental Quality (TCEQ)
C) Texas Department of Public Safety (DPS)
D) Public Utility Commission (PUC)
Answer: B) Texas Commission on Environmental Quality (TCEQ)
Rationale: TCEQ has primacy over the SDWA in Texas, meaning it is the state agency
responsible for enforcing federal drinking water standards. Primacy was initially granted
to TDH in 1978 before being transferred to TCEQ .
,Question 3
True or False: Operators have a responsibility to provide drinking water that meets
Federal and State Standards.
Answer: True
Rationale: Licensed water operators are responsible for ensuring that the water they
produce meets all federal and state drinking water standards, including EPA Maximum
Contaminant Levels (MCLs) and TCEQ regulations .
Question 4
The 4 national safety and quality standards for drinking water covered in the Safe
Drinking Water Act are physical, chemical, _____, and radiological.
A) Mineral
B) Thermal
C) Bacteriological
D) Mathematical
Answer: C) Bacteriological
Rationale: The SDWA establishes standards for physical, chemical, bacteriological, and
radiological contaminants. Bacteriological standards are particularly important because
they address waterborne pathogens that can cause immediate health effects .
Question 5
True or False: A public water system provides the public with piped water for human
consumption, serves at least 15 service connections, and regularly serves at least 25
individuals daily at least 60 days out of the year.
Answer: True
Rationale: This is the official definition of a public water system (PWS) under both
federal and Texas regulations. Systems meeting these criteria are subject to SDWA and
TCEQ regulation .
,Question 6
Which Texas agency originally assumed primacy over the Safe Drinking Water Act from
the EPA in 1978?
A) Texas Water Commission
B) Texas Department of Health (TDH)
C) Texas Railroad Commission
D) Texas Parks and Wildlife
Answer: B) Texas Department of Health (TDH)
Rationale: Primacy over the SDWA was initially granted to the Texas Department of
Health (TDH). This authority was later transferred to TCEQ, which currently administers
the program .
Question 7
True or False: The state requires bacteriological sample results to be kept for 2 years.
Answer: False
Rationale: TCEQ requires bacteriological sample results to be kept for 5 years, not 2
years. Longer retention periods are required for chemical analysis records .
Question 8
The state requires chemical analysis records to be kept at least _____ years.
A) 5
B) 7
C) 10
D) 15
Answer: C) 10 years
, Rationale: TCEQ requires chemical analysis records to be retained for at least 10 years.
This ensures that historical water quality data is available for regulatory review and
public health monitoring .
Question 9
The EPA requires a water system to keep a copy of each Consumer Confidence Report
for at least:
A) 1 year
B) 3 years
C) 5 years
D) 10 years
Answer: C) 5 years
Rationale: Consumer Confidence Reports (CCRs), which inform customers about water
quality and contaminant levels, must be retained for at least 5 years per EPA
requirements .
Question 10
Which Texas Administrative Code (TAC) chapter covers Drinking Water Standards?
A) 30 TAC Chapter 30, Subchapter F
B) 30 TAC Chapter 290, Subchapter F
C) 30 TAC Chapter 217
D) 30 TAC Chapter 290, Subchapter D
Answer: B) 30 TAC Chapter 290, Subchapter F
Rationale: 30 TAC Chapter 290 covers the rules and regulations for public water
systems. Subchapter F specifically addresses Drinking Water Standards, including
Maximum Contaminant Levels (MCLs) and monitoring requirements .
Question 11
