TCEQ Class C Water License Exam: Comprehensive Study Guide
Disclaimer: This guide is based on the publicly available TCEQ scope of knowledge and
is intended for study purposes. Always refer to the latest official TCEQ materials,
regulations (30 TAC), and the Texas Commission on Environmental Quality Rules and
Regulations for Public Water Systems for the most current information.
Section 1: Regulations and Reporting (15 Questions)
1. What is the primary state agency responsible for enforcing the Safe Drinking
Water Act (SDWA) in Texas?
ANSWER ✓ The Texas Commission on Environmental Quality (TCEQ).
2. What is the maximum contaminant level (MCL) for total trihalomethanes
(TTHMs) in a community water system?
ANSWER ✓ 0.080 mg/L.
3. A Level 1 Assessment is triggered under which rule when a routine sample is
positive for E. coli?
ANSWER ✓ The Ground Water Rule.
4. Who must be notified immediately in the event of an unresolved Tier 1
violation?
ANSWER ✓ The TCEQ, and potentially the mayor, city council, and general public as per
public notification requirements.
5. What is the purpose of a Consumer Confidence Report (CCR)?
ANSWER ✓ To inform customers annually about the quality of their drinking water and
its source.
6. What is the action level for lead in drinking water, based on the 90th percentile
of tap samples?
ANSWER ✓ 0.015 mg/L (or 15 parts per billion).
7. Surface water systems must filter their water unless they meet specific criteria
for what?
, ANSWER ✓ Filtration Avoidance Criteria, which includes stringent watershed control and
meeting Coliform, Turbidity, and Disinfection requirements.
8. How often must a surface water system using conventional filtration conduct
combined filter effluent turbidity monitoring?
ANSWER ✓ Continuously, and recorded at least every 15 minutes.
9. What is the maximum allowed turbidity for an individual filter at any time?
ANSWER ✓ 1.0 NTU for systems using conventional or direct filtration.
10. A boil water notice must be issued within what timeframe after a violation is
confirmed?
ANSWER ✓ Within 24 hours of the violation confirmation.
11. Under the Lead and Copper Rule, what is the frequency for tap water
monitoring if a system exceeds the action level?
ANSWER ✓ Every 6 months.
12. What is the minimum required free chlorine residual at the entry point to a
groundwater system with no disinfection waiver?
ANSWER ✓ A detectable residual (≥ 0.2 mg/L is a common benchmark, though the rule
requires "detectable").
13. What document outlines the specific monitoring and reporting requirements
for a public water system?
ANSWER ✓ The system's Monitoring Plan, as approved by TCEQ.
14. What is a Tier 2 violation, and what is the public notification timeline?
ANSWER ✓ A violation with potential to have serious adverse effects on human health.
Public notice must be provided within 30 days.
15. What is the purpose of a Sanitary Survey for a groundwater system?
ANSWER ✓ To identify and evaluate actual or potential sources of contamination and
deficiencies that could pose a risk to water quality. Required every 3-5 years.
Section 2: Water Sources and Treatment (20 Questions)
Disclaimer: This guide is based on the publicly available TCEQ scope of knowledge and
is intended for study purposes. Always refer to the latest official TCEQ materials,
regulations (30 TAC), and the Texas Commission on Environmental Quality Rules and
Regulations for Public Water Systems for the most current information.
Section 1: Regulations and Reporting (15 Questions)
1. What is the primary state agency responsible for enforcing the Safe Drinking
Water Act (SDWA) in Texas?
ANSWER ✓ The Texas Commission on Environmental Quality (TCEQ).
2. What is the maximum contaminant level (MCL) for total trihalomethanes
(TTHMs) in a community water system?
ANSWER ✓ 0.080 mg/L.
3. A Level 1 Assessment is triggered under which rule when a routine sample is
positive for E. coli?
ANSWER ✓ The Ground Water Rule.
4. Who must be notified immediately in the event of an unresolved Tier 1
violation?
ANSWER ✓ The TCEQ, and potentially the mayor, city council, and general public as per
public notification requirements.
5. What is the purpose of a Consumer Confidence Report (CCR)?
ANSWER ✓ To inform customers annually about the quality of their drinking water and
its source.
6. What is the action level for lead in drinking water, based on the 90th percentile
of tap samples?
ANSWER ✓ 0.015 mg/L (or 15 parts per billion).
7. Surface water systems must filter their water unless they meet specific criteria
for what?
, ANSWER ✓ Filtration Avoidance Criteria, which includes stringent watershed control and
meeting Coliform, Turbidity, and Disinfection requirements.
8. How often must a surface water system using conventional filtration conduct
combined filter effluent turbidity monitoring?
ANSWER ✓ Continuously, and recorded at least every 15 minutes.
9. What is the maximum allowed turbidity for an individual filter at any time?
ANSWER ✓ 1.0 NTU for systems using conventional or direct filtration.
10. A boil water notice must be issued within what timeframe after a violation is
confirmed?
ANSWER ✓ Within 24 hours of the violation confirmation.
11. Under the Lead and Copper Rule, what is the frequency for tap water
monitoring if a system exceeds the action level?
ANSWER ✓ Every 6 months.
12. What is the minimum required free chlorine residual at the entry point to a
groundwater system with no disinfection waiver?
ANSWER ✓ A detectable residual (≥ 0.2 mg/L is a common benchmark, though the rule
requires "detectable").
13. What document outlines the specific monitoring and reporting requirements
for a public water system?
ANSWER ✓ The system's Monitoring Plan, as approved by TCEQ.
14. What is a Tier 2 violation, and what is the public notification timeline?
ANSWER ✓ A violation with potential to have serious adverse effects on human health.
Public notice must be provided within 30 days.
15. What is the purpose of a Sanitary Survey for a groundwater system?
ANSWER ✓ To identify and evaluate actual or potential sources of contamination and
deficiencies that could pose a risk to water quality. Required every 3-5 years.
Section 2: Water Sources and Treatment (20 Questions)
