Texas Groundwater Operator C License: Complete Study Guide
(2026/2027)
Disclaimer: This guide is for study purposes only. Always refer to the official TCEQ Class
C Groundwater License exam outline, TCEQ Rules 30 TAC Chapter 290, and the latest
editions of recommended manuals for the most current information.
Section 1: Regulations and Administrative Procedures
1. What state agency is responsible for licensing and regulating public water
systems in Texas?
ANSWER ✓ The Texas Commission on Environmental Quality (TCEQ).
2. What is the primary federal law that ensures the safety of public drinking water?
ANSWER ✓ The Safe Drinking Water Act (SDWA).
3. Who has the ultimate legal responsibility for the safety of water provided by a
public water system?
ANSWER ✓ The owner of the public water system.
4. What is the operator's primary legal responsibility?
ANSWER ✓ To operate the system in compliance with all applicable state and federal
regulations.
5. What TCEQ rule contains the specific requirements for public drinking water?
ANSWER ✓ 30 Texas Administrative Code, Chapter 290 (30 TAC 290).
6. What is the minimum required sampling frequency for Total Coliform bacteria
for a groundwater system serving 1,000 people?
ANSWER ✓ One sample per month.
7. A routine sample tests positive for Total Coliform. What is the required
immediate follow-up action?
ANSWER ✓ Take a set of three repeat samples within 24 hours of being notified of the
positive result.
, 8. What is the Maximum Contaminant Level (MCL) for Nitrate (as N) in drinking
water?
ANSWER ✓ 10 mg/L.
9. 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).
10. Violations of drinking water standards are categorized as which types?
ANSWER ✓ Monitoring/reporting violations and Maximum Contaminant Level (MCL)
violations.
11. What is the required public notification method for a Tier 1 violation (poses an
immediate health risk)?
ANSWER ✓ Broadcast media (TV, radio), hand-delivery, or other method approved by
TCEQ within 24 hours.
12. How long must water system records, like chemical feed logs and compliance
reports, be kept on file?
ANSWER ✓ A minimum of 3 years, unless otherwise specified (some states require 10
years for certain reports).
13. What is a Cross-Connection?
ANSWER ✓ Any physical connection or arrangement between a potable water supply
and any source of contamination or pollution.
14. What is the purpose of a backflow prevention assembly?
ANSWER ✓ To prevent the reverse flow of water (and potential contaminants) from a
customer's premise back into the public water system.
15. What is the most common type of backflow prevention device required at
residential meter settings?
ANSWER ✓ A dual check valve or a pressure vacuum breaker, depending on local codes.
Section 2: Groundwater Sources and Wells
16. What is the water-bearing geological formation that yields water to a well
called?
ANSWER ✓ An aquifer.
(2026/2027)
Disclaimer: This guide is for study purposes only. Always refer to the official TCEQ Class
C Groundwater License exam outline, TCEQ Rules 30 TAC Chapter 290, and the latest
editions of recommended manuals for the most current information.
Section 1: Regulations and Administrative Procedures
1. What state agency is responsible for licensing and regulating public water
systems in Texas?
ANSWER ✓ The Texas Commission on Environmental Quality (TCEQ).
2. What is the primary federal law that ensures the safety of public drinking water?
ANSWER ✓ The Safe Drinking Water Act (SDWA).
3. Who has the ultimate legal responsibility for the safety of water provided by a
public water system?
ANSWER ✓ The owner of the public water system.
4. What is the operator's primary legal responsibility?
ANSWER ✓ To operate the system in compliance with all applicable state and federal
regulations.
5. What TCEQ rule contains the specific requirements for public drinking water?
ANSWER ✓ 30 Texas Administrative Code, Chapter 290 (30 TAC 290).
6. What is the minimum required sampling frequency for Total Coliform bacteria
for a groundwater system serving 1,000 people?
ANSWER ✓ One sample per month.
7. A routine sample tests positive for Total Coliform. What is the required
immediate follow-up action?
ANSWER ✓ Take a set of three repeat samples within 24 hours of being notified of the
positive result.
, 8. What is the Maximum Contaminant Level (MCL) for Nitrate (as N) in drinking
water?
ANSWER ✓ 10 mg/L.
9. 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).
10. Violations of drinking water standards are categorized as which types?
ANSWER ✓ Monitoring/reporting violations and Maximum Contaminant Level (MCL)
violations.
11. What is the required public notification method for a Tier 1 violation (poses an
immediate health risk)?
ANSWER ✓ Broadcast media (TV, radio), hand-delivery, or other method approved by
TCEQ within 24 hours.
12. How long must water system records, like chemical feed logs and compliance
reports, be kept on file?
ANSWER ✓ A minimum of 3 years, unless otherwise specified (some states require 10
years for certain reports).
13. What is a Cross-Connection?
ANSWER ✓ Any physical connection or arrangement between a potable water supply
and any source of contamination or pollution.
14. What is the purpose of a backflow prevention assembly?
ANSWER ✓ To prevent the reverse flow of water (and potential contaminants) from a
customer's premise back into the public water system.
15. What is the most common type of backflow prevention device required at
residential meter settings?
ANSWER ✓ A dual check valve or a pressure vacuum breaker, depending on local codes.
Section 2: Groundwater Sources and Wells
16. What is the water-bearing geological formation that yields water to a well
called?
ANSWER ✓ An aquifer.
