Texas Commission on Environmental Quality (TCEQ)Landscape
Irrigator License Exam | 160 Advanced Questions & Verified
Answers & Rationales | 2025/2026 | Latest Update | Instant
Download !!
Covers hydraulics, design, installation, backflow, licensing law, soil science, precipitation rates,
scheduling, wiring, troubleshooting & more
1. Which TCEQ license allows an individual to sell, design, consult, and install landscape irrigation
systems?
A. LV
B. LI
C. TI
D. LI (Landscape Irrigator)
Correct Answer: D
Rationale: The LI is the full, unrestricted irrigator license that permits all elements of irrigation work.
2. Which document contains Texas’ minimum standards for landscape irrigation?
A. Texas Water Code Chapter 341
B. TAC Title 30, Chapter 344
C. TCEQ Handbook Part 12
D. ANSI/IA Irrigation Code
Correct Answer: B
Rationale: All TCEQ irrigation regulations fall under TAC 30 §344, which governs design, installation, and
operation.
3. What is the maximum allowable separation distance between spray heads in a turf zone?
A. 30% of radius
B. 40% of radius
C. 90% of radius
D. 100% of radius (head-to-head coverage)
Correct Answer: D
Rationale: TCEQ mandates head-to-head distribution uniformity to reduce dry spots and runoff.
4. Which type of backflow preventer is required if chemicals (fertilizers) may enter the system?
A. AVB
B. PVB
C. Dual check
D. RPZ (Reduced Pressure Zone)
,Correct Answer: D
Rationale: RPZ assemblies protect against high hazard (health hazard) backflow situations.
5. An irrigation plan must be kept by the irrigator and provided to the property owner for:
A. 1 year
B. 2 years
C. 3 years
D. 7 years
Correct Answer: C
Rationale: TAC 30 §344 requires irrigators to maintain system records for at least 3 years.
6. A zone with 10 spray heads requires 1.5 GPM each. What is the total zone demand?
A. 10 GPM
B. 15 GPM
C. 20 GPM
D. 25 GPM
Correct Answer: B
Rationale: 1.5 GPM × 10 = 15 GPM.
7. A master valve should be installed:
A. Downstream of all control valves
B. In every controller
C. Upstream of all zone valves
D. At the backflow device
Correct Answer: C
Rationale: A master valve controls the entire system and shuts off water if a valve fails.
8. What is the minimum required separation of electrical wiring from irrigation pipe in the same
trench?
A. 3 inches
B. 6 inches
C. 12 inches
D. 24 inches
Correct Answer: C
Rationale: TCEQ requires 12 inches vertical separation for safety and serviceability.
9. Emitter drip systems require filtration of at least:
A. 40 microns
B. 80 microns
C. 120 microns
D. 200 microns
,Correct Answer: C
Rationale: Drip emitters clog easily; 120-micron filters are industry standard.
10. What is the most efficient irrigation method for shrub beds?
A. Rotors
B. Sprays
C. Drip irrigation
D. Impact heads
Correct Answer: C
Rationale: Drip reduces evaporation, runoff, and overspray, improving efficiency.
11. Which of the following must be included on an irrigation plan?
A. Owner’s phone number
B. Plant list
C. Zoning and station numbering
D. Brand of pipe glue
Correct Answer: C
Rationale: TCEQ requires zoning/station identification on all design plans.
12. Which soil type has the highest water-holding capacity?
A. Sand
B. Loamy sand
C. Clay
D. Gravel
Correct Answer: C
Rationale: Clay has small particles that retain moisture longer than other soils.
13. A controller should be installed at least ___ feet from a pool.
A. 1
B. 3
C. 5
D. 10
Correct Answer: C
Rationale: Electrical safety guidelines require at least 5 ft separation.
14. What is the pressure loss through a 1-inch 90° PVC elbow?
A. 0 psi
B. 0.2 psi
C. 1 psi
D. 3 psi
, Correct Answer: C
Rationale: Standard friction loss tables show approx. 1 psi loss for a 1" 90° turn.
15. What is the precipitation rate for a rotor applying 0.4 in/hr at 50% spacing efficiency?
A. 0.2 in/hr
B. 0.4 in/hr
C. 0.8 in/hr
D. 1.2 in/hr
Correct Answer: B
Rationale: Precipitation rate relates to nozzle output; spacing affects uniformity, not PR itself.
16. Who is responsible for ensuring the system meets TCEQ standards?
A. Installer
B. Inspector
C. Homeowner
D. Licensed irrigator (LI)
Correct Answer: D
Rationale: The design and operation responsibility falls on the licensed irrigator.
17. What is the typical working pressure for spray heads?
A. 10–20 psi
B. 20–30 psi
C. 40–50 psi
D. 55–70 psi
Correct Answer: B
Rationale: Most spray heads operate optimally around 25–30 psi.
18. Rotors typically require:
A. 10–15 psi
B. 15–20 psi
C. 30–70 psi
D. 80–100 psi
Correct Answer: C
Rationale: Rotors require higher pressure for correct throw distance.
19. What is the main function of a flow sensor?
A. Increase pressure
B. Filter debris
C. Detect leaks or abnormal flow
D. Add air to lines
Irrigator License Exam | 160 Advanced Questions & Verified
Answers & Rationales | 2025/2026 | Latest Update | Instant
Download !!
Covers hydraulics, design, installation, backflow, licensing law, soil science, precipitation rates,
scheduling, wiring, troubleshooting & more
1. Which TCEQ license allows an individual to sell, design, consult, and install landscape irrigation
systems?
A. LV
B. LI
C. TI
D. LI (Landscape Irrigator)
Correct Answer: D
Rationale: The LI is the full, unrestricted irrigator license that permits all elements of irrigation work.
2. Which document contains Texas’ minimum standards for landscape irrigation?
A. Texas Water Code Chapter 341
B. TAC Title 30, Chapter 344
C. TCEQ Handbook Part 12
D. ANSI/IA Irrigation Code
Correct Answer: B
Rationale: All TCEQ irrigation regulations fall under TAC 30 §344, which governs design, installation, and
operation.
3. What is the maximum allowable separation distance between spray heads in a turf zone?
A. 30% of radius
B. 40% of radius
C. 90% of radius
D. 100% of radius (head-to-head coverage)
Correct Answer: D
Rationale: TCEQ mandates head-to-head distribution uniformity to reduce dry spots and runoff.
4. Which type of backflow preventer is required if chemicals (fertilizers) may enter the system?
A. AVB
B. PVB
C. Dual check
D. RPZ (Reduced Pressure Zone)
,Correct Answer: D
Rationale: RPZ assemblies protect against high hazard (health hazard) backflow situations.
5. An irrigation plan must be kept by the irrigator and provided to the property owner for:
A. 1 year
B. 2 years
C. 3 years
D. 7 years
Correct Answer: C
Rationale: TAC 30 §344 requires irrigators to maintain system records for at least 3 years.
6. A zone with 10 spray heads requires 1.5 GPM each. What is the total zone demand?
A. 10 GPM
B. 15 GPM
C. 20 GPM
D. 25 GPM
Correct Answer: B
Rationale: 1.5 GPM × 10 = 15 GPM.
7. A master valve should be installed:
A. Downstream of all control valves
B. In every controller
C. Upstream of all zone valves
D. At the backflow device
Correct Answer: C
Rationale: A master valve controls the entire system and shuts off water if a valve fails.
8. What is the minimum required separation of electrical wiring from irrigation pipe in the same
trench?
A. 3 inches
B. 6 inches
C. 12 inches
D. 24 inches
Correct Answer: C
Rationale: TCEQ requires 12 inches vertical separation for safety and serviceability.
9. Emitter drip systems require filtration of at least:
A. 40 microns
B. 80 microns
C. 120 microns
D. 200 microns
,Correct Answer: C
Rationale: Drip emitters clog easily; 120-micron filters are industry standard.
10. What is the most efficient irrigation method for shrub beds?
A. Rotors
B. Sprays
C. Drip irrigation
D. Impact heads
Correct Answer: C
Rationale: Drip reduces evaporation, runoff, and overspray, improving efficiency.
11. Which of the following must be included on an irrigation plan?
A. Owner’s phone number
B. Plant list
C. Zoning and station numbering
D. Brand of pipe glue
Correct Answer: C
Rationale: TCEQ requires zoning/station identification on all design plans.
12. Which soil type has the highest water-holding capacity?
A. Sand
B. Loamy sand
C. Clay
D. Gravel
Correct Answer: C
Rationale: Clay has small particles that retain moisture longer than other soils.
13. A controller should be installed at least ___ feet from a pool.
A. 1
B. 3
C. 5
D. 10
Correct Answer: C
Rationale: Electrical safety guidelines require at least 5 ft separation.
14. What is the pressure loss through a 1-inch 90° PVC elbow?
A. 0 psi
B. 0.2 psi
C. 1 psi
D. 3 psi
, Correct Answer: C
Rationale: Standard friction loss tables show approx. 1 psi loss for a 1" 90° turn.
15. What is the precipitation rate for a rotor applying 0.4 in/hr at 50% spacing efficiency?
A. 0.2 in/hr
B. 0.4 in/hr
C. 0.8 in/hr
D. 1.2 in/hr
Correct Answer: B
Rationale: Precipitation rate relates to nozzle output; spacing affects uniformity, not PR itself.
16. Who is responsible for ensuring the system meets TCEQ standards?
A. Installer
B. Inspector
C. Homeowner
D. Licensed irrigator (LI)
Correct Answer: D
Rationale: The design and operation responsibility falls on the licensed irrigator.
17. What is the typical working pressure for spray heads?
A. 10–20 psi
B. 20–30 psi
C. 40–50 psi
D. 55–70 psi
Correct Answer: B
Rationale: Most spray heads operate optimally around 25–30 psi.
18. Rotors typically require:
A. 10–15 psi
B. 15–20 psi
C. 30–70 psi
D. 80–100 psi
Correct Answer: C
Rationale: Rotors require higher pressure for correct throw distance.
19. What is the main function of a flow sensor?
A. Increase pressure
B. Filter debris
C. Detect leaks or abnormal flow
D. Add air to lines
