FLORIDA UNDERGROUND UTILITY CONTRACTOR
EXAM STUDY QUESTIONS WITH CORRECT
(VERIFIED ANSWERS) PLUS RATIONALES Q&A
2025/2026|INSTANT DOWNLOAD PDF
1. What is the primary purpose of a trench box?
A. Prevent soil erosion
B. Protect workers from trench wall collapse
C. Support underground pipes
D. Measure trench depth
*Correct answer: B – Trench boxes are designed to shield workers and prevent
injury from potential cave-ins.
2. Which soil type is most stable according to OSHA classifications?
A. Type A
B. Type B
C. Type C
D. Type D
*Correct answer: A – Type A soil has the highest cohesion and is least likely to
collapse.
3. Before excavation, utility locates must be requested by calling:
A. 411
B. 811
C. 611
D. 511
*Correct answer: B – 811 is the national call-before-you-dig number.
4. The minimum depth for burying potable water lines in Florida is typically:
,A. 6 inches
B. 12 inches
C. 18 inches
D. 30 inches
*Correct answer: C – Florida codes generally require at least 18 inches of cover for
potable water piping.
5. What is the purpose of a mandrel test in sewer installation?
A. Test water quality
B. Test pipe deflection
C. Check soil compaction
D. Inspect pipe joints
*Correct answer: B – Mandrels ensure flexible pipes have not deflected beyond
allowable limits.
6. What is the primary purpose of a dewatering system?
A. Increase soil temperature
B. Remove groundwater from excavation
C. Compact the soil
D. Detect underground utilities
*Correct answer: B – Dewatering lowers the water table to allow safe excavation.
7. A gravity sewer line must be installed with:
A. No slope
B. A constant slope
C. A reverse slope
D. A variable slope
*Correct answer: B – Gravity sewers rely on uniform slope for proper flow.
, 8. For a 6-foot trench, OSHA requires:
A. No protection needed
B. Just a ladder
C. Protective system or sloping
D. Concrete reinforcement
*Correct answer: C – OSHA mandates protective systems at trenches ≥5 ft deep.
9. What type of drawing shows the horizontal layout of utilities?
A. Elevation
B. Profile
C. Plan view
D. Section
*Correct answer: C – Plan views display the overhead/horizontal layout.
10. The minimum separation between potable water and sewer lines is usually:
A. 6 inches
B. 12 inches
C. 24 inches
D. 36 inches
*Correct answer: D – Florida standards generally recommend 3 feet horizontal
separation.
11. A compaction test using a nuclear gauge measures:
A. Soil acidity
B. Moisture and density
C. Soil temperature
D. Groundwater levels
*Correct answer: B – Nuclear gauges verify soil density and moisture content.
EXAM STUDY QUESTIONS WITH CORRECT
(VERIFIED ANSWERS) PLUS RATIONALES Q&A
2025/2026|INSTANT DOWNLOAD PDF
1. What is the primary purpose of a trench box?
A. Prevent soil erosion
B. Protect workers from trench wall collapse
C. Support underground pipes
D. Measure trench depth
*Correct answer: B – Trench boxes are designed to shield workers and prevent
injury from potential cave-ins.
2. Which soil type is most stable according to OSHA classifications?
A. Type A
B. Type B
C. Type C
D. Type D
*Correct answer: A – Type A soil has the highest cohesion and is least likely to
collapse.
3. Before excavation, utility locates must be requested by calling:
A. 411
B. 811
C. 611
D. 511
*Correct answer: B – 811 is the national call-before-you-dig number.
4. The minimum depth for burying potable water lines in Florida is typically:
,A. 6 inches
B. 12 inches
C. 18 inches
D. 30 inches
*Correct answer: C – Florida codes generally require at least 18 inches of cover for
potable water piping.
5. What is the purpose of a mandrel test in sewer installation?
A. Test water quality
B. Test pipe deflection
C. Check soil compaction
D. Inspect pipe joints
*Correct answer: B – Mandrels ensure flexible pipes have not deflected beyond
allowable limits.
6. What is the primary purpose of a dewatering system?
A. Increase soil temperature
B. Remove groundwater from excavation
C. Compact the soil
D. Detect underground utilities
*Correct answer: B – Dewatering lowers the water table to allow safe excavation.
7. A gravity sewer line must be installed with:
A. No slope
B. A constant slope
C. A reverse slope
D. A variable slope
*Correct answer: B – Gravity sewers rely on uniform slope for proper flow.
, 8. For a 6-foot trench, OSHA requires:
A. No protection needed
B. Just a ladder
C. Protective system or sloping
D. Concrete reinforcement
*Correct answer: C – OSHA mandates protective systems at trenches ≥5 ft deep.
9. What type of drawing shows the horizontal layout of utilities?
A. Elevation
B. Profile
C. Plan view
D. Section
*Correct answer: C – Plan views display the overhead/horizontal layout.
10. The minimum separation between potable water and sewer lines is usually:
A. 6 inches
B. 12 inches
C. 24 inches
D. 36 inches
*Correct answer: D – Florida standards generally recommend 3 feet horizontal
separation.
11. A compaction test using a nuclear gauge measures:
A. Soil acidity
B. Moisture and density
C. Soil temperature
D. Groundwater levels
*Correct answer: B – Nuclear gauges verify soil density and moisture content.
