CO Utility Contractor Exam
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a utility easement?
A. To allow private property construction
B. To provide access for utility installation and maintenance
C. To increase property value
D. To restrict property sales
B. To provide access for utility installation and maintenance
Rationale: Easements give utility companies legal rights to access
and maintain utility lines and equipment.
2. When installing underground water lines, what is the recommended
minimum depth in frost-prone areas?
A. 12 inches
B. 18 inches
C. 36 inches
D. 48 inches
C. 36 inches
Rationale: Installing below the frost line prevents freezing and
potential pipe damage.
3. Which type of pipe is commonly used for natural gas distribution?
A. PVC
B. HDPE
C. Copper
D. Concrete
B. HDPE
Rationale: High-Density Polyethylene (HDPE) is flexible, corrosion-
resistant, and suitable for underground gas lines.
,4. What is the main safety concern when working near energized
electrical lines?
A. Tripping hazards
B. Electrical shock or electrocution
C. Noise pollution
D. Dust inhalation
B. Electrical shock or electrocution
Rationale: Direct contact or proximity to energized lines can cause
severe injury or death.
5. Which device is used to prevent backflow of contaminated water into
the potable water system?
A. Flow meter
B. Check valve
C. Pressure regulator
D. Gate valve
B. Check valve
Rationale: Check valves allow water to flow in one direction,
preventing contamination.
6. When performing trench excavation for utility installation, what is the
minimum slope for soil classified as Type C?
A. 1/4:1
B. 1/2:1
C. 1:1
D. 1.5:1
C. 1:1
Rationale: Type C soil is unstable, requiring a 1:1 slope
(horizontal:vertical) to reduce cave-in risk.
7. Which type of utility marking color represents water lines according to
standard color codes?
A. Red
B. Blue
C. Yellow
D. Green
B. Blue
Rationale: Blue indicates potable water lines in utility marking
standards.
, 8. What is the recommended minimum clearance between an overhead
power line and a construction vehicle?
A. 3 feet
B. 6 feet
C. 10 feet
D. 15 feet
C. 10 feet
Rationale: OSHA requires a minimum of 10 feet clearance to prevent
electrical accidents.
9. Which type of backfill material is preferred for stabilizing utility
trenches?
A. Loose topsoil
B. Gravel and sand mixture
C. Clay
D. Organic mulch
B. Gravel and sand mixture
Rationale: Gravel and sand provide proper drainage and compaction
to prevent trench collapse.
10. When tying into an existing sewer line, which method is
commonly used?
A. Socket fusion
B. Wye fitting installation
C. Butt welding
D. Threaded coupling
B. Wye fitting installation
Rationale: A wye fitting allows a smooth connection of a lateral line
into the main sewer line.
11. Which OSHA standard governs excavation and trenching safety?
A. 29 CFR 1910
B. 29 CFR 1926 Subpart P
C. 29 CFR 1915
D. 29 CFR 1920
B. 29 CFR 1926 Subpart P
Rationale: This subpart specifies safety requirements for trenching
and excavation work.
12. What is the primary function of a pressure-reducing valve in
water distribution systems?
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which of the following is the primary purpose of a utility easement?
A. To allow private property construction
B. To provide access for utility installation and maintenance
C. To increase property value
D. To restrict property sales
B. To provide access for utility installation and maintenance
Rationale: Easements give utility companies legal rights to access
and maintain utility lines and equipment.
2. When installing underground water lines, what is the recommended
minimum depth in frost-prone areas?
A. 12 inches
B. 18 inches
C. 36 inches
D. 48 inches
C. 36 inches
Rationale: Installing below the frost line prevents freezing and
potential pipe damage.
3. Which type of pipe is commonly used for natural gas distribution?
A. PVC
B. HDPE
C. Copper
D. Concrete
B. HDPE
Rationale: High-Density Polyethylene (HDPE) is flexible, corrosion-
resistant, and suitable for underground gas lines.
,4. What is the main safety concern when working near energized
electrical lines?
A. Tripping hazards
B. Electrical shock or electrocution
C. Noise pollution
D. Dust inhalation
B. Electrical shock or electrocution
Rationale: Direct contact or proximity to energized lines can cause
severe injury or death.
5. Which device is used to prevent backflow of contaminated water into
the potable water system?
A. Flow meter
B. Check valve
C. Pressure regulator
D. Gate valve
B. Check valve
Rationale: Check valves allow water to flow in one direction,
preventing contamination.
6. When performing trench excavation for utility installation, what is the
minimum slope for soil classified as Type C?
A. 1/4:1
B. 1/2:1
C. 1:1
D. 1.5:1
C. 1:1
Rationale: Type C soil is unstable, requiring a 1:1 slope
(horizontal:vertical) to reduce cave-in risk.
7. Which type of utility marking color represents water lines according to
standard color codes?
A. Red
B. Blue
C. Yellow
D. Green
B. Blue
Rationale: Blue indicates potable water lines in utility marking
standards.
, 8. What is the recommended minimum clearance between an overhead
power line and a construction vehicle?
A. 3 feet
B. 6 feet
C. 10 feet
D. 15 feet
C. 10 feet
Rationale: OSHA requires a minimum of 10 feet clearance to prevent
electrical accidents.
9. Which type of backfill material is preferred for stabilizing utility
trenches?
A. Loose topsoil
B. Gravel and sand mixture
C. Clay
D. Organic mulch
B. Gravel and sand mixture
Rationale: Gravel and sand provide proper drainage and compaction
to prevent trench collapse.
10. When tying into an existing sewer line, which method is
commonly used?
A. Socket fusion
B. Wye fitting installation
C. Butt welding
D. Threaded coupling
B. Wye fitting installation
Rationale: A wye fitting allows a smooth connection of a lateral line
into the main sewer line.
11. Which OSHA standard governs excavation and trenching safety?
A. 29 CFR 1910
B. 29 CFR 1926 Subpart P
C. 29 CFR 1915
D. 29 CFR 1920
B. 29 CFR 1926 Subpart P
Rationale: This subpart specifies safety requirements for trenching
and excavation work.
12. What is the primary function of a pressure-reducing valve in
water distribution systems?
