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Connecticut (CT) P-6 Journeyperson Sewer, Storm &
Water Lines Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple choice questions is designed for the Connecticut P-6
Journeyperson Sewer, Storm & Water Lines Exam, a closed-book, timed, computer-based
assessment that evaluates a candidate’s working knowledge of exterior underground
piping systems. The content covers drainage and venting (DWV) sizing and slope
requirements, water service sizing and pressure regulation, backflow prevention and
cross-connection control, trenching and excavation safety, pipe materials and joining
methods, OSHA job-site safety, and the interpretation of civil utility drawings with related
calculations. The exam focuses exclusively on the installation, replacement, alteration, or
repair of exterior water service, storm, and sewer lines (excluding interior work and septic
systems) and is administered by the State of Connecticut’s designated testing provider.
QUESTION 1
What is the minimum allowable slope for a 4-inch diameter building sewer pipe?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
CORRECT ANSWER: B
EXPERT RATIONALE: IPC requires 1/8 inch per foot for horizontal drainage piping 3
inches to 6 inches in diameter. Smaller pipes (2½″ or less) require 1/4 inch per foot.
QUESTION 2
Where must a cleanout be installed for an underground building sewer that is 135 feet
long?
A) At every change of direction greater than 90 degrees
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B) At the connection to the public sewer only
C) At intervals not exceeding 100 feet
D) Only at the upper terminal of the building sewer
CORRECT ANSWER: C
EXPERT RATIONALE: Code requires cleanouts every 100 feet horizontally, plus at each
aggregate change of direction exceeding 135 degrees and at the base of stacks.
QUESTION 3
A storm drain system is being connected 4 feet from a building foundation. What is the
minimum horizontal separation from the building that the storm drain must maintain
from the foundation, considering a 45-degree influence zone below footing?
A) 2 feet
B) 3 feet
C) 4 feet
D) 5 feet
CORRECT ANSWER: C
EXPERT RATIONALE: Underground pipes should be at least 2–4 feet from footings to
avoid undermining; 4 feet satisfies the required separation when combined with proper
bedding and slope.
QUESTION 4
A 2-inch water service pipe serving a single-family residence is being sized using fixture
unit counts. If the total cold water fixture unit count is 25, what is the minimum required
pipe size according to the Water Supply Fixture Unit table (using IPC/ASPE standards)?
A) ¾ inch
B) 1 inch
C) 1¼ inch
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D) 1½ inch
CORRECT ANSWER: B
EXPERT RATIONALE: For flush-tank water closets, 25 fixture units corresponds to a
minimum 1-inch supply pipe per IPC sizing tables.
QUESTION 5
What device must be installed on a potable water supply line connected to an irrigation
system with chemical injection to prevent backflow?
A) Dual check valve
B) Atmospheric vacuum breaker
C) Reduced pressure principle backflow preventer (RP)
D) Pressure vacuum breaker
CORRECT ANSWER: C
EXPERT RATIONALE: An RP is required for high-hazard applications such as chemical
injection, protecting against both backsiphonage and backpressure.
QUESTION 6
Which trench protective system is typically used for deep excavations where sloping
back to a safe angle is not possible?
A) Trench shield or trench box
B) Benching alone
C) Spoil pile used as a counterweight
D) No protection if under 5 feet deep
CORRECT ANSWER: A
EXPERT RATIONALE: Trench boxes/shields are engineered protective systems that shield
workers when sloping or benching is not practical, per OSHA 1926 Subpart P.
, 4|Page
QUESTION 7
When backfilling a trench for a newly laid ductile iron water main, what is the preferred
bedding material immediately around the pipe?
A) Native soil with large rocks
B) Compacted crushed stone or sand
C) Frozen soil chunks
D) Uncompacted clay
CORRECT ANSWER: B
EXPERT RATIONALE: Granular bedding such as crushed stone or sand provides uniform
support and allows proper compaction without damaging the pipe.
QUESTION 8
What is the minimum cover required over a PVC sewer pipe installed under a residential
driveway, per typical plumbing code?
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
CORRECT ANSWER: B
EXPERT RATIONALE: The IPC requires 12 inches for non-traffic areas and 18 inches
under light vehicular traffic such as driveways.
QUESTION 9
A plumber is connecting copper water service tubing underground. Which joining
method is NOT permitted for buried copper tube?
A) Brazed joints
B) Flared joints
Connecticut (CT) P-6 Journeyperson Sewer, Storm &
Water Lines Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple choice questions is designed for the Connecticut P-6
Journeyperson Sewer, Storm & Water Lines Exam, a closed-book, timed, computer-based
assessment that evaluates a candidate’s working knowledge of exterior underground
piping systems. The content covers drainage and venting (DWV) sizing and slope
requirements, water service sizing and pressure regulation, backflow prevention and
cross-connection control, trenching and excavation safety, pipe materials and joining
methods, OSHA job-site safety, and the interpretation of civil utility drawings with related
calculations. The exam focuses exclusively on the installation, replacement, alteration, or
repair of exterior water service, storm, and sewer lines (excluding interior work and septic
systems) and is administered by the State of Connecticut’s designated testing provider.
QUESTION 1
What is the minimum allowable slope for a 4-inch diameter building sewer pipe?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
CORRECT ANSWER: B
EXPERT RATIONALE: IPC requires 1/8 inch per foot for horizontal drainage piping 3
inches to 6 inches in diameter. Smaller pipes (2½″ or less) require 1/4 inch per foot.
QUESTION 2
Where must a cleanout be installed for an underground building sewer that is 135 feet
long?
A) At every change of direction greater than 90 degrees
,2|Page
B) At the connection to the public sewer only
C) At intervals not exceeding 100 feet
D) Only at the upper terminal of the building sewer
CORRECT ANSWER: C
EXPERT RATIONALE: Code requires cleanouts every 100 feet horizontally, plus at each
aggregate change of direction exceeding 135 degrees and at the base of stacks.
QUESTION 3
A storm drain system is being connected 4 feet from a building foundation. What is the
minimum horizontal separation from the building that the storm drain must maintain
from the foundation, considering a 45-degree influence zone below footing?
A) 2 feet
B) 3 feet
C) 4 feet
D) 5 feet
CORRECT ANSWER: C
EXPERT RATIONALE: Underground pipes should be at least 2–4 feet from footings to
avoid undermining; 4 feet satisfies the required separation when combined with proper
bedding and slope.
QUESTION 4
A 2-inch water service pipe serving a single-family residence is being sized using fixture
unit counts. If the total cold water fixture unit count is 25, what is the minimum required
pipe size according to the Water Supply Fixture Unit table (using IPC/ASPE standards)?
A) ¾ inch
B) 1 inch
C) 1¼ inch
,3|Page
D) 1½ inch
CORRECT ANSWER: B
EXPERT RATIONALE: For flush-tank water closets, 25 fixture units corresponds to a
minimum 1-inch supply pipe per IPC sizing tables.
QUESTION 5
What device must be installed on a potable water supply line connected to an irrigation
system with chemical injection to prevent backflow?
A) Dual check valve
B) Atmospheric vacuum breaker
C) Reduced pressure principle backflow preventer (RP)
D) Pressure vacuum breaker
CORRECT ANSWER: C
EXPERT RATIONALE: An RP is required for high-hazard applications such as chemical
injection, protecting against both backsiphonage and backpressure.
QUESTION 6
Which trench protective system is typically used for deep excavations where sloping
back to a safe angle is not possible?
A) Trench shield or trench box
B) Benching alone
C) Spoil pile used as a counterweight
D) No protection if under 5 feet deep
CORRECT ANSWER: A
EXPERT RATIONALE: Trench boxes/shields are engineered protective systems that shield
workers when sloping or benching is not practical, per OSHA 1926 Subpart P.
, 4|Page
QUESTION 7
When backfilling a trench for a newly laid ductile iron water main, what is the preferred
bedding material immediately around the pipe?
A) Native soil with large rocks
B) Compacted crushed stone or sand
C) Frozen soil chunks
D) Uncompacted clay
CORRECT ANSWER: B
EXPERT RATIONALE: Granular bedding such as crushed stone or sand provides uniform
support and allows proper compaction without damaging the pipe.
QUESTION 8
What is the minimum cover required over a PVC sewer pipe installed under a residential
driveway, per typical plumbing code?
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
CORRECT ANSWER: B
EXPERT RATIONALE: The IPC requires 12 inches for non-traffic areas and 18 inches
under light vehicular traffic such as driveways.
QUESTION 9
A plumber is connecting copper water service tubing underground. Which joining
method is NOT permitted for buried copper tube?
A) Brazed joints
B) Flared joints
