AZ A-12 Sewers, Drains & Pipe Laying
Contractor Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2027 Q&A | Instant
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1. What type of work is included within the Arizona A-12 Sewers, Drains
and Pipe Laying classification?
A) Only interior residential plumbing
B) Only highway paving
C) Sewer, storm-drain, water, gas, irrigation, septic and related pipe-laying
work
D) Only structural concrete work
Answer: C) Sewer, storm-drain, water, gas, irrigation, septic and related
pipe-laying work
Rationale: The A-12 classification covers a broad range of underground
piping work, including sewer access holes, storm drains, water and gas
,lines, irrigation, sewers, septic tanks, leach lines, dry wells, connections,
excavation and backfilling.
2. Which agency administers contractor licensing in Arizona?
A) Arizona Department of Transportation
B) Arizona Registrar of Contractors
C) Arizona Department of Environmental Quality
D) Arizona Corporation Commission
Answer: B) Arizona Registrar of Contractors
Rationale: The Arizona Registrar of Contractors (ROC) is responsible for
contractor licensing and classification requirements in Arizona.
3. What is the minimum passing score identified by the Arizona ROC for
the A-12 trade examination?
A) 60%
B) 65%
C) 70%
D) 80%
Answer: C) 70%
,Rationale: The ROC's A-12 examination information identifies 70% as the
minimum passing score.
4. What is the primary purpose of proper pipe bedding?
A) Increase pipe color
B) Support the pipe uniformly and protect it from damaging point loads
C) Eliminate the need for backfill
D) Increase water temperature
Answer: B) Support the pipe uniformly and protect it from damaging point
loads
Rationale: Proper bedding provides continuous support beneath the pipe
and helps maintain line, grade and structural performance.
5. When installing gravity sewer pipe, why is maintaining the designed
grade important?
A) To increase pipe weight
B) To provide adequate gravity flow
C) To eliminate manholes
D) To reduce pipe diameter
, Answer: B) To provide adequate gravity flow
Rationale: Gravity sewer systems depend on elevation difference to move
wastewater. Incorrect grade can produce inadequate flow, excessive
velocity or sediment accumulation.
6. A pipe has an elevation change of 2 feet over a horizontal distance of
100 feet. What is the approximate slope?
A) 0.2%
B) 1%
C) 2%
D) 20%
Answer: C) 2%
Rationale: Slope percentage equals rise divided by run multiplied by 100.
Thus, 2 ÷ 100 × 100 = 2%.
7. Which instrument is commonly used to establish and check pipe
elevation and grade?
A) Pipe wrench
B) Laser level
Contractor Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2027 Q&A | Instant
Download Pdf
1. What type of work is included within the Arizona A-12 Sewers, Drains
and Pipe Laying classification?
A) Only interior residential plumbing
B) Only highway paving
C) Sewer, storm-drain, water, gas, irrigation, septic and related pipe-laying
work
D) Only structural concrete work
Answer: C) Sewer, storm-drain, water, gas, irrigation, septic and related
pipe-laying work
Rationale: The A-12 classification covers a broad range of underground
piping work, including sewer access holes, storm drains, water and gas
,lines, irrigation, sewers, septic tanks, leach lines, dry wells, connections,
excavation and backfilling.
2. Which agency administers contractor licensing in Arizona?
A) Arizona Department of Transportation
B) Arizona Registrar of Contractors
C) Arizona Department of Environmental Quality
D) Arizona Corporation Commission
Answer: B) Arizona Registrar of Contractors
Rationale: The Arizona Registrar of Contractors (ROC) is responsible for
contractor licensing and classification requirements in Arizona.
3. What is the minimum passing score identified by the Arizona ROC for
the A-12 trade examination?
A) 60%
B) 65%
C) 70%
D) 80%
Answer: C) 70%
,Rationale: The ROC's A-12 examination information identifies 70% as the
minimum passing score.
4. What is the primary purpose of proper pipe bedding?
A) Increase pipe color
B) Support the pipe uniformly and protect it from damaging point loads
C) Eliminate the need for backfill
D) Increase water temperature
Answer: B) Support the pipe uniformly and protect it from damaging point
loads
Rationale: Proper bedding provides continuous support beneath the pipe
and helps maintain line, grade and structural performance.
5. When installing gravity sewer pipe, why is maintaining the designed
grade important?
A) To increase pipe weight
B) To provide adequate gravity flow
C) To eliminate manholes
D) To reduce pipe diameter
, Answer: B) To provide adequate gravity flow
Rationale: Gravity sewer systems depend on elevation difference to move
wastewater. Incorrect grade can produce inadequate flow, excessive
velocity or sediment accumulation.
6. A pipe has an elevation change of 2 feet over a horizontal distance of
100 feet. What is the approximate slope?
A) 0.2%
B) 1%
C) 2%
D) 20%
Answer: C) 2%
Rationale: Slope percentage equals rise divided by run multiplied by 100.
Thus, 2 ÷ 100 × 100 = 2%.
7. Which instrument is commonly used to establish and check pipe
elevation and grade?
A) Pipe wrench
B) Laser level
