ICC U2 UST Decommissioning Practice
Exam Questions and Answers with
Rationales Top Rated A+
1. A UST owner decides to permanently close a tank by removal. Which
consideration should be addressed before physical removal?
A. Whether the tank can be reused immediately
B. Applicable closure procedures, notifications, hazards, and site conditions
C. Whether the tank should be filled with fuel
D. Whether the dispenser can remain operating
Answer: B
Rationale: Permanent closure requires planning for applicable regulatory requirements,
notification, product removal, worker safety, environmental conditions, excavation, and
disposition of the tank and piping.
2. Which condition presents the greatest immediate fire/explosion concern during
UST decommissioning?
A. Wet soil
B. Flammable vapor in the presence of an ignition source
C. Clean gravel
D. A damaged access cover
Answer: B
Rationale: Petroleum vapors can form flammable mixtures with air. An ignition source such as a
spark, flame, or hot surface can cause a fire or explosion.
3. A contractor has removed all liquid product from a tank. Why might the tank
still require atmospheric testing?
A. Residual vapors can remain after liquid removal
B. Empty tanks always contain oxygen deficiency
,C. Testing determines the tank's capacity
D. Testing is used only to determine soil color
Answer: A
Rationale: Removing liquid does not necessarily eliminate hazardous vapors. Atmospheric
testing helps identify combustible, oxygen-deficient, or otherwise hazardous conditions.
4. Which action should occur if a combustible atmosphere is detected near
planned hot-work operations?
A. Start welding immediately
B. Eliminate or control the hazard and verify safe conditions before proceeding
C. Increase the amount of fuel present
D. Cover the monitor
Answer: B
Rationale: Hot work can ignite combustible vapors. Work should not proceed until the
hazardous condition has been appropriately controlled and the applicable hot-work requirements
are satisfied.
5. During excavation, a contractor discovers soil that smells strongly of
petroleum. What should the contractor do?
A. Assume the odor is insignificant
B. Evaluate the condition for possible contamination and follow applicable procedures
C. Spread the soil over the entire property
D. Add clean soil and continue without documentation
Answer: B
Rationale: Strong petroleum odors can indicate contamination. The condition should be
documented, evaluated, and managed under applicable environmental requirements.
6. Which of the following is most likely to provide evidence of a historical UST
release?
,A. Petroleum-stained soil
B. Newly installed pavement
C. Clean aggregate
D. A properly labeled vent
Answer: A
Rationale: Petroleum staining can indicate that regulated product has entered the surrounding
soil. It should be appropriately investigated rather than assumed to be harmless.
7. A UST has been removed, but contaminated soil remains in the excavation.
What is the best approach?
A. Ignore it because the tank is gone
B. Manage the contamination according to applicable assessment and corrective-action
requirements
C. Cover it permanently without documentation
D. Mix it with uncontaminated soil
Answer: B
Rationale: Removing the tank does not eliminate contamination that may already exist in the
surrounding soil. Appropriate investigation, containment, remediation, notification, or other
action may be required.
8. Which component should be considered part of the UST system when
evaluating decommissioning?
A. Underground product piping
B. Office furniture
C. Building paint
D. Parking lot lighting unrelated to the tank
Answer: A
Rationale: Product piping is an integral part of many UST systems and can contain residual
product or provide a pathway for releases.
9. Why should product piping be properly isolated before removal?
, A. To prevent residual product from being released
B. To increase system pressure
C. To improve fuel quality
D. To make the excavation deeper
Answer: A
Rationale: Piping may contain liquid or vapor even after the tank itself has been emptied.
Isolation reduces spill and vapor hazards.
10. An unknown underground pipe is encountered during tank excavation. What
is the safest approach?
A. Cut it immediately
B. Identify it and determine whether it contains product or connects to another system
C. Pull it out with an excavator
D. Leave it pressurized
Answer: B
Rationale: Unknown piping can contain petroleum, hazardous substances, electrical wiring, or
connections to other systems. Identification and isolation should precede disturbance.
11. What is the primary purpose of a closure site assessment?
A. To determine whether evidence of a release or contamination exists
B. To calculate the property owner's taxes
C. To determine the tank's resale value
D. To select landscaping materials
Answer: A
Rationale: Closure assessment helps identify evidence of releases and determine whether
additional environmental investigation or corrective action may be necessary.
12. A removed tank has a small perforation in its bottom. What does this finding
indicate?
A. The tank was definitely never used
B. The tank had physical deterioration that should be documented and evaluated for possible
Exam Questions and Answers with
Rationales Top Rated A+
1. A UST owner decides to permanently close a tank by removal. Which
consideration should be addressed before physical removal?
A. Whether the tank can be reused immediately
B. Applicable closure procedures, notifications, hazards, and site conditions
C. Whether the tank should be filled with fuel
D. Whether the dispenser can remain operating
Answer: B
Rationale: Permanent closure requires planning for applicable regulatory requirements,
notification, product removal, worker safety, environmental conditions, excavation, and
disposition of the tank and piping.
2. Which condition presents the greatest immediate fire/explosion concern during
UST decommissioning?
A. Wet soil
B. Flammable vapor in the presence of an ignition source
C. Clean gravel
D. A damaged access cover
Answer: B
Rationale: Petroleum vapors can form flammable mixtures with air. An ignition source such as a
spark, flame, or hot surface can cause a fire or explosion.
3. A contractor has removed all liquid product from a tank. Why might the tank
still require atmospheric testing?
A. Residual vapors can remain after liquid removal
B. Empty tanks always contain oxygen deficiency
,C. Testing determines the tank's capacity
D. Testing is used only to determine soil color
Answer: A
Rationale: Removing liquid does not necessarily eliminate hazardous vapors. Atmospheric
testing helps identify combustible, oxygen-deficient, or otherwise hazardous conditions.
4. Which action should occur if a combustible atmosphere is detected near
planned hot-work operations?
A. Start welding immediately
B. Eliminate or control the hazard and verify safe conditions before proceeding
C. Increase the amount of fuel present
D. Cover the monitor
Answer: B
Rationale: Hot work can ignite combustible vapors. Work should not proceed until the
hazardous condition has been appropriately controlled and the applicable hot-work requirements
are satisfied.
5. During excavation, a contractor discovers soil that smells strongly of
petroleum. What should the contractor do?
A. Assume the odor is insignificant
B. Evaluate the condition for possible contamination and follow applicable procedures
C. Spread the soil over the entire property
D. Add clean soil and continue without documentation
Answer: B
Rationale: Strong petroleum odors can indicate contamination. The condition should be
documented, evaluated, and managed under applicable environmental requirements.
6. Which of the following is most likely to provide evidence of a historical UST
release?
,A. Petroleum-stained soil
B. Newly installed pavement
C. Clean aggregate
D. A properly labeled vent
Answer: A
Rationale: Petroleum staining can indicate that regulated product has entered the surrounding
soil. It should be appropriately investigated rather than assumed to be harmless.
7. A UST has been removed, but contaminated soil remains in the excavation.
What is the best approach?
A. Ignore it because the tank is gone
B. Manage the contamination according to applicable assessment and corrective-action
requirements
C. Cover it permanently without documentation
D. Mix it with uncontaminated soil
Answer: B
Rationale: Removing the tank does not eliminate contamination that may already exist in the
surrounding soil. Appropriate investigation, containment, remediation, notification, or other
action may be required.
8. Which component should be considered part of the UST system when
evaluating decommissioning?
A. Underground product piping
B. Office furniture
C. Building paint
D. Parking lot lighting unrelated to the tank
Answer: A
Rationale: Product piping is an integral part of many UST systems and can contain residual
product or provide a pathway for releases.
9. Why should product piping be properly isolated before removal?
, A. To prevent residual product from being released
B. To increase system pressure
C. To improve fuel quality
D. To make the excavation deeper
Answer: A
Rationale: Piping may contain liquid or vapor even after the tank itself has been emptied.
Isolation reduces spill and vapor hazards.
10. An unknown underground pipe is encountered during tank excavation. What
is the safest approach?
A. Cut it immediately
B. Identify it and determine whether it contains product or connects to another system
C. Pull it out with an excavator
D. Leave it pressurized
Answer: B
Rationale: Unknown piping can contain petroleum, hazardous substances, electrical wiring, or
connections to other systems. Identification and isolation should precede disturbance.
11. What is the primary purpose of a closure site assessment?
A. To determine whether evidence of a release or contamination exists
B. To calculate the property owner's taxes
C. To determine the tank's resale value
D. To select landscaping materials
Answer: A
Rationale: Closure assessment helps identify evidence of releases and determine whether
additional environmental investigation or corrective action may be necessary.
12. A removed tank has a small perforation in its bottom. What does this finding
indicate?
A. The tank was definitely never used
B. The tank had physical deterioration that should be documented and evaluated for possible
