DECOMMISSIONING (CLOSRE) EXAM QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)
Q&A 2026 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of UST decommissioning?
A. Increase fuel storage capacity
B. Eliminate environmental contamination risks
C. Reduce tax obligations
D. Improve tank appearance
Rationale: Decommissioning ensures safe removal or closure to
prevent leaks and contamination.
Correct Answer: B
2. Which agency primarily regulates UST closure in the U.S.?
A. OSHA
B. EPA
C. DOT
D. FEMA
Rationale: The Environmental Protection Agency oversees UST
regulations.
Correct Answer: B
,3. What is the first step before UST closure begins?
A. Excavation
B. Product removal
C. Site landscaping
D. Painting tank exterior
Rationale: All product must be safely removed before closure.
Correct Answer: B
4. Why is vapor testing conducted during closure?
A. To increase fuel quality
B. To detect explosive atmospheres
C. To check water content
D. To measure tank size
Rationale: Vapor testing ensures safe working conditions.
Correct Answer: B
5. What is inerting in UST closure?
A. Filling tank with soil
B. Making tank invisible
C. Removing labels
D. Neutralizing explosive vapors
Rationale: Inerting reduces flammable vapors using gas or
foam.
Correct Answer: D
,6. Which document is required after closure?
A. Driving license
B. Closure report
C. Insurance card
D. Tax receipt
Rationale: Closure reports document compliance.
Correct Answer: B
7. What hazard is most associated with USTs?
A. Noise pollution
B. Soil and groundwater contamination
C. Air conditioning failure
D. Lighting issues
Rationale: Leaks can contaminate soil and groundwater.
Correct Answer: B
8. What must be done with residual sludge in a tank?
A. Burn it
B. Dispose according to hazardous waste rules
C. Bury it onsite
D. Flush into sewer
Rationale: Sludge may be hazardous and must be properly
disposed.
Correct Answer: B
, 9. Which method permanently removes a tank?
A. Abandonment in place
B. Removal
C. Painting
D. Sealing access lid
Rationale: Tank removal physically eliminates the structure.
Correct Answer: B
10. What is a common risk during tank excavation?
A. Electrical shortage
B. Structural collapse
C. Internet failure
D. Paint damage
Rationale: Excavation can destabilize surrounding soil.
Correct Answer: B
11. What gas is commonly associated with UST vapor hazards?
A. Oxygen
B. Methane
C. Nitrogen
D. Hydrogen chloride
Rationale: Hydrocarbon vapors like methane are flammable.
Correct Answer: B