Page 1 of 122
ICC U2 UST DECOMMISSIONING EXAM WITH COMPLETE
300 QUESTIONS AND CORRECT DETAILED SOLUTIONS
ALL WITH RATIONALES LATEST THIS YEAR 2026-2027
ICC U2 UST Decommissioning Exam — 300 Randomized Questions (1–300)
Exam Coverage Summary: Reporting Requirements (13%) | Site Preparation & Layout (6%) |
Tank Decommissioning & Cleaning (40%) | Storage & Transportation (8%) | Health & Safety for
UST Workers (33%)
Questions 1–60: Reporting Requirements
1. A gas station owner plans to permanently close an underground storage tank system. How
many days prior notice must typically be given to the state implementing agency before
permanent closure activities begin?
A. 10 days
B. 15 days
C. 30 days
D. 60 days
Answer: C — Regulations generally require 30-day notice prior to permanent closure, with an
additional 24-hour verbal notice before breaking concrete .
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2. During a UST removal, a release is confirmed. Within how many days must the owner or
operator submit a report to the state implementing agency summarizing initial abatement steps
and results?
A. 10 days
B. 20 days
C. 30 days
D. 45 days
Answer: B — Upon confirmation of a release during removal activities, a report summarizing
initial abatement steps must be submitted within 20 days .
3. How long must tank closure letters be retained by the owner or operator?
A. 1 year
B. 3 years
C. 5 years
D. Life of the tank
Answer: B — Tank closure letters must be kept for a minimum of 3 years .
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4. A written report submitted to the local agency after an unauthorized release is required to
include all of the following EXCEPT:
A. Description of actions taken to stop the release
B. Cause of the release
C. Method of disposal of released product
D. Date on which the release was discovered
Answer: B — The cause of the release is not required in the initial written report under CCR Title
23, Sec 2652(c) .
5. Records for UST construction, repairs, lining, and upgrades must be kept for:
A. 3 years
B. 10 years
C. 5 years
D. The life of the tank
Answer: D — Construction, repair, lining, and upgrade records must be kept for the life of the
tank under CCR Title 23, Sec 2712(b) .
6. A spill of petroleum that exceeds how many gallons must be reported within 24 hours?
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A. 10 gallons
B. 25 gallons
C. 50 gallons
D. 100 gallons
Answer: B — Spills exceeding 25 gallons must be reported within 24 hours; spills of 25 gallons or
less not cleaned up within 24 hours must also be reported .
7. An unauthorized release that does not escape from secondary containment only requires a
record on the operator's monitoring reports provided that:
A. It did not increase the hazard of fire
B. It did not cause deterioration of secondary containment
C. It was cleaned up within 8 hours of detection
D. All of the above
Answer: D — All three conditions must be met for a contained release to only require a
monitoring report record under H&SC Sec 25294 .
8. A service technician performs calibration and maintenance on an ATG probe. How long must
this maintenance record be kept on file?
ICC U2 UST DECOMMISSIONING EXAM WITH COMPLETE
300 QUESTIONS AND CORRECT DETAILED SOLUTIONS
ALL WITH RATIONALES LATEST THIS YEAR 2026-2027
ICC U2 UST Decommissioning Exam — 300 Randomized Questions (1–300)
Exam Coverage Summary: Reporting Requirements (13%) | Site Preparation & Layout (6%) |
Tank Decommissioning & Cleaning (40%) | Storage & Transportation (8%) | Health & Safety for
UST Workers (33%)
Questions 1–60: Reporting Requirements
1. A gas station owner plans to permanently close an underground storage tank system. How
many days prior notice must typically be given to the state implementing agency before
permanent closure activities begin?
A. 10 days
B. 15 days
C. 30 days
D. 60 days
Answer: C — Regulations generally require 30-day notice prior to permanent closure, with an
additional 24-hour verbal notice before breaking concrete .
, Page 2 of 122
2. During a UST removal, a release is confirmed. Within how many days must the owner or
operator submit a report to the state implementing agency summarizing initial abatement steps
and results?
A. 10 days
B. 20 days
C. 30 days
D. 45 days
Answer: B — Upon confirmation of a release during removal activities, a report summarizing
initial abatement steps must be submitted within 20 days .
3. How long must tank closure letters be retained by the owner or operator?
A. 1 year
B. 3 years
C. 5 years
D. Life of the tank
Answer: B — Tank closure letters must be kept for a minimum of 3 years .
, Page 3 of 122
4. A written report submitted to the local agency after an unauthorized release is required to
include all of the following EXCEPT:
A. Description of actions taken to stop the release
B. Cause of the release
C. Method of disposal of released product
D. Date on which the release was discovered
Answer: B — The cause of the release is not required in the initial written report under CCR Title
23, Sec 2652(c) .
5. Records for UST construction, repairs, lining, and upgrades must be kept for:
A. 3 years
B. 10 years
C. 5 years
D. The life of the tank
Answer: D — Construction, repair, lining, and upgrade records must be kept for the life of the
tank under CCR Title 23, Sec 2712(b) .
6. A spill of petroleum that exceeds how many gallons must be reported within 24 hours?
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A. 10 gallons
B. 25 gallons
C. 50 gallons
D. 100 gallons
Answer: B — Spills exceeding 25 gallons must be reported within 24 hours; spills of 25 gallons or
less not cleaned up within 24 hours must also be reported .
7. An unauthorized release that does not escape from secondary containment only requires a
record on the operator's monitoring reports provided that:
A. It did not increase the hazard of fire
B. It did not cause deterioration of secondary containment
C. It was cleaned up within 8 hours of detection
D. All of the above
Answer: D — All three conditions must be met for a contained release to only require a
monitoring report record under H&SC Sec 25294 .
8. A service technician performs calibration and maintenance on an ATG probe. How long must
this maintenance record be kept on file?
