Environmental Compliance Inspector Underground Storage Tanks (UST) Compliance 2 — Questions and Answers
Question 1: What is the primary purpose of cathodic protection on an underground storage tank system?
- To prevent corrosion of steel tank and piping components (Correct answer)
- To detect leaks in the tank bottom
- To neutralize acidic soils around the tank
- To improve structural integrity of concrete vaults
Correct answer: To prevent corrosion of steel tank and piping components
Cathodic protection counteracts the electrochemical process of corrosion by supplying an electrical current that prevents oxidation of the steel tank and piping.
Question 2: Under 40 CFR Part 280, how long must UST operating records (such as release detection monitoring results) generally be retained?
- At least 1 year for most records, with some records kept for the life of the system (Correct answer)
- Indefinitely for all records
- 3 years for all operational records
- Only until the next state inspection
Correct answer: At least 1 year for most records, with some records kept for the life of the system
Most UST operating records must be kept for at least one year, while certain records such as corrosion protection documentation must be kept for the operational life of the system.
Question 3: Which of the following is an acceptable method of release detection for petroleum UST systems under federal regulations?
- Automatic Tank Gauging (ATG) with inventory control (Correct answer)
- Daily visual inspection of the tank exterior only
- Weekly sniff testing by the owner
- Annual pressure testing as the sole method
Correct answer: Automatic Tank Gauging (ATG) with inventory control
Automatic Tank Gauging combined with inventory control is an EPA-approved release detection method that can identify small leaks by tracking changes in tank volume.
Question 4: What action must a UST owner or operator take within 24 hours of confirming a release from an underground storage tank?
- Notify the implementing agency (state or local authority) (Correct answer)
- Complete a full site assessment
- Hire a licensed remediation contractor
- Submit a corrective action plan to EPA
Correct answer: Notify the implementing agency (state or local authority)
Federal regulations require prompt notification of the implementing agency within 24 hours of a confirmed release so that oversight of corrective action can begin immediately.
Question 5: What is required when permanently closing an underground storage tank system?
- Emptying and cleaning the tank, assessing the site for contamination, and removing or filling the tank in place (Correct answer)
- Simply shutting off the supply lines and padlocking the fill cap
- Installing a vapor recovery cap on all openings
- Converting the tank to a monitoring well
Correct answer: Emptying and cleaning the tank, assessing the site for contamination, and removing or filling the tank in place
Permanent closure requires emptying and cleaning the tank to remove all residuals, conducting a site assessment to check for contamination, and either removing the tank or filling it with an inert solid material.
Question 6: Which of the following is an acceptable financial assurance mechanism for UST owners to demonstrate ability to pay for corrective action and third-party damages?
- Petroleum storage tank trust fund established by the state (Correct answer)
- A verbal commitment from the business owner
- Homeowner's insurance policy
- Letter of intent from a bank
Correct answer: Petroleum storage tank trust fund established by the state
State petroleum storage tank trust funds are a federally accepted financial assurance mechanism that demonstrates the owner can cover the costs of cleanup and liability.
Question 7: What does 'free product' refer to in the context of a UST release investigation?
- Liquid petroleum floating on the groundwater surface as a separate phase (Correct answer)
- Dissolved contaminants in groundwater above cleanup standards
- Petroleum vapors detected in soil above background levels
- Any petroleum product that has left the tank
Correct answer: Liquid petroleum floating on the groundwater surface as a separate phase
Free product is petroleum floating on the water table as a separate non-aqueous phase liquid (NAPL), which must be removed to the maximum extent practicable during corrective action.
