UST Tank Installation & Closure Procedures 2 — Questions and Answers
Question 1: What is the primary purpose of a spill bucket (spill containment manhole) installed at the fill port of a UST?
- To prevent surface water from entering the tank during rain
- To contain product spilled during tank filling operations (Correct answer)
- To house the overfill prevention valve
- To provide access for annual tank inspection
Correct answer: To contain product spilled during tank filling operations
Spill buckets are designed to capture product that overflows or drips from the delivery hose connection during tank filling, preventing releases to the environment.
Question 2: An overfill prevention device set to trigger at 90% tank capacity performs which action?
- Automatically seals the fill port shut
- Activates a high-level alarm to alert the delivery driver
- Closes a valve to restrict or stop product flow into the tank (Correct answer)
- Shuts down all dispensers connected to that tank
Correct answer: Closes a valve to restrict or stop product flow into the tank
A flow-restrictor (float valve) type overfill prevention device closes at 90% capacity, stopping or significantly reducing product flow to prevent the tank from overfilling.
Question 3: During UST installation, what minimum slope is generally required for gravity-return (suction) piping back toward the tank?
- 1/8 inch per foot
- 1/4 inch per foot (Correct answer)
- 1 inch per foot
- No slope is required for suction lines
Correct answer: 1/4 inch per foot
Suction piping must slope back to the tank at a minimum of 1/4 inch per foot so product drains back into the tank when the pump shuts off, reducing leak risk.
Question 4: What must be installed on all vent pipes of a UST system to prevent vapor ignition?
- Pressure/vacuum relief valves
- Flame arrestors (Correct answer)
- Check valves
- Ball valves
Correct answer: Flame arrestors
Flame arrestors are installed on UST vent pipes to prevent a flame from traveling through the vent line into the vapor space of the tank.
Question 5: When installing double-walled piping, the interstitial space between the inner and outer pipe serves what purpose?
- Provides insulation to keep fuel at a constant temperature
- Allows detection of leaks from the inner pipe before product reaches the environment (Correct answer)
- Reduces friction loss and improves flow rate
- Allows cathodic protection current to circulate uniformly
Correct answer: Allows detection of leaks from the inner pipe before product reaches the environment
The interstitial space of double-walled piping acts as secondary containment; sensors in this space detect leaks from the inner pipe before product can reach the soil or groundwater.
Question 6: What certification is required on UST equipment (tanks, piping, fittings) to demonstrate compliance with industry standards?
- UL listing or equivalent third-party certification (Correct answer)
- EPA direct approval stamp
- State fire marshal seal
- OSHA 1910 certification mark
Correct answer: UL listing or equivalent third-party certification
UST equipment must be listed or approved by a nationally recognized testing laboratory such as UL (Underwriters Laboratories) or equivalent third-party certifier.
Question 7: After completing a UST installation, within how many days must the owner/operator submit a notification to the implementing agency confirming installation is complete?
- 7 days
- 30 days (Correct answer)
- 60 days
- 90 days
Correct answer: 30 days
Under 40 CFR Part 280, owners/operators must notify the implementing agency within 30 days after bringing a new UST system into service.
UST Tank Installation & Closure Procedures 2
What is the primary purpose of a spill bucket (spill containment manhole) installed at the fill port of a UST?