UST Tank Installation & Closure Procedures 1 — Questions and Answers
Question 1: Before installing a new UST system, what must an owner/operator notify the implementing agency at minimum?
- 30 days before installation begins (Correct answer)
- 60 days before installation begins
- At least 7 days before installation begins
- No advance notice is required
Correct answer: 30 days before installation begins
EPA regulations require owners/operators to notify the implementing agency at least 30 days prior to installing a new UST system.
Question 2: Which backfill material is most commonly required around a steel UST tank to prevent corrosion and provide structural support?
- Native excavated soil
- Pea gravel or crushed stone (3/4 inch or less) (Correct answer)
- Sand mixed with clay
- Concrete slurry
Correct answer: Pea gravel or crushed stone (3/4 inch or less)
Pea gravel or clean crushed stone (3/4 inch or smaller) is the standard backfill because it is non-corrosive, drains well, and provides uniform support around the tank.
Question 3: What is the minimum depth of cover (burial depth) typically required over the top of a UST tank?
- 6 inches
- 12 inches
- 24 inches (Correct answer)
- 48 inches
Correct answer: 24 inches
Most codes and manufacturer specifications require a minimum of 24 inches (2 feet) of cover over the top of the tank to protect it from surface loads and frost.
Question 4: When installing a fiberglass-reinforced plastic (FRP) UST, which of the following installation requirements is unique compared to steel tanks?
- FRP tanks must be cathodically protected
- FRP tanks require anchor straps when high groundwater is anticipated (Correct answer)
- FRP tanks must be coated with epoxy before burial
- FRP tanks must be installed above the groundwater table
Correct answer: FRP tanks require anchor straps when high groundwater is anticipated
FRP tanks are buoyant and must be anchored with anchor straps or deadman anchors when high groundwater conditions exist to prevent flotation.
Question 5: During a UST installation, a vacuum or pressure test is typically conducted to verify what condition?
- Tank structural integrity and tightness (Correct answer)
- Cathodic protection system functionality
- Backfill compaction density
- Piping slope for gravity drainage
Correct answer: Tank structural integrity and tightness
Vacuum or pressure testing of the tank and piping before backfilling confirms structural integrity and that the system has no leaks.
Question 6: Which document must be obtained and retained before any UST installation project begins, demonstrating the installer's qualifications?
- A surety bond from the contractor
- Certification or licensing as required by the implementing agency (Correct answer)
- A letter of intent from the equipment manufacturer
- An EPA approval letter for the specific tank model
Correct answer: Certification or licensing as required by the implementing agency
Installers must hold certification or licensing as required by the state implementing agency, and documentation of these qualifications must be retained.
Question 7: Which of the following piping configurations is required under EPA rules to minimize the risk of product releases from UST piping?
- All underground piping must slope upward toward the dispenser
- Pressurized piping must have an automatic line leak detector and shear valves (Correct answer)
- Underground piping must be installed only in metallic conduit
- All piping joints must be welded; no threaded connections are allowed
Correct answer: Pressurized piping must have an automatic line leak detector and shear valves
Pressurized piping systems must include an automatic line leak detector that shuts down the pump and a shear (impact) valve at the dispenser to contain releases.
UST Tank Installation & Closure Procedures 1
Before installing a new UST system, what must an owner/operator notify the implementing agency at minimum?