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Leak Detection Methods for Petroleum Underground Storage Tanks and Piping


Quiz Questions

1.USTs stand for ________________________.
Underground storage tanks
Under storage turbines
2. EPA has identified the following methods that owners and operators may use to meet the federal leak detection requirements:
Secondary Containment with Interstitial Monitoring
Automatic Tank Gauging Systems (including continuous ATG systems)
True
False
3.Secondary containment often does not uses a barrier, an outer wall, a vault, or a liner around the UST or piping.
True
False
4.In automatic tank gauging systems a probe is permanently installed in the tank i.e. wired to a monitor to provide information on product level and temperature.
True
False
5.Vapor monitoring cannot be performed manually on a periodic basis or continuously using permanently installed equipment.
True
False
6.Groundwater monitoring senses the presence of liquid product floating on the groundwater. This method requires installation of monitoring wells at strategic locations in the ground near the tank and along the piping runs.
True
False
7.Manual tank gauging can be used only for tanks of ___________________________ capacity. This method requires keeping the tank undisturbed for at least 36 hours each week, during which the contents of the tank are measured twice at the beginning and twice at the end of the test period.
2,000 gallons or less
2,000 gallons or more
8.Tanks between 1,001 and 2,000 gallons can use the manual tank gauging method only in combination with periodic tank tightness testing.
True
False
9.NWGLDE is an acronym to _____________________________.
National Work Group on Leak Detection Evaluations
National Work Group on Leak Diagnostic Explanations
10.Secondary containment does not provide as a barrier between the tank and the environment.
True
False
11.Barriers do not include double-walled or jacketed tanks and internally fitted liners.
True
False
12.The ATGS must be able to detect a leak of 0.2 gallons per hour with certain probabilities of detection and of false alarm. Some ATGS can also detect a leak of 0.1 gallons per hour with the required probabilities.
True
False
13.SIR does not analyze inventory, delivery, and dispensing data collected over a period of time to determine whether or not a tank system is leaking.
True
False
14.To be allowable as monthly monitoring, a SIR method must be able to detect a leak at least as small as _____________ per hour and meet the federal regulatory requirements regarding probabilities of detection and of false alarm.
 0.2 gallons
20 gallons
15.A SIR methods ability to detect leaks declines as throughput increases. If you are considering using a SIR method for high throughput UST systems, check the methods evaluation to confirm that it will meet regulatory requirements and your needs.
True
False
16.Tightness test methods are also referred to as __________________________.
Preferred tank tests
Precision tank tests
17.Volumetric test methods generally do not involve measuring very precisely (in milliliters or thousandths of an inch) the change in product level in a tank over time.
True
False
18.UST inventories are determined each operating day by using a gauge stick and recording the data on a form. The level on the gauge stick is converted to a volume of product in the tank using a calibration chart, which is often furnished by the UST manufacturer.
True
False
19.No leak detection is required if the suction piping has (1) enough slope so that the product in the pipe can drain back into the tank when suction is released and (2) has only one check valve, which is as close as possible beneath the pump in the dispensing unit.
True
False
20.UST systems must have the combined method using tank tightness testing every 5 years for no more than10 years following corrosion protection, spill, and overfill upgrade of tanks or installation of new tanks.
True
False