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Underground Storage Tanks (USTs)

Field-Constructed Tanks and Airport Hydrant Systems - 2015 Requirements

In 2015, EPA revised the underground storage tank (UST) regulations. Below are the requirements for field-constructed tanks and airport hydrant systems.

UST systems with field-constructed tanks (called field-constructed tanks) and airport hydrant fuel distribution systems (called airport hydrant systems) that meet the UST definition are now regulated under subpart K of the UST regulation. These UST systems must meet the requirements described below.

On this page:

What is a Field-Constructed Tank?

A field-constructed tank is a tank constructed in the field. For example, tanks constructed of concrete that is poured in the field, or steel or fiberglass tanks primarily fabricated in the field are considered field-constructed.

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What is an Airport Hydrant System?

An airport hydrant system is an UST system which fuels aircraft and operates under high pressure with large diameter piping that typically terminates into one or more hydrants or fill stands. The airport hydrant system begins where fuel enters one or more tanks from an external source such as a pipeline, barge, rail car, or other motor fuel carrier.

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Notifications to the Implementing Agency

  • Not later than October 13, 2018 owners and operators must submit to the implementing agency a one-time notice of existence for these UST systems
  • After October 13, 2015 owners and operators must submit a notification form within 30 days of bringing an airport hydrant system or field constructed tank into use
  • After October 13, 2015 owners and operators must submit a notification of ownership change form within 30 days of acquiring one of these types of UST systems

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Financial Responsibility

Owners and operators must demonstrate financial responsibility at the time they submit the notification of existence form for tanks in use as of October 13, 2015 or the new UST system notification form for tanks brought into use after October 13, 2015.
State and federal UST system owners and operators are exempt from meeting the financial responsibility requirement.

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Repairs

Beginning on October 13, 2015 owners and operators must meet the same repair requirements as other regulated UST systems.

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Spill and Overfill

Not later than October 13, 2018, owners and operators of these UST systems installed on or before October 13, 2015 must meet the same spill and overfill requirements as other regulated UST systems.

Airport hydrant systems and field-constructed tanks installed after October 13, 2015 must meet the same spill and overfill requirements as other regulated UST systems at the time of installation.

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Corrosion Protection

For UST systems in use as of October 13, 2015 owners and operators must meet one of the following corrosion protection requirements for their tanks and piping in contact with the ground that routinely contain regulated substances by October 13, 2018:

  • The new UST system performance standards in 280.20(a) and (b), or
  • Be constructed of metal and cathodically protected according to a code of practice developed by a nationally recognized association or independent testing laboratory. Metal tanks greater than 10 years old without cathodic protection must also be assessed to ensure the tank is structurally sound and free of corrosion holes prior to adding cathodic protection.

UST systems installed after October 13, 2015 must meet the new UST system performance standards in 280.20(a) and (b) at the time of installation.

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Secondary Containment

Owners and operators of airport hydrant systems and field-constructed tanks must meet the same secondary containment requirements as other regulated UST systems except:

  • New and replaced piping associated with airport hydrant systems does not have to be secondarily contained and
  • New and replaced piping associated with field-constructed tanks greater than 50,000 gallons does not have to be secondarily contained.

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Release Detection – Tanks

Not later than October 13, 2018 factory built tanks associated with airport hydrant systems and field-constructed tanks with a capacity less than or equal to 50,000 gallons must meet the release detection requirements in subpart D.

Not later than October 13, 2018 field-constructed tanks with a capacity greater than 50,000 gallons must meet either the release detection requirements in subpart D (except groundwater monitoring and vapor monitoring must be combined with inventory control as described below) or use one or a combination of the following alternative methods of release detection:

  • Conduct an annual tank tightness test that can detect a 0.5 gallon per hour leak rate;
  • Use an automatic tank gauging system to perform release detection at least every 30 days that can detect a leak rate less than or equal to one gallon per hour. This method must be combined with a tank tightness test that can detect a 0.2 gallon per hour leak rate performed at least every three years;
  • Use an automatic tank gauging system to perform release detection at least every 30 days that can detect a leak rate less than or equal to two gallons per hour. This method must be combined with a tank tightness test that can detect a 0.2 gallon per hour leak rate performed at least every two years;
  • Perform vapor monitoring using a tracer compound placed in the tank system capable of detecting a 0.1 gallon per hour leak rate at least every two years;
  • Combine inventory control at least every 30 days that can detect a leak equal to or less than 0.50 percent of flow-through combined with one of the following:
    • A tank tightness test that can detect a 0.5 gallon per hour leak rate at least every two years; or
    • Vapor monitoring or groundwater monitoring at least every 30 days; or
  • Use another method approved by the implementing agency if the owner and operator can demonstrate that the method can detect a release as effectively as any of the alternative methods listed above.

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Release Detection – Piping

Not later than October 13, 2018 owners and operators of underground piping associated with field-constructed tanks less than or equal to 50,000 gallons must meet the release detection requirements in subpart D.

Not later than October 13, 2018 owners and operators of underground piping associated with airport hydrant systems and field-constructed tanks greater than 50,000 gallons must follow either the release detection requirements in subpart D (except groundwater monitoring and vapor monitoring must be combined with inventory control as described below) or use one or a combination of the following alternative methods of release detection:

  1. Perform a semiannual or annual line tightness test at or above the piping operating pressure in accordance with parameters in the table below.
Maximum Leak Detection Rate Per Test Section Volume
 
Test Section Volume
(Gallons)
Semiannual Test -
Leak Detection Rate Not To Exceed
(Gallons Per Hour)
Annual Test -
Leak Detection Rate Not To Exceed
(Gallons Per Hour)
< 50,000 1.0 0.5
≥ 50,000 to < 75,000 1.5 0.75
≥ 75,000 to < 100,000 2.0 1.0
≥ 100,000 3.0 1.5

Piping segments ≥ 100,000 gallons not capable of meeting the maximum 3.0 gallon per hour leak rate for the semiannual test may be tested at a leak rate up to 6.0 gallons per hour according to the following schedule:

Phase In For Piping Segments ≥ 100,000 Gallons In Volume
First test Not later than October 13, 2018 (may use up to 6.0 gph leak rate)
Second test Between October 13, 2018 and October 13, 2021 (may use up to 6.0 gph leak rate)
Third test Between October 13, 2021 and October 13, 2022 (must use 3.0 gph for leak rate)
Subsequent tests After October 13, 2022, begin using semiannual or annual line testing according to the Maximum Leak Detection Rate Per Test Section Volume table above
  1. Perform vapor monitoring using a tracer compound placed in the tank system capable of detecting a 0.1 gallon per hour leak rate at least every two years;
  2. Combine inventory control at least every 30 days that can detect a leak equal to or less than 0.50 percent of flow-through with one of the following:
    1. a line tightness test (conducted in accordance with option #1 using the leak rates for the semiannual test) at least every two years; or
    2. vapor monitoring or groundwater monitoring at least every 30 days; or
  3. Use another method approved by the implementing agency if the owner and operator can demonstrate that the method can detect a release as effectively as any of the alternative methods listed above.

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Operation and Maintenance

Owners and operators must meet the following operation and maintenance requirements for airport hydrant systems and field-constructed tanks:

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Recordkeeping

Owners and operators must meet the same recordkeeping requirements as other regulated UST systems.

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Closure

Not later than October 13, 2015, owners and operators must meet the same closure requirements other regulated UST systems except as follows:

When directed by the implementing agency, the owner and operator of a field-constructed tank or airport hydrant system closed before October 13, 2015 must assess the excavation zone and close the UST system if releases from the UST system may, in the judgment of the implementing agency, pose a current or potential threat to human health and the environment.

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Cleanup

Owners and operators must meet the same cleanup requirements as other regulated UST systems.

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