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State-Specific Considerations for SPCC Plans in Delaware

Posted: February 8th, 2022

Authors: Sahil B. 

This blog is part of a series that will cover key state-specific requirements for petroleum containing aboveground storage tanks (ASTs) with respect to Spill Prevention, Control, and Countermeasure (SPCC) compliance with 40 CFR Part 112.7(j).  In this edition, I will walk through key requirements in Delaware (DE).

The Delaware Department of Environmental Resources and Environmental Control (DNREC) has implemented AST regulations at Title 7 Delaware Administrative Code (Del.C.) §1352.  Similar to many other states, Delaware also regulates ASTs containing hazardous substances; however, the focus of this article will be on the potentially more stringent discharge prevention and containment requirements for oil-containing ASTs.

Title 7 Del.C. §1352 Parts B and C contain technical regulations for which ASTs must comply.  In general, ASTs containing a regulated substance (e.g., petroleum products) with a capacity of 12,499 gallons or greater are subject to the Part B and C regulations.  However, it is important to note that ASTs containing diesel, kerosene, and heating fuel have a different regulatory threshold and are only subject to these regulations if the capacity of the AST is greater than 40,000 gallons.

Some of the key requirements for facilities subject to the Part B and C technical regulations include meeting the following for ASTs installed after June 11, 2004 (compliance dates for existing ASTs installed before June 11, 2004, can be found in Title 7 Del.C. §1352):

  • Installing ASTs with a release prevention barrier (RPB). Acceptable RPBs for field constructed tanks include impervious liners with a permeability of 10-7 centimeters per second (cm/s) or less, impervious concrete foundations, and double-bottomed tanks with leak detection monitoring.  Shop-fabricated tanks have two additional methods of complying with the RPB requirement, which are installing a double-walled tank with leak detection monitoring and steel containment.
  • Constructing dikes or curbing used for secondary containment to contain 110% of the volume of the largest AST plus six inches of freeboard for precipitation. Similar to the permeability requirements that have been discussed in the previous bullet and several of the other articles in this series, this diking requirement is more stringent than what U.S. EPA requires under the SPCC regulations at 40 CFR Part 112.
  • Installing leak detection, overfill, and spill prevention equipment. All subject ASTs must be equipped with a leak detection system, level gauge, and overfill prevention device.  The overfill prevention device requirements vary depending on whether transfer operations are continuously monitored or not.  Transfer operations that are not continuously monitored require regulated ASTs to be equipped with an automatic flow shut off device that activates at no more than 95% of its capacity.  Whereas the minimum requirement for continuous monitored transfer operations is to equip the AST with a visual and audible high level alarm.  Note that the regulations also specify testing requirements for these devices (e.g., testing the overfill prevention system at least every 93 days and calibrating the level gauge at least every 12 months).  This is another example of a more stringent requirement since SPCC regulations state these devices must be tested regularly, without defining a frequency.
  • Maintaining inventory control records. For example, records must be kept daily when any transfers (i.e., adding or withdrawing) from regulated ASTs occur, with a maximum interval of seven days between measurements.  Most automatic tank gauge (ATG) systems are able to be configured to maintain these records.  Note that formal inventory control records are not a requirement under the SPCC regulations.
  • Conducting formal external inspections of the tank and secondary containment at least every five years. It is important to note that this may be more frequent than what inspection standards otherwise present, particularly for shop-fabricated tanks.  The regulations also specify requirements for internal AST inspections; however, these vary considerably based on AST construction and chosen inspection standard.  In contrast, SPCC inspection requirements are typically based on what the applicable industry standard requires.

Other Requirements

Facilities subject to the Title 7 Del.C. §1352 Part B and C regulations are also required to prepare a release preparedness plan.  The main difference in requirements between a release preparedness plan and an SPCC plan are that release preparedness plans must also address contaminated soil, fire, explosion, and health and safety contingencies.  Release preparedness plan requirements can be addressed in an SPCC plan or in another contingency plan at your facility.

Stay tuned for upcoming articles that will continue to cover additional AST requirements in other states.  If you have questions on AST compliance in Delaware or another state, please feel free to reach out to me at sbharucha@all4inc.com or 571-392-2592 x505 or Paul Hagerty at phagerty@all4inc.com or 610-422-1168.


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