FACT SHEET

Final Amendments to the Standards of Performance for Volatile Organic Liquid Storage
Vessels (Including Petroleum Liquid Storage Vessels)

ACTION

•	On January 8, 2021, the U.S. Environmental Protection Agency (EPA) completed a final
action that amends the 1987 Standards of Performance for Volatile Organic Liquid Storage
Vessels (Including Petroleum Liquid Storage Vessels) for which Construction,
Reconstruction, or Modification Commenced after July 23,1984 (NSPS subpart Kb).

•	The 1987 NSPS set emission standards for volatile organic compounds (VOC) emitted from
storage vessels containing volatile organic liquids. It also set storage vessel inspection
procedures that, in certain circumstances, require storage vessels to be emptied and
degassed to be inspected.

o For some tanks in certain circumstances, the standards require the owner or

operator to empty and degas the tank so that an inspection can be conducted from
inside the tank (required at least once every 10 years),
o The owner or operator would enter the tank and conduct visual inspections for

holes, tears, or other openings,
o Emptying and degassing events are undesirable primarily because owners or
operators must take the storage vessel completely out-of-service; extra storage
capacity is needed, and air emissions are created during these events.

•	On June 29, 1999, EPA finalized the National Emission Standards for Hazardous Air
Pollutants (NESHAP) for Storage Vessels (Tanks)—Control Level 2, that, in certain
circumstances, allow for less cumbersome in-service inspections, without emptying and
degassing the storage tank.

•	This final action allows owners or operators of storage vessels, subject to the 1987 NSPS
and equipped with either an external floating roof (EFR) or internal floating roof (IFR), to
elect to comply with the requirements specified in the 1999 NESHAP in lieu of the 1987
standards subject to certain caveats and exceptions for monitoring, recordkeeping and
reporting.

•	These amendments provide owners or operators with the flexibility to choose the
appropriate standard. This final notice does not change the underlying compliance dates
under the 1987 NSPS.

BACKGROUND

•	The 1987 Standards of Performance for Volatile Organic Liquid Storage Vessels (including
Petroleum Liquid Storage Vessels) for which Construction, Reconstruction, or Modification
Commenced After July 23, 1984, is applicable to large storage tanks, which store volatile
organic liquids across a variety of industries, such as petroleum refineries, chemical plants
and portions of the oil and gas industry.

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•	Since 2018, EPA has received a significant uptick in the number of owners or operators
requesting alternatives to conducting out-of-service inspections of storage tanks subject to
the 1987 NSPS.

•	EPA has received more than 300 requests from facilities seeking permission to conduct in-
service inspections to demonstrate compliance with the 1987 NSPS subpart Kb. These one-
off requests are time consuming and burdensome.

FOR MORE INFORMATION

•	The fact sheet and a copy of the final rule are available on EPA's website at
https://www.epa.gov/stationarv-sources-air-pollution/volatile-organic-liquid-storage-
vessels-including-petroleum-storage.

•	Today's action and other background information are also available electronically at
https://www.regulations.gov/, EPA's electronic public docket and comment system.

•	For further technical information about the rule, contact Neil Feinberg of EPA's Office of Air
Quality Planning and Standards, at (919) 541-2214 orfeinberg.stephen@epa.gov.

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