power generation facilities regulated by the NRC. This indicated that
although these tanks were subject to some parts of the UST regulation,
EPA intended to continue evaluating the applicability of full
regulation of these tanks at a future date. EPA reconsidered these
tanks and is making a final determination. EPA is excluding these tanks
from most requirements in this final UST regulation; however, the
regulatory requirements in subparts A and F for these systems remain
the same.
Installation Requirements for Partially Excluded Tanks
    In the 1988 UST regulation, deferred USTs containing radioactive
material and emergency generator UST systems at nuclear power
generation facilities regulated by NRC were required to meet the
interim prohibition requirements of Sec.  280.11 (that is, corrosion
protected, made of non-corrodible materials, or otherwise designed and
constructed to prevent releases during the operating life of the
facility due to corrosion or structural failure). While NRC's
regulation addresses design and installation standards, interim
prohibition requirements have been in effect since the 1988 UST
regulation. Accordingly, owners and operators have had to follow this
requirement since the effective date of the 1988 UST regulation. EPA
has no information suggesting that maintaining this requirement has
been an issue for owners and operators. After considering commenters'
feedback, EPA concluded that the historic level of regulation for these
tanks is appropriate and provides adequate environmental controls to
ensure environmental protection. Therefore, this final UST regulation
continues to require that owners and operators of these tanks comply
with the requirements of Sec.  280.11. Because EPA is partially
excluding these systems, the term interim prohibition no longer
applies. Therefore, EPA is rewording the title of Sec.  280.11 to
Installation requirements for partially excluded UST systems. In
addition, EPA is changing Sec.  280.11(a) to reflect that these
requirements are installation requirements rather than prohibitions on
installation.
    After considering comments and additional information, this final
UST regulation excludes owners and operators of these tanks from 40 CFR
part 280, subparts B (UST Systems: Design, Construction, Installation
and Notification); C (General Operating Requirements); D (Release
Detection); E (Release Reporting, Investigation, and Confirmation); G
(Out-of-Service UST Systems and Closure); H (Financial Responsibility);
J (Operator Training); and K (UST Systems with Field-Constructed Tanks
and Airport Hydrant Fuel Distribution Systems). Owners and operators of
these tank systems are still required to comply with subparts A
(Program Scope and Installation Requirements for Partially Excluded

UST Systems) and F (Release Response and Corrective Action for UST
Systems Containing Petroleum or Hazardous Substances).
    This final UST regulation also amends Sec.  280.10(c)(4) which
refers to facilities licensed under 10 CFR part 50. This change is
consistent with the regulatory citation listed in the Spill Prevention,
Control, and Countermeasure provision in 40 CFR part 112 and also
applies to installation of these tanks at NRC facilities in the future.

D. Other Changes

1. Changes to Overfill Prevention Equipment Requirements
    Through extensive stakeholder outreach, EPA identified vent line
flow restrictors (also called ball float valves) as a significant
concern for operability and safety. As a result, this final UST
regulation modifies the 1988 UST regulation by eliminating vent line
flow restrictors as an option for meeting the overfill prevention
equipment requirement for new tank installations and when overfill
prevention equipment is replaced. EPA makes this change to: reduce the
frequency of UST releases due to operability issues, address system
safety concerns, and address personnel safety concerns. Below are the
issues:
     Operability--For a vent line flow restrictor to operate
properly, the device must restrict the flow of regulated substance into
the UST when the flow restrictor engages. If the tank top is not liquid
or vapor tight, flow into the UST is not restricted because vapors
continue to escape through non-tight areas. If vapors continue to
escape from the UST, there is no pressure buildup in the vapor area of
the tank, resulting in no reduced flow rate into the UST. Examples
where non-tight tank tops may result in ineffective flow restrictors
include: loose tank bungs or other tank top components; tanks with
coaxial stage I vapor recovery installed; and tanks with both tank top
and remote fill areas.
     System safety--Vent line flow restrictors can create
safety concerns when they activate. USTs can become over pressurized
and be damaged during deliveries when product is pumped into the tank.
PEI's recommended practice for installation, RP 100, advises against
using vent restriction devices because the vent line flow restrictor
pressurizes the UST, creating a hazardous condition when the device
operates as designed.
     Personnel safety--Delivery personnel can be sprayed with
regulated substances when they disconnect the delivery hose from the
fill pipe because pressure can build up in the tank when the vent line
flow restrictor activates.
    Owners and operators may continue to use flow restrictors not in
vent lines (such as flow restrictors in fill pipes), automatic shutoff
devices, and high level alarms to meet the overfill prevention
requirement for their UST systems.
    Owners and operators using a vent line flow restrictor before the
effective date of this final UST regulation may continue using it to
meet the overfill prevention requirement, as long as it operates
properly by restricting the flow of regulated substances into the UST
when the device activates. Flow restrictors in vent lines must be
periodically inspected for proper operation according to section B-3,
Overfill Prevention Equipment Inspections. This means that the flow
restrictor will need to be accessible to the person inspecting the
overfill prevention device. In addition, owners and operators may
continue to use flow restrictors in UST system vent lines for reasons
other than meeting the overfill prevention requirement, as long as the
flow restrictors do not interfere with operation of the overfill
prevention equipment being used.
    Most commenters supported this change to the 1988 UST regulation.
Several even suggested requiring retrofits of vent line flow
restrictors with another type of overfill prevention equipment. Because
EPA is concerned about imposing too many additional costs on owners and
operators of existing UST systems, EPA is not requiring retrofits of
existing vent line flow restriction devices, as long as they operate
properly, alert delivery personnel, and prevent overfills. Some
commenters suggested EPA continue to allow the use of vent line flow
restrictors if they meet the criteria set forth in PEI's RP 100. EPA
reviewed the PEI recommended practice and noted that the code sets
criteria for the allowed use of vent line flow restrictors. However,
more importantly, the code advises against using vent line flow
restrictors for overfill prevention under any circumstance because they
pressurize the UST, creating a hazardous condition when the device
operates as designed. Consistent with PEI's RP 100 advisory, EPA is not
allowing owners and operators to use vent line flow restrictors in new
tanks or when overfill prevention equipment is replaced. Finally,
several commenters suggested EPA continue to allow the use of vent line
flow restrictors, as long as the flow restrictor can be shown to
operate effectively. Because it is difficult to determine if flow
restrictors in vent lines will effectively restrict flow when the tank
is close to being full, EPA is not allowing their use in new UST system
installations or when overfill prevention equipment is replaced.
However, the final UST regulation allows continued use of vent line
flow restrictors installed before the effective date of the final UST
regulation, as long as they operate properly, alert delivery personnel,
and prevent overfills.
2. Internal Linings that Fail the Periodic Lining Inspection and Cannot
Be Repaired
    About 3 percent of tanks rely on internal lining as the sole method
of corrosion protection to meet the 1988 UST regulation.\104\ Tanks
that were internally lined to meet the 1988 UST regulation corrosion
protection requirement at Sec.  280.21 are typically older, bare steel
tanks installed before 1986. The 1988 UST regulation preamble says that
internal lining, when used as the sole method for corrosion protection,
is not regarded as a permanent upgrade. However, it is adequate if the
lining continues to meet original design specifications. If the
internal lining no longer meets original design specifications and
cannot be repaired according to industry codes, then the lined tank is
subject to unprotected tank requirements and must be replaced after
1998. However, this language, which was in the 1988 UST regulation
preamble, was inadvertently omitted from the 1988 UST regulation.
---------------------------------------------------------------------------

    \104\ E\2\, Incorporated, memoranda and analyses submitted under
Contract EP-W-05-018, U.S. Environmental Protection Agency.
Underground Storage Tanks/Leaking Underground Storage Tanks
Analytical And Technical Support. These supporting materials are
located in the docket EPA-HQ-UST-2011-0301.
---------------------------------------------------------------------------

    This final UST regulation modifies the 1988 UST regulation by
requiring owners and operators to permanently close an UST that uses
internal lining as the sole method of corrosion protection for the tank
when the lining inspection determines the internal lining is no longer
performing according to original design specifications and the internal
lining cannot be repaired according to a code of practice developed by
a nationally recognized association or independent testing laboratory.
EPA understands that codes of practice for internal lining inspections
in use as of publication of this final UST regulation contain pass or
fail criteria for the internal lining and criteria for allowing repairs
to an internal lining that fails the internal lining inspection.

    Owners and operators using internal lining as the sole method of
corrosion protection for the tank may continue using that method as
long as the internal lining is periodically inspected according to
Sec.  280.21(b)(1)(ii) and the internal lining passes the inspection or
is repaired so it meets original design specifications according to a
code of practice developed by a nationally recognized association or
independent testing laboratory.
    Consistent with current EPA policy,\105\ tanks using the
combination of cathodic protection and internal lining for corrosion
protection are not required to be closed if the internal lining fails
and cannot be repaired, as long as the cathodic protection is operated
and maintained according to Sec.  280.31 and the tank was assessed and
found to be structurally sound and free of corrosion holes when the
cathodic protection was added to the tank. In addition, owners and
operators may use internal linings for purposes other than meeting
EPA's corrosion protection upgrade requirement (for example, internal
linings used for compatibility or secondary containment).
---------------------------------------------------------------------------

    \105\ EPA UST Technical Compendium Question And Answer # 14:
www.epa.gov/oust/compend/nus.htm.
---------------------------------------------------------------------------

    Most commenters supported this change to the 1988 UST regulation.
Some even suggested more restrictive requirements: either phasing out
internal lining as a corrosion protection upgrade or permanently
closing an UST if the lining inspection failed. EPA is not requiring
these more restrictive approaches because we think internal lining
repairs can be appropriate and protect the environment when conducted
according to a code of practice developed by a nationally recognized
association or independent testing laboratory. In addition, requiring
permanent closure under these more restrictive circumstances would
place additional financial burdens on UST owners and operators. Several
commenters offered adding cathodic protection and relining the tank as
alternatives to permanent closure. EPA is not including these options
in this final UST regulation because internally lined tanks that fail
the lining inspection and cannot be repaired according to a code of
practice are generally older and are nearing or past the end of their
useful lives.
3. Notification
    This final UST regulation adds a one-time notification of existence
for UST systems with field-constructed tanks and UST systems identified
as airport hydrant fuel distribution systems. In addition, it adds a
new notification requirement for ownership changes; provides a new form
for making notification of ownership changes; and makes minor changes
to the notification language and notification form.
    EPA agrees with commenters who opposed requiring one-time
notification of existence for emergency power generator UST systems as
was proposed. Commenters explained, and EPA agrees, that since the 1988
UST regulation deferred these systems only from the release detection
requirements in subpart D, owners should have notified the appropriate
implementing agency within 30 days of bringing an UST system into use
in accordance with the notification requirements in subpart B.
Therefore, in this final UST regulation, the requirement to submit a
one-time notification of existence applies only to owners of UST
systems with field-constructed tanks and airport hydrant fuel
distribution systems. (This one-time notification of existence does not
apply to wastewater treatment tank systems, UST systems containing
radioactive material that are regulated under the Atomic Energy Act of
1954, and UST systems that are part of an emergency generator system at
nuclear power generation facilities regulated by the Nuclear Regulatory
Commission under 10 CFR part 50 previously deferred in the 1988 UST
regulation and partially excluded in this final UST regulation.)
    Furthermore, EPA agrees with commenters' requests to extend the
time frame of 30 days in the 2011 proposed UST regulation for owners of
UST systems with field-constructed tanks and airport hydrant fuel
distribution systems to submit their one-time notification of
existence. To provide owners more time for identifying and gathering
information about these previously deferred systems, EPA is allowing
owners of existing UST systems with field-constructed tanks and airport
hydrant fuel distribution systems to submit a one-time notification of
existence within 3 years of the effective date of this final UST
regulation. EPA is requiring owners of UST systems with field-
constructed tanks and airport hydrant fuel distribution systems brought
into use after the effective date of the final UST regulation to submit
notification forms; this notification requirement has been in place
since 1986 for all UST owners bringing new USTs into use. See subpart K
for other requirements related to UST systems with field-constructed
tanks and airport hydrant fuel distribution systems.
    Several commenters requested EPA allow 60 days instead of 30 days
to submit a notification of ownership change, noting that the 30-day
requirement is too stringent. One commenter stated that the time frame
should be relaxed to account for large organizations where paperwork
could involve a significant amount of time to process. Another stated
that 30 days would be too short and unduly burdensome on small
businesses. While EPA fully considered these comments, EPA thinks it is
important for the ownership change notification requirement to be
consistent with the new tank notification requirement (within 30 days
of bringing an UST into use) in place since 1988. In addition, the
ownership change notification form is shorter and takes less time to
complete than the new tank notification form. As a result, this final
UST regulation requires owners to submit a notification of ownership
change within 30 days of assuming ownership of regulated UST systems.
    In this final UST regulation, EPA provides a new notification form
titled Notification of Ownership Change for Underground Storage Tanks
under appendix II. This form supplants the List of Agencies Designated
to Receive Notifications in appendix II of the 1988 UST regulation. The
list, published in 1988, contained agency names, addresses, and phone
numbers, many of which are no longer accurate. EPA considered updating
the list, but given the frequency with which contact information
changes, decided it is pointless to publish information in the final
UST regulation since it will quickly become obsolete. Rather, owners
can obtain current agency contact information on EPA's Web site at
www.epa.gov/oust.
    Two commenters indicated it was unclear who the implementing agency
is and whether owners and operators need to notify both the state and
EPA. In this final UST regulation, EPA is clarifying that owners must
submit notification forms to the appropriate implementing agency. The
term implementing agency is defined in the UST regulation and owners
can obtain current contact and other information regarding their
implementing agency on EPA's Web site at www.epa.gov/oust. In practice,
EPA expects most owners will submit notification forms only to their
respective state as their implementing agency, except in instances
where the implementing agency is EPA. For example, EPA is the
implementing agency for USTs located in Indian country; thus, owners
with USTs in Indian country will submit their

notification forms to EPA. Owners should also be aware that individual
states may have state versions of notification forms which owners
should use instead when submitting to the implementing agency. EPA is
revising the regulatory language in Sec.  280.22(a) and (b) and
including language in subpart K to reflect that state forms may be used
if the state requires owners to use notification forms that differ from
those in appendices I and II.
    Lastly, EPA is amending the notification form in appendix I and the
ownership change form in appendix II to incorporate comments regarding
specific items on these forms. For example, two commenters noted that
owners of previously deferred UST systems would be unable to complete
the Certification of Installation section of the Notification for
Underground Storage Tanks form because they were not subject to this
requirement when the UST system was brought into use. In addition,
records of installation for these previously deferred UST systems are
likely to be nonexistent given the passage of time since installation.
EPA agrees with these commenters and is revising the notification form
to indicate that only owners of UST systems with field-constructed
tanks and airport hydrant fuel distribution systems brought into use
after the effective date of this final UST regulation need to complete
this section.
4. Compatibility
Regulated Substance and Motor Fuel Definitions
    This final UST regulation revises the regulated substance
definition to clarify that UST systems containing petroleum derived
from non-crude oil products are regulated. The preamble to the
supplement of the proposed 1988 UST regulation indicates that petroleum
products can be derived from other materials, such as biomass, plant
material, organic waste, coal, and shale oil.\106\ Petroleum is
comprised of a complex blend of hydrocarbons regardless of its source
material.
---------------------------------------------------------------------------

    \106\ ``40 CFR parts 280 and 281 USTs; Supplement to Proposed
Rule,'' 52 FR 48640 (December 23, 1987).
---------------------------------------------------------------------------

    Many people applied the definition of regulated substance in the
1988 UST regulation to petroleum UST systems only if the petroleum was
derived from crude oil. This final UST regulation clarifies that
petroleum derived from non-crude oil based products, such as green
gasoline, is a regulated substance under 40 CFR part 280. This
clarification is consistent with the preamble to the 1988 UST
regulation, which indicates petroleum is not limited to being derived
from crude oil.
    This final UST regulation also modifies the definition of motor
fuel to better accommodate new motor fuels that may be marketed and
stored in the future. The definition in the 1988 UST regulation listed
motor fuel products. This led to confusion as to whether new fuels,
such as petroleum blended with ethanol or biodiesel, are motor fuels.
This final UST regulation clarifies the definition of motor fuel and
explains that it is any fuel typically used to operate a motor engine.
In addition, EPA received comments to change the motor fuel definition
from petroleum and petroleum-based substances to a complex blend of
hydrocarbons. EPA agrees that using the phrase complex blend of
hydrocarbons eliminates ambiguity; it provides a clearer definition of
motor fuel by including complex blends of hydrocarbons that may not be
petroleum or petroleum-based. EPA is making this change in this final
UST regulation.
Compatibility
    EPA understands that the chemical and physical properties of
ethanol and biodiesel can be more degrading to certain UST system
materials than petroleum alone. As the use of ethanol- and biodiesel-
blended fuels increases, EPA is concerned that not all UST system
equipment or components are compatible with these fuel blends. For
purposes of compatibility, EPA uses the term equipment to mean a group
of components assembled together by the manufacturer. Compatibility can
be determined for all components of a piece of equipment. Compatibility
determinations for equipment are typically useful when an UST system is
newly installed or when a complete piece of equipment is replaced.
Examples of equipment include the piping system, STP assembly, and
automatic shutoff device assembly. A component is considered an
individual piece of an UST system and is typically a single piece of
the equipment. Component compatibility is determined on a piece by
piece basis. A component compatibility determination is typically
needed when performing repairs on an UST system where only parts of a
piece of equipment are replaced. Examples of components include
gaskets, seals, and other individual pieces that form a piece of
equipment.
    Gasoline containing 10 percent or less ethanol (E10) has been used
in parts of the United States for many years. UST equipment and
component manufacturers accommodated the E10 market by producing
compatible equipment and components. According to the Renewable Fuels
Association, ethanol is blended into over 90 percent of all gasoline
sold in the United States,\107\ predominantly as E10. Recently, the
United States has been moving toward use of higher blends of ethanol,
due in part to federal and state laws encouraging increased use of
biofuels. While most UST system equipment and components are compatible
with E10, fuel blends containing greater than 10 percent ethanol do not
have a long history of storage and may not be compatible with certain
materials in existing UST systems. According to a 2011 report published
by the U.S. Department of Energy's Oak Ridge National Laboratory,\108\
some elastomeric materials are particularly affected by intermediate
ethanol blends and certain sealants may not be suitable for any
ethanol-blended fuels. A 2007 report from Underwriters Laboratories
(UL) \109\ evaluated the effect of 85 percent ethanol and 25 percent
ethanol blends on dispenser components. Results indicated some
materials used in the manufacture of seals degraded more when exposed
to 25 percent ethanol test fluid than when exposed to 85 percent
ethanol test fluid. Other literature suggests ethanol fuel blends can
be more aggressive toward certain materials than independent fuel
constituents, with maximum polymer swelling observed at approximately
15 percent ethanol by volume.\110\ Based on this information, this
final UST regulation clarifies the compatibility requirements for
owners and operators storing regulated substances containing greater
than 10 percent ethanol.
---------------------------------------------------------------------------

    \107\ Renewable Fuels Association, Building Bridges to a More
Sustainable Future: 2011 Ethanol Industry Outlook. http://www.ethanolrfa.org/page/-/2011%20RFA%20Ethanol%20Industry%20Outlook.pdf?nocdn=1.
    \108\ Oak Ridge National Laboratory, Intermediate Ethanol Blends
Infrastructure Materials Compatibility Study: Elastomers, Metals,
and Sealants (March 2011).
    \109\ Underwriters Laboratories, Inc., Underwriters Laboratories
Research Program on Material Compatibility and Test Protocols for
E85 Dispensing Equipment (December 2007). Available in the UST
Docket under Docket ID No. EPA-HQ-UST-2010-0651.
    \110\ Westbrook, P.A., Compatibility and Permeability of
Oxygenated Fuels to Materials in Underground Storage and Dispensing
Equipment (January 1999). Available in the UST Docket under Docket
ID No. EPA-HQ-UST-2010-0651.
---------------------------------------------------------------------------

    This final UST regulation also clarifies the compatibility
requirements for owners and operators storing regulated substances
containing greater than 20 percent biodiesel. Although the total use of
biodiesel is significantly less than that of ethanol, biodiesel has

become increasingly available across the United States and may be
incompatible with certain materials in UST systems. For example, pure
biodiesel (B100) has known compatibility issues with certain materials.
According to the U.S. Department of Energy's National Renewable Energy
Laboratory (NREL) Biodiesel Handling and Use Guide, Fourth
Edition,\111\ ``B100 will degrade, soften, or seep through some hoses,
gaskets, seals, elastomers, glues, and plastics with prolonged
exposure. . . . Nitrile rubber compounds, polypropylene, polyvinyl, and
Tygon[supreg] materials are particularly vulnerable to B100.''
---------------------------------------------------------------------------

    \111\ National Renewable Energy Laboratory, Biodiesel Handling
and Use Guide, Fourth Edition, (2009). Available in the UST Docket
under Docket ID No. EPA-HQ-UST-2010-0651.
---------------------------------------------------------------------------

    In contrast, the properties of very low blends of biodiesel, such
as B5 or less, are so similar to those of petroleum diesel that the
American Society for Testing and Materials (ASTM) International
considers conventional diesel that contains up to 5 percent biodiesel
to meet its Standard Specification for Diesel Fuel Oils.\112\ For
biodiesel blends between 5 and 100 percent, there is very little
compatibility information; however, NREL's handling and use guide
concludes that biodiesel blends of B20 or less have less of an effect
on materials and very low blends of biodiesel, such as B5 and B2, ``. .
. have no noticeable effect on materials compatibility.'' \113\ In
addition, fleet service sites have stored B20 in UST systems for years,
and EPA is not aware of compatibility-related releases associated with
those UST systems storing B20. Therefore, this final UST regulation
requires tank owners and operators who store greater than 20 percent
biodiesel in their UST systems demonstrate compatibility of UST
equipment or components by one of the options listed in Sec.  280.32.
---------------------------------------------------------------------------

    \112\ ASTM Standard D975, 2010c, Standard Specification for
Diesel Fuel Oils, ASTM International, West Conshohocken, PA, 2010,
DOI: 10.1520/D0975-10C, www.astm.org.
    \113\ National Renewable Energy Laboratory, Biodiesel Handling
and Use Guide, Fourth Edition, (2009). Available in the UST Docket
under Docket ID No. EPA-HQ-UST-2010-0651.
---------------------------------------------------------------------------

    This final UST regulation retains the requirement for owners and
operators to use UST systems made of or lined with materials that are
compatible with the substance stored in the UST system. It does not
change the compatibility requirement in the 1988 UST regulation, but
does add several options for owners and operators to demonstrate that
their UST systems are compatible with regulated substances containing
greater than 10 percent ethanol, greater than 20 percent biodiesel, or
any other regulated substances identified by the implementing agency.
Owners and operators of these UST systems must meet one of the
following options:

 Use equipment or components that are certified or listed by a
nationally recognized, independent testing laboratory for use with the
fuel stored
 Use equipment or components approved by the manufacturer to be
compatible with the fuel stored

    In addition, owners and operators may use another option determined
by the implementing agency to be no less protective of human health and
the environment than the methods listed above.
    These options provide owners and operators flexibility in
demonstrating compatibility while still protecting human health and the
environment. In the past, owners and operators typically demonstrated
compatibility by using equipment or components certified or listed by a
nationally recognized, independent testing laboratory, such as UL. Many
pieces of UST equipment and components in the ground today were
manufactured before regulated substances containing ethanol or
biodiesel existed and are not approved by nationally recognized,
independent testing laboratories for use with these fuel blends.
Currently, certain tanks and piping have been tested and are listed by
UL for use with higher-level ethanol blends. However, many other pieces
of equipment and components of UST systems, such as leak detection
devices, sealants, and containment sumps, may not be listed by UL or
another nationally recognized, independent testing laboratory for use
with these blends.
    In addition, EPA is not aware of any nationally recognized,
independent testing laboratory that has performed compatibility testing
on UST system equipment or components with biodiesel-blended fuels.
Absent certification or listing from a nationally recognized,
independent testing laboratory or other verification that the equipment
or component may be used with anything other than conventional fuels,
the suitability of an UST system for use with biodiesel blends is
questionable. As a result, EPA is providing several options for
demonstrating compatibility to reduce the risk of releases due to
material incompatibility. Owners and operators storing regulated
substances blended with greater than 10 percent ethanol or greater than
20 percent biodiesel must meet the compatibility requirements before
storing those regulated substances.
    For equipment and components tested and approved by a nationally
recognized, independent testing laboratory, owners and operators may
demonstrate compatibility solely by keeping records of the equipment
and components. In this instance, the testing laboratory's listing,
labeling, or approval demonstrates the equipment or component's
suitability to be used with the regulated substance stored. This means
owners and operators will be able to demonstrate compatibility by
retaining equipment or component records.
    Owners and operators may also demonstrate compatibility by
obtaining manufacturer's approval of the equipment or component. The
manufacturer's approval must be in writing and include an affirmative
statement that the equipment or component is compatible with the fuel
blend stored. The manufacturer's approval must also specify the range
of fuel blends for which the equipment or component is compatible. The
manufacturer's approval must be issued from the equipment or component
manufacturer, not another entity, such as the installer or distributor.
A manufacturer's approval enables owners and operators to demonstrate
compatibility for equipment or components not approved for use by a
nationally recognized, independent testing laboratory. It also provides
implementing agencies with verification that the equipment or component
is compatible with the fuel stored.
    Implementing agencies may approve other options for complying with
the compatibility requirement for regulated substances containing
greater than 10 percent ethanol or greater than 20 percent biodiesel if
they are no less protective of human health and the environment than
manufacturer's approval or a listing, labeling, or approval by a
nationally recognized, independent testing laboratory. This provides
implementing agencies with flexibility to consider other approaches
they determine to be appropriate. For example, in lieu of an
affirmative compatibility determination, implementing agencies may
allow secondarily contained UST systems using interstitial monitoring
to store regulated substances containing greater than 10 percent
ethanol or 20 percent biodiesel. The rationale is that a leak from the
primary containment will be contained by secondary containment and
detected by interstitial monitoring equipment before regulated
substances reach the environment.
    Although these options for demonstrating compatibility apply to

UST systems storing regulated substances containing greater than 10
percent ethanol and greater than 20 percent biodiesel, this final UST
regulation extends the compatibility demonstration requirement to other
regulated substances identified by implementing agencies. This provides
implementing agencies with the flexibility to require a demonstration
of compatibility if there are concerns about other existing regulated
substances and when new regulated substances, such as biobutanol, enter
the fuel market.
    EPA received comments about the difficulty in determining whether
some UST system equipment or components currently installed in the
ground are compatible with ethanol and biodiesel blended fuels. In
fact, EPA thinks there are many cases where some equipment or
components of UST systems in the ground as of 2014 are not compatible
with newer fuels. Unless owners and operators specifically requested
all of the UST system be compatible with higher ethanol or biodiesel
blends, installers probably installed lower cost options for certain
UST system equipment, such as a STP assembly, which may not be
compatible with some newer fuels. Non-compatible equipment or
components, such as equipment in containment sumps, are usually easier
to upgrade or replace than the tank or piping because they are
typically located in areas not requiring excavation. In addition, EPA
provides various options for meeting the compatibility requirement. To
protect the environment from releases of ethanol blends greater than 10
percent, biodiesel blends greater than 20 percent, or any other
regulated substance identified by the implementing agency, owners and
operators must do one of the following:

 Demonstrate the UST system is compatible through certification
or listing by a nationally recognized, independent testing laboratory
or manufacturer approval
 Replace equipment or components not compatible or for which
compatibility cannot be determined
 Use another option determined by an implementing agency to be
no less protective of human health and the environment
 Not store these regulated substances in the UST system

    These options provide owners and operators with adequate
flexibility when demonstrating compatibility and determining whether
certain regulated substances may be stored in the UST system.
    Some commenters suggested adding other options owners and operators
could use for determining compatibility. One suggested addition was
certification by a professional engineer (P.E.), who would perform an
on-site UST system analysis to determine compatibility. In order to
perform this analysis, a P.E. would need to know the manufacturer and
model of all UST system equipment or components. Because this
information cannot be entirely obtained through visual observation, a
P.E. would need to obtain records of the equipment to make an
assessment and then search for relevant equipment listings or
manufacturer certifications. This means a P.E. certification is
equivalent to the options in this final UST regulation. EPA does not
object to a P.E. performing a records review; however, we think it is
impractical for a P.E. to perform a visual assessment of an UST system
and make a compatibility determination in the absence of equipment
records and certifications. Therefore, EPA is not explicitly allowing a
P.E. to make a compatibility determination in the absence of UST system
information and compatibility certifications.
    Some commenters suggested EPA use a tiered approach to demonstrate
compatibility for UST systems storing regulated substances containing
greater than 10 percent ethanol and greater than 20 percent biodiesel,
and choose one method of determining compatibility. EPA interprets
tiered approach to mean requiring the more stringent option first,
which is listing by a nationally recognized, independent testing
laboratory. If the more stringent option is not available, the second
tier would allow manufacturer's approval. This final UST regulation
does not include a tiered approach because EPA thinks using this method
for demonstrating compatibility makes the final UST regulation too
complicated for implementing agencies as well as owners and operators.
Even if the UST system equipment or components have a listing from a
nationally recognized, independent testing laboratory, we do not always
know whether compatibility testing was part of the listing. EPA thinks
manufacturers will only issue written claims of compatibility if they
have sufficient information to support such claims.
    The 2011 proposed UST regulation required owners and operators
retain these records:

 For all new and replaced equipment or components--so it is
easier to demonstrate whether or not the equipment or component is
compatible with the regulated substance stored
 For UST systems storing greater than 10 percent ethanol,
greater than 20 percent biodiesel, or other regulated substance
identified by the implementing agency--to demonstrate the UST system is
compatible with these regulated substances or compliance with
alternatives allowed by the implementing agency

    However, after careful consideration of comments, this final UST
regulation does not require owners and operators maintain records for
all new and replaced equipment. EPA decided it is too onerous for
owners and operators to maintain this information, which may not
transfer when facilities change ownership.
    To make it easier for UST owners and operators to comply with the
compatibility requirement, this final UST regulation requires that
owners and operators notify the implementing agency at least 30 days
before switching to a regulated substance containing greater than 10
percent ethanol, greater than 20 percent biodiesel, or any other
regulated substance identified by the implementing agency. This
notification prior to switching fuels gives the implementing agency an
opportunity to inquire about the compatibility of the UST system before
owners and operators begin storing the new regulated substance. This
notification requirement already exists in some states. For example,
Colorado, North Carolina, and South Carolina require UST owners submit
a completed compatibility checklist prior to storing some newer fuel
blends. To notify, owners and operators may contact implementing
agencies via EPA's Web site at www.epa.gov/oust/.
    This final UST regulation requires owners and operators maintain
records that demonstrate compliance with Sec.  280.32(b) for as long as
the UST system stores greater than 10 percent ethanol, greater than 20
percent biodiesel, or other regulated substances identified by the
implementing agency. Owners and operators must retain records for these
regulated substances in order to meet this compatibility requirement.
    The 2011 proposed UST regulation preamble included an extensive
list of UST system equipment and components that must be compatible but
that list was not in the 2011 proposed UST regulation. Based on
commenter input, this final UST regulation includes a list of UST
system equipment and components that owners and operators

must demonstrate to be compatible when using the manufacturer's
approval and certification or listing options. The UST system equipment
or components that owners and operators must demonstrate to be
compatible are those related to the tank, piping, containment sumps,
pumping equipment, release detection equipment, spill prevention
equipment, and overfill prevention equipment. These items are a subset
of an UST system, as defined by Sec.  280.12, which, if incompatible,
could lead to a release.
    This changes protect human health and the environment from
potential releases from incompatible UST systems. These changes are not
overly burdensome, nor do they require costly retrofits. They give
owners and operators flexibility, yet provide EPA with confidence that
UST systems are compatible with new fuel blends when owners and
operators use one or more of the options to determine compatibility.
This final UST regulation provides owners and operators with certainty
about which options are allowed for demonstrating UST system
compatibility with the substances stored.
    Finally, EPA is removing from the compatibility section of the 1988
UST regulation API Recommended Practice 1627, which is a code of
practice related to methanol-blended fuels. EPA included this code of
practice in the 1988 UST regulation to help owners and operators
demonstrate compliance with the compatibility requirement for methanol-
blended fuels. However, EPA's subsequent review of this code revealed
no substantial information about determining compatibility of UST
systems with methanol-blended fuels. In August 2010, API published an
updated version of API Recommended Practice 1626, which is a code of
practice for storing and handling of ethanol-blended fuels. In the 2011
proposed UST regulation, EPA removed this code of practice because the
proposed UST regulation provided specific requirements about how owners
and operators may demonstrate compatibility for their UST systems.
However, because commenters pointed out the code of practice includes
requirements for demonstrating compatibility of UST systems with
ethanol-blended fuels, EPA is including it as a code of practice that
may be useful in complying with the compatibility section in this final
UST regulation.
5. Improving Repairs
Changes to the Definition of Repair
    This final UST regulation adds these UST system components to the
definition of repair: piping; spill prevention equipment; overfill
prevention equipment; corrosion protection equipment; and release
detection equipment. The 1988 UST regulation definition of repair used
the generic term UST system component and provided no detail about what
an UST system component is. By adding these UST system components, EPA
is making it clear that these specific components are subject to the
repairs allowed section of the final UST regulation. This means owners
and operators performing repairs on these UST system components must
follow the repairs allowed section (Sec.  280.33).
    Owners and operators commonly fix UST components that have not
caused a release of regulated substance from the UST system. However,
the repair definition in the 1988 UST regulation did not consider these
types of fixes as repairs since they were not associated with releases.
This final UST regulation removes the link that a repair is only
associated with a release, requiring owners and operators meet the
repairs allowed section (Sec.  280.33) when fixing UST system
components that have failed to function properly, even if they have not
caused a release of product from the UST system. This change means
owners and operators must perform repairs in accordance with a code of
practice developed by a nationally recognized association or
independent testing laboratory and test or inspect the repaired
equipment. This change ensures repair activities separate from a
release are conducted properly. For example, under the 1988 UST
regulation, fixing a cathodic protection system was not considered a
repair. In this final UST regulation, this activity is considered a
repair that must meet the repair requirements in Sec.  280.33.
    EPA proposed adding a suspected release as part of the definition
of repair, so repairs associated with suspected releases are covered
under the repair definition. However, based on comments received, EPA
is not including suspected release as part of the definition of repair
in this final UST regulation because that circumstance is already
covered under the ``failed to function properly'' language in the
repair definition. EPA disagrees with commenters suggesting EPA remove
the ``failed to function properly'' language because EPA thinks repairs
need to occur both when a release occurs and when UST system equipment
fails to function properly.
    Finally, based on comments received, EPA is adding clarifying
language to the repair definition to ensure UST system component
repairs restore components to proper operating condition.
Tests or Inspections After Repairs
    This final UST regulation adds new testing or inspection
requirements for spill, overfill, and secondary containment equipment
following a repair and allows owners and operators up to 30 days
following the repair to test or inspect the repaired UST component. EPA
acknowledges that some secondary containment can be tested through
normal release detection if vacuum, pressure, or liquid-filled methods
of interstitial monitoring are used as the method of release detection.
In these cases, the secondary containment test occurs automatically,
making it unnecessary to perform additional testing.
    EPA agrees with commenters about using the term inspecting rather
than testing as it relates to the operability of overfill prevention
equipment. Performing inspections will avoid potentially overfilling
the tank while ensuring the overfill prevention equipment operates
properly. EPA is revising the overfill prevention equipment test to be
an overfill prevention equipment inspection.
    EPA agrees with commenters who indicated that testing or inspection
following repair should only apply to the component or components
repaired and not to the entire UST system. This final UST regulation
requires testing or inspection, as appropriate, following a repair only
for those UST system components repaired and not to all components at
the UST site. In addition, EPA is requiring owners conduct a test of
the secondary containment area (including containment sumps) only if
the secondary containment area is repaired and that area is used for
interstitial monitoring. Note that all secondary containment areas must
use interstitial monitoring for tanks and piping installed 180 days
after the effective date of this final UST regulation (see section A-2,
Secondary Containment for additional information). Repairs to the
primary containment areas of a tank or piping may be tested using other
options for tanks and piping listed in the repairs section.
    Several commenters expressed concern that replacing UST system
components that have not yet failed to function properly would trigger
the repair requirements. If owners and

operators choose to replace UST system components, those components
must meet the installation requirements in Sec.  280.20(d). Therefore,
replaced UST system components do not have to meet the repair
requirements in Sec.  280.33.
    EPA solicited comments about whether to consider requiring tests or
inspections of spill, overfill, and secondary containment areas before
returning the UST system to service, rather than within 30 days of the
repair. Many commenters were supportive of requiring testing or
inspection before bringing the UST system back into service. However,
this final UST regulation allows owners and operators up to 30 days
following the repair to conduct testing or inspections. EPA thinks
owners and operators need to test or inspect the repaired component as
soon as possible following the repair. However, EPA understands there
are circumstances where testing or inspection before returning the UST
system to service may be impractical (for example, weather conditions,
remote locations, or the need to schedule a test). In these examples,
the UST system would remain out of service until the test or inspection
is completed, resulting in unnecessary UST system down time for owners
and operators. Thirty days allows some flexibility for completing the
test or inspection, while allowing the UST system to return to service.
6. Vapor Monitoring and Groundwater Monitoring
    This final UST regulation retains vapor monitoring and groundwater
monitoring as methods of release detection for tanks and piping
installed before the effective date of this final regulation, as long
as owners and operators demonstrate proper installation and performance
through a site assessment. In addition, this final UST regulation
revises the recordkeeping requirement in Sec.  280.45, which means
owners and operators must maintain site assessments according to Sec.
280.43(e)(6) and (f)(7) for as long as these release detection methods
are used.
    In the 2011 proposed UST regulation, EPA phased out vapor
monitoring and groundwater monitoring over a five year time frame.
However, EPA received significant comments in support of retaining
these release detection methods. Many commenters presented
circumstances where EPA should allow owners and operators to use vapor
monitoring and groundwater monitoring such as: Until the system is
replaced and the secondary containment requirement is triggered; or
when the UST implementing agency already has or will establish
additional criteria for use. In addition, commenters suggested EPA
continue allowing certain UST systems to use vapor monitoring and
groundwater monitoring, specifying emergency generator tanks, certain
high-throughput UST systems, or specific low-throughput systems. EPA
also received numerous requests to expand our proposed release
detection options for airport hydrant fuel systems and field-
constructed tanks to allow the use of vapor monitoring or groundwater
monitoring. Under the 2011 proposed UST regulation, these options are
not acceptable release detection options for owners and operators of
airport hydrant systems and field-constructed tanks.
    EPA agrees with commenters that owners and operators of emergency
generator tanks, certain high-throughput UST systems, and specific low-
throughput systems could benefit from continued use of vapor monitoring
and groundwater monitoring until owners and operators replace their UST
systems to meet the secondary containment requirement necessitating
interstitial monitoring. EPA thinks that requiring owners and operators
to maintain the site assessment will increase environmental protection
appreciably beyond the 1988 UST requirements. Implementing agencies
have noted that site assessments often do not exist for vapor or
groundwater monitoring. Thus, by requiring site assessment records, we
will ensure vapor and groundwater monitoring wells are properly located
and function as effective release detection. EPA also thinks that
allowing these release detection options to be customized and used for
airport hydrant systems and field-constructed tanks will make it easier
for owners and operators to comply with the release detection
requirement.
    Therefore, this final UST regulation continues to allow vapor and
groundwater monitoring as long as owners and operators maintain a site
assessment that demonstrates the release detection method meets the
requirements in this final UST regulation. Owners and operators of
airport hydrant systems and field-constructed tanks will have to meet
the requirements for vapor monitoring and groundwater monitoring
described in subpart K (see section C-2 for additional information).
    The 1988 UST regulation defined criteria for the use of both
release detection methods as explicitly as possible, given the large
variation of site-specific conditions at UST sites across the country.
EPA supports UST implementing agencies' efforts to better define site
assessment criteria specific to their local geology in addition to what
is required in the UST regulation. EPA also acknowledges and supports
several UST implementing agencies' efforts in conducting construction
certification and recertification inspections. However, EPA has not
analyzed the economic burden construction certification and
recertification inspections would place on UST implementing agencies
and potentially UST system owners and operators. Therefore, this final
UST regulation does not require installation inspections,
certification, or recertification inspections of monitoring wells. EPA
expects UST implementing agencies will continue reviewing and accepting
site assessments according to their program policies.
    In the event of a confirmed release at an UST site, vapor
monitoring and groundwater monitoring are no longer acceptable options
for release detection unless a new site assessment for the release
detection method is conducted. If a release is confirmed, an owner and
operator will have to remediate the site according to 40 CFR part 280,
subpart F. Following site remediation, and as long as replacement of
the UST system does not trigger the secondary containment requirement,
an owner and operator must obtain a new site assessment to verify
appropriate use of these methods, if the owner and operator chooses to
continue using vapor monitoring or groundwater monitoring as the
primary release detection method. Otherwise, owners and operators must
use another method of release detection according to subpart D or
subpart K.
    At the time of the 2011 proposed UST regulation, EPA estimated
approximately 5 percent of all active UST systems were using vapor
monitoring or groundwater monitoring to comply with release monitoring
requirements.\114\ Commenters confirmed that 5 percent of vapor
monitoring and groundwater monitoring was accurate. EPA also confirmed
that although the methods are used very infrequently in the majority of
jurisdictions, there is considerably high use in certain states.
Arkansas, Louisiana, and Mississippi have a significant number of
owners and operators using vapor monitoring, groundwater monitoring, or
a combination of the two methods.

Estimated use of both methods in these states is 29 percent, 12
percent, and 65 percent, respectively. Confirmation of high use in one
particular geographic area of the country influenced EPA's decision to
continue allowing use of these methods.
---------------------------------------------------------------------------

    \114\ E\2\, Incorporated, memoranda and analyses submitted under
Contract EP-W-05-018, U.S. Environmental Protection Agency.
Underground Storage Tanks/Leaking Underground Storage Tanks
Analytical And Technical Support. These supporting materials are
located in the docket EPA-HQ-UST-2011-0301.
---------------------------------------------------------------------------

    EPA agrees with comments about major benefits for UST system owners
and operators to use backup release detection, whether it is vapor
monitoring, groundwater monitoring, or another method. However, neither
the 1988 UST regulation nor this final UST regulation requires a
secondary 30 day release detection method.
    EPA discussed several issues in the 2011 proposed UST regulation
that prompted our proposal to no longer allow vapor monitoring and
groundwater monitoring as primary methods of release detection.
However, the requirement in this final UST regulation for owners and
operators to maintain the record of a site assessment for as long as
the method is used will address most of these issues.
    If the site assessment is available when inspecting USTs, UST
implementing agencies can confirm proper installation and use of
monitoring wells. For example, if inspectors find what they believe to
be insufficient numbers of wells or wells improperly located to
sufficiently monitor all portions of the tank or piping that routinely
contain product, inspectors will be able to reference the site
assessment to determine adequacy of the wells.
    The site assessment will also help UST implementing agencies
determine whether certain conditions, which allow users to switch
between vapor monitoring and groundwater monitoring due to seasonal
variations, have been met. Monitoring wells must be properly
constructed and installed to meet all criteria in Sec.  280.43(e) and
(f). Wells used for vapor monitoring must allow vapors to collect;
wells used for groundwater monitoring must be screened to prevent
clogging and intercept the water table at both high and low groundwater
conditions while being sealed from the ground to the top of the filter
pack. Information regarding acceptability of the same wells used for
both methods of release detection must be documented in the site
assessment.
    In the 2011 proposed UST regulation, EPA discussed issues that were
specific to vapor monitoring. These issues will be addressed when
owners and operators maintain the site assessment for as long as the
method is used. The site assessment will contain information on site
conditions, such as whether porosity of the surrounding soil is
sufficient. The site assessment will confirm that vapors to be
monitored will be unaffected by groundwater, rainfall, or soil
moisture. Perhaps the most crucial information in the site assessment
is the background contamination level at the site. This will allow
owners, operators, and implementing agencies to determine whether that
level interferes with monitoring methods. It also marks the threshold
for determining a release has occurred when monitoring for petroleum
hydrocarbons.
    Maintaining the site assessment also addresses specific groundwater
monitoring issues EPA discussed. Groundwater at times can be more than
20 feet from the ground surface, due to seasonal water table
variations. This can result in the depth to groundwater requirement not
being met. Unless an analysis is performed and valid documentation
regarding use of the wells for vapor monitoring during low water table
conditions is included in the site assessment, the wells will be
restricted for groundwater monitoring use only.
    In cases where there is no site assessment or an assessment does
not sufficiently ensure requirements in Sec.  280.43(e) or (f) are met,
UST system owners and operators must reassess the site and maintain
documentation required in Sec.  280.43(e)(6) and (f)(7) in order to
continue using groundwater or vapor monitoring as a method of release
detection. At a minimum, a professional engineer or professional
geologist, or equivalent licensed professional with experience in
environmental engineering, hydrogeology, or other relevant technical
discipline acceptable to the UST implementing agency must sign the new
site assessment.
    EPA understands that in Arkansas, Louisiana, and Mississippi, where
the methods are commonly used and account for the majority of use in
the country, most UST system owners and operators or the UST
implementing agency have sufficient documentation of the site
assessment. This means most owners and operators in those states will
not need to conduct a new site assessment to comply with this final UST
regulation. Owners and operators in other areas of the country may need
to conduct a site assessment in order to continue using vapor
monitoring or groundwater monitoring.
    This final UST regulation also addresses another major aspect
associated with vapor monitoring and groundwater monitoring methods.
Equipment that is used as part of these release detection methods
requires proper operation and maintenance in order to provide optimal
monitoring results. Operation and maintenance requirements for
electronic and non-electronic equipment are addressed in the release
detection equipment testing requirement discussed in section B-5 and
the walkthrough inspection requirement in section B-1, respectively.
7. Interstitial Monitoring Results, Including Interstitial Alarms,
Under Subpart E
    This final UST regulation clarifies UST owners' and operators'
responsibilities regarding interstitial monitoring results, including
alarms, under 40 CFR part 280, subpart E. Specifically, EPA is making
these changes:

 Sec.  280.50(b)--adding liquid in interstitial spaces of
secondarily contained UST systems as an example of an unusual operating
condition and adding to the list of criteria for not being required to
report a suspected release that any liquid in the interstitial space
not used as part of the interstitial monitoring method must be removed
 Sec.  280.50(c)--clarifying that an alarm during release
detection monitoring is subject to the reporting requirement and
describing exceptions to the reporting requirement
 Sec.  280.52(a)--adding owners and operators as appropriate
must conduct secondary containment testing, and clarifying actions UST
owners and operators must take if a test confirms a leak into the
interstitial space or indicates a release to the environment

    The 1988 UST regulation implicitly covered interstitial monitoring
when reporting suspected releases because it was a method of release
detection. This final UST regulation makes changes to explicitly cover
interstitial monitoring and reinforce that a leak into an interstitial
space of a secondarily contained UST system also indicates a potential
threat to the environment; leaks must be investigated, addressed, and
as necessary, reported.
    This final UST regulation requires interstitial monitoring for all
new or replaced tanks and piping (see section A-2, Secondary
Containment). As new systems are installed, interstitial monitoring
will become more widely used as a method of release detection. With
this in mind, EPA wants UST owners and operators to clearly understand
how interstitial monitoring results, including interstitial alarms,
must be handled.
    In the 1988 UST regulation, EPA indicated that product or water in
the

interstice, and alarms signifying the presence of those conditions, are
unusual operating conditions and must be investigated appropriately.
However, EPA did not indicate how UST owners and operators were to
address discrepancies with interstitial spaces. As a result, some UST
owners and operators were uncertain about how best to respond to
interstitial monitoring results and alarms associated with interstitial
monitoring that indicate a release may have occurred. To alleviate
uncertainty for owners and operators, EPA provides information below
about interstitial monitoring and responses to alarms.
    This final UST regulation revises Sec.  280.50(b) by adding
interstitial spaces of secondarily contained UST systems and clarifying
the presence of liquid in this space as an unusual operating condition
unless the liquid is used for interstitial monitoring or meets the
requirements described in Sec.  280.43(g)(2)(iv). Water in the
interstitial space (presumably from a breach in the secondary wall) and
product in the interstitial space (presumably from a breach in the
primary wall) are the two typically encountered liquids discovered in
the interstice. However, EPA is using the broader term liquid to cover
water, product, or other substances in the liquid-phase in the
interstitial space. Any liquid in this space not used for interstitial
monitoring or not meeting the requirements described in Sec.
280.43(g)(2)(iv) indicates there is an UST system problem that needs to
be resolved. As a result, EPA is specifying this as an unusual
operating condition and is requiring UST owners and operators
investigate and address it.
    Several commenters suggested changes to Sec.  280.50(b) of the 2011
proposed UST regulation. Suggestions included: Deleting that water or
product in the interstice is reportable and clarifying the requirement
that the unexplained presence of water or product is an unusual
operating condition. Based on comments, EPA in Sec.  280.50(b) of this
final UST regulation is using the term liquid, rather than water or
product, to address any liquid in the interstitial space. To add
clarity to this final UST regulation, EPA is also restructuring the
section to provide subsections with separate examples of unusual
operating conditions. This final UST regulation also allows owners and
operators to not remove or report liquid under two conditions: Within
secondary barriers described in Sec.  280.43(g)(2)(iv), as long as
interstitial monitoring is not rendered inoperative, or the liquid is
used as part of the interstitial monitoring method.
    EPA is clarifying in Sec.  280.50(c) that an alarm during release
detection monitoring, which indicates a potential release or compromise
of the interstitial space, is subject to the reporting requirement. UST
owners and operators must appropriately address all release detection
monitoring alarms. For example, some interstitial monitoring systems
will trigger an alarm, which indicates a potential release or that the
interstitial space has been compromised. In subpart E, EPA is adding
interstitial monitoring to emphasize its importance because the
secondary containment requirement for new and replaced systems in
section A-2 will increase the use of interstitial monitoring. UST
owners and operators are not required to report alarms from defective
system equipment or components or alarms that are investigated and
determined to be a non-release. Also, UST owners and operators do not
have to report leaks, which are contained in the interstitial space;
but owners and operators must investigate and repair problems. Except
as provided in Sec.  280.43(g)(2)(iv), any liquid in the interstitial
space not used as part of the interstitial monitoring method, such as
brine filled, must be removed.
    Several commenters misunderstood EPA's discussion regarding
reporting alarms. In the 2011 proposed UST regulation, EPA intended
that owners and operators need to investigate all alarms, but only
report confirmed releases and suspected releases that could not be
ruled out by an investigation. Commenters suggested these changes to
EPA's 2011 proposed UST regulation at Sec.  280.50(c): Deleting
language pertaining to alarms; changing language regarding the time
allowed to repair, recalibrate, or replace defective system equipment;
and including an exception for reporting alarms that have been
confirmed to be false alarms. Based on comments, EPA in Sec.  280.50(c)
of this final UST regulation is expanding and describing exceptions to
reporting monitoring results, including investigation of an alarm from
a release detection method that indicates a release may have occurred.
    EPA is adding secondary containment testing, as appropriate, to the
release investigation and confirmation steps in Sec.  280.52(a) of the
final UST regulation. EPA thinks it is important to clarify actions UST
owners and operators must take if a test confirms a leak into the
interstitial space or indicates a release has occurred. If a leak into
the interstice is confirmed, an UST owner and operator must correct or
address the problem. In addition to options listed in the 1988 UST
regulation, this final UST regulation includes closure as an option
when an owner and operator confirms a release. Nothing in this final
UST regulation changes the requirement in subpart F for an UST owner
and operator to take corrective action if a release occurred.
    In the 2011 proposed UST regulation, EPA suggested that UST owners
and operators follow integrity test requirements, now referred to as
secondary containment testing, of the interstitial area. Many
commenters noted that tank tightness testing or line tightness testing
may be more appropriate tests to confirm a suspected release under
certain circumstances, and UST system owners and operators should be
allowed the choice of determining which test to use. EPA agrees and is
revising Sec.  280.52(a) to indicate use of secondary containment
testing as appropriate.
    EPA received several comments about the terms release and leak used
throughout the 2011 proposed UST regulation and the 1988 UST
regulation. Historically, EPA used these terms interchangeably. As a
result of EPA's new secondary containment and interstitial monitoring
requirement (see section A-2, Secondary Containment), there is now a
subtle but important distinction between the terms. The term release is
defined in the Solid Waste Disposal Act. EPA provides the same
definition of release in the UST regulation at Sec.  280.12. Release
means any spilling, leaking, emitting, discharging, escaping, leaching
or disposing from an UST into groundwater, surface water or subsurface
soils. A release always reaches the environment. The term leak in this
final UST regulation is a more general term that includes both cases of
when a regulated substance enters into a contained area (such as
secondary containment) but has not yet reached the environment and when
a regulated substance reaches the environment (a release). Therefore,
the term release is a subset of the more general term leak. Note that
leaks and releases have investigation and reporting requirements in
subpart E.
    As a result of distinguishing between a leak and a release, EPA is
clarifying the definition of release detection. The 1988 UST regulation
defined release detection as determining whether a release of a
regulated substance occurred from the UST system into the environment
or into the interstitial space between the UST system and its secondary
barrier or secondary

containment around it. This final UST regulation revises the definition
of release detection to clarify regulated substances entering into the
interstitial space are leaks instead of releases. This final UST
regulation defines release detection as determining whether a release
of a regulated substance occurred from the UST system into the
environment or a leak occurred into the interstitial space between the
UST system and its secondary barrier or secondary containment around
it. This change allows EPA to continue to use the term release
detection as it applies to both leaks and releases.

E. General Updates

1. Incorporate Newer Technologies
    Since EPA promulgated the 1988 UST regulation, newer tank, piping,
and release detection technologies have been developed and are being
used. EPA is incorporating several of these newer technologies in this
final UST regulation. In addition, because the 1988 UST regulation
closure requirements unintentionally restrict use of a newer tank
within a tank technology, EPA is revising closure requirements to
provide additional flexibility for implementing agencies to allow
field-constructed tank technologies that construct a tank within an
existing closed tank. However, EPA is not specifically including field-
constructed tank within a tank technologies in the new tank standards
section in Sec.  280.20 of the final UST regulation, because the tank
construction technologies currently covered in this section include
both factory constructed and field-constructed technologies. Note that
Sec.  280.20(d) requires new UST systems, including tank within a tank
technologies, to be properly installed according to a code of practice
developed by a nationally recognized association or independent testing
laboratory and the manufacturer's instructions.
Clad and Jacketed Tanks
    This final UST regulation adds steel tanks that are clad or
jacketed with a non-corrodible material to the list of specific new
tank design and construction options for UST systems. EPA estimates 10
percent of regulated tanks today are jacketed with a non-corrodible
material and 18 percent are clad with a non-corrodible material.\115\
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    \115\ E\2\, Incorporated, memoranda and analyses submitted under
Contract EP-W-05-018, U.S. Environmental Protection Agency.
Underground Storage Tanks/Leaking Underground Storage Tanks
Analytical And Technical Support. These supporting materials are
located in the docket EPA-HQ-UST-2011-0301.
---------------------------------------------------------------------------

    The 1988 UST regulation allowed a steel-fiberglass-reinforced-
plastic composite tank (also called a fiberglass clad tank), but did
not specifically include other non-corrodible claddings. In addition to
fiberglass, manufacturers in 2014 are using other non-corrodible
materials claddings for steel tanks, which are listed by UL standard
1746, External Corrosion Protection Systems for Steel Underground
Storage Tanks. These tank technologies are effective at preventing
corrosion of the portion of the steel tank shell in contact with the
ground. EPA considers a cladding to be a non-corrosive dielectric
material, bonded to a steel tank with sufficient durability to prevent
external corrosion during the tank's life.
    Because they were not commonly used at the time, EPA did not
include jacketed tanks in the 1988 UST regulation. These tanks are now:
More commonly used; UL 1746 listed for external corrosion protection;
and effective in preventing corrosion of the steel tank shell. EPA
considers the tank jacket to be a non-corrosive dielectric material
that: is constructed as secondary containment or jacketed around a
steel tank; has sufficient durability to prevent external corrosion of
the steel tank shell during a tank's life; and prevents a regulated
substance released from the primary steel tank wall from reaching the
environment.
Non-Corrodible Piping
    The 1988 UST regulation allowed fiberglass-reinforced plastic
piping, but did not specifically include other non-corrodible piping
options such as flexible plastic piping. Both fiberglass and flexible
plastic piping are listed under the UL 971 standard, Nonmetallic
Underground Piping for Flammable Liquids. Non-corrodible piping not
made of fiberglass-reinforced plastic (in particular, flexible plastic
piping) was installed at UST sites beginning in the 1990s and has
evolved over the past 20 years. Flexible plastic piping is made of
various non-corrodible materials, such as polyethylene and
polyurethane. EPA estimates at least 13 percent of regulated piping
currently installed is made of non-corrodible materials that are not
fiberglass-reinforced plastic.\116\ This final UST regulation revises
fiberglass-reinforced piping to be non-corrodible piping and allows UST
owners and operators to install other types of non-corrodible piping,
such as flexible plastic, without requiring implementing agencies to
make a determination on the suitability of those materials.
---------------------------------------------------------------------------

    \116\ E\2\, Incorporated, memoranda and analyses submitted under
Contract EP-W-05-018, U.S. Environmental Protection Agency.
Underground Storage Tanks/Leaking Underground Storage Tanks
Analytical And Technical Support. These supporting materials are
located in the docket EPA-HQ-UST-2011-0301.
---------------------------------------------------------------------------

Release Detection Technologies
    The 1988 UST regulation allowed UST owners and operators to use
other methods that meet release detection performance criteria listed
at Sec.  280.43(h). Although continuous in-tank leak detection (CITLD)
and SIR were allowed under Sec.  280.43(h), EPA is including both by
name and providing specific performance criteria in this final UST
regulation for the reasons described below.
CITLD
    The 1988 UST regulation allowed ATG systems as a recognized method
of release detection. However, ATG systems were generally listed with
performance requirements consistent with performing a static test. ATG
systems rely on system down time and the absence of product delivery or
dispensing activities to perform release detection. In static testing
mode, an ATG system analyzes product level and determines whether a
leak is present during that down time. UST owners and operators also
use ATG systems as a means of continually monitoring tanks for
potential releases. CITLD has evolved as a reliable means of providing
release detection equivalent to other methods specified in Sec.
280.41. Within this category of methods, this final UST regulation
allows continuous in-tank methods where the system incrementally
gathers measurements to determine a tank's leak status within the 30-
day monitoring period.
    One commenter asked EPA to further clarify the term CITLD. That
commenter said EPA presented language in the 2011 proposed UST
regulation that confused CITLD, continuous statistical leak detection
(CSLD), and SIR because each is a statistically based release detection
method. EPA agrees with the commenter and is clarifying use of the term
CITLD, which encompasses all statistically based methods where the
system incrementally gathers measurements on an uninterrupted or nearly
uninterrupted basis to determine a tank's leak status. Currently, there
are two major groups that fit into this category: CSLD (also referred
to as continuous automatic tank gauging methods) and continual
reconciliation. Both groups typically use sensors permanently installed
in the tank to obtain inventory measurements. They are combined with a
microprocessor in

the ATG system or other control console that processes the data.
Continual reconciliation methods are further distinguished by their
connection to dispensing meters that allow for automatic recording and
use of dispensing data in analyzing tanks' leak status. SIR, which we
describe below, is not a continually operating method that fits into
the CITLD category.
    This final UST regulation formally recognizes CITLD as a release
detection method in Sec.  280.43(d). Per Sec.  280.41, a conclusive
pass or fail result must be obtained within the 30-day monitoring
period. All monitoring records must be maintained according to Sec.
280.45. Another method of release detection is required in the event of
an inconclusive result. For example, in the event of an inconclusive
result, UST owners and operators may perform an in-tank static test
using an ATG system or use another method of release detection.
SIR
    This final UST regulation adds SIR as a release detection method
and provides performance criteria for its use. SIR must:
     Report a quantitative result with a calculated leak rate;
     Be capable of detecting a leak rate of at least 0.2 gallon
per hour or a release of 150 gallons within a 30-day period with a
probability of detection of not less than 0.95 and a probability of
false alarm of no greater than 0.05; and
     Use a threshold that does not exceed one-half the minimum
detectable leak rate.
    A quantitative result with a calculated leak rate is necessary to
effectively perform release detection using SIR. Some SIR methods are
qualitative based methods that simply provide a result of pass or fail
without any additional information for UST owners and operators to
gauge the validity of reported results. Based on information in the
NWGLDE list,\117\ approximately 85 percent of SIR methods listed are
quantitative-based methods. Many state UST implementing agencies
already only allow quantitative methods. This final UST regulation only
allows quantitative SIR as an option for meeting the release detection
requirement.
---------------------------------------------------------------------------

    \117\ National Work Group On Leak Detection Evaluations' List Of
Leak Detection Evaluations For Storage Tank Systems: http://www.nwglde.org/.
---------------------------------------------------------------------------

    Consistent with the performance criteria described in the other
methods option for release detection, this final UST regulation
maintains the performance standards of a 0.2 gallon per hour release or
a release of 150 gallons within a 30-day period with a probability of
detection of 0.95 and a probability of false alarm of 0.05. The 2011
proposed UST regulation did not include the additional standard of 150
gallons within a 30-day period for SIR. EPA agrees with the commenter
who noted the importance of the 150 gallons criteria if SIR methods are
used for monitoring piping for release detection; as a result, we are
retaining this performance standard for SIR in the final UST regulation
because EPA and some other implementing agencies allow UST system
owners and operators to use SIR for piping release detection.
    Like other release detection methods, SIR must be capable of
detecting a release of 0.2 gallon per hour or less with a probability
of detection (Pd) of at least 0.95 and probability of false alarm (Pfa)
of no more than 0.05. In a normal probability distribution, SIR data
typically analyzed through the calculation of the reportable values of
minimum detectable leak rate (MDL) and the leak declaration threshold
(T) are related as follows:

 MDL is always greater than T
 Pd = (1-Pfa), then MDL = 2 times T (i.e., T = \1/2\ MDL)

    Any analysis of data indicating a threshold value greater than one-
half minimum detectable leak rate should be investigated as a suspected
release.
    One commenter asked EPA to further clarify SIR. The commenter said
EPA presented language in the 2011 proposed UST regulation that
confused statistically based release detection methods currently in
use. EPA agrees and is modifying the description of SIR in this final
UST regulation at Sec.  280.43(h) to narrow the focus of statistically
based methods, which fit under this section. SIR encompasses only those
statistically based methods where inventory data is gathered over a
period and typically provided to a vendor who analyzes the data to
determine the leak status of the tank. These methods do not include
systems that incrementally gather measurements on an uninterrupted or
nearly uninterrupted basis to determine the tank's leak status
described in Sec.  280.43(d) under continuous in tank leak detection.
    This final UST regulation addresses these issues associated with
SIR:
 SIR is not the same as inventory control
    [cir] Historically, users, vendors, and regulators have incorrectly
associated SIR with inventory control in Sec.  280.43(a). SIR is more
sophisticated than inventory control and not subject to the same
requirement to combine it with tank tightness testing and limit its use
to 10 years. Section 280.50(c)(3) allows owners and operators to use a
second month of inventory control data to confirm initial possible
failure results. However, this allowance does not apply to SIR.
Therefore, any failed SIR result must be investigated as a suspected
release. Also, in the event of an inconclusive result, UST owners and
operators must use another method of release detection to determine the
leak status of the tank.
 Results for release detection, including SIR, are required
within the 30-day monitoring period
    [cir] EPA considered including a requirement in the final UST
regulation that UST owners and operators obtain a record of SIR results
within 30 days. However, this requirement is already covered in the
release detection requirements. As Sec.  280.41(a)(1) states, ``Tanks .
. . must be monitored for releases at least every 30 days using one of
the methods listed in Sec.  280.43(d) through (i) . . .'' In this final
UST regulation, EPA is adding a subsection to formally recognize SIR. A
definitive result of pass or fail that identifies the tank's leak
status is required within the 30-day monitoring period for all release
detection methods, including SIR.
 Owners and operators must use another method of release
detection if SIR results are inconclusive
    [cir] For years, implementing agencies have been concerned about
inconclusive results when using SIR for release detection. In 1993, EPA
issued a policy regarding inconclusive SIR results,\118\ which says all
methods used to meet release detection requirements in Sec.  280.41
must obtain a conclusive result of pass or fail within the 30-day
monitoring period. All monitoring records must be maintained according
to Sec.  280.45. For SIR, this means UST owners and operators must
obtain a report determining release status within the 30-day monitoring
period. Another method of release detection is required when results
are inconclusive; prior to sufficient data gathered to generate an
initial report at startup; or when a report is not available for any
month of

monitoring. Owners and operators have not performed release detection
until the release status of the UST system has been conclusively
determined.
---------------------------------------------------------------------------

    \118\ UST Technical Compendium, question and answer number
21:http://epa.gov/oust/compend/rd.htm.
---------------------------------------------------------------------------

 Initial SIR report at startup
    [cir] SIR methods need to gather data over a period in order to
determine whether the tank is leaking. In some cases, implementing
agencies have addressed significant lag times between when data is
collected and when a tank status determination is available to owners
and operators. NWGLDE's list of third-party evaluated methods indicates
the data collection period required for SIR methods ranges from 15 to
90 days. However, most methods require between 23 and 30 days to gather
sufficient measurements that provide an accurate result. Any method
that goes beyond a 30-day monitoring period is inconsistent with and
does not meet the release detection requirement. It is imperative that
UST owners and operators determine the status of their tanks within the
established monitoring period to avoid increased risk of releases.
Therefore, owners and operators must use another release detection
method at least once every 30 days until a SIR result is obtained.
After that, owners and operators must have a SIR result at least once
every 30 days.
 Meeting the 30-day monitoring requirement
    [cir] EPA received several comments regarding the lack of
timeliness associated with determining whether a leak exists when using
SIR. In many instances, monitoring results are not produced until the
next monitoring period or well beyond. These commenters also provided
several suggestions for EPA to address the lag time between UST owners
and operators collecting leak detection data and receiving late
reporting on the leak status of the tank. EPA reiterates its
established regulatory requirement that tanks must be monitored for
releases at least once every 30 days.
    [cir] Commenters provided other options for how owners and
operators can meet the release detection requirement. One possible
option is for EPA to require owners and operators perform a SIR
analysis every 15 days using the last 30 days of data. This option
results in a more frequent analysis of the UST system's leak status.
EPA agrees this option would allow owners and operators to meet the
release detection requirement. Another option suggested was for EPA to
add a requirement that SIR results must be returned to owners within
seven days of the end of the data collection period; other commenters
indicated various other times. EPA disagrees with this option because
it would not meet the requirement to conduct release detection at least
once every 30 days. Providing additional time for one method to
determine whether a leak has occurred would be both unfair to UST
system owners and operators using other release detection methods, as
well as result in decreased environmental protection. To meet the
release detection requirement for SIR, owners and operators could
conduct a more frequent analysis, as one commenter suggested, or send
data more expeditiously by electronic means. EPA is retaining the 30-
day release detection requirement, which allows owners and operators to
use whatever method they choose, as long as the method meets
performance standards. UST system owners and operators can discuss
changing their methods or data collection procedures with their SIR
vendors in order to meet EPA's release detection requirement.
Interstitial Monitoring
    The 2011 proposed UST regulation included three methods of
continuous interstitial monitoring--vacuum, pressure, and liquid-filled
methods--in Sec.  280.43(g). EPA proposed these methods in conjunction
with the periodic secondary containment testing requirement. Based on
comments, EPA removed references to continuous interstitial monitoring
in this final UST regulation. Because continuous interstitial
monitoring is not discussed in this final UST regulation, EPA does not
include language pertaining to continuous vacuum, pressure, or liquid-
filled methods of interstitial monitoring in Sec.  280.43(g). This does
not impact release detection methods allowed under Sec.  280.43(g).
2. Updates to Codes of Practice Listed in the UST Regulation
    This final UST regulation updates the codes of practice (also
called standards or recommended practices) listed in the 1988 UST
regulation to reflect new codes, changes to code names, and new
nationally recognized associations and independent testing
laboratories. The 1988 UST regulation relied on codes of practice
developed by nationally recognized associations or independent testing
laboratories to implement many of the requirements. EPA will continue
to rely on codes of practice in this final UST regulation.
    EPA reviewed information from more than 25 code making groups on
more than 200 codes of practice, which have been developed or revised
since the 1988 UST regulation.\119\ As a result, EPA is:
---------------------------------------------------------------------------

    \119\ E\2\, Incorporated, memoranda and analyses submitted under
Contract EP-W-05-018, U.S. Environmental Protection Agency.
Underground Storage Tanks/Leaking Underground Storage Tanks
Analytical And Technical Support. These supporting materials are
located in the docket EPA-HQ-UST-2011-0301.

 Updating titles and designations of existing codes of
practice;
 Adding applicable codes of practice developed after the 1988
UST regulation was finalized;
 Moving codes of practice that were misplaced in the 1988 UST
regulation; and
 Removing codes of practice that:
    [cir] Are out of date, no longer available, withdrawn, or
rescinded;
    [cir] No longer provide any information appropriate to or relevant
to the final UST regulation where it was referenced; or
    [cir] Are no longer needed.

    For example, EPA listed the Association for Composite Tanks ACT-100
tank standard in Sec.  280.20(a)(3) of the 1988 UST regulation as a
code of practice for meeting the clad tank requirement. EPA is removing
this code of practice from this final UST regulation because both the
association and code of practice no longer exist.
    In several cases, EPA is moving a code of practice from one section
of the final UST regulation to another. For example, EPA is moving
Steel Tank Institute Standard F841, Standard for Dual Wall Underground
Steel Storage Tanks from Sec.  280.43(g)--interstitial monitoring to
Sec.  280.20(a)(2), which covers steel tanks. EPA thinks it makes more
sense for this to be included under the UST design and construction
standards, rather than as a release detection standard. EPA used
similar rationale when relocating other codes of practice in this final
UST regulation.
    As in the preamble to the 1988 UST regulation, this final UST
regulation does not require use of a specific version or edition of any
code. The consensus codes are frequently revised and updated. EPA
recognizes that requiring use of the most recent edition of a code of
practice would cause undue confusion in the regulated community. For
example, owners and operators install UST systems according to codes

of practice current at the time of installation, but may not have
equipment in the ground that meets codes that are current 10 years
later. EPA concludes that the industry codes in effect at the date of
publication of this final UST regulation are protective of human health
and the environment. Using future editions of codes instead of editions
now in effect is not required, but is encouraged; updated codes will
probably provide for newer, more effective technologies and practices.
Using past codes, which have been replaced by new editions prior to the
effective date of this final UST regulation, is not allowed because
some past recommended industry practices may not represent current
codes of practice or may not adequately cover the regulatory
requirement.
    Consistent with the preamble to the 1988 UST regulation, this final
UST regulation interprets the term nationally recognized organization
to mean a technical or professional organization that has issued
standards formed by the consensus of its members. The organization
should consider all relevant viewpoints and interests, including those
of consumers and future or existing potential industry participants.
The resulting standards should be widely accepted and based on a broad
range of technical information, and performance criteria should be
central elements of the resulting standards. EPA regards the following
organizations, whose codes of practice are listed in this final UST
regulation, as examples of nationally recognized organizations:

American Petroleum Institute (API)
American Society for Testing and Materials (ASTM)
Fiberglass Tank and Pipe Institute (FTPI)
National Association of Corrosion Engineers (NACE)
National Fire Protection Association (NFPA)
National Leak Prevention Association (NLPA)
Petroleum Equipment Institute (PEI) Steel Tank Institute (STI)
Underwriters Laboratory (UL)
EPA received broad support for updating the codes of practice listed in
the final UST regulation. Several commenters pointed out errors to
titles or designations in the 2011 proposed UST regulation. This final
UST regulation corrects these errors.

    EPA received comments on the 2011 proposed UST regulation asking
that we add or remove several codes of practice. EPA reviewed PEI's
recommended practice for testing and verification of spill, overfill,
leak detection, and secondary containment equipment (RP 1200), and in
this final UST regulation is including it in areas where testing or
inspecting UST equipment is required. EPA also reviewed and is
including PEI's recommended practice for the inspection and maintenance
of UST systems (RP 900) in the walkthrough inspections portion of this
final UST regulation. EPA is not including the Canadian code for
installing fiber reinforced plastic linings (ULC/ORD-C58.4-05), because
this final UST regulation no longer allows owners and operators to
install internal linings to meet the corrosion protection upgrade.
Owners may continue using internal linings for other reasons such as
compatibility or secondary containment; but EPA determined there are no
appropriate areas in this final UST regulation to list lining codes of
practice for those purposes. Also, EPA is not including PEI's
recommended practice for the inspection and maintenance of motor fuel
dispensing equipment (RP 500), because it is a standard for inspecting
motor fuel dispensing equipment and Subtitle I of the SWDA does not
give EPA the authority to regulate aboveground equipment such as motor
fuel dispensing equipment. Finally, EPA is not including STI's storage
tank maintenance standard (R-111) as an option for periodic walkthrough
inspections because the content of the 2011 version of this code of
practice only focused on water and contaminants in the tank along with
compatibility. Except for a monthly inspection checklist, this code of
practice does not describe how to conduct a periodic walkthrough
inspection. If STI changes this code of practice, implementing agencies
may determine whether the newer version is adequate for meeting the
periodic walkthrough inspection requirement in this final UST
regulation.
    In the 2011 proposed UST regulation, EPA asked for input on whether
the requirement to follow codes of practice and manufacturer's
instructions under the installation requirements in Sec.  280.20(d)
should apply to just tanks and piping (as stated in the 1988 UST
regulation) or apply to the UST system as a whole. Both the 1988 UST
regulation and this final UST regulation define UST system as the
underground storage tank, connected underground piping, underground
ancillary equipment, and containment system, if any. Commenters
strongly supported requiring installation of the UST system, rather
than just tanks and piping, according to a code of practice developed
by a nationally recognized association or independent testing
laboratory and according to manufacturer's instructions. For these
reasons, this final UST regulation replaces tanks and piping with UST
system in Sec.  280.20(d).
3. Updates To Remove Old Upgrade and Implementation Deadlines
    This final UST regulation removes references to the 1998 deadline
and old phase in schedules, while continuing to allow testing of
corrosion protection and release detection. These changes acknowledge
that the 1998 deadline for upgrading UST systems with release
prevention and the 1990s release detection and financial responsibility
deadlines passed more than a decade ago. In addition, as of 2010
implementing agencies have inspected all regulated UST systems at least
once for compliance with release detection, release prevention, and
financial responsibility requirements.
    EPA will no longer allow owners and operators to upgrade UST
systems if they never met the 1998 upgrade requirements, unless the
implementing agency determines the UST system is acceptable to upgrade.
Owners and operators must permanently close non-upgraded UST systems
according to the closure requirements in subpart G. Non-upgraded UST
systems are older and have been in the ground for more than two
decades. In addition, metal USTs and piping without corrosion
protection pose a significant risk to human health and the environment,
because unprotected metal in contact with soil corrodes. EPA is
allowing implementing agencies to make case-by-case determinations on
when to allow upgrades. EPA does not expect implementing agencies to
allow continued use of tanks or piping not upgraded with corrosion
protection. However, some implementing agencies may decide to allow
owners and operators of UST systems with corrosion protection, but
without spill or overfill prevention, to add spill or overfill
prevention instead of requiring permanent closure.
    EPA will continue to allow UST systems with field-constructed tanks
and airport hydrant systems to be upgraded with spill, overfill, and
corrosion protection under subpart K of the UST regulation. See section
C-2 for additional information on upgrading these UST systems.
    To meet the release detection requirement, Sec.  280.41 of the 1988
UST regulation allowed owners and operators of USTs not upgraded with
corrosion protection to use a

combination of monthly inventory control with annual tank tightness
testing until December 22, 1998. Since owners and operators no longer
have the option to use inventory control and annual tightness testing,
EPA is removing this option from this final UST regulation.
    In response to comments received, EPA is removing the definition of
petroleum marketing firm from subpart H of this final UST regulation.
EPA only used the term petroleum marketing firm in the compliance dates
section as it related to when these firms needed to meet the financial
responsibility requirements. Since the compliance dates for
conventional UST systems have passed more than a decade ago, the term
no longer needs to be defined.
4. Editorial Corrections and Technical Amendments
    This final UST regulation includes editorial corrections and
technical amendments to the 1988 UST regulation. Editorial corrections
include: Correcting misspellings; capitalizing words; removing unused
acronyms; using conventional number formatting; and appropriately
referring to parts, subparts, sections, and paragraphs. In addition,
this final UST regulation adds technical amendments, which include
updating the final UST regulation to incorporate statutory changes that
occurred since the 1988 UST regulation was promulgated and clarifying
longstanding Agency interpretations and policies. EPA is making the
following technical amendments in this final UST regulation:
     Sec.  280.10(c)(4)--EPA is revising the Nuclear Regulatory
Commission citation to be consistent with the Spill Prevention Control
and Countermeasures requirements in 40 CFR part 112. This final UST
regulation partially excludes emergency generator systems at nuclear
power generation facilities licensed by the Nuclear Regulatory
Commission that are subject to Nuclear Regulatory Commission
requirements regarding design and quality criteria, including but not
limited to 10 CFR part 50. EPA originally proposed only deleting
appendix A from the regulatory citation. However, EPA agrees with
commenters that using language consistent with the Spill Prevention
Control and Countermeasures requirements in 40 CFR part 112 provides
clarity and consistency for owners and operators of emergency generator
UST systems at nuclear power generation facilities.
     Sec.  280.12--EPA is revising exclusion (ii) of the
definition of UST to incorporate a revision in section 9001 of the
Solid Waste Disposal Act.
     This final UST regulation adds a technical amendment to
Sec.  280.43(b), which codifies longstanding Agency policy adding
additional flexibility for using manual tank gauging. This change
updates UST capacity allowances and testing durations when using manual
tank gauging. Since 1990, EPA allowed these deviations from the 1988
UST regulation through policy and included them in outreach
publications.
     The 2011 proposed UST regulation removed the requirement
for inventory control for the automatic tank gauging release detection
method in Sec.  280.43(d) because some interpreted the language as
requiring both inventory control and automatic tank gauging. However,
EPA agrees with commenters who indicated the language is necessary to
ensure automatic tank gauging equipment meets inventory control
performance standards in Sec.  280.43(a). More specifically, EPA is
keeping the regulatory language to ensure owners and operators continue
to measure for water as described in the inventory control requirement.
This final UST regulation departs from the proposal and retains
language established in the 1988 UST regulation that automatic tank
gauging equipment also must meet the inventory control requirements.
This final UST regulation does not require owners and operators to
perform inventory control in addition to automatic tank gauging.
     This final UST regulation expressly states which new
operation and maintenance requirements owners and operators do not have
to meet for UST systems in temporary closure. Owners and operators of
temporarily closed UST systems that are empty do not have to perform
the following periodic release detection operation and maintenance
testing and inspections in subparts C and D: 30 day release detection
checks, annual sump checks, and annual hand-held release detection
checks described in the walkthrough inspection section (see section B-
1); testing of containment sumps used for interstitial monitoring
described in the secondary containment testing section (see section B-
4); and testing of release detection equipment described in the release
detection equipment testing section (see section B-5). These
requirements are unnecessary as long as the temporarily closed UST
system is empty because release detection is not required in the first
place. In addition, owners and operators of any UST system in temporary
closure are not required to conduct the following periodic operation
and maintenance testing and inspections for spill prevention equipment
and overfill prevention equipment in subpart C: Spill prevention
equipment testing (see section B-2); overfill prevention equipment
inspections (see section B-3); or spill prevention equipment checks
described in walkthrough inspections (see section B-1). Spill and
overfill testing or inspections are not required for UST systems in
temporary closure because those systems are not receiving deliveries of
regulated substances. Finally, as a conforming amendment, this final
UST regulation adds subpart K to the release detection citation because
new release detection requirements for field-constructed tanks and
airport hydrant systems are included in that subpart.
     This final UST regulation amends the definition of the
term accidental release in Sec.  280.92 so it matches the definition
described in the preamble to the 1988 UST regulation for the financial
responsibility requirements (53 FR 43334). EPA intended the definition
in the preamble to be included in the 1988 UST regulation, but failed
to include the concept of releases as a result of operating the UST.
Through this amendment, EPA is clarifying that owners and operators are
required to have financial responsibility for releases arising from
operating USTs (including releases due to filling USTs and releases
occurring at dispensers).
     Sec.  280.94(a)(1)--EPA proposed to include the local
government option citations in this section. However, those options are
not included in this final UST regulation because they are already
included in Sec.  280.94(a)(2).
     Sec.  280.97(b)(1) and (2)--EPA added the local government
options as part of the reference since those options are also viable
financial responsibility mechanisms.
     To make the local government bond rating test consistent
with the requirements of the financial test in Sec.  280.94, this final
UST regulation adds a new subsection to Sec.  280.104.
     To ensure the definition of UST technical standards in
subpart I, Lender Liability, includes all of the preventative and
operating requirements in this final UST regulation, EPA revised the
definition to include subparts J and K as part of the preventative and
operating requirements under 40 CFR part 280.
     To add clarity about the statement for shipping tickets
and invoices in appendix III, this final UST regulation revises the
appendix.
     Finally, the final UST regulation revises sections that
use the terms operating life or properly closed to be permanently
closed or when a change-

in-service occurs; this amendment will clearly indicate when the
regulated operating life of an UST system ends. This final UST
regulation does not define an operating life or proper closure. Rather,
it describes permanent closure and change-in-service.

F. Alternative Options EPA Considered

    In developing this final UST regulation (hereafter the Selected
Option), EPA considered and evaluated variations of a subset of the
regulatory requirements using two alternative options (hereafter Option
1 and Option 2). The table below highlights differences between the
Selected Option and Options 1 and 2. Some of the regulatory
requirements do not vary across the options (for example, notification
of ownership changes is required in all three). As a result, regulatory
changes discussed earlier in the preamble, but not listed here, mean
those changes are in effect in all three options. Overall, Options 1
and 2 consist of regulatory changes that are more and less stringent,
respectively, than those of the Selected Option.

                                Comparison of Selected Option and Options 1 and 2
----------------------------------------------------------------------------------------------------------------
                                                                        Options
        Regulatory requirement        --------------------------------------------------------------------------
                                               Selected                    1                        2
----------------------------------------------------------------------------------------------------------------
Walkthrough inspections..............  30 days................  30 days (per 2011        Quarterly.
                                                                 proposed UST
                                                                 regulation) *.
Overfill prevention equipment          3 years................  Annual.................  Not required.
 inspections.
Spill prevention equipment tests.....  3 years................  Annual.................  3 years.
Containment sump tests...............  3 years................  Annual.................  Not required.
Elimination of flow restrictors in     Required...............  Required...............  No change from 1988 UST
 vent lines for all new tanks and                                                         regulation.
 when overfill devices are replaced.
Operability checks for release         Annual (plus annual      Annual (per 2011         Annual (plus annual
 detection equipment.                   check of sumps).         proposed UST             check of sumps).
                                                                 regulation) *.
Groundwater and vapor monitoring for   Continue to allow with   5-year phase out (per    No change from 1988 UST
 release detection.                     site assessment.         2011 proposed UST        regulation.
                                                                 regulation) *.
Remove release detection deferral for  Required...............  Required (per 2011       Required.
 emergency generator tanks.                                      proposed UST
                                                                 regulation) *.
Requirements for demonstrating         Required...............  Required (per 2011       No change from 1988 UST
 compatibility for fuels containing                              proposed UST             regulation.
 >E10 and >B20.                                                  regulation) *.
Remove deferrals for airport hydrant   Regulate under           Require airport hydrant  Maintain deferral.
 fuel distribution systems and UST      alternative release      systems and field-
 systems with field-constructed tanks.  detection requirements.  constructed tanks
                                                                 notify implementing
                                                                 agency and report
                                                                 releases (with no
                                                                 other new
                                                                 requirements).
----------------------------------------------------------------------------------------------------------------
* In the 2011 proposed UST regulation, these regulatory changes generally consisted of more or stricter
  requirements than what is in the final UST regulation. For example, the 30-day walkthrough inspections in the
  2011 proposed UST regulation included monthly check of sumps. Please see the 2011 proposed UST regulation for
  details.

    Below we explain Options 1 and 2, as well as our rationale for
each. (Note that EPA conducted a regulatory impact analysis for all
three options. The results are discussed in the RIA document titled
Assessment of the Potential Costs, Benefits, and Other Impacts of the
Final Revisions to EPA's Underground Storage Tank Regulations, which is
available in the docket for this action.)
EPA's Rationale for Option 1
    EPA considered keeping walkthrough inspections as described in the
2011 proposed UST regulation. However, based on concerns from
commenters regarding the proposed walkthrough inspection requirements,
EPA decided to revise the components of the walkthrough inspection. See
section B-1 for details regarding this final UST regulation on
walkthrough inspections.
    EPA also considered requiring annual inspections of overfill
prevention equipment, annual spill prevention equipment tests, and
annual containment sump testing. After reviewing comments, considering
the benefits of establishing one consistent implementation time frame
across as many regulatory requirements as possible, as well as
assessing the cost of requiring annual tests and inspections, EPA is
requiring owners and operators inspect overfill prevention equipment
and test spill prevention equipment and containment sumps once every
three years. This balances the benefits of ensuring properly
functioning equipment with the potential administrative burden and
costs imposed on owners and operators.
    When considering operability checks for release detection
equipment, EPA examined the possibility of keeping the operability
checks as described in the 2011 proposed UST regulation. However, based
on comments, EPA decided to revise some components of the operability
checks. This resulted in allowing owners and operators to perform some
release detection checks on an annual basis instead of every 30 days.
See section B-5 for details regarding release detection equipment
testing.
    EPA also considered maintaining the 2011 proposed option of a five
year phase out of groundwater and vapor monitoring as permissible
release detection methods. Based on concerns from states where
groundwater and vapor monitoring are used frequently by owners and
operators, EPA is retaining groundwater and vapor monitoring as long as
owners and operators demonstrate proper installation and performance
through a site assessment that must be maintained as long as the
methods are used. See section D-6 for details regarding groundwater and
vapor monitoring.
    EPA also considered maintaining its 2011 proposed requirements for
release detection of emergency generator tanks and for demonstrating
compatibility. However, as discussed in earlier sections (C-1 for
emergency generator tanks and D-4 for compatibility), EPA is

revising these requirements in response to comments. For emergency
generator tanks, we are revising the implementation time frame for
consistency with other implementation dates. For compatibility, EPA is
removing the recordkeeping requirement for new installations to make it
easier for owners and operators to be in compliance. EPA is also adding
a list of equipment that must demonstrate compatibility with storing
ethanol blends greater than 10 percent or biodiesel blends greater than
20 percent, or any other regulated substance identified by the
implementing agency. This will help owners and operators understand
which UST equipment must be demonstrated to be compatible.
    Lastly, EPA considered requiring owners and operators of airport
hydrants systems and field-constructed tanks submit a one-time notice
of existence in addition to reporting confirmed releases to the
implementing agency. Owners and operators of these systems would not be
subject to any additional regulatory requirements under Option 1. After
weighing the availability of release detection options for these
systems, the applicability of other requirements in this final UST
regulation, and the potential human health and environmental impact of
releases from these systems, EPA is fully regulating these systems. See
C-2 for EPA's rationale for regulating airport hydrant systems and
field-constructed tanks.
EPA's Rationale for Option 2
    In comparing costs with benefits of the final regulatory changes,
EPA weighed different frequencies for walkthrough inspections and
periodic equipment inspections or tests. EPA assessed quarterly
walkthrough inspections, and not requiring overfill prevention
equipment inspections and containment sump testing as ways to reduce
potential cost impacts on owners and operators. Compared to the 30-day
requirement, quarterly walkthrough inspections would reduce costs to
owners and operators. However, EPA thinks a period less frequent than
30 days for walkthrough inspections would considerably reduce benefits.
High operator turnover and the frequency of deliveries both contribute
to the need for 30-day walkthrough inspections. With that in mind,
today EPA is requiring 30-day walkthrough inspections so owners and
operators can consistently and routinely verify proper spill prevention
and release detection performance. This will ensure problems are
detected before a release occurs.
    EPA also considered not requiring overfill prevention equipment
inspections and containment sump testing. However, as explained in
sections B-3, Overfill Prevention Equipment Inspections and B-4,
Secondary Containment Tests, tank overfills and containment sump areas
account for a significant amount of releases from UST systems. As a
result, EPA is requiring overfill prevention equipment inspections and
containment sump testing (for containment sumps used for interstitial
monitoring) once every three years. Overfill prevention equipment
inspections will ensure overfill prevention equipment is operating
properly. Similarly, containment sump testing will ensure that
containment sumps used for interstitial monitoring will be liquid
tight.
    To reduce total compliance costs of this final UST regulation for
owners and operators, EPA considered allowing continued use of flow
restrictors in vent lines (that is, ball float valves) as an acceptable
form of overfill prevention equipment. After considering public
comments, EPA maintains its position that vent line flow restrictors
present problems for operability and safety reasons. As described in
section D-1, EPA is eliminating ball float valves as an overfill
prevention equipment option for all new tanks and when overfill
prevention equipment is replaced in existing tanks.
    EPA considered maintaining the existing requirements for
groundwater and vapor monitoring, in particular retaining the two as
permissible release detection methods with no changes to the 1988 UST
regulation. However, given the numerous concerns that have arisen over
the years regarding these two release detection methods, such as
misapplications and improper designs of monitoring wells, EPA is
retaining these two release detection methods only if owners and
operators demonstrate proper installation and performance through a
site assessment. See section D-6 for details regarding groundwater and
vapor monitoring.
    EPA also considered only retaining the current requirement for
owners and operators to use UST systems made of or lined with materials
that are compatible with the substance stored in the UST system.
However, EPA understands that the chemical and physical properties of
ethanol and biodiesel can be more degrading to certain UST materials
than petroleum alone. As the use of ethanol- and biodiesel-blended
fuels increases, EPA is concerned that not all UST system equipment or
components are compatible with these fuels. Therefore, EPA is requiring
owners and operators demonstrate compatibility of certain UST system
components when storing ethanol blends greater than 10 percent and
biodiesel blends greater than 20 percent. Owners and operators can
demonstrate compatibility of required components by using one of the
three options described in this final UST regulation. See section D-4
for details regarding compatibility.
    Finally, EPA considered maintaining deferrals for airport hydrant
systems and field-constructed tanks. However, as explained above, after
weighing the availability of release detection options for these
systems, the applicability of the other requirements in this final UST
regulation, and the potential human health and environmental impact of
releases from these systems, EPA is fully regulating these systems. See
C-2 for EPA's rationale for regulating airport hydrant systems and
field-constructed tanks.

V. Updates to State Program Approval Requirements

    EPA is making changes to the 1988 SPA regulation (40 CFR part 281)
to make it consistent with certain Energy Policy Act requirements and
certain revisions to the 1988 UST regulation (40 CFR part 280).
Commenters generally supported EPA changing portions of the 1988 SPA
regulation and making it consistent with revisions to the 1988 UST
regulation. Commenters supported EPA keeping the general format of the
1988 SPA regulation and not making the final SPA regulation as explicit
or prescriptive as this final UST regulation.
    EPA is making these substantive changes to the 1988 SPA regulation.

 Sec.  281.12(b)--adding definitional exceptions for several
Energy Policy Act definitions
 Sec. Sec.  281.30(a), 281.33(c)(2), and 281.33(d)(3)--require
secondary containment for new or replaced tanks and piping and under-
dispenser containment for new motor fuel dispenser systems for UST
systems located within 1,000 feet of a potable drinking water well or
community water system, unless a state requires manufacturer and
installer financial responsibility according to section 9003(i)(2) of
the Solid Waste Disposal Act
 Sec. Sec.  281.30(a)(1) and 281.33(d)(3)--exclude safe suction
piping, airport hydrant system piping, and field-constructed tank
piping from being required to meet the secondary containment and
interstitial monitoring requirements

 Sec.  281.30(b)--eliminate flow restrictors for new or
replaced overfill prevention
 Sec.  281.30(c)--add notification for ownership changes
 Sec. Sec.  281.31 and 281.33(b)--delete upgrading requirements
and eliminate phase-in schedule; add phase-in schedule for airport
hydrant fuel distribution systems and UST systems with field-
constructed tanks
 Sec.  281.32(c)--add requirement for states to include
provisions for demonstrating compatibility with new and innovative
regulated substances or other regulated substances identified by
implementing agencies or include other provisions determined by the
implementing agency to be no less protective of human health and the
environment than the provisions for demonstrating compatibility
 Sec. Sec.  281.32(e) and (f) and 281.33(a)(3)--add periodic
testing or inspection of spill and overfill prevention equipment,
containment sumps used for interstitial monitoring of piping, and
mechanical and electronic release detection components; and operation
and maintenance walkthrough inspections, as well as maintaining
associated records
 Sec.  281.33(c)--limit use of monthly inventory control in
combination with tank tightness testing conducted every five years for
the first ten years after the tank is installed or upgraded, if the
tank was installed prior to a state receiving SPA
 Sec.  281.33(e)--require hazardous substance USTs to only use
secondary containment with interstitial monitoring
 Sec.  281.34(a)(1)--add interstitial space may have been
compromised to suspected releases
 Sec.  281.37--eliminate phase-in requirement for financial
responsibility
 Sec.  281.39--require operator training according to Sec.
9010 of the Solid Waste Disposal Act
 Sec.  281.41(a)(4)--add authority to prohibit deliveries

    EPA is making these technical changes to the SPA regulation.

 Sec.  281.10--change subpart to part
 Sec. Sec.  281.11(c), 281.20(d), 281.21(a)(2), 281.23,
281.50(a), and formerly Sec.  281.51--eliminate interim approval
 Sec.  281.12(a)(2)--change Indian lands to Indian country
 Formerly Sec.  281.32(e)--eliminate requirement to maintain
upgrade records
 Formerly Sec.  281.38--eliminate reserved section for
financial responsibility for USTs containing hazardous substances
 Move Sec.  281.39 to Sec.  281.38--Lender Liability
 Sec. Sec.  281.50(e) and 281.51(c)(1)--clarify how to provide
public notice to attract statewide attention
 Sec.  281.51, formerly Sec.  281.52--add requirement for
approved states to submit a revised application within three years of
40 CFR part 281 changes that require a program revision
 Sec.  281.61--move Sec.  281.60(b) to Sec.  281.61(b)(2)

Background Information

    The 1988 SPA regulation in 40 CFR part 281 sets criteria state UST
programs must meet to receive EPA's approval to operate in lieu of the
federal UST program. The 1988 SPA regulation sets performance criteria
states must meet to be considered no less stringent than the federal
UST regulation (hereafter 40 CFR part 280) and provides requirements
for states to have adequate enforcement. It also details the components
of a SPA application.
    EPA is changing the 1988 SPA regulation and making it consistent
with this final UST regulation. By doing so, EPA will require states to
adopt requirements similar to the final UST regulation, in order to
obtain or retain SPA. Commenters supported maintaining the general
format of the 1988 SPA regulation and EPA is keeping that general
format. We are not making this final SPA regulation as explicit or
prescriptive as this final UST regulation. Finally, EPA is making
technical corrections and adding a deadline for states to apply for
revised state program approval.

Addressing Energy Policy Act Requirements and 40 CFR Part 280 Changes

How SPA Works
    This final UST regulation primarily impacts the 1988 SPA regulation
in 40 CFR part 281, subpart C--Criteria for No Less Stringent. As of
2014, 40 states, including the District of Columbia and Puerto Rico,
have state program approval and state UST requirements apply in lieu of
the federal requirements. To ensure these jurisdictions and any other
states or territories obtaining SPA adopt these 40 CFR part 280