records must: List each component tested; indicate whether each
component meets the criteria listed or needed to have action taken; and
describe any action taken to correct an issue. The requirement to
maintain records for three years is consistent with the three year
compliance inspection cycle; maintaining records will allow owners and
operators to demonstrate compliance with this operation and maintenance
requirement.
    Based on comments received and EPA's goal to align all
implementation dates for consistency and easier compliance, this final
UST regulation requires owners and operators meet operation and
maintenance for release detection requirements no later than three
years after the effective date of the final UST regulation. This is a
change from the 2011 proposed UST regulation, which required that
owners and operators meet this requirement no later than one year after
the effective date of the final UST regulation.
    The 2011 proposed UST regulation used the term line leak detector
as a component that must be tested. Based on comments received, this
final UST regulation uses the term automatic line leak detector. This
is consistent with

how EPA has historically referenced line leak detectors in the 1988 UST
regulation. These devices can be electronic or mechanical and are
described in Sec.  280.44(a). Commenters also asked EPA to add the
performance criteria of 3 gallons per hour at 10 pounds per square inch
line pressure to the simulated ALLD test required for the line leak
detector. This is unnecessary since the 2011 proposed UST regulation
required this performance standard for the simulated test by
referencing Sec.  280.44(a). This final UST regulation maintains that
ALLDs, whether electronic or mechanical, must meet the annual simulated
leak test of 3 gallons per hour at 10 pounds per square inch line
pressure within 1 hour.
    One commenter noted his experience with testing release detection
equipment, which verified electrical circuitry, but during operation
the connected device still did not function to its intended precision.
This commenter recommended EPA change the term test to functionality
test. EPA thinks this change is unnecessary. The operation and
maintenance requirements for release detection feature minimum
performance criteria for testing. Each method used to meet the
requirement (manufacturer's instructions, a code of practice, or
requirements developed by the implementing agency) must, at a minimum,
cover each listed component and the stated performance criteria.
    EPA disagrees with the commenter who said EPA should allow self-
diagnostic equipment. Similar to the commenter in the previous
paragraph, EPA is concerned that self-diagnostic equipment might verify
electrical circuitry or communication, but not actually test equipment
functionality. EPA requires testing to be performed in a manner that
verifies equipment operation according to performance standards
provided for each piece of release detection equipment. For example,
testing ALLDs must involve simulating a system leak not greater than 3
gallons per hour at 10 pounds per square inch line pressure within 1
hour, or equivalent. ALLDs connected to ATG systems or other
controllers may themselves be used to test electronic communication,
but unless capable of simulating an appropriate leak in the system, do
not meet the performance standard and, therefore, cannot be used to
meet this requirement.
    In this final UST regulation, EPA is deleting language from the
2011 proposed UST regulation about inspecting and testing the leak
sensing O-ring. Commenters requested EPA clarify what a leak sensing O-
ring is. This O-ring is specific to the functional element of
mechanical line leak detectors and is, therefore, only present on
certain types of ALLDs. In addition, all functional elements will be
tested as part of the simulated leak test conducted at 3 gallons per
hour at 10 psi or equivalent for all ALLDs.
    This final UST regulation allows use of groundwater and vapor
monitoring as methods of release detection, but with some restrictions
(see section D-6). For owners and operators choosing groundwater or
vapor monitoring as their method of release detection, this final UST
regulation requires that hand held electronic devices such as
photoionization devices meet the operation and maintenance requirements
for release detection equipment. Non electronic hand held devices, such
as measuring sticks and groundwater bailers, are covered in section B-
1, Walkthrough Inspections.

C. Addressing Deferrals

    This final UST regulation addresses airport hydrant fuel
distribution systems and USTs with field-constructed tanks. In
addition, this final UST regulation removes the release detection
deferral for UST systems that store fuel solely for use by emergency
power generators. As a result, these UST systems may no longer be
subject to Spill Prevention, Control, and Countermeasure (SPCC)
requirements. Finally, this final UST regulation partially excludes
from Part 280 requirements wastewater treatment tank systems, UST
systems containing radioactive material regulated under the Atomic
Energy Act, 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. To the extent these systems
were regulated by the SPCC requirements, they will continue to be
regulated by those requirements.
    In this final UST regulation, EPA partially excludes from part 280
requirements the aboveground storage tanks associated with airport
hydrant fuel distribution systems and USTs with field-constructed
tanks. These aboveground storage tanks are part of the UST system, but
are excluded from most of this final UST regulation because they are
not underground. At the time of the 1988 UST regulation, facilities
with an aggregate completely buried storage capacity greater than
42,000 gallons and located near navigable waters of the United States
or adjoining shorelines were subject to both UST regulations and SPCC
regulations. Since then, the SPCC regulation has been amended and
exempts completely buried storage tanks, as well as connected
underground piping, underground ancillary equipment, and containment
systems when fully subject to the technical requirements of 40 CFR part
280. Partially excluded aboveground storage tanks which are part of the
UST system may be subject to SPCC requirements.
1. UST Systems Storing Fuel Solely for Use by Emergency Power
Generators--Require Release Detection
    This final UST regulation eliminates the deferral for UST systems
storing fuel solely for use by emergency power generators (also
referred to as emergency generator tanks). This means emergency
generator tanks are no longer deferred from release detection
requirements in 40 CFR part 280, subpart D and are subject to all UST
requirements.
    This final UST regulation requires owners and operators of UST
systems storing fuel solely for use by emergency power generators begin
meeting these requirements:

 For systems installed after the effective date of this final
UST regulation, at the time of installation
     For systems installed on or before the effective date of
this final UST regulation, within three years of the effective date of
this final UST regulation

    EPA is regulating UST systems storing fuel solely for use by
emergency power generators because the rationale in the 1988 UST
regulation for deferring release detection no longer applies. To allow
time for developing workable release detection requirements, EPA in the
1988 UST regulation deferred release detection requirements for UST
systems storing fuel solely for use by emergency power generators. The
1988 UST regulation preamble indicated that monthly monitoring
requirements were unworkable because these tanks often were located at
unmanned stations in remote areas and visited infrequently.
    EPA always intended for these systems to meet release detection
requirements when appropriate release detection methods became
available. Since the 1988 UST regulation, release detection
technologies have matured greatly. In addition, technology is now
available to perform release detection at remote sites. Emergency
generator tanks can now be monitored for releases by the majority of
methods listed in subpart D. EPA estimates about 30 percent of
emergency generator tanks already have release detection.
    Effective remote monitoring methods for release detection are now
available

and currently used to monitor unmanned UST systems storing fuel solely
for emergency generator tanks. Numerous companies perform remote
monitoring for releases at these unmanned sites. When there is a
suspected release, a remote monitor transmits a visual or audible alarm
to a receiving console at a manned location. This provides owners and
operators with real-time release detection data so owners and operators
can quickly respond to suspected releases at sites with unmanned
emergency generator tanks.
    Several commenters raised concerns that release detection methods
may not properly operate on some emergency generator tanks and
suggested changes to the release detection requirement. Commenters
reported these issues:

 Looped piping systems, which is piping configured to run
continuously with integrated supply and return lines, cannot be
properly isolated or does not have a sufficient quiet period to perform
a precision test when using automatic tank gauging
 Emergency generator tanks with copper piping may pose issues
with meeting the release detection requirement due to system
configurations
 Most emergency generator tanks are single walled and are
limited to automatic tank gauging as the form of release detection
 Emergency generator tanks with day tanks and aboveground
piping may need anti-siphon valves

    Other commenters suggested EPA limit the type of release detection,
such as statistical inventory reconciliation (SIR), owners and
operators may use on emergency generator tanks and that EPA should
require owners and operators install electronic line leak detectors,
which have a positive system shutdown of any product flow in the event
of a leak. Other commenters recommended EPA clarify that automatic line
leak detectors can go to alarm mode only and not shut down or restrict
product flow when a leak is suspected in emergency generator tanks used
during a crisis.
    EPA agrees that not all release detection methods may be suitable
for all configurations of emergency generator tanks. EPA discussed the
applicability of SIR on emergency generator tanks in general with
several SIR vendors and received conflicting responses. A challenge to
performing release detection is establishing a usage rate of product
based on the run time of the system during operation. Although EPA
thinks it is difficult to achieve accurate results, we do not have
enough information at this time to determine that SIR or other methods
that rely on metered data are unacceptable for use on emergency
generator tanks. Owners and operators must carefully consider whether
these methods meet the release detection requirement for their UST
systems. To meet the release detection requirement, some systems may
require reconfiguration and addition of components such as anti-siphon
valves to separate sections of the system. Some emergency generator
tanks use safe suction piping, in which case release detection for
piping is not required. However, release detection technologies have
advanced since EPA issued the 1988 UST regulation and there are now
various options available to meet this requirement. EPA understands
some commenters want to require owners and operators to install
automatic line leak detectors, which only shut off at the STP or
allowing only certain release detection methods for these systems.
However, to provide flexibility to owners and operators while
continuing to protect human health and the environment, this final UST
regulation allows owners and operators to choose the most appropriate
release detection methods, including automatic line leak detectors that
trigger an alarm only and not necessarily shut down the pump, for their
systems. For an unmanned facility, the alarm must be transmitted to a
monitoring center where someone can hear or see the alarm and quickly
respond to a suspected release.
    One commenter suggested EPA define what is mission critical as it
relates to emergency generator tanks. While EPA acknowledges the need
for operating emergency generator tanks during an emergency, we think
it is unnecessary to define the term mission critical or make
exceptions for the release detection requirement for these tanks. The
concern is that owners and operators of these systems should not have
to shut down their systems during an emergency if they encounter a
suspected release. EPA understands this concern but thinks owners and
operators can perform release detection and respond to suspected
releases while continuing to operate the UST system.
    Emergency generator tanks are located throughout the country. EPA's
review of several state databases revealed these systems are located at
hospitals, universities, communication utilities, military
installations, and other locations relying on backup power sources.
Based on information from these databases, EPA estimates UST systems
storing fuel solely for use by emergency power generators represent
approximately 3 percent of the active tank population.
    Additionally, about 20 states currently require release detection
for emergency generator tanks. Automatic tank gauging and secondary
containment with interstitial monitoring are the most common release
detection methods used for emergency generator tanks. Line tightness
testing, automatic line leak detectors, or secondary containment with
interstitial monitoring are the most common release detection methods
used for piping. With technology now available to detect releases from
emergency generator tanks and because they pose a risk to human health
and the environment, this final UST regulation removes the deferral
from release detection.
    The 2011 proposed UST regulation required owners and operators meet
the release detection requirement within one year of the effective date
of the final UST regulation. Several commenters raised concerns that a
one-year time frame to meet this requirement is insufficient for owners
and operators to assess, budget, and install release detection.
Commenters also wanted EPA to establish a single implementation date,
which is consistent with effective dates for release detection on other
previously deferred tanks. EPA agrees that extending the time frame
will allow owners and operators sufficient time for planning and
installing necessary equipment to meet the release detection
requirement; but we disagree with commenters who suggested a five to
ten year implementation date. EPA also agrees that establishing a
single effective date, which is consistent with other effective dates
for the release detection requirement, decreases the tracking burden on
implementing agencies as well as owners and operators. Based on support
for increasing the final implementation date for release detection from
one year and EPA's goal of aligning regulatory implementation dates to
make compliance easier for owners and operators, EPA is requiring
owners and operators of emergency generator tanks installed on or
before the effective date of this final UST regulation to meet the
release detection requirement within three years of the effective date
of this final UST regulation. Emergency generator tanks installed after
the effective date of this final UST regulation must meet the release
detection requirements when installed.
    The 2011 proposed UST regulation required that no later than 30
days after the effective date of the final UST regulation, owners of
UST systems storing fuel solely for use by emergency

power generators notify implementing agencies that their systems exist.
Commenters stated that this requirement is unnecessary because the 1988
UST regulation excluded emergency generator tanks from only the release
detection requirement. EPA agrees with commenters. This final UST
regulation does not include this one-time notification requirement for
emergency generator tanks.
2. Airport Hydrant Fuel Distribution Systems and UST Systems With
Field-Constructed Tanks
    This final UST regulation removes the 1988 deferral and requires
owners and operators of airport hydrant fuel distribution systems
(referred to as airport hydrant systems) comply with applicable
requirements. However, EPA is tailoring the requirements to the unique
nature of airport hydrant systems. Airport hydrant systems function and
are designed differently than conventional USTs. Unlike conventional
USTs, airport hydrant systems consist of networks of large diameter
underground piping operating at high pressures to deliver fuel to
aircraft. In addition, operation and maintenance requirements for
airport hydrant systems may differ from those for conventional UST
systems.
    This final UST regulation removes the 1988 deferral and requires
owners and operators of UST systems with field-constructed tanks comply
with applicable requirements. Similar to airport hydrant systems, EPA
is tailoring the requirements to the unique nature of field-constructed
tanks. UST systems with field-constructed tanks (referred to as field-
constructed tanks) range from conventional sizes to very large
capacities greater than 2 million gallons.
    A few commenters suggested EPA write regulations specifically for
airport hydrant systems and field-constructed tanks, since they are
distinctly different from conventional USTs. EPA agrees that airport
hydrant systems and field-constructed tanks are different from
conventional USTs. Additionally, EPA thinks it would help owners and
operators if the requirements for airport hydrant systems and field-
constructed tanks are in a separate subpart of the final UST
regulation. In order to help owners and operators of these systems
comply, this final UST regulation adds subpart K (UST Systems with
Field-Constructed Tanks and Airport Hydrant Fuel Distribution Systems)
and places most regulatory requirements for both airport hydrant
systems and field-constructed tanks in one location. Since 1988, owners
and operators of these systems have been required to comply with the
requirements for subparts A (Program Scope and Interim Prohibition) and
F (Release Response and Corrective Action for UST Systems Containing
Petroleum or Hazardous Substances).
    This final UST regulation requires airport hydrant systems and
field-constructed tanks installed on or before the effective date of
the final UST regulation begin meeting the requirements of subpart K
according to the schedule below. Airport hydrant systems and field-
constructed tanks installed after the effective date of this final UST
regulation must meet the requirements at the time of installation.

------------------------------------------------------------------------
              Requirement                         Effective date
------------------------------------------------------------------------
Upgrading UST systems, general           Three years after the effective
 operating requirements, and operator     date of this final UST
 training.                                regulation.
Release detection......................  Three years after the effective
                                          date of this final UST
                                          regulation.
Release reporting, response, and         On the effective date of this
 investigation; closure; financial        final UST regulation.
 responsibility and notification,
 except as provided in Sec.
 280.251(2)(b).
------------------------------------------------------------------------

    This final UST regulation modifies the 2011 proposed UST regulation
by revising the definition of airport hydrant fuel distribution system
and defining a field-constructed tank.
    An airport hydrant fuel distribution system (also called airport
hydrant system) is defined as an UST system which fuels aircraft and
operates under high pressure with large diameter piping that typically
terminates into one or more hydrants (fill stands). The airport hydrant
system begins where fuel enters one or more tanks from an external
source, such as a pipeline, barge, rail car, or other motor fuel
carrier.
    A field-constructed tank is defined as a tank constructed in the
field. For example, a tank constructed of concrete that is poured in
the field, or a steel or fiberglass tank primarily fabricated in the
field is considered field-constructed.
Overview of Actions
Release Detection--Tanks
    This final UST regulation requires airport hydrant system tanks and
field-constructed tanks meet these requirements:
     These tanks must be monitored using release detection
methods specified in subpart D:
    [cir] Shop fabricated tanks and
    [cir] Field-constructed tanks with a capacity less than or equal to
50,000 gallons
     Field-constructed tanks with a capacity greater than
50,000 gallons must either be monitored using release detection methods
specified in subpart D (except tanks using groundwater and vapor
monitoring must combine that method with inventory control as described
in the alternatives below) or use one of the alternatives below
    [cir] Conduct an annual tank tightness test that can detect a 0.5
gallon per hour (gph) leak rate
    [cir] At least once every 30 days, use an automatic tank gauging
system to perform release detection, which can detect a leak rate of 1
gallon per hour or less; and at least once every three years, use a
tank tightness test that can detect a 0.2 gallon per hour leak rate
    [cir] At least once every 30 days, use an automatic tank gauging
system to perform release detection, which can detect a leak rate of 2
gallons per hour or less; and at least every two years, use a tank
tightness test that can detect a 0.2 gallon per hour leak rate
    [cir] At least every two years, perform vapor monitoring (conducted
according to Sec.  280.43(e) for a tracer compound placed in the tank
system) capable of detecting a 0.1 gallon per hour leak rate
    [cir] At least every 30 days, perform inventory control, conducted
according to Department of Defense (DoD) Directive 4140.25; Air
Transport Association (ATA) Airport Fuel Facility Operations and
Maintenance Guidance Manual; or equivalent procedures that can detect a
leak equal to or less than 0.5 percent of flow through and either
    [ssquf] At least every two years, perform a tank tightness test
that can detect a 0.5 gallon per hour leak rate or
    [ssquf] At least every 30 days, perform vapor monitoring or
groundwater monitoring (conducted according to Sec.  280.43(e) or (f),
respectively, for the stored regulated substance)

    The implementing agency may approve another method of release
detection if the owner or operator can demonstrate the method can
detect a release as effectively as any of methods listed above. In
comparing methods, the implementing agency shall consider the size of
release the method can detect and frequency and reliability of
detection.
Release Detection--Piping
    Underground piping associated with field-constructed tanks less
than or equal to 50,000 gallons must meet the release detection
requirements in subpart D of the final UST regulation.
    Underground piping associated with airport hydrant systems and
field-constructed tanks greater than 50,000 gallons must meet these
requirements:
     Piping must be monitored using release detection methods
specified in subpart D, except that piping using groundwater and vapor
monitoring must combine that method with inventory control as described
in the alternatives below, or
 Use one of these alternatives
    [cir] Perform a semiannual or annual line tightness test at or
above operating pressure according to the table below

           Maximum Leak Detection Rate per Test Section Volume
------------------------------------------------------------------------
                                            Semiannual
                                            test--leak     Annual test--
                                             detection    leak detection
      Test section volume (gallons)        rate not  to     rate not to
                                              exceed          exceed
                                           (gallons per    (gallons per
                                               hour)           hour)
------------------------------------------------------------------------
<50,000.................................             1.0            0.5
>=50,000 to <75,000.....................             1.5            0.75
>=75,000 to <100,000....................             2.0            1.0
>=100,000...............................             3.0            1.5
------------------------------------------------------------------------

    Piping segment volumes greater than or equal to 100,000 gallons,
which are not capable of meeting the 3 gallons per hour leak rate for
semiannual testing, may be tested at a leak rate up to 6 gallons per
hour according to this schedule:

        Phase In for Piping Segments >=100,000 Gallons in Volume
------------------------------------------------------------------------

------------------------------------------------------------------------
First test...........................  Not later than three years after
                                        the effective date of this final
                                        UST regulation (may use up to 6
                                        gph leak rate).
Second test..........................  Between three and six years after
                                        the effective date of this final
                                        UST regulation (may use up to 6
                                        gph leak rate).
Third test...........................  Between six and seven years after
                                        the effective date of this final
                                        UST regulation (must use 3 gph
                                        leak rate).
Subsequent tests.....................  Beginning seven years after the
                                        effective date of this final UST
                                        regulation, use semiannual or
                                        annual line testing according to
                                        the Maximum Leak Detection Rate
                                        Per Test Section Volume table
                                        above.
------------------------------------------------------------------------

    [cir] At least every two years, perform vapor monitoring according
to Sec.  280.43(e) for a tracer compound placed in the tank system
capable of detecting a 0.1 gallon per hour leak rate
    [cir] At least every 30 days, perform inventory control, conducted
according to DoD Directive 4140.25, ATA Airport Fuel Facility
Operations and Maintenance Guidance Manual, or equivalent procedures,
that can detect a leak equal to or less than 0.5 percent of flow
through and either
    [ssquf] At least every two years, perform a line tightness test
using the leak detection rate for the semiannual test in Sec.
280.252(d)(2(i) or
    [ssquf] At least every 30 days, perform vapor monitoring or
groundwater monitoring (conducted according to Sec.  280.43(e) or (f),
respectively, for the stored regulated substance) or

     The implementing agency may approve another method of
release detection if the owner or operator can demonstrate that the
method can detect a release as effectively as any of the methods listed
above; in comparing methods, the implementing agency shall consider the
size of release the method can detect and the frequency and reliability
of detection.
Release Prevention
    This final UST regulation requires airport hydrant systems and
field-constructed tanks meet corrosion protection, spill, overfill, and
walkthrough inspection requirements. Corrosion protection installed on
airport hydrant systems and field-constructed tanks must meet either:

 New tank and piping standards described in Sec.  280.20,
except that new and replaced hydrant piping and piping associated with
field-constructed tanks greater than 50,000 gallons need not be
secondarily contained or
 Airport hydrant systems and field-constructed tanks installed
on or before the effective date of the final UST regulation must either
meet the corrosion protection upgrade requirements in Sec.
280.252(b)(1) or the new tank and piping standards described above

    Airport hydrant systems and field-constructed tanks installed on or
before the effective date of the final UST regulation that are not
upgraded according to Sec.  280.252(b) within three years of the
effective date of the final UST regulation must be permanently closed
according to subpart G. The presence of an internal lining does not
meet the corrosion protection upgrade requirement.
    Owners and operators of airport hydrant systems and field-
constructed tanks must install spill and overfill prevention equipment
and meet the

periodic spill testing and overfill inspection requirements of Sec.
280.35. Owners and operators must install the equipment and conduct the
first spill test and overfill inspection no later than three years
after the effective date of this final UST regulation and every three
years thereafter. For airport hydrant systems brought into use after
the effective date of this final UST regulation, spill and overfill
prevention equipment requirements must be met at installation.
    Owners and operators must conduct walkthrough inspections that meet
the requirements of Sec.  280.252(c). Owners and operators must conduct
the first inspection within three years after the effective date of the
final UST regulation. In addition to the items inspected as part of the
walkthrough inspection for other regulated UST systems, owners and
operators of airport hydrant systems must inspect hydrant pits and
hydrant piping vaults every 30 days for areas that do not require
confined space entry according to the Occupational Safety and Health
Administration (OSHA) and annually for areas that do require confined
space entry. Owners and operators must keep documentation of the
inspection according to Sec.  280.36(b).
Notification
    This final UST regulation requires owners and operators of
regulated airport hydrant systems and field-constructed tanks meet
these notification requirements:

 For airport hydrant systems and field-constructed tanks
currently installed, owners and operators must submit no later than 3
years after the effective date of this final UST regulation a one-time
notification to their implementing agency that their systems exist
 For airport hydrant systems and field-constructed tanks
installed after the effective date of the final UST regulation, owners
and operators must provide their implementing agency a notification of
each newly installed system within 30 days of bringing each system into
use
 Owners must provide their implementing agency a notification
of ownership change for each newly acquired airport hydrant system or
field-constructed tank within 30 days of the date on which the new
owner assumes ownership
Financial Responsibility
    This final UST regulation requires owners and operators of airport
hydrant systems and field-constructed tanks that have not been
permanently closed meet the financial responsibility requirements in
subpart H at the time the one-time notification of existence is
submitted to the implementing agency. Owners and operators who install
these systems after the effective date of this final UST regulation
must meet the financial responsibility requirements at installation.
This requirement does not apply to state or federal owners of airport
hydrant systems and field-constructed tanks.
Partially Excluded Components
    This final UST regulation excludes aboveground storage tanks
associated with airport hydrant systems and field-constructed tanks
from the requirements of subparts B, C, D, E, G, J, and K. Owners and
operators 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) for these tanks.
Operator Training
    This final UST regulation requires owners and operators of airport
hydrant systems and field-constructed tanks meet the operator training
requirements in subpart J.
Closure Requirements for Previously Closed Tanks
    When directed by the implementing agency, owners and operators of
airport hydrant systems and field-constructed tanks permanently closed
before the effective date of this final UST regulation must assess the
excavation zone and close the UST system according to subpart G if
releases from the UST may, in the judgment of the implementing agency,
pose a current or potential threat to human health and the environment.
Background
    Tanks and piping associated with airport hydrant systems and field-
constructed tanks can store millions of gallons of fuel and handle
large volumes of regulated substances on a daily basis. Leaks from
these systems can contaminate subsurface soil beneath the airport apron
and runways, groundwater, and nearby surface water systems, posing a
significant risk to human health and the environment. As a result, EPA
is removing the deferral.
    Some commenters indicated EPA needed to justify that airport
hydrant systems and field-constructed tanks are leaking in order to
regulate them. The 1988 UST regulation required owners and operators
report only confirmed releases from these tanks to implementing
agencies. Owners and operators were not required to report suspected
releases to implementing agencies, which sometimes resulted in gaps for
ensuring proper site investigations or transmission of sufficient
release information. As a result, implementing agencies have little to
no available historical records regarding releases of regulated
substances from airport hydrant systems and field-constructed tanks.
    In the 2011 proposed UST regulation, EPA provided details on
several releases that previously occurred at airport hydrant systems.
Since that time, EPA identified additional information on releases from
both DoD and commercial airport hydrant systems. For example, at
Hartsfield Jackson International Airport in Georgia, active remediation
and free product recovery is ongoing (as of 2014) due to a 1988 release
of an estimated 14,000 gallons of jet fuel.\44\ In 2003, an estimated
100,000 gallons of jet fuel leaked from the valves and flanges of an
airport hydrant system at Minneapolis-St. Paul International Airport in
Minnesota. Some of the jet fuel was released into the sanitary sewer
and nearby waterway. During the investigation of the jet fuel release,
personnel discovered a second jet fuel leak at a different concourse;
this leak impacted the stormwater system and produced oily sheens in
the Minnesota River. Responsible parties agreed to pay civil penalties
and complete environmental projects, including continued site
remediation and fuel recovery.\45\ In 1983 at Camp Lejeune, North
Carolina, investigators discovered multiple feet of free product while
using a hand auger to investigate the cause of a fuel inventory
discrepancy.\46\ In addition, from the 1960s to the 1980s, thousands of
gallons of jet fuel leaked from a former airport hydrant system at Pope
Air Force Base, North Carolina. At one time, it was noted that as much
as 75,000 gallons of free product was floating on top of the
groundwater because of these releases. As of 2014, the site is
undergoing remediation.\47\ In addition, at Marine Corps Air Station
Cherry Point, North Carolina there have been multiple releases from the
airport

hydrant system underground piping. The station was cited twice in the
1990s for contaminating soil and groundwater under this fuel facility
due to leaking tanks or fuel spills. An extensive environmental
remediation effort is underway in 2014 to clean this site.
Contamination from many of the releases combined and migrated to form a
single plume.
---------------------------------------------------------------------------

    \44\ Corrective Action Plan--Part B: Hartsfield-Jackson
International Airport, Concourse Pit. Number 19 Fuel Spill.
    \45\ http://www.pca.state.mn.us/index.php/about-mpca/mpca-news/
current-news-releases/news-release-archive-2005/airport-agrees-to-
pay-$540000-for-environmental-violations.html?nav=0.
    \46\ http://www.tftptf.com/New_ATSDR3/RR_DRAFT_RAO.pdf.
    \47\ Federal Remediation Technologies Roundtable Abstracts of
Remediation Case Studies, Volume 3 http://epa.gov/tio/download/frtr/abstractsvol3.pdf.
---------------------------------------------------------------------------

    In the 2011 proposed UST regulation, EPA also provided details on
several previous releases that occurred from field-constructed tanks.
Since that time, EPA identified additional anecdotal information on
releases from field-constructed tanks. At Adak Island, Alaska's Tank
Farm A, records show fuel was released at various times from 21,000 to
420,000 gallon field-constructed tanks and piping. As of 2014, all
tanks have been removed, but the former fuel farm is still undergoing
remediation through long term monitoring and monitored natural
attenuation.\48\ Also at Adak Island, an overfill during a fuel
transfer caused 142,800 gallons of diesel fuel to leak from a 4.8
million gallon underground field-constructed tank into the immediate
and surrounding environment, causing harm to native wildlife.\49\
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    \48\ Tank Farm A http://dec.alaska.gov/Applications/SPAR/CCReports/Site_Report.aspx?Hazard_ID=686.
    \49\ http://www.darrp.noaa.gov/northwest/adak/pdf/ADAK_DARPEA_FINAL_Draft%20PDF.pdf.
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    Releases can have a major impact on human health and the
environment. Release prevention equipment, regular release detection
tests, operator training, periodic walkthrough inspections, and proper
operation and maintenance are keys to preventing and quickly
identifying releases before they contaminate the surrounding
environment. This final UST regulation adds these requirements for
airport hydrant systems and field-constructed tanks in order to help
prevent and quickly detect leaks from these systems into the
environment.
Definition of an Airport Hydrant System
    The 1988 UST regulation did not provide a definition for airport
hydrant system. In the 2011 proposed UST regulation, EPA provided a
definition of an airport hydrant system to clarify what components
would be regulated. However, that definition was based on an airport
hydrant system that received fuel at a single delivery point, designed
with all components operating in tandem, and included only the
immediate piping and tank directly feeding the airport hydrant piping.
To clarify for owners and operators, EPA presented scenarios of typical
airport hydrant systems in a guidance document provided during the
public comment period.
    After publishing the 2011 proposed UST regulation, EPA met with
stakeholders to gather more information on airport hydrant system
design and operation.50 51 EPA also provided another
iteration of the schematics that contained better defined airport
hydrant system scenarios. However, some commenters still were confused
about which specific components of an airport hydrant system would be
regulated.\52\
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    \50\ January 28, 2012, March 29, 2012, and October 19, 2012
meetings with representatives from Airlines for America.
    \51\ February 28, 2013 and March 18, 2013 meetings with DoD's
Defense Logistics Agency Energy.
    \52\ Airport Hydrant Systems Scenarios Revised, dated February
28, 2012.
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    Many commenters requested that EPA provide guidance on how to
perform the calculations to determine whether the airport hydrant
system meets the definition of an underground storage tank and
requested clarification of system components. In response to these
comments, EPA is providing guidance below.
    In order for an airport hydrant system to be subject to the final
UST regulation, it must first meet the definition of an underground
storage tank. Airport hydrant systems are not regulated UST systems
under 40 CFR part 280, unless 10 percent or more of the total capacity
of the system is beneath the surface of the ground. When performing the
calculation, include all tanks and underground piping that are part of
the airport hydrant system. An airport hydrant system may have one or
more of the following connected together: Aboveground tanks,
underground tanks, field-constructed tanks, or factory constructed
tanks. Below are two examples. Note that aboveground piping is not
included when calculating the total volume.
    Example 1: A 1 million gallon aboveground storage tank (AST)
connected to underground piping with a capacity of 100,000 gallons does
not meet the definition of an UST, as explained below:

1 million gallons (AST) + 100,000 gallons (underground pipe) = 1.1
million gallons total volume
1.1 million gallons x 10% = 110,000 gallons

    The volume of the underground piping (100,000 gallons) is less than
10 percent of the total volume of the tanks and underground piping
(110,000 gallons).
    Example 2: A 2 million gallon AST feeds two 100,000 gallon field-
constructed underground storage tanks and two 50,000 gallon underground
tanks constructed in the factory which feed 100,000 gallons of
underground hydrant piping. Calculating these values yields a total
system capacity of 2,400,000 gallons with 400,000 gallons underground.
More than 16% of this airport hydrant system is underground making it
an UST.
    In response to comments on the proposed definition, EPA is
clarifying the definition of an airport hydrant system in this final
UST regulation. EPA determined that multiple tanks grouped or
interconnected together can function as one system to fuel an airport
hydrant system. EPA agrees with commenters that it would not be
feasible to separate these tanks to define an airport hydrant system.
EPA also found that other tanks not directly connected to the
underground airport hydrant piping also could feed the airport hydrant
system. The Agency is concluding that an airport hydrant system may
consist of interconnected aboveground and underground storage tanks
(that could be constructed in the factory or field-constructed) and
piping that function as integral and interchangeable components of the
fueling system. Field-constructed tanks that are part of the airport
hydrant system are treated as part of the airport hydrant system and
not independent UST systems that are field-constructed. The airport
hydrant system begins when regulated substance enters from an external
source such as a pipeline, barge, rail car, or other motor vehicle
carrier, but does not include the external source. Airport hydrant
systems use large diameter piping and operate at pressures higher than
those of a conventional UST. This final definition alleviates
stakeholder uncertainty on which components of an airport hydrant
system must meet the UST regulation by including all integral
components that form an airport hydrant system and deliver fuel to the
aircraft. These systems include underground piping and ASTs or USTs
that hold aircraft fuel (for example, settling tanks or product
recovery tanks). They do not include tanks or underground piping not
storing aircraft fuel (for example, additive tanks) or tanks and
underground piping not connected to the airport hydrant system (for
example, a system that fuels an emergency power generator for a pump
house). In addition, EPA is aware there may be instances where an
airport hydrant system might include permanently installed dispensing

equipment at the end of the hydrant piping instead of a fill stand.
However, since these systems still operate under high pressure and
contain large diameter piping, we consider them to be airport hydrant
systems.
Definition of a Field-Constructed Tank
    The preamble to the 1988 UST regulation described a field-
constructed tank as a tank usually constructed of steel or concrete and
shaped like flat vertical cylinders, with a capacity of greater than
50,000 gallons. Tanks that are primarily factory built, but assembled
in the field, are considered factory built tanks. For example, welding
two halves of a factory constructed tank together in the field does not
qualify the tank as a field-constructed tank. Several commenters
requested EPA define field-constructed tank in the final UST regulation
in order for implementing agencies and owners and operators to know
which tanks are applicable. While EPA thinks this term is self-evident,
this final UST regulation defines field-constructed tank as a tank
constructed in the field. For example, a tank constructed of concrete
that is poured in the field, or a steel or fiberglass tank primarily
fabricated in the field is considered field-constructed. Please note
this definition excludes those tanks with components primarily
manufactured in a factory with minimal assembly in the field. EPA
considers those tanks are factory built tanks. Field-constructed tanks
vary from sizes smaller than 50,000 gallons to sizes very large in
capacity. Large capacity tanks may exceed size or shape limitations
that prohibit transportation of the tank in whole to the UST site.
Field-constructed tanks present an engineering, design, or
transportation concern that cannot be addressed by fabrication in a
factory or are more ideally addressed through in-field construction.
This definition includes tanks that are mounded or partially buried,
such as those defined in 40 CFR part 112, if 10 percent or more of the
volume of the system is beneath the ground's surface or otherwise
covered with earthen material. EPA considers a field-constructed tank
that is part of a wastewater treatment system to be partially excluded
from the final UST regulation according to Sec.  280.10(c). See section
C-3 for additional information on the partial exclusion for wastewater
treatment tank systems.
Universe of Field-Constructed Tanks and Airport Hydrant Systems
Affected
    UST systems with field-constructed tanks are generally very large
and, in the event of a release, pose a substantial threat to human
health and the environment. Typical tank sizes range from 20,000
gallons to greater than 2 million gallons. EPA is aware of
approximately 330 UST systems with field-constructed tanks owned by the
Department of Defense and 12 field-constructed tanks owned by the
Department of Energy (DOE).
    One commenter objected to EPA regulating airport hydrant systems
because the 2011 proposed UST regulation addressed airport hydrant
systems at military facilities and did not include systems at
commercial airports. When issuing the 2011 proposed UST regulation, EPA
thought the universe of these systems was mainly owned by DoD, based on
information from DoD and commercial airport representatives. The 2011
proposed UST regulation also assumed the universe included two
commercial airports with airport hydrant systems. Airlines for America
(A4A, formerly known as Air Transport Association of America, Inc.)
provided additional information during the public comment period that
suggested nine commercial airports would be affected by the final UST
regulation. As a result of the comments received, EPA did extensive
research to confirm which commercial airports might be affected by the
final UST regulation. EPA met with personnel from DoD and from eight of
the nine suggested commercial airport facilities to gather additional
information and determine the universe of airport hydrant systems that
would have to comply with the final UST
regulation.53 54 55 56 Additionally, EPA listened to
concerns and answered questions about the 2011 proposed UST regulation.
EPA also met with release detection vendors to determine whether
commercial airports and DoD facilities could achieve release detection
compliance within the specified time frames.57 58 59 EPA
concluded that of the nine airports A4A named, eight would possibly be
affected by the final UST regulation. Based on these meetings, EPA
found that most of the commercial airport hydrant systems have release
prevention and detection equipment currently installed on them and
airport personnel are already performing various activities that can be
modified to meet the final UST regulation.
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    \53\ Discussions With Commercial Airports That May Be Affected
By The Final UST Regulation dated February 6, 2013.
    \54\ Note that EPA did not meet with personnel from Indianapolis
International Airport however, A4A and vendors stated that the
airport hydrant system is equipped with the necessary equipment to
meet requirements in the final UST regulation.
    \55\ January 28, 2013 and March 29, 2012 meetings with A4A.
    \56\ February 28, 2013 and March 18, 2013 meetings with DoD's
Defense Logistics Agency Energy.
    \57\ June 20, 2012 and May 19, 2013 meeting with Hansa Consult
of North America, LLC.
    \58\ June 20, 2012 meeting with VISTA Precision Solutions.
    \59\ August 15, 2012 meeting with Ken Wilcox and Associates.
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Process for Obtaining Public Comment
    One commenter suggested that EPA:

 Did not follow all requirements to allow stakeholder input
prior to issuing the 2011 proposed UST regulation
 Did not allow stakeholders adequate time to provide comments
 Failed to follow the correct public notice procedures
 Failed to inform stakeholders of two commercial airports that
might be affected by the final UST regulation
 May have led commercial airport stakeholders to doubt that any
commercial airport hydrant systems would be affected by the final UST
regulation
    The commenter also suggested EPA should withdraw the 2011 proposed
UST regulation because the administrative record and resulting proposal
conflicted with Executive Order 13563 (Improving Regulation and
Regulatory Review).\60\

    \60\ On January 18, 2011, President Obama issued Executive Order
13563, which directed federal agencies to develop a preliminary plan
which outlined the agency's approach for periodically reviewing
regulations to determine whether any rules ``should be modified,
streamlined, expanded, or repealed so as to make the agency's
regulatory program more effective or less burdensome in achieving
the regulatory objectives.''
---------------------------------------------------------------------------

    EPA disagrees with these comments. We performed extensive
stakeholder outreach both prior to developing the 2011 proposed UST
regulation and during the public comment period. In addition, EPA
followed procedures required by the Administrative Procedure Act for
providing public notice and requesting public comment through the
Federal Register. In order to allow additional time for airport
authorities to perform a preliminary assessment and respond to the 2011
proposed UST regulation, EPA extended the public comment period by two
months as requested by commenters.\61\ EPA met with all interested
stakeholders who requested meetings, including representatives of
commercial airports. EPA carefully researched information provided
during the public comment period; this included verifying methods of
release detection currently

in use at commercial airports and DoD facilities, as well as what
methods would be technically feasible at those facilities. When issuing
the 2011 proposed UST regulation, EPA thought Lambert-St. Louis
International Airport and Denver International Airport were the only
commercial airports that would be affected by the final UST regulation.
EPA identified these airports in a meeting with Airlines for America.
During that meeting, the Agency also received additional information on
other airports possibly affected by the proposal.\62\ While EPA did not
specifically identify the two commercial airports that would
potentially be affected by the final UST regulation, the 1988 UST
regulation has been in effect for over two decades and portions of it
have applied to airport hydrant systems since that time. Owners and
operators of these systems have been required to comply with those
applicable portions of the UST regulation since 1988, and it has been
the responsibility of owners and operators to determine whether their
airport hydrant systems are regulated since the effective date of the
1988 UST regulation. Nonetheless, EPA stated in the 2011 proposed UST
regulation that airport hydrant systems are ``. . . mainly owned by the
Department of Defense (DoD) . . .,'' not that DoD is the sole owner of
all airport hydrant systems. This statement indicates there are non-DoD
owned airport hydrant systems that could be affected by this final UST
regulation.
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    \61\ January 5, 2012 request from A4A for a 60-day extension for
more time to review and query its membership and potentially
affected airports for a more complete understanding of the 2011
proposed UST regulation and potential costs.
    \62\ January 28, 2012 meeting with A4A.
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Impacts of Regulating Airport Hydrant Systems and Field-Constructed
Tanks
    Commenters generally supported removing the deferral for these
systems. However, there were some commenters who opposed regulating
these systems. A few commenters were concerned about the costs for
owners and operators to comply with the release detection requirements
of the final UST regulation. EPA acknowledges that some release
detection methods may result in additional costs to owners and
operators. However, EPA carefully researched current release detection
efforts at commercial airports and DoD facilities and used that
information to estimate costs. See the RIA, which is available in the
docket for this action, for additional information about how we
estimated costs.
Other Regulations That Affect Airport Hydrant Systems and Field-
Constructed Tanks
    To avoid overlapping regulations, several commenters suggested EPA
evaluate other requirements that owners and operators of airport
hydrant systems and field-constructed tanks perform as part of fuel
management programs. One commenter also asserted that this evaluation
was necessary to comply with Executive Order No. 13563.\63\ After
issuing the 2011 proposed UST regulation, EPA performed this evaluation
by gathering information on fuel management programs (such as release
prevention, repairs, operation and maintenance, inspections, and
operator training) owners and operators at these facilities must
perform in order to meet other federal, state, and industry
regulations.\64\ For example, EPA found that requirements administered
by the Federal Aviation Authority (FAA), such as 14 CFR part 139
(Certification of Airports), and directives, such as ATA 103 and United
Facilities Criteria (UFC) 3-460-03, require owners and operators of
airport hydrant systems inspect airport hydrant systems and connected
components. EPA also found that 14 CFR part 139 (Certification of
Airports) emphasizes overall airport safety practices.
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    \63\ Executive Order 13563 requires federal agencies to avoid
implementing unnecessary redundant requirements and promulgate
regulations that are less burdensome to the regulated community.
    \64\ EPA performed an assessment of the following additional
requirements that owners and operators follow: 40 CFR part 112
(SPCC); 14 CFR part 139 (FAA); A4A 123; ATA 103; ATA O&M Guidance;
UFC 3-460-1 [Proposed UST Requirements Compared To Existing Facility
Requirements And Recommended Practices].
---------------------------------------------------------------------------

    One commenter asked whether EPA evaluated the SPCC requirements for
regulating underground portions of airport hydrant systems. Another
commenter suggested that EPA evaluate the effectiveness of existing
state requirements for field-constructed tanks.\65\ EPA is aware that
commercial airports and DoD facilities comply with SPCC requirements
for their airport hydrant systems and field-constructed tanks. However,
UST and SPCC regulations are complementary. The SPCC regulation focuses
on oil discharges that could impact navigable waters, while the UST
regulation focuses mainly on day-to-day maintenance and operation to
prevent releases to soil and groundwater. For example, the SPCC
regulation requires a tank inspection, such as an American Petroleum
Institute (API) Standard 653 inspection, which ensures aboveground
storage tanks and piping are structurally sound. In addition,
regulatory overlap is mitigated by the SPCC regulation, which allows
UST release detection as a method to meet its tank inspection
requirement. The SPCC regulation requires owners and operators conduct
integrity and leak testing of buried piping at the time of
installation, modification, construction, relocation, or replacement,
but does not specify a method, frequency, or leak rate. The UST
regulation is more specific and requires periodic release detection
testing of underground piping.
---------------------------------------------------------------------------

    \65\ New York allows owners and operators to perform a modified
American Petroleum Institute Standard 653 inspection combined with
monitoring well release detection for large field-constructed tanks.
---------------------------------------------------------------------------

    EPA thinks that other regulatory programs (such as SPCC and FAA)
lack the necessary specificity or do not meet equivalency criteria we
deem are necessary for these UST systems. Additionally, even though
some A4A documents provide many recommended practices that owners and
operators of airport hydrant systems and field-constructed tanks may
follow for their fuel management programs, these practices are not
regulatory requirements, and airports have the option of following
them. Moreover, EPA developed a final UST regulation that is cost
effective to the extent practical and is the least burdensome to owners
and operators, yet still protects human health and the environment.
This final UST regulation does not impose redundant requirements.
Rather, it contains complementary requirements that will protect human
health and the environment.
Effect on Airport Operations
    One commenter suggested the requirements in the 2011 proposed UST
regulation were not legally or technically viable for commercial
airports. That commenter said EPA should develop a separate regulation
specific to commercial airport hydrant systems. In addition, a few
commenters were concerned that removing the deferral for airport
hydrant systems would cause service disruptions due to installing
release prevention and detection equipment. Those commenters also said
performing release prevention and detection would cause massive service
delays, affect military missions, and threaten national security and
the National Airspace System.
    Based on discussions with DoD prior to issuing the 2011 proposed
UST regulation and talking to DoD and potentially affected airports
after issuing it, EPA concluded that most facilities already have the
necessary equipment to meet many of the requirements in the final UST
regulation. EPA also concluded from those conversations that release
detection is normally performed during service downtimes or when

operations are minimal. Some airport hydrant systems have the
capability of transferring product flow to other sections of the
airport hydrant system to avoid system downtime. DoD stated that leak
testing is performed according to prescribed requirements in Florida
and California and at least biennially in other states when funding
allows. Where feasible, piping is normally tested in segments to meet
testing leak rates; piping segments can be isolated to find leaks more
efficiently. EPA learned that some airport hydrant systems are capable
of bypassing areas when airport hydrant piping is being tested; this
avoids total system shutdown and allows continued airport operation. In
addition, many airport personnel perform daily operations and
maintenance activities, such as hydrant pit inspections and leak
monitoring, on airport hydrant system components to avoid product loss,
ensure fuel quality, and ensure personnel safety.
    This final UST regulation incorporates many of those tasks that
operators normally perform regularly to prevent and detect leaks from
these systems. However, to meet the final UST regulation, owners and
operators may need to make minor modifications to their current
activities. Since many airports have mechanisms in place and are
already performing release monitoring, meeting requirements in the
final UST regulation will not severely affect airport operations or
cause service delays severe enough to significantly affect the military
mission or disrupt the National Airspace System. EPA concluded that the
information we gathered since issuing the 2011 proposed UST regulation
supports regulating these systems as required in the final UST
regulation. In addition, this final UST regulation includes changes to
ensure compliance requirements are less disruptive and further mitigate
concerns regarding service disruptions, such as adding options owners
and operators may use to meet the release detection requirement.
Implementation Time Frame
    EPA is aware that this final UST regulation adds new requirements
for owners and operators, as well as implementing agencies which have
not fully regulated airport hydrant systems and field-constructed tanks
in the past. A few commenters voiced concerns that the proposed
implementation time frames would not give owners and operators, or
implementing agencies, adequate time to assess these systems and
determine the proper course of action. EPA thinks providing a single
effective date is important because it reduces the burden on
implementing agencies, owners, and operators to track various
compliance deadlines. EPA is also allowing owners and operators who use
periodic tightness testing for certain piping to phase in release
detection requirements up to seven years. Additionally, EPA thinks
three years gives owners and operators sufficient time for planning and
installing necessary equipment to meet the requirements in this final
UST regulation.
Other Comments
    Commenters generally supported changing the applicability date for
previously closed systems of airport hydrant systems and field-
constructed tanks, giving implementing agencies the flexibility to
require a site assessment and proper closure of systems closed between
the effective date of the 1988 UST regulation and this final UST
regulation. EPA agrees with commenters. As a result, this final UST
regulation requires owners and operators of field-constructed tanks and
airport hydrant systems, which were permanently closed before the
effective date of this final UST regulation, to conduct a site
assessment and close the UST system according to the closure
requirements if directed to do so by the implementing agency.
    In the 2011 proposed UST regulation, EPA asked commenters if we
should consider alternative options for closing very large UST systems
in place. Most commenters recommended that large field-constructed
tanks either be removed or filled with an inert solid material to
prevent releases of residual contamination to the environment. Others
suggested EPA allow some flexibility when closing these UST systems in
place. EPA agrees with commenters that implementing agencies may need
to have more flexibility in addressing these systems at closure. EPA is
modifying the closure requirement in Sec.  280.71(b) of the final UST
regulation to allow closure in place in a manner approved by the
implementing agency. This addition provides implementing agencies the
option to determine that owners and operators may close the UST system
in place without filling it with an inert solid material.
    One commenter recommended that EPA, in the final UST regulation,
directly reference the military construction standard associated with
field-constructed tank design and construction discussed in the
preamble to the 2011 proposed UST regulation. EPA agrees with the
commenter and is adding the military construction criteria UFC 3-460-
01--Petroleum Fuel Facilities to this final UST regulation.\66\
Although design standards are now available for aboveground field-
constructed tanks, EPA is not aware of standards written according to a
national code of practice developed by a nationally recognized or
independent testing laboratory for non-military field-constructed tanks
and airport hydrant systems. If demand arises and a commercial standard
is not developed to address the need, owners and operators may use the
UFC, where applicable.
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    \66\ UFC 3-460-01--Petroleum Fuel Facilities is a military
construction criteria that includes basic requirements for the
design of fueling systems; the design of receiving, dispensing, and
storage facilities; ballast treatment and sludge removal; corrosion
and fire protection; and environmental requirements.
---------------------------------------------------------------------------

Release Detection
Background
    In the preamble to the 1988 UST regulation, EPA discussed the large
volumes of product throughput, large capacities, and long lengths of
large diameter piping for airport hydrant systems. At the time, EPA
believed release detection was not feasible for airport hydrant
systems. These systems were monitored for releases periodically, but no
single leak test existed as an industry standard. Inventory control was
often used, but its sensitivity was limited due to the large product
volumes airport hydrant systems typically handle. To allow more time
for gathering information, EPA in the 1988 UST regulation deferred
regulating airport hydrant systems from release detection requirements
in subpart D. EPA also deferred UST systems with field-constructed
tanks from most requirements in the 1988 UST regulation, due to a lack
of appropriate release detection methods. At that time, EPA believed
the majority of release detection methods applied to factory built tank
systems and did not adequately work for UST systems with field-
constructed tanks or airport hydrant systems.
Challenges of Conventional Release Detection Methods
    Standard release detection methods can successfully test and detect
releases on pressurized piping at commercial service stations, but that
is not the case for airport hydrant systems and large diameter piping
associated with field-constructed tanks. For a variety of reasons, the
piping of most airport hydrant systems and field-constructed tanks
cannot meet release detection

requirements in the 1988 UST regulation. High product throughput makes
it difficult and expensive to achieve the same leak rate thresholds
established for traditional UST systems within a reasonable time frame.
Product temperature fluctuations present challenges for release
detection testing of conventional underground piping. However, release
detection for piping of airport hydrant systems and large diameter
piping associated with field-constructed tanks poses greater
challenges. As temperatures fluctuate, product expands or contracts,
increasing or decreasing product volume and pressure. The magnitude of
piping associated with these systems creates an even greater
temperature fluctuation; there are varying temperature gradients
throughout the length of piping. Fluctuating line pressure during a
release detection test can mask an existing release or falsely indicate
one occurred. In addition, the out of service period needed to test
airport hydrant piping could range from one to several days after the
last product transfer.
    Removing airport hydrant systems from service for extended periods
will greatly impede their purpose of rapid and timely delivery of fuel
to aircraft. When using pressure based testing methods to produce
accurate leak test results, airport hydrant system piping needs to be
isolated in appropriately sized segments. Some airport hydrant systems
have numerous isolation points with connections for release detection
equipment. Others have longer underground piping segments with
isolation valves for testing located up to 0.5 miles apart. The greater
the volume of a segment, the more time it takes to obtain a valid
result at a given leak rate. Although technology is available, it may
be cost prohibitive and require significant facility down time for
owners and operators to monitor airport hydrant systems for releases at
the rates and frequencies required in the 1988 UST regulation.
    EPA also recognizes that most release detection methods for factory
built tanks are capable of monitoring UST systems with field-
constructed tanks up to 50,000 gallons. After evaluating current
methods, EPA realized existing release detection options for tanks in
subpart D of the 1988 UST regulation are generally not applicable to
UST systems greater than 50,000 gallons because most methods are
limited by tank capacity. EPA acknowledges the complexities in
performing release detection on tanks significantly larger than 50,000
gallons. It is critical to allow sufficient time for a tank to reach a
state of equilibrium prior to performing a test. As tank size
increases, the time for a tank to reach an equilibrium increases
significantly. Based on discussions with release detection vendors,
many larger tanks require multiple inactive days to yield an accurate
test result.
    DoD owns most UST systems with field-constructed tanks. Taking
these tanks out of service for multiple days to meet the 1988 release
detection requirement would, in some cases, impede DoD's mission, be
impractical to sustain, and result in significant costs.
Release Detection Is Now Available
    While release detection used for conventional USTs may not work
well for airport hydrant systems and field-constructed tanks greater
than 50,000 gallons, release detection methods specifically designed
for these UST systems are now available. Over the last 25 years, the
petroleum services industry has developed release detection
technologies for airport hydrant systems and field-constructed tanks.
The NWGLDE lists Large Diameter Line Leak Detection Method (6 Inches
Diameter Or Above) and Bulk Underground Storage Tank Leak Detection
Method (50,000 Gallons Or Greater), both of which identify methods
capable of detecting releases from airport hydrant systems and field-
constructed tanks.\67\ EPA contacted several vendors to determine the
strengths and limitations of release detection methods for these UST
systems. EPA also talked with DoD's Defense Logistics Agency (DLA)
Energy \68\ about challenges in addressing release detection
requirements in states, such as California, which do not defer airport
hydrant systems from release detection. Because they perform release
detection on airport hydrant systems in other states, DLA Energy has
significant information about airport hydrant system release detection.
As of this final UST regulation, some state UST programs require
release detection for UST systems with field-constructed tanks and
airport hydrant systems.\69\
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    \67\ National Work Group On Leak Detection Evaluation's List Of
Leak Detection Evaluations For Storage Tank Systems. http://www.nwglde.org/.
    \68\ Defense Logistics Agency Energy was formerly known as
Defense Energy Support Center.
    \69\ Tasks 2-4, Work Assignment 1-25: Preliminary Assessment and
Scoping of Data Related to Potential Revisions to the UST
Regulations; Industrial Economics (IEc) Inc. identified 17 state UST
programs that regulate airport hydrant systems. EPA's Office of
Underground Storage Tanks gathered additional information from seven
of nine select state UST programs to identify the extent of the
state's release detection requirements and compare those
requirements to the release detection requirements in EPA's proposed
2011 UST regulation.
---------------------------------------------------------------------------

Feasibility of Proposed Release Detection Options for Piping
    In order to allow owners and operators flexibility to meet the
release detection requirement, EPA proposed these four alternatives for
underground piping associated with airport hydrant systems and field-
constructed tanks greater than 50,000 gallons:

 Pressure based line testing methods
 Continuous interstitial monitoring
 Automatic line leak detector combined with interstitial
monitoring and
 Other methods approved by implementing agencies

    EPA requested comment or additional data on the proposed release
detection requirements to determine their feasibility. Several
commenters said the options in the 2011 proposed UST regulation were
insufficient and requested EPA provide options that offered owners and
operators more choices. A4A provided EPA with the names of nine
commercial airports that could be affected by the final UST regulation
and the feasibility of applying the release detection methods discussed
in the 2011 proposed UST regulation to these airports. This information
helped EPA further refine this final airport hydrant system
requirements, including release detection.
    A4A stated that the only feasible choice EPA provided was pressure
based methods and substantial retrofits would be required to meet the
requirements at Chicago O'Hare International Airport (ORD), John F.
Kennedy International Airport (JFK), and possibly other airports.
However, EPA through our analysis and in depth discussions with those
airports, thinks the airport hydrant system at JFK, as currently
configured, may not meet the definition of an UST in this final UST
regulation; this means the requirements would not apply. In addition,
if planned capital upgrades are completed on one of ORD's airport
hydrant systems, that system may not meet the definition of an UST and
would not be subject to this final UST regulation. If configurations
for either of these airport hydrant systems change in the future, the
owner and operator must re-evaluate the system to determine if it meets
the definition of UST in this final UST regulation. Owners and
operators are responsible for determining whether their airport hydrant
systems meet the definition of an UST and, if necessary, comply with
this final UST regulation.
    As a result of comments and while developing the final UST
regulation, EPA met with DoD, A4A, personnel

representing potentially impacted commercial airports, and release
detection vendors to develop release detection methods for the final
UST regulation and determine how or if commercial airports and DoD
facilities could achieve compliance within the specified time
frames.70 71 72 73 74 From those discussions, EPA found that
most, if not all, of the potentially affected commercial airports have
or will have mechanisms in place to achieve compliance with the release
detection requirements in this final UST regulation. In addition,
owners and operators already implement release detection according to
technical requirements in states where airport hydrant systems are not
deferred. EPA found that many of these airport hydrant systems perform
a type of inventory management and hydrostatic testing of the piping
system to detect pressure changes in the UST system. EPA determined
that although the 1988 UST regulation did not require airport hydrant
system owners and operators perform these tests, both DoD facilities
and commercial airports have already been performing various fuel
management methods to monitor and track fuel inventories.
---------------------------------------------------------------------------

    \70\ January 28, 2012 and March 29, 2012 meetings with
representatives from Airlines for America.
    \71\ February 28, 2013 and March 18, 2013 meetings with DoD's
Defense Logistics Agency Energy.
    \72\ June 20, 2012 and May 19, 2013 meeting with Hansa Consult
of North America, LLC.
    \73\ June 20, 2012 meeting with VISTA Precision Solutions.
    \74\ August 15, 2012 meeting with Ken Wilcox and Associates.
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Release Detection Options for Piping in the Final UST Regulation
    Based on comments, EPA is providing flexibility for owners and
operators of piping associated with airport hydrant systems and field-
constructed tanks greater than 50,000 gallons to meet the release
detection requirements. This final UST regulation modifies the piping
release detection options in the 2011 proposed UST regulation and
incorporates some of the methods currently used at commercial airports
and DoD facilities. Owners and operators of these systems may use
existing piping release detection options provided in subpart D (except
for passive groundwater and vapor monitoring, which must be combined
with inventory control as described below), or they may use alternative
piping release detection methods in Sec.  280.252(d)(2). EPA thinks
these options are reasonable and represent an appropriate balance of
practicality and protectiveness. Piping associated with field-
constructed tanks 50,000 gallons or less in capacity must use the
release detection options listed in subpart D.
Pressure Based Testing
    The final UST regulation allows owners and operators to perform
pressure based testing methods according to performance criteria
dependent on volume of the line segment tested. These criteria provide
specific performance thresholds for both semiannual and annual testing.
Owners and operators may perform semiannual or annual line testing at
or above operating pressure with a probability of detection of 0.95 and
a probability of false alarm of 0.05. This method allows owners and
operators to meet a variable leak rate based on piping test section
volume. The leak rate ranges from 1 to 3 gallons per hour, depending on
piping volume for semiannual testing and from 0.5 to 1.5 gallons per
hour for annual testing. The final UST regulation establishes 3 gallons
per hour as the maximum threshold because the majority of available
testing methods are capable of meeting this leak rate.
    For the first six years (or two test periods), piping segments that
cannot meet a 3 gallons per hour threshold are allowed to meet a higher
threshold of up to 6 gallons per hour. Available methods are capable of
testing segments to a leak rate of 6 gallons per hour. The higher
threshold provides for use of existing test methods during the first
six year period. Six years will provide owners and operators time to
upgrade their piping systems to meet the up to 3 gallons per hour
threshold for semiannual testing. Between years six and seven, owners
and operators must conduct one additional tightness test that, at a
minimum, meets the semiannual testing threshold. In the seventh year,
owners and operators must begin meeting the semiannual or annual line
tightness testing requirements according to the requirements in Sec.
280.252(d)(2)(i). EPA is providing a three year phase-in period for the
remaining release detection options, because these methods will not
require significant construction or upgrades for implementation.
    EPA asked commenters whether other release detection options should
be considered for underground piping associated with airport hydrant
systems and field-constructed tanks greater than 50,000 gallons. Based
on comments, EPA is adding inventory control, groundwater and vapor
monitoring, and other methods for piping as release detection options
in this final UST regulation.
Inventory Control
    EPA reviewed performance standards for daily inventory control
procedures used by DoD and the commercial airports identified by
A4A.75 76 Based on performance standards for daily inventory
control procedures performed by both DoD and A4A, EPA is allowing
inventory control as part of a combination method of release detection.
EPA chose 0.5 percent of flow through as the performance standard for
inventory control because this value represents the maximum tolerance
allowed under the performance standard for products typically stored or
handled by airport hydrant systems. Owners and operators may conduct
inventory control according to DoD Directive 4140.25, ATA's Airport
Fuel Facility Operations and Maintenance Guidance Manual, or equivalent
procedures. EPA is allowing this method in combination with either a
pressure based line tightness test using the leak rates from the
semiannual test in Sec.  280.252(d)(2)(i) at least once every two
years, or passive groundwater or vapor monitoring once every 30 days as
described below.
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    \75\ DoD's Bulk Petroleum Management Policy--DoD 4140.25-M,
Volume II--Petroleum Management, Chapter 10--Accountability (June
22, 1994) is accessible on line at: http://www.dtic.mil/whs/directives/corres/pdf/414025-m-vol2-chapter10.pdf. This standard
recognizes that petroleum products are subject to losses and gains.
The tolerance factor that represents the amount of fuel which might
be lost or gained under normal conditions varies by product and
status of fuel (i.e., storage or in transit). These values in the
policy represent standard tolerances (i.e., system flow-through) for
various products in transit and storage: (1) Aviation and motor gas
= 0.5 percent and 0.5 percent; (2) JP4 = 0.5 percent and 0.3
percent; (3) Jet Fuel, Distillates, Residuals = 0.5 percent and 0.25
percent; and (4) JP5, JP8, DF2, F76, etc. = varies by individual
agreements with airports and 0.5 percent.
    \76\ EPA reviewed Airlines For America Guidance--ATA Airport
Fuel Facility Operation and Maintenance Guidance Manual, Revision
2004.1; and ATA Spec 123: Procedures for the Accounting of Jet Fuel
Inventory 2011.2. The two documents provide guidance for operators
to investigate, report, or explain any variances exceeding 0.1 percent.
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Groundwater and Vapor Monitoring
    EPA proposed to phase out groundwater and vapor monitoring as
release detection methods in the 2011 proposed UST regulation. However,
this final UST regulation retains these methods with modifications. See
section D-6 for more information. These methods are also allowed with
some modifications in subpart K. EPA divided vapor monitoring into two
categories: Active monitoring for chemical markers or tracers and
passive monitoring for stored product in the tank system. Owners and
operators of these systems

may use active vapor monitoring methods characterized by testing or
monitoring of chemical markers or a tracer compound placed in the tank
system, according to Sec.  280.43(e) to detect a release of at least
0.1 gallon per hour with probabilities of detection and false alarm of
0.95 and 0.05, respectively. Owners and operators choosing this option
must conduct this test at least once every two years. This method may
be used as a stand-alone method of release detection.
    Owners and operators may also combine passive vapor or groundwater
monitoring with inventory control, described above, that can detect a
release of at least 0.5 percent of flow through at least every 30 days.
Passive vapor monitoring or groundwater monitoring must be conducted at
least every 30 days according to Sec.  280.43(e) or (f), respectively.
Other Methods for Piping
    The final UST regulation maintains the option for owners and
operators to use alternative methods of release detection for piping
approved by the implementing agency, as discussed in the 2011 proposed
UST regulation. This provides flexibility for owners and operators to
comply by using methods or a combination of methods equivalent to the
requirements in Sec.  280.252(d)(2). EPA recognized that other methods
not included in Sec.  280.252(d)(2) could be acceptable, as long as
they are as effective and are approved by implementing agencies. The
performance criteria for piping release detection methods in Sec.
280.252(d)(2) provide owners and operators with information about how
to demonstrate the effectiveness of release detection methods that must
be approved by the implementing agency.
Proposed Release Detection Options for Piping Not Included in the Final
UST Regulation
    Because piping segments associated with airport hydrant systems and
field-constructed tanks can contain large volumes of regulated
substances, EPA asked commenters if it was feasible to require ALLDs to
detect a leak at 3 gallons per hour at 10 pounds per square inch line
pressure within one hour or equivalent. EPA anticipated receiving
information on the appropriate leak rate for ALLDs on this piping. EPA
did not receive any indication that current performance standards of
ALLDs could be modified for these systems. Although some portions of
existing systems may be able to use this option, EPA agrees it is not
feasible to use an ALLD with interstitial monitoring on piping
associated with airport hydrant systems and field-constructed tanks.
    This final UST regulation modifies the 2011 proposed UST
regulation; owners and operators of airport hydrant systems or piping
associated with field-constructed tanks greater than 50,000 gallons are
not provided specific requirements in this final UST regulation for
using continuous interstitial monitoring and the combination of
automatic line leak detectors with interstitial monitoring for piping.
Many of these systems lack secondary containment and automatic line
leak detectors cannot adapt to the operating pressures of these
systems. In the 2011 proposed UST regulation, EPA asked if testing the
piping for airport hydrant systems and field-constructed tanks at
operating pressure was sufficient. The 1988 UST regulation requires
owners and operators test conventional systems at one and a half times
operating pressure. EPA is aware that airport hydrant system piping
operates at high pressures and agrees with commenters who stated that
testing above operating pressure might be infeasible. This final UST
regulation requires owners and operators to test these systems at least
at operating pressure, because these large piping systems operate at
pressures much higher than conventional gasoline stations. However, EPA
is allowing testing at or above operating pressure, but is not
providing a set value. Professional testers can decide the appropriate
pressure to test these systems, as long as the pressure is at least the
operating pressure of the system.
Release Detection Requirements for Tanks Associated With Airport
Hydrant Systems and Field-Constructed Tanks
    This final UST regulation establishes release detection
requirements for tanks associated with airport hydrant systems and
field-constructed tanks. Airport hydrant systems may consist of a
series of large capacity shop fabricated tanks, although some airport
hydrant systems use field-constructed tanks. Shop fabricated tanks and
field-constructed tanks with a capacity less than or equal to 50,000
gallons must meet the requirements in subpart D. Field-constructed
tanks with capacity greater than 50,000 gallons must either be
monitored using release detection methods in subpart D (except for
passive groundwater and vapor monitoring which must be combined with
inventory control as described below) or use one of the alternative
methods for tanks listed at Sec.  280.252(d)(1).
Feasibility of Proposed Release Detection Options for Field-Constructed
Tanks
    To allow owners and operators more flexibility in meeting the
release detection requirement, EPA proposed these four alternatives for
UST systems with field-constructed tanks greater than 50,000 gallons:
     Annual tank tightness test
     Automatic tank gauging system that can detect a 1 gph leak
combined with a tank tightness test every three years
     Automatic tank gauging system that can detect a 2 gph leak
combined with a tank tightness test every two years and
     Other methods approved by the implementing agency
    EPA requested comment or additional data on the proposed release
detection options to determine their feasibility. Most commenters
thought the release detection options were appropriate and sufficient.
One commenter thought EPA should include chemical marker or tracer
testing. Another commenter thought EPA should expand the types of
release detection methods specified in the final UST regulation to
include use of sensors, probes, monthly visual inspections, or other
methods approved by the implementing agency.
    EPA met with and obtained information from DoD and release
detection vendors throughout the regulatory process. EPA researched
suggested release detection options and standard practices conducted by
DoD following the public comment period for the 2011 proposed UST
regulation. EPA found that these facilities perform inventory
management on their UST systems. EPA determined that although not
performed as specified in the 1988 UST regulation, some DoD facilities
are performing fuel management methods to monitor and track fuel
inventories for their field-constructed tanks.77 78
---------------------------------------------------------------------------

    \77\ Final Report--Validation of the Low-Range Differential
Pressure (LRDP) Leak Detection System for Small Leaks in Bulk Fuel
Tanks Environmental Security Technology Certification Program, U.S.
Department of Defense.
    \78\ DoD 4140.25-M: Management of Bulk Petroleum Products,
Storage, and Distribution Facilities, Volume V http://www.dtic.mil/whs/directives/corres/html/414025m_vol1_3.html.
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Release Detection Options for Field-Constructed Tanks in the Final UST
Regulation
    Based on comments and additional information from DoD as well as
commercial airports about their operations, EPA is including in this
final UST regulation all release

detection options discussed in the 2011 proposed UST regulation. EPA is
also adding three other options to this final UST regulation. Owners
and operators of field-constructed tanks less than or equal to 50,000
gallons must meet the release detection requirements in subpart D.
Owners and operators of field-constructed tanks greater than 50,000
gallons must use the alternative release detection methods described in
subpart K or the release detection options in subpart D (except that
groundwater and vapor monitoring must be used in combination with
inventory control as described below). EPA thinks these options are
reasonable and will quickly detect releases when they occur.
Tank Tightness Testing
    In the 2011 proposed UST regulation, EPA discussed the option of
owners and operators performing annual tank tightness testing that can
detect a 0.5 gallon per hour leak rate. EPA proposed this performance
standard based on information about leaks from several field-
constructed tanks. The information indicated leak rates from the tanks
ranged from 0.31 gph to 10 gph, with a median leak rate of 0.58 gph.
EPA determined that most available methods were capable of meeting the
proposed leak rate of 0.5 gph. EPA did not receive comments regarding
the performance standard during the public comment period. The final
UST regulation retains the option for owners and operators to perform
annual underground tank tightness testing that can detect a 0.5 gallon
per hour leak rate.
Automatic Tank Gauging Combinations with Tank Tightness Testing
    This final UST regulation allows owners and operators to combine an
automatic tank gauging system with a tank tightness test that achieves
different leak rates during different periods of performance. One
combination uses an automatic tank gauging system performing release
detection at least every 30 days that can detect a leak rate less than
or equal to 1 gallon per hour with a tank tightness test that can
detect a 0.2 gallon per hour leak rate performed at least every three
years. Another combination couples an automatic tank gauging system
performing release detection at least every 30 days that can detect a
leak rate less than or equal to 2 gallons per hour with a tank
tightness test that can detect a 0.2 gallon per hour leak rate
performed at least every two years. This automatic tank gauging
requirement is different from the release detection requirement in the
1988 UST regulation for factory built tanks. These leak rates and time
frames for release detection testing are appropriate because they will
detect releases within a reasonable time frame, given the large tank
sizes and time needed to perform testing on these tanks.
Inventory Control
    This final UST regulation allows inventory control combined with
one of these methods: passive groundwater monitoring every 30 days,
passive vapor monitoring every 30 days, or a 0.5 gallon per hour tank
tightness test performed at least once every two years. The inventory
control option must meet the same requirements as inventory control for
piping associated with airport hydrant systems and field-constructed
tanks described in the Release Detection Options for Piping in the
Final UST Regulation section above.
Groundwater and Vapor Monitoring
    This final UST regulation allows active vapor monitoring for tanks
using the same requirements as described in the Release Detection
Options for Piping in the Final UST Regulation section above. In
addition, owners and operators may also use a combination method
incorporating inventory control and passive vapor monitoring or
groundwater monitoring using the requirements described in the Release
Detection Options for Piping in the Final UST Regulation section above.
Other Methods for Field-Constructed Tanks
    Implementing agencies may approve another method if the owner and
operator demonstrate the method can detect a release as effectively as
any of the other five methods described in the Release Detection
Options for Field-Constructed Tanks section. In comparing methods, an
implementing agency shall consider the size of release the method can
detect and frequency and reliability of detection. Other methods are
described in Other Methods for Piping.
Release Detection Recordkeeping
    This final UST regulation requires owners and operators maintain
records of release detection for field-constructed tanks and airport
hydrant systems in accordance with Sec.  280.45. The results of any
sampling, testing, or monitoring must be maintained for at least one
year except as follows: Tank tightness testing; line tightness testing;
and vapor monitoring using a tracer compound placed in the tank system
must retain records until the next test is conducted. EPA is requiring
owners and operators maintain these records until the next test is
conducted because owners and operators can choose different time frames
to conduct release detection testing. This additional flexibility
results in some testing occurring at frequencies ranging from less than
one year to up to three years.
Release Prevention
    As with all other regulated UST systems, this final UST regulation
requires airport hydrant systems and field-constructed tanks meet
corrosion protection, spill, and overfill requirements, as well as
walkthrough inspections.
Corrosion Protection
    This final UST regulation requires all airport hydrant systems and
field-constructed tanks that routinely contain regulated substances and
are in contact with the ground to meet corrosion protection
requirements in Sec.  280.252(b)(1). Metal tanks and piping which are
encased or surrounded by concrete have no metal in contact with the
ground and are not subject to the corrosion protection requirements.
Because interim prohibition for deferred UST systems in the 1988 UST
regulation has been in effect since May 1985, many of these systems are
already equipped with corrosion protection (that is, constructed of:
Non-corrodible material, coated and cathodically protected steel,
fiberglass reinforced plastic, or steel tank clad with fiberglass
reinforced plastic). In this final UST regulation, EPA renames Sec.
280.11 to Installation requirements for partially excluded UST systems.
For corrosion protection, airport hydrant systems and field-constructed
tanks must meet the requirements in Sec.  280.252(b)(1). Owners and
operators must meet this requirement within three years of the
effective date of this final UST regulation.
    This final UST regulation does not allow an internal lining as a
method for meeting the corrosion protection upgrade requirement. EPA is
not allowing an internal lining as corrosion protection because it does
not protect steel in contact with the ground from corroding and causing
a release to the environment. Field-constructed tanks and tanks
associated with airport hydrant systems, which are not upgraded
according to Sec.  280.252(b), and are installed on or before the
effective date of this final UST regulation must be permanently closed
according to Sec.  280.70.
Spill and Overfill Prevention
    EPA concludes that using properly functioning equipment, which is

operated according to manufacturer guidelines, is necessary to protect
human health and the environment. After discussions with industry, DoD,
and commercial airport personnel, EPA understands that existing airport
hydrant systems are generally already equipped with spill and overfill
prevention equipment to prevent spills and overfills. This final UST
regulation requires owners and operators of airport hydrant systems and
field-constructed tanks to have spill and overfill prevention equipment
and conduct testing or inspections of the equipment. This will ensure
the systems and tanks operate properly, contain releases, and decrease
the likelihood of a leak into the environment. Owners and operators
must install spill and overfill prevention equipment and conduct the
first test or inspection within three years of the effective date of
this final UST regulation, then at least once every three years
thereafter. For more information on spill prevention equipment testing
and overfill prevention equipment inspections, see sections B-2 and B-
3, respectively.
Walkthrough Inspections
    Owners and operators need to properly operate and maintain their
UST system equipment in order to prevent and quickly detect releases.
Therefore, this final UST regulation adds requirements for owners and
operators of airport hydrant systems and field-constructed tanks to
perform periodic walkthrough inspections to prevent and quickly detect
releases.
    EPA found that owners and operators of airport hydrant systems are
required to ensure safety and fuel quality, and frequently inspect
these systems as part of other requirements and recommendations to
ensure system components are operating properly. In addition, EPA
understands that airport hydrant systems and some field-constructed
tank facilities are already performing operation and maintenance
inspections that ensure their systems and associated spill and overfill
equipment are operating properly. Thus, EPA found these requirements
will impose little, if any, additional burden at these facilities. This
final UST regulation requires owners and operators of airport hydrant
systems and field-constructed tanks conduct walkthrough inspections
according to Sec.  280.36. In addition, EPA is requiring owners and
operators inspect hydrant pits and hydrant piping vaults. These areas
are unique to airport hydrant systems. It is important to look at
hydrant pits and hydrant piping vaults as part of periodic walkthrough
inspections to ensure these areas are: Free of liquid and debris, not
damaged, and free of leaks. Owners and operators must inspect these
areas at least once every 30 days if OSHA confined space entry is not
required or at least annually if OSHA confined space entry is required.
See 29 CFR part 1910 for information about OSHA confined space entry.
Some owners and operators already periodically check these areas using
the ATA guidance manual, Airport Fuel Facility Operations and
Maintenance Guidance Manual. Owners and operators must conduct the
first inspection within three years of the effective date of the final
UST regulation. For more information on walkthrough inspections, see
section B-1.
Secondary Containment
    This final UST regulation does not require secondary containment
for new and replaced piping associated with field-constructed tanks
greater than 50,000 gallons in capacity or piping associated with
airport hydrant systems. EPA understands this piping typically is
larger diameter and runs for long distances, making it difficult to
slope the piping to an interstitial monitoring area. In addition, EPA
understands it is difficult to keep water out of the interstitial area
of long piping runs. Since nearly all this piping is steel, corrosion
can occur in the interstitial area when an electrolyte, such as water,
is in the interstitial area. This corrosion can significantly shorten
the piping's operational life. Corrosion protection on the outside of
the piping protects the part of the piping in contact with the ground
from corrosion, but does not protect the inside part of piping from
corrosion. To prevent corrosion caused by water in the interstitial
area, owners and operators would need to add corrosion protection
inside the interstitial area of piping, which EPA realizes would be
difficult to do. Given these issues, EPA has determined that requiring
secondary containment for these piping runs is not practical.
    However, EPA is requiring secondary containment for new and
replaced piping associated with field-constructed tanks 50,000 gallons
or less that do not feed airport hydrant system piping. EPA understands
that new, smaller field-constructed tanks, such as those constructed
within tanks following permanent closure of an existing UST, typically
have piping similar to that installed at commercial gasoline stations.
This piping can effectively meet the secondary containment requirements
and better protect the environment. For more information, see section
A-2, Secondary Containment.
Notification
    The 1988 UST regulation did not require owners of airport hydrant
systems or field-constructed tanks to comply with the notification
requirements of Sec.  280.22, which included certifying proper
installation of airport hydrant systems. The 2011 proposed UST
regulation required owners and operators of airport hydrant systems and
field-constructed tanks installed prior to the effective date of the
final UST regulation provide notification of existence to implementing
agencies within 30 days of the effective date of this final UST
regulation. This final UST regulation modifies the 2011 proposed UST
regulation by requiring owners and operators provide a one-time
notification of existence to implementing agencies no later than 3
years after the effective date of this final UST regulation. EPA agrees
with commenters that airport hydrant system owners and operators need
more than 30 days to provide the one-time notification of existence.
This change allows owners and operators, as well as implementing
agencies, time to identify airport hydrant systems covered by the final
UST regulation and gives implementing agencies time to include these
systems in their inventories. The final UST regulation does not
consider currently installed tanks, including airport hydrant systems,
as new UST systems. Therefore, EPA is requiring owners and operators
only certify proper installation for airport hydrant systems and field-
constructed tanks installed on or after the effective date of the final
UST regulation according to Sec.  280.22. In addition, EPA is requiring
owners notify within 30 days of ownership change. See section D-3 for
more information on notification requirements.
Financial Responsibility
    Because EPA is eliminating the deferral for airport hydrant systems
and field-constructed tanks, they are no longer be excluded from the
financial responsibility requirements in subpart H. Owners and
operators who install these UST systems after the effective date of
this final UST regulation must comply with the financial responsibility
requirements at installation. Owners and operators of airport hydrant
systems and field-constructed tanks in use as of the effective date of
this final UST regulation must have financial responsibility when they
submit the one-time notification of existence for

these systems. However, subpart H exempts federal and state entities,
which means that federal and state owners and operators of airport
hydrant systems and field-constructed tanks do not have to meet the
financial responsibility requirement.
Operator Training
    EPA is aware that commercial airports are required to follow fuel
facility training requirements of 14 CFR part 139; however, those
requirements do not cover specifics of the UST requirements. This final
UST regulation requires owners and operators of airport hydrant systems
and field-constructed tanks meet the operator training requirements of
subpart J. Owners and operators of some airport hydrant systems that
are considered underground storage tanks may have already complied with
state operator training requirements. For example, personnel from
General Mitchell Field in Wisconsin report that operators have received
Wisconsin class A and B operator training certification. All owners and
operators must begin meeting this requirement not later than three
years after the effective date of this final UST regulation. For more
information see section A-1, Operator Training.
Partially Excluded Components
    EPA regulates UST systems, including tanks and underground piping,
in 40 CFR part 280 and aboveground tanks in 40 CFR part 112 (Oil
Pollution Prevention). Facilities with greater than 1,320 gallons of
aboveground oil storage capacity that could reasonably be expected to
discharge oil into navigable waters or adjoining shorelines are subject
to the SPCC regulation under the authority of the Clean Water Act.\79\
The SPCC regulation includes requirements for oil spill prevention,
preparedness, and response to prevent oil discharges into navigable
waters and adjoining shorelines. The SPCC regulation also requires
regular inspections of aboveground valves, piping, and appurtenances
along with integrity and leak testing of buried piping at the time of
installation, modification, construction, relocation, or replacement.
Facilities regulated by the SPCC regulation must also prepare and
maintain a written SPCC plan that includes measures to prevent, prepare
for, and respond to oil discharges that threaten navigable waters or
adjoining shorelines.
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    \79\ http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=b843807afdc641b203ffec44aa671d36&rgn=div5&view=text&node=40:<IP_ADDRESS>.7&idno=40.
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    Aboveground storage tanks associated with airport hydrant systems
and field-constructed tanks covered in this final UST regulation do not
have to meet many of the requirements in the UST regulation because
they are neither beneath the surface of the ground, nor in contact with
the ground. For these reasons, the SPCC regulation is the most
effective means of addressing the aboveground storage tanks associated
with UST systems. Airport hydrant systems that do not meet the
definition of UST system because the underground portion is less than
10 percent of the system capacity may be subject to the SPCC regulation
for both the aboveground and underground portions of the system.
Underground storage tank components such as hydrant pits and piping
vaults are considered part of the UST system and subject to the
requirements in 40 CFR part 280.
Complementary Regulation of Partially Buried Tanks
    Partially buried (also called partially covered) field-constructed
tanks may be regulated by both this final UST regulation and the SPCC
regulation. The SPCC regulation exempts only completely buried storage
tanks subject to all of 40 CFR part 280.\80\ Additionally, the SPCC
regulation covers tanks situated on top of the ground's surface or
partially buried (for example, bunkered, also referred to as mounded
tanks) and considers these to be aboveground storage tanks. If 10
percent or more of the total capacity of the tank or tanks and
underground piping is underground, the tank system meets the definition
of an UST regulated by 40 CFR part 280 or state equivalent program
approved under 40 CFR part 281. Therefore, these containers or systems
are covered by both SPCC and UST regulations. These regulations are
complementary because the SPCC regulation focuses on oil discharges
that could impact navigable waters or shorelines, while the UST
regulation focuses primarily on day-to-day maintenance and operation to
prevent releases that impact soil and groundwater.
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    \80\ 40 CFR 112.2 defines completely buried as any container
completely below grade and covered with earth, sand, gravel,
asphalt, or other material. Containers in vaults, bunkered tanks, or
partially buried tanks are considered aboveground storage containers
for purposes of the part.
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Change from Deferred to Partially Excluded
    The 2011 proposed UST regulation used the term deferred for
aboveground storage tanks associated with airport hydrant systems and
field-constructed tanks considered to be UST systems. The proposal
indicated that although these aboveground storage tanks would be
subject to some parts of the final UST regulation, EPA intended to
continue evaluating whether to fully regulate them in the future. EPA
reconsidered these aboveground storage tanks and is making the final
determination that the SPCC requirements are the most effective means
for addressing oil discharges from aboveground storage tanks. This
final UST regulation excludes from subparts B, C, D, E, G, J, and K
aboveground storage tanks associated with airport hydrant systems and
field-constructed tanks. Aboveground storage tanks that are part of an
UST system must continue to meet the requirements of subparts A and F.
3. Wastewater Treatment Tank Systems that Are Not Part of a Wastewater
Treatment Facility Regulated Under Sections 402 or 307(b) of the Clean
Water Act
    In the 2011 proposed UST regulation, EPA removed the existing
deferral in Sec.  280.10(c)(1) for wastewater treatment tank systems
that are not part of a wastewater treatment facility regulated under
sections 402 or 307(b) of the Clean Water Act. Since the 1988 UST
regulation, owners and operators of these systems (hereafter referred
to as wastewater treatment tanks) were deferred from complying with 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); and H
(Financial Responsibility). Owners and operators have been required to
comply with requirements for interim prohibition and release response
and corrective action (40 CFR part 280, subparts A and F) since the
effective date of the 1988 UST regulation. However, removing the
deferral, as discussed in the 2011 proposed UST regulation, would have
required owners and operators comply with all subparts of 40 CFR part
280.
Change from Deferred to Partially Excluded
    The 1988 UST regulation used the term deferred for wastewater
treatment tanks. Although these tanks were subject to some parts of the
UST regulation, EPA intended to continue evaluating whether or not to
regulate 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.
    EPA deferred wastewater treatment tanks in the 1988 UST regulation
due to uncertainty about the number of tanks that existed and the
appropriateness of release detection for these systems. EPA's intent in
removing the deferral for these tanks in the 2011 proposed UST
regulation was to regulate them further, which would protect human
health and the environment from discharges of regulated substances
contained in these systems. EPA used the proposal to obtain additional
information on these systems, and determine if there were appropriate
release prevention and detection technologies available to fully
regulate them according to the UST regulation. According to commenter
responses, EPA determined that these tanks are often subject to other
environmental regulations; it may not be technically feasible to
install release prevention and detection equipment on these systems due
to varying designs of these systems; and many of these systems contain
mostly water and are not significant sources of contamination.
Installation Requirements for Partially Excluded Tanks
    In the 1988 UST regulation, deferred wastewater treatment tanks
were required to meet the interim prohibition requirements at 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).
Therefore, these tanks are already equipped with corrosion protection
if they were installed after the effective date of the 1988 UST
regulation. EPA thinks it is appropriate to maintain this requirement,
which ensures these tanks are provided with some degree of corrosion
protection to prevent releases into the environment. 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.
    Many commenters did not support removing the deferral to regulate
these UST systems and were unsure of the universe of wastewater
treatment tanks. To address this concern, EPA developed a February 2012
document describing wastewater treatment tanks that would have been
regulated under the final UST regulation.\81\ Several commenters also
voiced concern that regulating these systems may result in unintended
consequences (for example, impracticability of technical requirements
and dual regulation) for owners and operators and implementing
agencies. To help determine the feasibility of the 2011 proposed UST
regulation, EPA asked several stakeholders about operating various
types of wastewater treatment tanks.82 83 84 EPA also
gathered information from commenters about implementing other
regulations that apply to these systems.85 86 87 88 After
considering commenters' feedback, EPA concluded that the historic level
of regulation for these tanks is appropriate and provides adequate
controls to ensure environmental protection.
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    \81\ http://www.epa.gov/oust/fedlaws/wwtts_2-29-12_final.pdf.
    \82\ April 2012 telephone conversation with Tom Groves, New
England Interstate Water Pollution Control Commission.
    \83\ April 2012 telephone conversation with Ming Pan,
Massachusetts Department of Environmental Protection.
    \84\ April 2012 telephone conversation with Joe Cerutti,
Massachusetts Department of Environmental Protection.
    \85\ March 2012 telephone conversation with Kevin Brackney, Nez
Perce Tribe.
    \86\ April 2012 telephone conversation with Chris Wiesberg,
Missouri Department of Natural Resources.
    \87\ April 2012 telephone conversation with Mary Hansen,
Washington State Department of Ecology.
    \88\ May 2012 telephone conversation with Candace Cady, Utah
Department of Environmental Quality.
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    This final UST regulation excludes owners and operators of
wastewater treatment 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). EPA is basing this decision on
maintaining the installation requirement (Sec.  280.11), other
regulatory controls in place, and the additional information gathered.
Owners and operators of wastewater treatment 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).
4. USTs Containing Radioactive Material and Emergency Generator UST
Systems at Nuclear Power Generation Facilities Regulated by the Nuclear
Regulatory Commission
    In the 2011 proposed UST regulation, EPA maintained the existing
deferral in Sec.  280.10(c)(2) and (3) for USTs containing radioactive
material and for emergency generator UST systems at nuclear power
generation facilities regulated by the United States Nuclear Regulatory
Commission (NRC). Since the 1988 UST regulation, owners and operators
of these tanks were deferred from complying with 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); and H (Financial
Responsibility). Owners and operators have been required to comply with
requirements for interim prohibition and release response and
corrective action (40 CFR part 280, subparts A and F) since the
effective date of the 1988 UST regulation.
    After review of DOE Orders and NRC regulations,\89\ EPA determined
these requirements are comparable to EPA requirements for new and
existing USTs regarding spill and overfill control (Sec.  280.30);
operation and maintenance of corrosion protection (Sec.  280.31); and
release detection (40 CFR part 280, subpart D). DOE established
standards for facility operations that: protect the public and
environment from exposure to radiation from radioactive

materials; 90 91 92 protect workers; \93\ provide industrial
safety; \94\ and ensure compliance with applicable federal, state, and
local laws, as well as Executive Orders and other DOE directives. DOE
uses orders to regulate radioactive materials at their facilities.
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    \89\ Contract No. GS-10F-0309N, EPA Work Order No. EP-G10S-
00001, Work Order No. 1004, Task 2, Subtask c, Quick Turnaround
Request No. 6, Release Response and Corrective Action.
    \90\ DOE Order 435.1 Chg 1, Radioactive Waste Management,
ensures management of DOE radioactive waste (i.e. high-level,
transuranic, low-level, and the radioactive component of mixed
waste) is consistent with Atomic Energy Act of 1954
responsibilities, in a manner that provides radiological protection
from DOE operations. (see https://www.directives.doe.gov/directives-documents/400-series/0435.1-BOrder-chg1.)
    \91\ DOE M 435.1-1 Admin Chg 2, Radioactive Waste Management
Manual, further describes the requirements and establishes specific
responsibilities for implementing DOE O 435.1, Radioactive Waste
Management. It prescribes the following requirements and specific
responsibilities for new or modified existing systems: Secondary
containment designed to detect and contain releases, and compatible
with material stored (Chapter II P(2)(b)); spill/overfill control
(Chapter II(P)(2)(i)); release detection for tanks (Chapter
II(Q)(2)(a)(1)), and other storage components (Chapter II(Q)(2)(c));
release detection for failed containment and/or other abnormal
conditions (Chapter II(P)(2)(j)); monitoring and/or leak detection
for secondary containment (Chapter IIP(2)(j)); corrosion protection
(Chapter II(Q)(2)(a)(2),(3)); monitoring and physical inspections
(Chapter II(T)) and corrective action (Chapter I(2)(F)(20)). (see
https://www.directives.doe.gov/directives-documents/400-series/0435.1-DManual-1-admchg2.)
    \92\ DOE O 458.1 Admin Chg 3, Radiation Protection of the Public
and the Environment (see https://www.directives.doe.gov/directives-documents/400-series/0458.1-BOrder-AdmChg3).
    \93\ 10 CFR part 835, Occupational Radiation Protection (see
http://www.ecfr.gov/cgi-bin/text-idx?SID=dc937acd7069e30635139ca1ee3a44a0&node=pt10.4.835&rgn=div5).
    \94\ DOE O 440.1B Admin Chg 1, Worker Protection Program for DOE
(Including the National Nuclear Security Administration) Federal
Employees (see https://www.directives.doe.gov/directives-documents/400-series/0440.1-BOrder-b-admchg1).
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    NRC regulations at 10 CFR part 50 require that construction permit
applications include a design and safety analysis, health and safety
risk assessment of facility operations, and determination of the
adequacy of controls for accidental releases into the environment for
the life of the operating unit. NRC regulations also require facilities
meet minimum design, installation, testing, and performance
criteria.\95\ Appendix B of 10 CFR part 50 requires a quality assurance
report that includes testing of facility structures, systems, and
components.\96\ NRC also developed guidance documents to assist
operators with licensing compliance.\97\
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    \95\ see http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html.
    \96\ Ibid.
    \97\ Ibid.
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    EPA was concerned with whether NRC and DOE cleanup standards for
radionuclides adequately protect groundwater 98 99 100 and
was unfamiliar with how NRC regulates releases of petroleum products or
enforces cleanup of releases.
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    \98\ February 1997 letter from EPA to the NRC expressing
concerns over the NRC's proposal for increasing dose limits and
eliminating the requirement to protect groundwater that could be
used as drinking water.
    \99\ December 1997 letter from EPA to DOE expressing concerns
that DOE's draft rule 10 CFR part 834 (Radiation Protection of the
Public and the Environment) needs to be consistent with CERCLA and
that inconsistencies exist between the draft rule and CERCLA and NCP
guidance.
    \100\ October 2002 Memorandum of Understanding between EPA and
NRC to identify the interactions for only the decommissioning and
decontamination of NRC-licensed sites and ensure dual regulation
does not occur regarding the cleanup and reuse of NRC-licensed
sites.
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    The 1988 UST regulation contains prescriptive procedures UST owners
and operators must follow in responding to releases into the
environment. NRC regulations are performance-based actions; they
identify performance measures that are designed to ensure an adequate
safety margin and offer incentives for licensees to improve safety
without formal regulatory intervention.\101\ Accordingly, DOE created
orders to supplement EPA regulations for USTs at DOE facilities already
subject to the 1988 UST regulation.\102\ NRC requires that facilities
perform site remediation as part of the decommissioning process, but
there are currently no NRC regulations that require remediation at
active facilities, unless dose limits are exceeded.\103\
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    \101\ Contract No. GS-10F-0309N, EPA Work Order No. EP-G10S-
00001, Work Order No. 1004, Task 2, Subtask c, Quick Turnaround
Request No. 6, Release Response and Corrective Action.
    \102\ Ibid.
    \103\ Ibid.
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    EPA concludes it is appropriate to continue requiring release
response and corrective action for these tanks, if the need arises. Due
to the sensitive nature of these facilities, implementing agencies have
flexibility to establish appropriate response and remediation
requirements for owners and operators at these facilities.
Move from Deferred to Partially Excluded
    The 1988 UST regulation used the term deferred for USTs containing
radioactive material and for emergency generator UST systems at nuclear