-------
The OSWRO NESHAP are applied on an individual process vent basis and require each
affected process vent to be controlled. In, contrast, the RCRA air standards are applied on a
facility basis and require that owners or operators to reduce total organic emissions from all
affected process vents at the facility to below 1.4 kg/h (3 Ib/h) and 2.8 Mg/yr (3.1 ton/yr) or
install and operate a control device(s) that reduces total organic emissions from all affected
process vents at the facility by 95 weight percent. If the total emissions from all affected
process vents at a the facility exceed either the daily or annual emission limitations then
controls are required; if total emissions are below both of the emission limit criteria then no
controls are required for the process vents under subpart AA.
For those affected process vents under either the OSWRO NESHAP required to be
vented to a control device, the technical air emission control requirements for the closed vent
system and control device are relatively consistent. Both rules require installation and
operation of an organic recovery or destruction control device that meet certain design,
operational, and performance criteria. The performance requirements are summarized in
Table 3-7.
Table 3-7.
Control Device Performance Requirements for both the OSWRO NESHAP and
RCRA Air Standards
Control Device Type
Enclosed Combustion Devices
[e.g., thermal incinerator, catalytic incinerator,
boiler, or process heater)
Organic Recovery Devices
(e.g., carbon adsorber or condenser)
Flares
Performance Requirement
• 95 % destruction efficiency
or
• 20 ppmv exit concentration
or
• minimum residence and temperature,
(e.g., 760 °C and 0.5 sec) .
• 95 % overall recovery
design and operational criteria (e.g., no
visible emissions)
Equipment leaks. The EPA has promulgated a number of NESHAP equipment leak
standards in 40 CFR parts 61 and 63. The OSWRO NESHAP cross-references several of
these existing NESHAP subparts. The rule allows the owner/operator the option of
complying with the 40 CFR 61 subpart V or 40 CFR 63 subpart H. The RCRA air standards
specifies all of equipment leak requirements in subpart BB in parts 264 and 265. The
technical requirements under the RCRA air standards in subpart BB are essentially the same as
the technical requirements in 40 CFR 61 subpart V.
3-19
-------
There are two primary techniques for reducing equipment leak emissions that form the
basis of these EPA equipment leak standards: 1) modifying or replacing existing equipment,
and 2) implementing a leak detection and repair (LDAR) program. The equipment
requirements (e.g., installing caps on open-ended lines or installing closed-loop sampling
systems) are essentially the same in all of the EPA equipment leak standards. There are no
differences in these technical requirements between the NESHAP subparts cross-referenced
by the OSWRO NESHAP and the RCRA air standards. Table 3-8 presents a summary of
equipment modifications that can be used for each equipment component type subject to the
equipment leak standards.
Table 3-8.
Equipment Modifications for Equipment Leak Standards
Equipment Component Type
Pumps
Compressors
Pressure relief devices
Valves
Connectors
Open-ended lines
Sampling connections
Modification
• Sealless design
• Closed-vent system
• Dual mechanical seal with barrier
fluid maintained at a higher
pressure than the pumped fluid
• Closed-vent system
• Dual mechanical seal with barrier
fluid maintained at a higher
pressure than the compressed gas
• Closed-vent system
• Rupture disk assembly
• Sealless design
• Weld together
• Blind, cap, plug, or second valve
• Closed-loop sampling
The LDAR program is routinely administered at a facility to detect and repair equipment
that is "leaking" (i.e., emitting sufficient amounts of organics to the atmosphere to warrant
reduction of these emissions by repairing the equipment). A portable monitoring device is
used to identify equipment leaks from individual pieces of equipment. The control
effectiveness of any given LDAR program is dependent on a number of factors including leak
definition and monitoring frequency as well as initial and final leak frequencies. The EPA
equipment leak standards vary in how the LDAR program is implemented with respect to leak
definition and monitoring frequency as well as initial and final leak frequencies. Some
standards specify the leak definition (e.g.-, 10,000 ppmv) and monitoring frequency (e.g.,
3-20
-------
monthly or quarterly) and others specify the final leak frequency. The equipment leak
standards under both 40 CFR 61 subpart V and the RCRA air standards in subpart BB both
require a monthly LDAR with a leak definition of 10,000 ppmv. In contrast, 40 CFR 63
subpart H of part 63 that has a lower leak definition for pumps and valves (e.g., 500 ppmv for
Phase II and HI) and specifies the monitoring frequency based on the leak frequency.
3.3.4 Which technical requirements apply to an affected source when it must use air
emission controls under both the OSWRO NESHAP and the RCRA air
standards?
Tanks. Surface Impoundments, and Containers. The RCRA air standards under
subpart CC applicability exempt any hazardous waste management unit that the owner or
operator certifies is equipped with and operating air emission controls in accordance with the
OSWRO NESHAP (or any other applicable Clean Air Act regulation under 40 CFR part 60,
61, or 63). It is important to note that this exemption only applies to those units using organic
air emission controls to comply with an applicable CAA regulation.
Process Vents. The EPA amended the applicability provision of Subpart AA by adding a
new §264.1030(e) and §265.1030(d). This provision states that a process vent is not subject
to the Subpart AA standards provided the owner or operator certifies that all Subpart
AA-regulated process vents at the facility are equipped with and operating air emission
controls in accordance with the requirements of an applicable Clean Air Act regulation
codified in Part 60, 61, or 63.
Therefore, the Subpart AA process vent applicability exemption is only available at a
facility where each and every process vent that would otherwise be subject to Subpart AA is
equipped with and operating air emission controls in compliance with an applicable CAA
standard under Part 60, 61, or 63. The various individual vents could be regulated under
different CAA rules as long as all vents (otherwise subject to Subpart AA) are controlled
under an applicable CAA rule.
As with the similar exemption provisions in Subparts BB and CC, to comply with the
requirements at paragraphs §264.1030(e) or§265.1030(d) and thus qualify for the applicability
exemption, the emissions from each Subpart AA process vent must be routed through a
closed-vent system to an air emission control device. A process vent that is in compliance
with a CAA standard under an exemption from control requirements (i.e., is not equipped
with and operating a control device) does not meet the criteria established in the provisions
paragraph §264.1030(e) or §265.1030(d) of Subpart AA. Therefore, a unit that does not use
the required air emission controls but is in compliance with a NESHAP through an "emission
averaging" or "bubbling" provision does not qualify for the exemption. Similarly, if the Clean
Air Act standard for the particular unit is' no control (for example, because the MACT floor
for the source category is no control and the Agency decided not to apply controls more
stringent than the floor), the exemption from the RCRA standards under §264.1030(e) or
3-21
-------
§265.1030(d) of Subpart AA would not apply since the unit would not. actually be controlled
(i.e., equipped and operating air emission controls) under provisions of the MACT standard.
To take the above example a step further, at a facility where all but one of the
Subpart AA process vents are equipped with air emission controls for compliance under CAA
rules and the one uncontrolled Subpart AA process vent is also in compliance with a CAA
regulation but is not controlled for air emissions, the facility's Subpart AA process vents do
not meet the applicability exemption criteria as stated in Subpart AA and thus are not exempt
from the rule under §264.1030(e) or §265.1030(d).
Equipment Leaks. The amendments to the Subpart BB rules, published on December 8,
1997 (62 FR 64636-64671), revised the recordkeeping provisions of Subpart BB to eliminate
owner or operator burden caused by regulatory overlap of the various EPA equipment leak
regulations under the Clean Air Act and RCRA. The Subpart BB recordkeeping provisions in
Section 264.1064(m) and Sec. 265.1064(m) were amended to allow any equipment that
contains or contacts hazardous waste that is subject to Subpart BB and also subject to
regulations in 40 CFR Part 60, 61, or 63 to determine compliance with Subpart BB by
documentation of compliance with the relevant provisions of the Clean Air Act rules codified
under 40 CFR Part 60, Part 61, or Part 63. As noted in the preamble to these amendments,
"because compliance with Subpart BB is demonstrated through recordkeeping, this
recordkeeping revision has the effect of exempting equipment that would otherwise be subject
to Subpart BB from Subpart BB requirements, provided the equipment is operated,
monitored, and repaired in accordance with an applicable CAA standard, and appropriate
records are kept to that effect."
Paragraph §264.1064 (m) in the recordkeeping requirements states that the owner or
operator "...may elect to determine compliance with this subpart either by documentation
pursuant to §264.1064 of this subpart [i.e., Subpart BB], or by documentation of compliance
with the regulations at 40 CFR Part 60, Part 61, or Part 63 pursuant to the relevant provisions
of the regulations at 40 CFR Part 60, Part 61, or Part 63." The corresponding Part 265
language is the same. The objective of the amendment was to eliminate any owner or
operator burden caused by regulatory overlap. In making the revision to paragraph (m) in
§264.1064 and §265.1064 of Subpart BB, the Agency intended that, for a piece of equipment
subject to equipment leak regulations under the CAA as well as RCRA Subpart BB,
compliance with the CAA rules rather than the RCRA Subpart BB requirements would be an
adequate demonstration of compliance and in effect eliminate the need to demonstrate
compliance under Subpart BB of the RCRA Air Rules. Based on EPA Headquarters'
interpretation, the provisions in 40 CFR 264.1064(m) and 265.1064(m) are intended to allow
a facility owner or operator to demonstrate compliance with all of subpart BB, through
documentation of compliance with regulations under one of the specified parts of the CAA,
such as the OSWRO NESHAP. Simply put, if a facility has equipment that is subject to
relevant provisions (i.e., provisions for operating, monitoring, and repairing subpart BB
equipment) under regulations within the specified CAA parts, that equipment is exempt from
40 CFR part 264 subpart BB and therefore no potential exists for overlap with the OSWRO
3-22
-------
NESHAP. To be eligible for the exemption provided by 40 CFR 264.1064(m) or
265.1064(m): the relevant CAA requirements must be applicable to the subpart BB
equipment; the relevant CAA requirements must include provisions for operation, monitoring,
and repair of the Subpart BB equipment; the relevant CAA requirements must be codified
within 40 CFR part 60, 61, or 63; and compliance with the relevant CAA requirements must
be documented in the facility operating record.
3.4 FACILITY PERMITTING CONSIDERATIONS
3.4.1 What is the relationship between a facility's CAA Title V operating permit
with the facility's RCRA Subtitle C permit?
A facility subject to both the OSWRO NESHAP and the RCRA air standards may be
required to have two operating permits, one permit for each of the separate regulatory
programs. One of the OSWRO NESHAP applicability conditions is the facility is a major
source of HAP emissions. Under CAA Title V, owners and operators of facilities that are
major sources of HAP emissions are required to have an operating permit (see 40 CFR
part 70). Under RCRA subtitle C, owners and operators of TSDF that handle hazardous
waste are required to have an operating permit
According to the EPA's Operating Permits Group of the OAQPS Information Transfer
and Program Integration Division, a Title V operating permit for a major source must be
comprehensive with respect to including all emission units and all applicable requirements that
apply to the units (see 40 CFR 70.3(c)(l)). That is, the permit must include all "applicable
requirements" for all emission units within the fenceline (except for "insignificant activities")
and contain an explanation of any exemptions from otherwise "applicable requirements." An
"applicable requirement" is essentially all emission limitations and standards and other
requirements through State implementation plans (SIP), NSPS, MACT, NESHAP, and other
CAA requirements. For example, the RCRA air emission standards are not an "applicable
requirement" under Title V because they are not CAA requirements (RCRA is a separate
statute). The CAA standards under Part 60, 61, or 63 are applicable requirements and as such
should be included in the CAA Title V operating permit, as applicable to the facility. All
terms and conditions in the permit that are required by the CAA or applicable requirements
are federally-enforceable. In fact, all Federally-approved rules/requirements are independently
enforceable outside of CAA permitting programs. For example, SIP requirements become
federally-enforceable when EPA approves the SIP; NSPS, MACT, and NESHAP are
federally-enforceable as of their effective date. Therefore, CAA requirements under 40 CFR
Parts 60, 61, or 63 are independently enforceable regardless of whether or not the
requirements have been incorporated into the facility's Title V permit. An owner or operator
with sources subject to regulations under 40 CFR Part 60, 61, or 63 must comply with the
applicable requirements of these regulations regardless of the CAA Title V permit status.
The operating permit term is 5 years. The requirements for permit content are described
3-23
-------
in 40 CFR 70.6. Each permit must include the emission limits and standards including
operational requirements and limits that assure compliance with all applicable requirements at
the time of permit issuance. All the terms and conditions of the permit, including any "permit
shield" granted under 40 CFR 70.6(f), remain in effect until the renewal permit has been
issued or denied. Any permit noncompliance constitutes a violation of the Act and is grounds
for enforcement action. Section 70.6(f) allows the permitting authority to include a provision
stating that compliance with the conditions of the permit shall be deemed compliance with any
applicable requirements as of the date of permit issuance provided: (1) such applicable
requirements are included and specifically identified in the permit; or (2) the permitting
authority determines in writing that other requirements specifically identified are not
applicable to the source, and the permit includes the determination or a concise summary of it.
This means, in general, that once the applicable requirement is translated into permit terms,
the source must only comply with the Title V permit terms.
3.4.2 How does the program policy of a "permit shield" as implemented under the
CAA differ from the "permit-as-a-shield" policy implemented under RCRA?
The program policy of a "permit shield" as implemented under the CAA is significantly
different than the "permit-as-a-shield" policy implemented under RCRA. The RCRA
"permit-as-a-shield" policy allows a permitted TSDF to be shielded from compliance with
regulatory requirements promulgated after the RCRA permit is issued; i.e., compliance with
the RCRA permit constitutes compliance with the RCRA program. In general, under this
policy, if a new standards is added to 40 CFR Part 264 and is not in the facility's RCRA
permit, the owner or operator is typically not required to comply with that particular standard
until the permit is reopened (most likely for renewal at the permit's expiration date) and the
requirements of the standard can be added to the facility's permit. This is not the case under
the CAA where any "shielded" requirements must be specifically identified in the Title V
permit. The CAA requires that the facility's permit must be reopened to include newly
promulgated requirements if more than 3 years remain in the term of the permit. If not, the
requirements are included in the permit renewal. In either case, the facility owner or operator
must comply with any new regulations under 40 CFR part 60, 61, or 63, which are
independently enforceable, as of their effective date.
3.4.3 Can the sources in a facility's CAA Title V operating permit be different than
those listed in the facility's RCRA Subtitle C permit?
Yes. There are circumstances where a particular unit or source may be listed in a
facility's RCRA Subtitle C permit but not included or listed in the facility's CAA Title V
permit. For example, a unit may not be listed in the Title V permit for a major source if it is
an "insignificant activity." State permitting programs have varying definitions of "insignificant
activity." Some use a emissions threshold for HAPs (e.g., 2 tpy) and such limits should only
be subject to generally applicable requirements of the SIP. Portable units moved onto the site
. 3-24
-------
for a short period of time also may not be listed in the permit for a major source. A portable
source cannot be a major source. In cases where a particular unit or source is not included or
listed in a facility's Title V permit, the unit is not exempt from any applicable CAA
requirements under Sections 111 and 112. As this discussion illustrates, in limited cases a
HWMU at a facility could be subject to and in compliance with a particular CAA rule but the
facility's Title V permit may not clearly identify or list the applicability of the rule.
3-25
-------