[Federal Register Volume 64, Number 138 (Tuesday, July 20, 1999)]
[Rules and Regulations]
[Pages 38950-38992]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-17943]



[[Page 38949]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 63



National Emission Standards for Hazardous Air Pollutants for Source 
Categories: National Emission Standards for Off-Site Waste and Recovery 
Operations; Rule and Proposed Rule

  Federal Register / Vol. 64, No. 138 / Tuesday, July 20, 1999 / Rules 
and Regulations  

[[Page 38950]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[FRL-6377-5]
RIN 2060-AH96


National Emission Standards for Hazardous Air Pollutants for 
Source Categories: Off-Site Waste and Recovery Operations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule; amendments to rule.

-----------------------------------------------------------------------

SUMMARY: The EPA is taking direct final action on amendments to the 
national emission standards for hazardous air pollutants (NESHAP) for 
off-site waste and recovery operations (OSWRO) that the EPA promulgated 
on July 1, 1996, under authority of section 112 of the Clean Air Act 
(CAA). The rule applies to owners and operators of facilities that are 
major sources of hazardous air pollutants (HAP) and manage certain 
wastes, used oil, or used solvents received from off-site locations. 
The EPA is amending specific provisions in the rule to resolve issues 
and questions raised after promulgation of the final rule. In addition, 
the EPA is amending other rule language to correct technical omissions; 
to make specific requirements consistent and up-to-date with recent 
decisions made by the Agency for other related air rules; and to 
correct typographical, printing, and grammatical errors. The amendments 
do not significantly change the EPA's original projections for the 
rule's environmental benefits, compliance costs, burden on industry, or 
the number of affected facilities.

DATES: Effective Date. This rule is effective on September 20, 1999 
without further notice, unless the EPA receives adverse comment by 
August 19, 1999. If we receive such comment, we will publish a timely 
withdrawal in the Federal Register informing the public that the rule 
will not take effect.

ADDRESSES: Comments. Interested parties having adverse comments on this 
action may submit these comments in writing (in duplicate, if possible) 
to Docket No. A-92-16 at the following address: Air and Radiation 
Docket and Information Center (6102), U.S. Environmental Protection 
Agency, 401 M Street, SW, Room 1500, Washington, DC 20460. The EPA 
requests that a separate copy of the comments also be sent to the 
contact person listed below. The docket is located at the above address 
in Room M-1500, Waterside mall (ground floor).
    Today's document and other materials related to this direct final 
rulemaking are available for review in the docket. Copies of this 
information may be obtained by request from the Air Docket by calling 
(202) 260-7548. A reasonable fee may be charged for copying docket 
materials.

FOR FURTHER INFORMATION CONTACT: Ms. Elaine Manning, Waste and Chemical 
Processes Group, Emission Standards Division (MD-13), U.S. 
Environmental Protection Agency, Research Triangle Park, NC, 27711, 
telephone number (919) 541-5499, facsimile number (919) 541-0246, 
electronic mail address ``[email protected]''.

SUPPLEMENTARY INFORMATION:

Regulated Entities

    Entities potentially regulated by this action include the following 
types of facilities if the facility receives ``off-site material'' as 
defined in the rule, and the facility is determined to be a major 
source of HAP emissions as defined in 40 CFR 63.2.

------------------------------------------------------------------------
             Category                  Examples of regulated entities
------------------------------------------------------------------------
Industry..........................  Businesses that receive waste, used
                                     oil, or used solvent from off-site
                                     locations and manage this material
                                     in any of the following waste
                                     management or recovery operations:
                                     hazardous waste treatment, storage,
                                     and disposal facilities (TSDF);
                                     hazardous wastewater treatment
                                     operations exempted from air
                                     emission control requirements in 40
                                     CFR part 264 or 265; nonhazardous
                                     wastewater treatment facilities
                                     other than publicly-owned treatment
                                     works; used solvent recovery
                                     operations; recovery operations
                                     that recycle or reprocess hazardous
                                     waste and are exempted from
                                     regulation as a TSDF in 40 CFR part
                                     264 or 265; and used oil re-
                                     refineries.
Federal Government................  Federal agency facilities that
                                     operate any of the waste management
                                     or recovery operations that meet
                                     the description of the entities
                                     listed under the ``Industry''
                                     category in this table.
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that the EPA is now 
aware could potentially be regulated by this action.
    A comprehensive list of Standard Industrial Classification (SIC) 
codes cannot be compiled for businesses potentially regulated by this 
action due to the structure of the rule. The rule may be applicable to 
any business that receives waste, used oil, or used solvent from an 
off-site location and then manages this material in one of the 
operations or processes specified in the rule. Thus, for many 
businesses subject to the rule, the regulated sources (i.e., off-site 
waste management or recovery operations) are only a small part of the 
overall manufacturing process or service conducted at the facility. In 
these cases, the SIC code indicates the primary product produced or 
service provided at the facility rather than the presence of an off-
site waste management or recovery operation at the site which is 
operated to support the predominate function of the facility. For 
example, SIC code classifications likely to have off-site waste 
management or recovery operations at some (but not all) facilities 
include, but are not limited to, petroleum refineries (SIC code 2911), 
industrial organic chemical manufacturing (SIC code 286x), plastic 
materials and synthetics manufacturing (SIC code 282x), and 
miscellaneous chemical products manufacturing (SIC code 289x). However, 
the EPA also is aware of off-site waste management or recovery 
operations potentially subject to the rule being located at a few 
facilities listed under SIC codes for refuse systems, waste management, 
business services, miscellaneous services, and nonclassifiable. Thus, 
the SIC code alone for a given facility does not determine whether the 
facility is or is not potentially subject to this rule.
    To determine whether your facility is regulated by the action, you 
should carefully examine the applicability criteria in Sec. 63.680 
under 40 CFR part 63, subpart DD. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section of this 
document.

Internet

    The text of today's document is also available on the EPA's web 
site on the Internet under recently signed rules at the following 
address: http://

[[Page 38951]]

www.epa.gov/ttn/oarpg/rules.html. The EPA's Office of Air and Radiation 
(OAR) homepage on the Internet also contains a wide range of 
information on the air toxics program and many other air pollution 
programs and issues. The OAR's homepage address is: http://www.epa.gov/
oar/.

Electronic Access and Filing Addresses

    The official record for this rulemaking, as well as the public 
version, has been established for this rulemaking under Docket No. A-
92-16 (including comments and data submitted electronically). A public 
version of this record, including printed, paper versions of electronic 
comments, which does not include any information claimed as 
confidential business information (CBI), is available for inspection 
from 8 a.m. to 5:30 p.m., Monday through Friday, excluding legal 
holidays. The official rulemaking record is located at the address 
listed in the ADDRESSES section at the beginning of this document.
    Interested parties having adverse comments on this action may 
submit those comments electronically to the EPA's Air and Radiation 
Docket and Information Center at: ``A-and-R-D[email protected].'' 
Electronic comments must be submitted as an ASCII file avoiding the use 
of special characters and any form of encryption. Comments and data 
will also be accepted on disks in WordPerfect in 6.1 file format or 
ASCII file format. All comments and data in electronic form must be 
identified by the docket number (A-92-16). No CBI should be submitted 
through electronic mail. Electronic comments may be filed online at 
many Federal Depository Libraries.

Judicial Review

    Under section 307(b)(1) of the CAA, judicial review of an NESHAP is 
available only by filing a petition for review in the U.S. Court of 
Appeals for the District of Columbia Circuit within 60 days of today's 
publication of this final rule. Under section 307(b)(2) of the CAA, the 
requirements that are the subject of today's document may not be 
challenged later in civil or criminal proceedings brought by the EPA to 
enforce these requirements.

Outline

    The information in this document is organized as follows.

I. Statutory Authority
II. Background
III. Amendments to Subpart DD--National Emission Standards for Off-
Site Waste and Recovery Operations
    A. Applicability
    B. Definitions
    C. Standards: General
    D. Standards: Off-Site Material Treatment
    E. Standards: Tanks
    F. Standards: Process Vents
    G. Standards: Closed-Vent Systems and Control Devices
    H. Testing Methods and Procedures
    I. Inspection and Monitoring Requirements
    J. Notification and Reporting Requirements
    K. HAP List for Subpart DD
IV. Amendments to Subpart OO--National Emission Standards for 
Tanks--Level 1
    A. Definitions
    B. Standards--Tank Fixed Roof
    C. Test Methods and Procedures
    D. Inspection and Monitoring Requirements
V. Amendments to Subpart PP--National Emission Standards for 
Containers
    A. Definitions
    B. Test Methods and Procedures
    C. Inspection and Monitoring Requirements
VI. Amendments to Subpart QQ--National Emission Standards for 
Surface Impoundments
    A. Definitions
    B. Test Methods and Procedures
    C. Inspection and Monitoring Requirements
VII. Amendments to Subpart RR--National Emission Standards for 
Individual Drain Systems
VIII. Amendments to Subpart VV--National Emission Standards for Oil-
Water Separators and Organic-Water Separators
    A. Definitions
    B. Standards--Pressurized Separator
    C. Test Methods and Procedures
    D. Inspection and Monitoring Requirements
IX. Administrative Requirements
    A. Docket
    B. Executive Order 12866: Regulatory Planning and Review
    C. Executive Order 12875: Enhancing the Intergovernmental 
Partnerships
    D. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    E. Executive Order 13084: Consultation and Coordination with 
Indian Tribal Governments
    F. Unfunded Mandates Reform Act
    G. Regulatory Flexibility Act
    H. Paperwork Reduction Act
    I. Submission to Congress and the General Accounting Office
    J. National Technology Transfer and Advancement Act

I. Statutory Authority

    The statutory authority for this action is provided by sections 
101, 112, 114, 116, and 301 of the CAA, as amended (42 U.S.C. 7401 et 
seq.).

II. Background

    The EPA, under 40 CFR part 63, subpart DD promulgated National 
Emission Standards for Hazardous Air Pollutants from Off-Site Waste and 
Recovery Operations (hereinafter referred to as the ``OSWRO NESHAP'') 
on July 1, 1996 (see 61 FR 34140). The OSWRO NESHAP establishes 
standards to control HAP emissions from certain waste management and 
recovery operations that are not subject to Federal air standards under 
other subparts in 40 CFR parts 61 or 63. Subpart DD specifies the 
rule's applicability, standards for affected sources, compliance 
requirements, and reporting and recordkeeping provisions. In addition, 
subpart DD cross-references other subparts in 40 CFR part 63 for the 
specific air emissions control requirements to be used for affected 
tanks, surface impoundments, containers, individual drain systems, and 
oil-water and organic-water separators. The cross-referenced subparts 
are Subpart OO--National Emission Standards for Tanks--Level 1, Subpart 
PP--National Emission Standards for Containers, Subpart QQ--National 
Emission Standards for Surface Impoundments, Subpart RR--National 
Emission Standards for Individual Drain Systems, and Subpart VV--
National Emission Standards for Oil-Water Separators and Organic-Water 
Separators.
    Since the promulgation of the OSWRO NESHAP, the EPA has received 
many inquiries asking for the Agency's interpretation of specific 
provisions of the rule. In addition, the Chemical Manufacturers 
Association (CMA), the Environmental Technology Council (ETC), and the 
Hazardous Waste Management Association (HWMA) petitioned for judicial 
review of the final rule, as provided for in CAA section 307(b), with 
respect to certain provisions regarding rule applicability, 
definitions, process vent standards, test methods, and inspection and 
monitoring requirements.
    To resolve issues and questions raised after promulgation of the 
final rule, the EPA decided that technical amendments to subparts DD, 
OO, PP, QQ, RR, and VV in 40 CFR part 63 are appropriate and to use a 
direct final rulemaking action to promulgate these amendments. Also, as 
part of this action, the EPA is amending other rule language to correct 
technical omissions; to make specific requirements consistent and up-
to-date with recent EPA decisions made for other related air rules; and 
to correct terminology, typographical, printing, and grammatical 
errors. The amendments do not significantly change the EPA's original 
projections for the rule's compliance costs, environmental benefits, 
burden on industry, or the number of affected facilities.
    The EPA is publishing these amendments to subparts DD, OO, PP, QQ, 
RR, and VV in 40 CFR part 63 without prior proposal, because we

[[Page 38952]]

view the amendments to be noncontroversial and anticipate no adverse 
comment. The amendments do not change the substantive requirements of 
the rule. However, in the ``Proposed Rules'' section of today's Federal 
Register publication, we are publishing a separate document that will 
serve as the proposal of the identical amendments to these subparts if 
adverse comments are filed. The amendments will be effective 60 days 
from today's date without further notice, unless we receive adverse 
comment by the date specified in the DATES section at the beginning of 
this document. If the EPA receives adverse comment on these amendments, 
we will publish a timely withdrawal in the Federal Register informing 
the public that the amendments will not take effect. We will address 
the comments in a subsequent final rule based on the proposed rule. We 
will not institute a second comment period for these amendments. Any 
parties interested in commenting on the amendments must do so at this 
time (see ADDRESSES section at the beginning of this document).

III. Amendments to Subpart DD--National Emission Standards for Off-
Site Waste and Recovery Operations

    The EPA is amending 40 CFR part 63, subpart DD, to clarify the 
Agency's intent for applying and implementing specific rule 
requirements and to correct unintentional omissions and editorial 
errors. Also, we are amending the OSWRO NESHAP to make the applicable 
provisions of the rule consistent (to the extent permissible and 
practicable under the CAA) with a related set of air standards for 
hazardous waste treatment, storage, and disposal facilities (TSDF) 
established under the Resource Conservation Recovery Act (RCRA) in 40 
CFR part 264, subpart CC and 40 CFR part 265, subpart CC. A summary of 
amendments to 40 CFR part 63, subpart DD, and the rationale for the 
amendments is presented below.

A. Applicability

    The EPA is amending Sec. 63.680 to clarify which types of materials 
received at a plant site are ``off-site materials'' and to clarify the 
designation of the affected sources at a plant site subject to the rule 
as discussed below. In addition, the EPA is extending the compliance 
date by 7 months to February 1, 2000. We believe this is appropriate to 
allow affected sources time to comply with today's amended rule.
1. ``Off-Site Material''
    The OSWRO NESHAP applies to those plant sites that are a ``major 
source'' as defined in 40 CFR 63.2 and receive ``off-site material'' as 
specified in subpart DD. For implementing the OSWRO NESHAP, a material 
is an ``off-site material'' if the material meets all three of the 
criteria specified in Sec. 63.680(b)(1). To clarify that a given 
material must meet all three criteria to be considered an ``off-site 
material,'' the wording in Sec. 63.680(b)(1)(ii) and (b)(1)(iii) is 
revised by replacing the word ``material'' with the phrase ``waste, 
used oil, or used solvent.''
    Section 63.680(b)(2) lists specific categories of wastes that are 
not considered ``off-site material'' regardless if the waste contains 
HAP or is received from an off-site location. The rule language is 
amended to clarify the compliance liability of an owner or operator 
potentially subject to the OSWRO NESHAP but receiving a waste that is 
exempted from the rule because it is already complying with air 
emission control requirements under the National Emission Standards for 
Benzene Waste Operations (40 CFR part 61, subpart FF) or the National 
Emission Standards for Organic Hazardous Air Pollutants from the 
Synthetic Organic Chemical Manufacturing Industry under 40 CFR part 63 
(the HON). Section 63.680(b)(2)(v) is revised to clarify that a waste 
is not an ``off-site material'' under the OSWRO NESHAP when it is 
transferred from a chemical manufacturing plant or other facility 
subject to the HON provisions for wastewater under 40 CFR part 63, 
subpart G (i.e., Sec. 63.132 through 63.147), and the owner or operator 
of the facility from which the waste is transferred complies with the 
HON provisions in Sec. 63.132(g). Similarly, Sec. 63.680(b)(2)(vi) is 
revised to clarify that a waste is not an ``off-site material'' under 
the OSWRO NESHAP when it is transferred from a chemical manufacturing 
plant, petroleum refinery, or coke by-product recovery plant subject to 
40 CFR part 61, subpart FF, and the owner or operator of the facility 
from which the waste is transferred complies with the provisions of 
Sec. 61.342(f) of the Benzene Waste Operations NESHAP.
    Finally, the list of wastes not considered off-site material under 
the OSWRO NESHAP is amended by adding another waste category under 
Sec. 63.680(b)(2)(viii). This category is RCRA hazardous waste stored 
for 10 days or less at a transfer facility and in compliance with the 
provisions for hazardous waste transporters in 40 CFR part 263. When 
the EPA was developing the OSWRO NESHAP, the Agency did not intend that 
subpart DD be applicable to those waste management operations that 
serve to consolidate multiple, small hazardous waste shipments into a 
single, larger load which then can be more efficiently delivered to the 
final destination for the waste. For example, a hazardous waste 
transporter may use a fleet of trucks to pickup small shipments of 
hazardous waste from many different waste generators; deliver these 
shipments to an interim transfer facility where the small shipments are 
unloaded; store the waste in the shipping containers at the 
transporter's facility for a short period (10 days or less); and then, 
when a sufficient quantity of waste has been collected, consolidate the 
containers as a single load on another truck or railcar for shipment of 
the waste to the facility where the waste is to be treated or disposed.
2. Designation of Affected Sources
    Section 63.680(c) is revised to clarify for a plant site subject to 
the OSWRO NESHAP which processes, units, and equipment are designated 
as affected sources under the rule. These amendments are format and 
editorial revisions that do not substantively change the affected 
sources regulated under the rule, but are made to clarify the EPA's 
intent and improve ease of implementing these affected source 
designations.
    First, the designation of ``off-site material management units'' in 
Sec. 63.680(c)(1) is revised to clarify that a given tank or container 
cannot be subject to both the air standards for off-site material 
management units (as applicable to the particular type of unit) and for 
process vents. Language is added to clarify that if a tank or container 
is equipped with a vent that serves as a process vent for one of the 
six treatment processes specified in the rule, then the unit is not 
part of the ``off-site material management unit'' affected source. 
Instead, the unit (i.e., the process vent on this unit) is subject to 
the standards for process vents in Sec. 63.683(c). The standards for 
off-site material management units in Sec. 63.683(b) do not apply to 
the unit. An example of such a case is the vent on a distillate 
receiver vessel serving a distillation column used for reprocessing 
used solvent. Although the distillate receiver vessel meets the 
definition for a ``tank'' in the rule, it is not regulated as a tank 
under Sec. 63.683(b), but instead the vessel is considered part of the 
``process vent'' affected source.

[[Page 38953]]

    Second, the designation of ``process vents'' in Sec. 63.680(c)(2) 
is revised to explicitly state the six types of treatment processes 
vented to the atmosphere that are considered ``process vent'' affected 
sources under the OSWRO NESHAP. The EPA intended the air standards for 
process vents under the OSWRO NESHAP to apply to the same types of 
processes that the Agency regulates under related RCRA air rules for 
process vents in 40 CFR part 264, subpart AA, and 40 CFR part 265, 
subpart AA. These processes are distillation processes, fractionation 
processes, thin-film evaporation processes, solvent extraction 
processes, steam stripping processes, and air stripping. The revision 
to Sec. 63.680(c)(2) includes detailed descriptions for each of the six 
treatment process types. The description included for each type of 
process is consistent with the definition used by the EPA for the 
process under the RCRA air rules in 40 CFR part 264, subpart AA, and 40 
CFR part 265, subpart AA.
    Finally, the criteria designating which equipment components are 
subject to the equipment leak standards under the OSWRO NESHAP are 
moved from Sec. 63.683(b)(3) to Sec. 63.680(c)(3). This is a format and 
editorial revision to facilitate ease of understanding and implementing 
the rule and does not change the criteria used to designate which 
equipment components are subject to the leak standards under the rule.

B. Definitions

    The amendments revise several existing rule definitions and add two 
new definitions to Sec. 63.681. These definition changes are made in 
support of other amendments that the EPA has made to subpart DD to 
resolve applicability issues and to clarify the intent of certain 
standards under the rule.
    The definition for a ``used solvent'' as used in Sec. 63.680(b) to 
determine which types of materials received at a plant site are ``off-
site materials'' is revised to mean a mixture of aliphatic hydrocarbons 
or a mixture of one and two ring aromatic hydrocarbons used as a 
solvent which because of such use is contaminated by physical or 
chemical impurities. This wording revision is made to clarify that only 
solvents considered under the rule to be an ``off-site material'' are 
those spent or otherwise contaminated solvents resulting from use by a 
consumer (e.g., solvents used for cleaning, degreasing, paint 
stripping, etc.) and subsequently returned to a facility for recycling 
or reprocessing.
    The ``process vent'' definition is revised to be consistent with 
revisions made to Sec. 63.680(c)(2) designating the ``process vent'' 
affected sources under the OSWRO NESHAP (see section III.A.2 of this 
document). Additional wording is also added to the definition for a 
``process vent'' to clarify that for the purpose of implementing the 
OSWRO NESHAP, a process vent is neither a vent used as a safety device 
(as defined in the rule) nor an open-ended line or other vent that is 
subject to the rule's equipment leak control requirements in 
Sec. 63.691.
    A new definition is added for the term ``off-site material 
service'' for use in the revisions made to Sec. 63.680(c)(3) 
designating the equipment leak affected sources under the OSWRO NESHAP 
(see section III.A.2 of this document). ``Off-site material service'' 
means any time when a pump, compressor, agitator, pressure relief 
device, sampling connection system, open-ended valve or line, valve, 
connector, or instrumentation system contains or contacts off-site 
material.
    The definition for ``HAP'' or ``hazardous air pollutants'' as used 
throughout subpart DD is clarified. The definition is revised to mean 
the specific organic chemical compounds, isomers, and mixtures listed 
in Table 1 of subpart DD. The definition for ``volatile organic 
hazardous air pollutant concentration'' (also referred to as ``VOHAP 
concentration'') is revised to clarify that the VOHAP concentration of 
an off-site material by definition is measured using Method 305 in 40 
CFR part 63, appendix A. However, as an alternative to using Method 
305, an owner or operator may determine the HAP concentration of an 
off-site material using any one of the alternative test methods 
specified in Sec. 63.694(b)(2)(ii). When one of these alternative test 
methods is used to determine the speciated HAP concentration of an off-
site material, the individual compound concentration may be adjusted by 
the corresponding fm305 value listed in Table 1 of subpart 
DD to determine an equivalent VOHAP concentration.
    The definition for ``point-of-treatment'' is revised to clarify 
procedures for demonstrating compliance with the off-site material 
treatment standards in Sec. 63.684. ``Point-of-treatment'' is revised 
to mean the point after the treated material exits the treatment 
process but before the first point downstream of the process where the 
organic constituents in the treated material have the potential to 
volatilize and be released to the atmosphere. For applying this 
definition to the rule, the first point downstream of the treatment 
process exit is not a fugitive emission point due to an equipment leak 
from any of the following equipment components: pumps, compressors, 
valves, connectors, instrumentation systems, or safety devices.
    Several definition amendments are made to clarify the requirements 
for air emission control equipment under Sec. 63.693. The definition 
for a ``control device'' is revised to clarify that a control device 
means equipment used for recovering, removing, oxidizing, or destroying 
organic vapors. The definition for a ``cover'' is revised to clarify 
that a cover must provide a continuous barrier over the off-site 
material, and that each cover opening (e.g., access hatches, sampling 
ports) must be in the closed position when the opening is not in use. A 
new definition is added to the rule for the term ``flow indicator'' in 
conjunction with amendments to the closed-vent system standards in 
Sec. 63.693(c) (see section III.G.1 of this document). A ``flow 
indicator'' means a device that indicates whether gas is flowing, or 
whether the valve position would allow gas to flow in a bypass line.
    Finally, the definition for a ``safety device'' is amended to mean 
a closure device (e.g., a pressure relief valve, frangible disc, 
fusible plug) which functions to prevent physical damage or permanent 
deformation to equipment by venting gases or vapors from the equipment 
during unsafe conditions resulting from an unplanned, accidental, or 
emergency event. The EPA has made this revision to the wording of the 
definition to provide owner and operator flexibility in the use and 
location of these necessary devices. Wording changes clarify that a 
safety device may be used on not just the air pollution control 
equipment operated to comply with the rule but also on the controlled 
source's process and ancillary equipment. Also, instead of venting a 
safety device directly to the atmosphere when emergency relief is 
necessary, a common practice at some facilities is to vent the safety 
device directly to equipment designed specifically and solely to 
contain or control the vented gases and vapors. The EPA made a second 
wording change to clarify that the EPA did not intend to preclude from 
the control equipment operating conditions allowed under the rule, the 
opening of a safety device when used with additional safety equipment.

C. Standards: General

    Several revisions are made to the exemptions from air standards 
allowed

[[Page 38954]]

under the OSWRO NESHAP for ``off-site material management unit'' and 
``process vent'' affected sources. These amendments do not 
significantly change the HAP emission reductions and the implementation 
costs expected for the rule. Also, the format and organization used for 
the section is revised to improve the ease of understanding and 
applying the standards. The requirements and exemptions are grouped 
together by affected source type. For example, all of the requirements 
and exemptions applicable to off-site material management units are now 
found in Sec. 63.683(b).
1. Off-Site Material Management Unit Exemptions
    Amendments are made to two of the exemptions for off-site material 
management units in Sec. 63.683(b). First, the exemption in 
Sec. 63.683(b)(2)(iii) for a tank or surface impoundment used for a 
biological treatment process is revised to eliminate a redundant 
qualification condition. As originally published, to qualify for this 
exemption the OSWRO NESHAP required an owner or operator to demonstrate 
that the biological treatment process achieves two conditions: (1) an 
overall HAP reduction efficiency of 95 percent or more, and (2) a HAP 
biodegradation efficiency of 95 percent or more. Upon review of this 
requirement, the EPA concluded that demonstrating a HAP biodegradation 
efficiency of 95 percent or more also means that the process achieves 
an overall HAP reduction efficiency of at least 95 percent. 
Consequently, requiring an owner or operator electing to qualify for 
this exemption to perform the determination of overall HAP reduction 
efficiency is unnecessary. Therefore, Sec. 63.683(b)(2)(iii) is amended 
by deleting the requirement to demonstrate that the process achieves a 
HAP reduction efficiency greater than or equal to 95 percent.
    The exemption in Sec. 63.683(b)(2)(iv) for an off-site material 
management unit in which RCRA hazardous waste is managed according to 
the applicable conditions specified by the RCRA Land Disposal 
Restrictions (LDR) in 40 CFR part 268, is amended. This provision is 
revised to clarify application of the exemption to those situations 
when the off-site material is a type of hazardous waste not prohibited 
from land disposal or is composed of a mixture of different hazardous 
wastes. The EPA previously addressed this question in amendments to 
related RCRA air rules in 40 CFR part 264, subpart CC and 40 CFR part 
265, subpart CC (see 62 FR 64636, December 8, 1997). The preamble to 
these amendments provides a detailed discussion of this provision, how 
it interacts with the RCRA LDR, and how the EPA interprets the 
application of this exemption in specific situations (see 62 FR 64643). 
The EPA is amending Sec. 63.683(b)(2)(iv) by adopting the same rule 
language used for the provision in the RCRA air rules.
2. Process Vent Exemptions
    Amendments for process vents in Sec. 63.683(c) add new provisions 
to exempt certain vents that are part of a ``process vent'' affected 
source from the air rule standards. Three specific exemptions for 
process vents are provided in the amended rule. These exemptions do not 
significantly change the level of HAP emission reduction achieved under 
the OSWRO NESHAP for process vents.
    The first exemption is added to be consistent with an exemption 
already provided in the rule for off-site material management units. A 
process vent is exempted from the air emission control requirements of 
the OSWRO NESHAP if the HAP emissions from the vent are already being 
controlled in compliance with the provisions specified in another 
subpart in 40 CFR part 61 or 40 CFR part 63.
    The EPA is also adding exemptions for certain process vent streams 
with low flow, low HAP concentration characteristics, in response to 
comments received after promulgation of the rule, regarding the 
technical difficulty and high cost of controlling these process vent 
streams to achieve standards under the OSWRO NESHAP. The EPA 
acknowledges that, under certain circumstances, it may be technically 
difficult and costly to control a low flow, low HAP concentration vent 
stream to a level that achieves the standard for process vents 
specified in the rule (i.e., removal or destruction of the HAP from 
each individual affected process vent gas stream by 95 percent or more 
on a mass basis). For example, use of a thermal vapor incinerator to 
control a low flow, low organic HAP concentration vent stream may only 
achieve a 95 percent emission reduction by incurring the substantially 
higher equipment and operating costs required to overcome the technical 
limitations of enclosed combustion control devices. Other conventional 
air emission control devices commonly used at existing OSWRO sources 
(e.g., carbon adsorbers, condensers, catalytic vapor incinerators) also 
have technological constraints relative to controlling low flow, low 
concentration vent streams. Consequently, the level of potential HAP 
emission reduction that can be achieved for the low flow, low organic 
HAP concentration vent streams typically emitted from processes 
regulated by the OSWRO NESHAP is limited, in practical terms, by the 
technical limitations of conventional air pollution control devices and 
the costs to overcome these limitations.
    The EPA reconsidered the potential HAP emission reduction levels 
achievable when conventional air emission control devices are applied 
to low flow, low organic HAP concentration vent streams from OSWRO 
processes. The EPA decided that it is reasonable and appropriate to 
exempt from the air emission control requirements under the OSWRO 
NESHAP those process vent streams for which the potential for HAP 
emission reduction is small and the application of conventional air 
emission control devices is not practical.
    To exempt very low flow rate vent streams, the EPA selected an 
approach consistent with the approach the Agency has used for other 
NESHAP to exempt these types of process vent streams. A process vent is 
exempted from the air emission control requirements of the OSWRO NESHAP 
if the owner or operator determines the process vent stream flow rate 
to be less than 0.005 standard cubic meters per minute. Considering the 
range of the vent stream organic HAP concentrations typically emitted 
from the types of processes regulated by the OSWRO NESHAP, the 
potential HAP emission reductions achieved by controlling process vent 
streams below this flow rate cutoff value are extremely low regardless 
of the organic HAP concentration level.
    The EPA decided that it is not appropriate to exempt OSWRO process 
vent streams with flow rates greater than 0.005 standard cubic meters 
per minute independent of considering the organic HAP concentration of 
the vent stream. Even though a given process vent stream has a low 
organic HAP concentration, the level of total organic HAP emissions to 
the atmosphere can still be substantial if the gas stream volume 
emitted is moderately high. Considering the organic HAP concentration 
of process vent streams for OSWRO sources, the EPA concluded that 
requiring control of those process vent streams having both a flow rate 
below 6.0 standard cubic meters per minute and a total organic HAP 
concentration less than 20 parts per million by volume (ppmv) does not 
provide sufficient HAP emission reductions from these sources to 
justify the substantial compliance costs for the OSWRO facility owner 
and operator. Therefore, the EPA is

[[Page 38955]]

amending the OSWRO NESHAP to exempt those affected process vent streams 
having a flow rate less than 6.0 standard cubic meters per minute and a 
total HAP concentration in the vent stream less than 20 ppmv. This 
process vent exemption requires that both the process vent flow rate 
and the organic HAP concentration criteria be met to qualify for the 
exemption.

D. Standards: Off-Site Material Treatment

    Use of air emission controls for an affected off-site material 
management unit or process vent is not required under the OSWRO NESHAP 
if the HAP contained in the off-site material is removed or destroyed 
before placing the material in the affected unit. To comply with this 
provision, the rule provides alternative treatment standards in 
Sec. 63.684. Revisions are made to several of the alternative treatment 
standards allowed under the rule. These amendments do not significantly 
change the HAP emission reductions and the implementation costs 
expected for the rule.
    Some facility owners and operators misinterpreted the VOHAP 
concentration treatment alternative under Sec. 63.684(b)(1)(ii), as 
published in the July 1996 version of the rule, to apply only to off-
site material streams with a VOHAP concentration less than 500 parts 
per million by weight (ppmw), and that the EPA was requiring treatment 
of these low HAP streams contrary to the general standards stated in 
Sec. 63.683. This is not the EPA's intent, and the rule language is 
amended to clarify that this alternative is used for the situation 
where the off-site material entering a treatment process is composed of 
a mixture of off-site material streams having an average VOHAP 
concentration greater than 500 ppmw with off-site material streams 
having an average VOHAP concentration less than 500 ppmw.
    The HAP efficiency treatment alternative in Sec. 63.684(b)(3) is 
amended to clarify that this treatment alternative is not applicable to 
a biological degradation process conducted in open tanks or surface 
impoundments (for open biodegradation processes an owner or operator 
may comply with Sec. 63.684(b)(4)). Demonstrating an overall HAP 
reduction efficiency for a treatment process that is open to the 
atmosphere does not ensure that the HAP in the off-site material is 
actually destroyed or removed. A portion or all of the volatile organic 
HAP constituents present when the off-site material enters the process 
may volatilize directly to the atmosphere from the exposed surface of 
the material in an open tank or surface impoundment before this 
material finally exits the process.
    Also in Sec. 63.684(b)(3), a correction is made to the value of the 
HAP removal efficiency performance level required in circumstances 
where the off-site material stream entering the treatment process has 
an average VOHAP concentration equal to or greater than 10,000 ppmw at 
the point-of-delivery. The value for HAP removal efficiency performance 
level is corrected to read 99 percent (not 95 percent as published in 
July 1996). A treatment process can only meet the second condition of 
the standard that requires the average VOHAP concentration of the off-
site material at the point-of-treatment to be less than 100 ppmw by 
achieving a HAP removal efficiency of at least 99 percent.
    The biodegradation treatment alternative in Sec. 63.684(b)(4) is 
amended to clarify that this alternative applies only to a biological 
degradation treatment process conducted in open tanks or surface 
impoundments. Also, consistent with the amendment made by the EPA to 
the exemption in Sec. 63.683(b)(2)(iii) for a tank or surface 
impoundment used for biological treatment (see section III.B.1 of this 
document), Sec. 63.684(b)(4)(i) is revised to eliminate the redundant 
condition requiring determination of the overall HAP reduction 
efficiency for the biodegradation process.
    Provisions are added in Sec. 63.684(e)(4) requiring the owner or 
operator to establish and implement a procedure to monitor appropriate 
parameters that demonstrate proper operation of a biological treatment 
unit according to the evaluation required in Sec. 63.694(h). Under this 
requirement, the owner or operator must list the operating parameters 
monitored and state the frequency of monitoring to ensure that the 
biological treatment unit is operating between the minimum and maximum 
operating parameter values to establish that the unit is continuously 
achieving the relevant performance requirement.

E. Standards: Tanks

    The standards for a tank required under Sec. 63.685(b)(1) to use 
Tank Level 1 controls are amended to provide two alternatives for 
complying with the rule. First, an alternative is added to the rule 
(see Sec. 63.685(c)(2)(ii)) to explicitly clarify that the owner or 
operator of the tank may instead choose to use the more stringent Tank 
Level 2 controls to comply with the rule. The EPA's intent is that an 
owner or operator may select a more stringent control level than the 
minimum control requirement. Second, an alternative is added to the 
rule (see Sec. 63.685(c)(2)(iii)) for the special circumstance when a 
tank is used as an interim transfer point to transfer off-site material 
from containers to another off-site material management unit. An 
example of such a tank is an in-ground tank into which organic-
contaminated debris is dumped from roll-off boxes or dump trucks, and 
then this debris is promptly transferred from the tank to a 
macroencapsulation unit by a backhoe. This alternative allows the cover 
to be removed during those periods of time when the material transfer 
activity is occurring. At all other times, air emissions from the tank 
must be controlled in accordance with the provisions specified in 40 
CFR part 63, subpart OO--National Emission Standards for Tanks--Level 
1. The EPA previously included provisions for these types of tanks in 
the related air rules for waste management units under the RCRA subpart 
CC air rules in 40 CFR parts 264 and 265 (see docket A-92-16, document 
VI-B-2).
    The standards in Sec. 63.685(b)(4) for a tank that manages off-site 
material having a maximum HAP vapor pressure that is equal to or 
greater than 76.6 kilopascals (kPa) are amended to provide two 
additional compliance alternatives. These additional compliance 
alternatives are using either (1) a pressure tank, or (2) a tank 
located inside an enclosure vented through a closed vent system to an 
enclosed combustion device. These two additional control alternatives 
provide a level of HAP emission control equivalent to the original 
control requirement (i.e., venting the tank directly to a control 
device), while at the same time providing greater compliance 
flexibility to the owners and operators subject to the rule.
    The requirements in Sec. 63.685(h) for owners and operators 
electing to use the Tank Level 2 control alternative of a pressure tank 
are amended to allow the purging of inert materials from the pressure 
tank. Inert material purging is a short duration maintenance procedure 
required by good engineering practice to ensure proper operation of 
this type of tank system.
    The requirements in Sec. 63.685(i) for owners and operators 
electing to use the Tank Level 2 control alternative of an enclosure 
vented to an enclosed combustion control device are amended to add a 
provision allowing a safety device to open anytime conditions require 
it to do so to avoid an unsafe condition. The EPA included this safety 
provision for all of the other tank control alternatives under the 
OSWRO NESHAP, but the provision

[[Page 38956]]

inadvertently was not included in the regulatory language for this Tank 
Level 2 control alternative when the final rule was published in July 
1996.

F. Standards: Process Vents

    The air emission control requirements for process vents in 
Sec. 63.690(b) are amended to clarify that for the purpose of complying 
with this standard, the EPA considers a primary condenser associated 
with an affected process to be part of the process and not the air 
emission control device. The primary condenser is a condenser for which 
the predominant function is the recovery or capture of solvents or 
other organics for use, reuse, or sale. The EPA considers a secondary 
condenser or other organic recovery device that is operated downstream 
of the primary condenser to be a control device for the purpose of 
complying with the OSWRO NESHAP.

G. Standards: Closed-Vent Systems and Control Devices

    Amendments to the standards for closed-vent systems and control 
devices in Sec. 63.693 correct technical omissions, update specific 
requirements consistent with recent decisions made by the EPA for other 
NESHAP, and correct terminology, typographical, printing, and 
grammatical errors. These amendments do not significantly change the 
HAP emission reductions and implementation costs expected for the rule.
1. Closed-Vent System Requirements
    The inspecting and monitoring requirements for a closed-vent system 
in Sec. 63.693(b)(5) are amended to add an alternative procedure. This 
alternative allows an owner or operator to inspect and monitor the 
closed-vent system according to the procedure specified in 40 CFR part 
63, subpart H--National Emission Standards for Organic Hazardous Air 
Pollutants for Equipment Leaks (specifically the procedure in 
Sec. 63.172(f) through (h)). Although some details of the subpart H 
procedure vary from the procedure already specified in the OSWRO 
NESHAP, both procedures achieve the same overall result of ensuring 
that the closed-vent system continues to operate properly after its 
initial installation and testing. This amendment allows those owners 
and operators who are already inspecting and monitoring other closed-
vent systems at their facility using the subpart H procedure to comply 
with another NESHAP allowing the flexibility to use a common procedure 
for all of the affected closed-vent systems at the facility.
    Section 63.693(c) is amended to update the requirements for those 
situations when a closed-vent system bypass device is installed to be 
consistent with other recently promulgated NESHAP. The revised language 
does not significantly change the technical requirements but does 
clarify the requirements for an owner or operator choosing to use a 
flow indicator to comply with the provision. The rule requires that 
this device merely indicate the presence of gas flow through the bypass 
line or duct. The device does not need to measure or quantify the flow 
rate (although a flow measurement device can be used to comply with 
this provision of the rule if an owner or operator chooses to do so).
2. General Control Device Requirements
    The requirements in Sec. 63.693(b)(8) for using a design analysis 
to demonstrate that a given control device achieves the applicable 
performance requirements of the rule are amended. If the design 
analysis prepared by the owner or operator is determined by the 
Administrator to be incomplete or deficient, the amended rule allows 
the Administrator to first request that the design analysis be revised 
or amended by the owner or operator to correct the deficiencies 
identified by the Administrator. If the owner or operator and the 
Administrator still do not agree on the acceptability of using this 
revised design analysis to demonstrate that the control device achieves 
the applicable performance requirements, then the disagreement is to be 
resolved using the results of a performance test conducted by the owner 
or operator.
3. Carbon Adsorption System Requirements
    The monitoring requirements in Sec. 63.693(d)(3) for carbon 
adsorption control devices are amended to clarify the requirements. 
Section 63.693(d)(3)(i) is amended to clarify that owners and operators 
choosing this monitoring alternative for regenerative-type carbon 
adsorption systems must monitor both total regeneration stream mass 
flow and the carbon bed temperature. Section 63.693(d)(3)(ii) is 
amended to add a requirement that the daily average concentration level 
of organic compounds in the exhaust stream from the control device must 
be monitored. The EPA considers an averaging time to be necessary to 
properly determine compliance.
    The spent carbon management requirements in Sec. 63.693(d)(4) are 
amended to add two more alternatives. The amendments add the 
alternatives of using: (1) a thermal treatment unit using air emission 
controls according to the control device standards under the OSWRO 
NESHAP, or (2) a thermal treatment unit using organic air emission 
controls according to another NESHAP in 40 CFR part 61 or 40 CFR part 
63. These changes make this requirement consistent with other air rules 
that affect similar waste management sources (see section 
264.1088(c)(3)(ii) and section 265.1089(c)(3)(ii)).
4. Condenser Requirements
    The monitoring requirements in Sec. 63.693(e)(3) for condenser 
control devices are amended to clarify the requirements. Section 
63.693(e)(3)(i) and (ii) are amended to require monitoring of either 
the daily average exhaust gas temperature or the daily average 
concentration level of organic compounds in the exhaust stream. The EPA 
considers monitoring one of these parameters to be necessary to 
properly determine compliance.
5. Vapor Incinerator Requirements
    The monitoring requirements in Sec. 63.693(f) for vapor 
incinerators are amended to add a requirement that owners and operators 
measure and record the daily average of the particular parameter being 
monitored (i.e., temperature or concentration). The EPA considers 
monitoring these parameters to be necessary to properly determine 
compliance.
6. Boiler and Process Heater Requirements
    The monitoring requirements in Sec. 63.693(g) for boilers and 
process heaters are amended to include provisions requiring that the 
monitoring systems for boilers and process heaters used as control 
devices measure and record the daily average of the particular 
parameter being monitored (i.e., temperature or concentration). The 
provision of a daily averaging time for control device monitoring 
parameters is necessary to properly determine compliance.
7. Flare Requirements
    The requirements in Sec. 63.693(h) for flares are amended to 
clarify the compliance demonstration and monitoring procedures to be 
used for a flare. Section 63.693(h)(2) is added to the rule to specify 
the procedure an owner or operator must use to demonstrate that the 
flare achieves the requirements in 40 CFR 63.11(b). This amendment is 
added because the cross-reference to the General Provisions in 40 CFR 
part 63, subpart A, as specified in

[[Page 38957]]

the version of the final rule published in July 1996, does not explain 
the specific flare compliance demonstration procedure that an owner or 
operator is to use for the OSWRO NESHAP.
    The flare monitoring requirements are now specified in 
Sec. 63.693(h)(3) and are amended to require that the owner or operator 
record for each 1-hour period whether the required pilot flame monitor 
was continuously operating and whether a flame was present during each 
hour as required. This change is made to add an averaging time.

H. Testing Methods and Procedures

1. Alternative Methods for Determination of Average VOHAP Concentration
    The EPA is adding three more alternative methods in 
Sec. 63.694(b)(ii) that an owner or operator may choose to determine 
the average HAP concentration of an off-site material. The methods 
added are Method 625 in 40 CFR part 136, appendix A, and Method 8260 
and Method 8270 in ``Test Methods for Evaluating Solid Waste, Physical/
Chemical Methods,'' EPA Publication No. SW-846, Third Edition, 
September 1986, as amended by Update I, November 15, 1992 (or any more 
recent, updated version of these methods approved by the EPA). The EPA 
developed these methods for use in implementing rules under the Clean 
Water Act and RCRA, respectively. The methods measure the concentration 
of organic pollutants in municipal and industrial wastewaters. 
Commenters suggested that these methods are also applicable to the 
OSWRO NESHAP for the determination of off-site material HAP 
concentration. After review of the methods, the EPA decided that using 
the three methods for direct measurement of the HAP concentration of 
certain off-site material is reasonable and adding them to the OSWRO 
NESHAP is appropriate. The EPA believes that with the addition of these 
methods, the rule now provides a range of alternatives for determining 
the HAP concentration of an off-site material such that every owner and 
operator of facilities subject to the OSWRO NESHAP have available 
practical and inexpensive VOHAP determination alternatives.
    It is important to note that for each of the alternative methods 
allowed under Sec. 63.694(b)(ii) (i.e., the listed methods other than 
Methods 305 and 25D), there is a published list of chemical compounds 
that the EPA considers the method appropriate to measure. An owner or 
operator may only use an alternative method to measure compounds that 
are on the list associated with that method, unless the specified 
validation procedures are also performed. Furthermore, for a VOHAP 
concentration determination, the owner or operator must evaluate the 
total mass of HAP compounds in an off-site material (i.e., all 
compounds listed in Table 1 of subpart DD). Therefore, the owner or 
operator is responsible for determining that the analytical method used 
for a VOHAP concentration determination is sufficient to evaluate all 
of the applicable organic compounds contained in the off-site material. 
If an owner or operator chooses to use an alternative to Method 305 to 
analyze an off-site material that contains unknown compounds or many 
different compounds, performing ``screening'' analyses may first be 
necessary to verify that the alternative method chosen is, in fact, 
appropriate to evaluate all the necessary compounds.
    The alternative test methods measure the total concentration of the 
HAP constituents listed in Table 1 of subpart DD. The VOHAP 
concentration of an off-site material by definition is the fraction by 
weight of those compounds listed in Table 1 as measured using Method 
305. Owners and operators may choose to ``correct'' the HAP values 
measured by an alternative method to equate to the VOHAP values that 
would be measured using Method 305. This correction is made by 
multiplying the total concentration measured values times the 
appropriate ``fm305 factor'' listed in Table 1 of subpart DD 
to obtain the Method 305 VOHAP concentration equivalent.
    Method 625 is appropriate for determining the HAP concentration of 
an off-site material provided that the corrections for the measured 
compounds in Table 7 of the method are made. Methods 8260 and 8270 are 
also considered appropriate provided that formal quality assurance 
procedures are established, followed, and recorded to address those 
elements of the methods considered relevant for measuring the actual 
concentration of organic compounds. The quality assurance program must 
address procedures to minimize the loss of compounds due to 
volatilization, biodegradation, reaction, or sorption during the sample 
collection, storage, and preparation steps, as well as addressing the 
overall accuracy and precision of the specific method used.
    None of the alternative methods specify sample collection and 
handling procedures considered adequate by the EPA to minimize the 
volatilization of organics from the sample before analysis. Therefore, 
to ensure that a representative sample of an off-site material is 
analyzed, an owner or operator that chooses to use either Method 624, 
625, 1624, 1625, 8260, or 8270 for the OSWRO NESHAP is required to 
develop and follow a written sampling plan. This plan describes a step-
by-step procedure for collecting representative samples of the off-site 
materials such that material integrity is maintained and minimal loss 
of organics from the sample occurs throughout the collection and 
analysis process. An example of an acceptable sampling plan is one that 
incorporates sample collection and sample handling procedures similar 
to those specified in Method 25D. The sampling plan is to be maintained 
on-site in the facility records.
    The provisions in Sec. 63.694(c)(ii) listing the alternative 
methods for determining the average VOHAP concentration of an off-site 
material at the point-of-treatment are revised and simplified to cross-
reference all of the methods allowed under Sec. 63.694(b)(ii).
2. Equation Corrections
    The equation in Sec. 63.694(b)(2)(iii) used for calculating the 
average VOHAP concentration of an off-site material is amended to 
correct the rule citation used to define the term ``Ci.'' 
The correct citation is Sec. 63.694. The same correction is made for 
the terms ``Ci'' in the equation in Sec. 63.694(c)(3), ``y'' 
and ``Cy'' in the equation in Sec. 63.694(e)(4), and 
``Qbj'' and ``Cbl'' in the equation in 
Sec. 63.694(g)(4).
    The equation in Sec. 63.694(c)(3) used for calculating the average 
VOHAP concentration on a mass-weighted basis is corrected to clarify 
the inputs to the equation. In the equation, the value for 
Qt is the sum of the Qi's used in the equation. 
This value represents the sum or total off-site material quantity used 
to characterize the off-site material over the averaging period. Each 
VOHAP concentration determination must have a corresponding off-site 
material quantity that represents the amount of material generated or 
received over the averaging period used to determine the VOHAP 
concentration value. To calculate a mass-weighted average VOHAP 
concentration over the averaging period, multiply each VOHAP 
concentration by the quantity of material it represents and then divide 
by the total quantity of material (i.e., the sum of the individual off-
site material quantities).
3. Procedure for Determination of No Detectable Emissions
    Several amendments are made to the procedure for determination of 
no

[[Page 38958]]

detectable emissions in Sec. 63.694(k). As discussed in the appropriate 
later sections of this document, the same changes are made to the 
procedure as specified in 40 CFR part 63, subparts OO, PP, QQ, and VV.
    The procedure is amended to allow either methane or n-hexane to be 
used as the calibration gas for the detection instrument. It is the 
EPA's intent that the calibration procedure be consistent with the 
procedure as applied to related air rules (e.g., see the equipment leak 
test methods and procedures at sections 264.1063 and 265.1063). 
Therefore, the requirement for calibration gases in Sec. 63.694(k)(4) 
is amended to provide the owner or operator the choice of using methane 
or n-hexane as allowed under these other rules.
    Section 63.694(k)(6) is amended to allow an owner or operator the 
option of choosing to adjust or not adjust the detection instrument 
readings to account for the background organic concentration level. 
Frequently at a source, the maximum organic concentration value 
measured by the detection instrument is well below the organic 
concentration value that defines ``no detectable emissions.'' In this 
case, requiring an ambient background correction is an unnecessary 
step. Thus, the EPA decided that it is reasonable and appropriate for 
the correction of the measured value for the ambient background level 
to be an option used at the owner's or operator's discretion. If an 
owner or operator chooses to adjust the instrument readings for the 
background level, the background level value must be determined 
according to the procedures in Method 21 of 40 CFR part 60, appendix A.
    Finally, the procedure is amended to add provisions for 
determination of no detectable emissions from a seal used around a 
rotating shaft that passes through a cover opening. In this case, if 
the arithmetic difference between the maximum organic concentration 
indicated by the instrument and the background level is less than 
10,000 ppmv, then the potential leak interface is determined to operate 
with no detectable organic emissions. This addition is made for 
consistency with other related EPA air rules regarding the 
determination of no detectable emissions.
4. Determination of Process Vent Stream Flow Rate and Total HAP 
Concentration
    A new Sec. 63.694(m) is added to subpart DD specifying the testing 
methods and procedures that an owner or operator must follow to 
determine a process vent stream flow rate and total organic HAP 
concentration. These new requirements are added to the rule to support 
the amendments to Sec. 63.683(b) adding exemptions for process vents 
based on the vent stream flow rate and total organic HAP concentration 
(see section III.F of this document). The procedures and test methods 
added to the rule for these determinations are the EPA reference 
methods in appendix A of 40 CFR part 60 for measuring gas stream flow 
rates and organic concentrations.

I. Inspection and Monitoring Requirements

    Section 63.695 is amended to consolidate the inspection and 
monitoring requirements under subpart DD in this section, update the 
control device monitoring requirements to be consistent with recent 
decisions made by the EPA for compliance assurance monitoring of 
sources subject to using air emission controls under a NESHAP, and to 
make minor technical modifications. The amendments do not significantly 
change the estimated inspection and monitoring costs for the rule.
    The inspection requirements for covers, closed-vent systems, and 
transfer systems in Sec. 63.695 are amended to make allowances for 
units or equipment that an owner or operator determines to be unsafe to 
inspect on an annual interval. The rule requires that the owner or 
operator perform an initial inspection of the control equipment used to 
comply with the rule, and follow-up inspections at least once per 
calendar year. A new paragraph under Sec. 63.695(f) is added to the 
rule that provides that following the initial inspection of an air 
pollution control device, an owner or operator may perform subsequent 
inspections at intervals longer than 1 year when the owner or operator 
determines that performing the applicable inspection and monitoring 
procedures would expose a worker to dangerous, hazardous, or otherwise 
unsafe conditions. In such a case, the owner or operator is required 
to: (1) Prepare written documentation that explains the reasons why the 
equipment is unsafe to inspect or monitor on an annual basis; and (2) 
develop and implement a written plan and schedule to inspect and 
monitor the air pollution control equipment using the applicable 
procedures specified in this section during times when a worker can 
safely access the air pollution control equipment. The required 
inspections and monitoring must be performed as frequently as 
practicable but do not need to be performed more frequently than the 
periodic schedule that would otherwise be applicable to the air 
pollution control equipment under the provisions of the rule. For 
example, when the rule requires a cover to be inspected at least once 
per calendar year, inspection of a cover designated as ``unsafe to 
inspect'' need not be performed more frequently than once during a 
calendar year if during that year unscheduled process shutdowns or 
other unexpected events create multiple times when a worker could 
safely access the cover.
    A provision is added to the inspection requirements in 
Sec. 63.695(b)(1) for tanks and in Sec. 63.695(d)(1) for transfer 
systems to clarify that in the case where a tank or transfer system is 
buried partially or entirely underground, inspection is required only 
for those portions of the equipment and those connections to the 
equipment (such as fill ports, access hatched, or gauge wells) that 
extend to or above the ground surface and can be opened to the 
atmosphere. It was not the EPA's intent that those portions of the tank 
or transfer system that are located below ground and, consequently, not 
easily accessible, be inspected annually. The EPA previously included 
this provision in other related air rules for waste management units 
(e.g., the RCRA subpart CC air rules in 40 CFR parts 264 and 265).
    The control device monitoring requirements under the rule are 
revised and updated to be consistent with the EPA's application of 
compliance assurance monitoring to sources under a NESHAP. A new 
Sec. 63.695(e) is added to consolidate the control device monitoring 
requirements. This section establishes the technical specifications for 
continuous monitoring of control device operating parameters; 
establishes the criteria for calculating the daily average value for 
each monitored operating parameter; incorporates a requirement that the 
owner or operator establish appropriate operating parameter limits for 
the range of conditions at which the control device must be operated to 
continuously achieve the applicable performance requirements; and 
defines the conditions under which an excursion for a given control 
device is determined to have occurred based on the monitoring data 
results.
    The EPA considers an excursion to be a failure to achieve the 
applicable standards due to improper operation of the control device. 
The rule allows one excused excursion for a control device per 
semiannual period for any reason. Should any additional excursions 
occur during this period (other than those that occur during the 
specific conditions listed in Sec. 63.695(e)(6)(i)), each of these

[[Page 38959]]

additional excursions is a violation of the standard. Conditions under 
which an excursion of the operating parameter limit is not a violation 
of the standard are: (1) periods of startup, shutdown, and malfunction 
if during the period the affected unit or facility is operated 
according to the facility's startup, shutdown, and malfunction plan; 
and (2) periods of non-operation of the unit or process that is vented 
to the control device that result in cessation of HAP emissions to 
which the monitoring applies.

J. Notification and Reporting Requirements

    The notification requirements in Sec. 63.697(a) are amended to 
allow owners and operators of existing sources subject to the amended 
OSWRO NESHAP, to file an initial notification (as required in 
Sec. 63.9(b)) on or before 30 days after the date that today's 
amendments become effective. This provision is added to the rule in 
recognition by the EPA that, as a result of the clarifying amendments 
made by today's direct final rulemaking, there may be some facility 
owners and operators who now understand, for the first time, that their 
facility is subject to the OSWRO NESHAP.
    The reporting requirements in Sec. 63.697(b)(4) are amended by 
adding language to clarify the type of information the owner or 
operator should include in the semiannual report regarding control 
device excursions. The semiannual report must include a description of 
all excursions, as defined in the subpart, that have occurred during 
the 6-month reporting period. This includes excursions caused when the 
daily average value of a monitored operating parameter is outside the 
established operating parameter limit as well as excursions caused by a 
lack of adequate monitoring data.

K. HAP List for Subpart DD

    Table 1 in subpart DD lists the specific organic chemical 
compounds, isomers, and mixtures that are HAP for the purpose of 
implementing the requirements of OSWRO NESHAP. Two changes are made to 
this table. First, the listing for the compound, 1,1-dimethyl 
hydrazine, is deleted from Table 1. As discussed in the preamble for 
the final rule (see 61 FR 34140), 1,1-dimethyl hydrazine was one of the 
specific compounds that EPA decided to delete from its proposed HAP 
list for this rulemaking because of the low potential for the compound 
to be emitted from the type of waste management and recovery operations 
subject to the rule. This compound inadvertently was not deleted from 
the version of Table 1 published in July 1996.
    Table 1 also is amended to clarify that for the glycol ethers 
chemical group listing in the table, only those glycol ethers that have 
a Henry's Law constant value equal to or greater than 0.1 Y/X (1.8 x 
10--6 atm/gm-mole/m3) at 25  deg.C must be 
included in the determination of the VOHAP concentration. The group of 
glycol ether chemicals contains a large number of compounds that have 
Henry's Law constant values both above and below this cutoff value. 
Therefore, rather than attempt to list the specific glycol ether 
compounds in the table and potentially omit a given glycol ether HAP, 
the criteria for identifying which glycol ether compounds must be 
included in the VOHAP determination was added to the rule.

IV. Amendments to Subpart OO--National Emission Standards for 
Tanks--Level 1

    The EPA is amending 40 CFR part 63, subpart OO, to clarify several 
specific rule requirements, to correct minor typographical and 
terminology errors, and to make the provisions of subpart OO consistent 
with the technical amendments made to 40 CFR part 63, subpart DD, where 
applicable. The amendments to 40 CFR part 63, subpart OO, are 
summarized below.

A. Definitions

    The definition for a ``safety device'' specified in Sec. 63.901 is 
amended to incorporate the same changes made to the definition for a 
``safety device'' for 40 CFR part 63, subpart DD, in Sec. 63.681. These 
changes are discussed in section III.B of this document.

B. Standards--Tank Fixed Roof

    The standards for fixed roof tanks in Sec. 63.902 are amended with 
additional language to clarify the EPA's intent for compliance with two 
specific provisions. First, Sec. 63.902(a) is amended to specifically 
state that the standards under this section do not apply to a fixed 
roof tank that is also equipped with an internal floating roof. Second, 
Sec. 63.902(b) is amended with additional language to specifically 
state that a facility owner or operator is allowed to install a closure 
device on a tank manifold system or header vent when a series of tanks 
have their vents (i.e., tank openings) connected to a common header. 
This amendment makes EPA's application of the fixed roof standards to a 
tank connected to a manifold system consistent with other air rules 
that affect similar waste management sources (see 62 FR 64648, December 
8, 1997).

C. Test Methods and Procedures

    The procedure for determination of no detectable organic emissions 
specified in Sec. 63.905 is amended to incorporate the same revisions 
and additions made to the procedure for 40 CFR part 63, subpart DD, in 
Sec. 63.694(k). The specific amendments are discussed in section III.G 
of this document.

D. Inspection and Monitoring Requirements

    The inspection and monitoring provisions for owners and operators 
that use a tank equipped with a fixed roof is amended by adding a new 
paragraph (d) to Sec. 63.906 which allows alternative inspection 
intervals longer than 1 year when an owner or operator determines that 
performing a required inspection or monitoring procedures would expose 
a worker to dangerous, hazardous, or otherwise unsafe conditions. The 
alternative inspection interval provision is the same as that for 40 
CFR part 63, subpart DD, in Sec. 63.695(f). The alternative inspection 
interval provision and related compliance requirements are discussed in 
section III.I of this document.

V. Amendments to Subpart PP--National Emission Standards for 
Containers

    The EPA is amending 40 CFR part 63, subpart PP, to clarify several 
definitions, to correct minor typographical and terminology errors, and 
to make the provisions of subpart PP consistent with the technical 
amendments made to 40 CFR part 63, subpart DD, where applicable. The 
amendments to 40 CFR part 63, subpart PP, are summarized below.

A. Definitions

    Two of the definitions in Sec. 63.921 are revised to clarify the 
EPA's intent in applying each definition to provisions in the rule. The 
definition for an ``empty container'' is revised to remove redundant 
language regarding a container that meets the definition of an ``empty 
container'' used for implementing RCRA hazardous waste rules (see 40 
CFR 261.7(b)). The definition for a ``safety device'' is amended to 
incorporate the same revision made to the definition for a ``safety 
device'' for 40 CFR part 63, subpart DD, in Sec. 63.681. This change is 
discussed in section III.B of this document.

B. Test Methods and Procedures

    The procedure for determination of no detectable organic emissions 
specified in Sec. 63.925 is amended to incorporate the same revisions 
and additions made

[[Page 38960]]

to the procedure for 40 CFR part 63, subpart DD, in Sec. 63.694(k). The 
specific amendments are discussed in section III.G of this document.

C. Inspection and Monitoring Requirements

    The EPA has received questions regarding the implementation of the 
inspection requirements for containers using either Container Level 1 
or Container Level 2 controls as specified under the rule. The EPA is 
amending several provisions in Sec. 63.926 to clarify which containers 
are required to be inspected and when these inspections need to be 
performed.
    The regulatory language in Sec. 63.926(a)(1) is amended to clarify 
when the initial inspection must be performed for a container that 
already contains a regulated material when it is delivered to a 
facility. A visual inspection is required when the owner or operator 
first accepts possession of the container at the facility site if the 
container is not emptied (i.e., does not meet the conditions for an 
``empty container'' as defined in the rule) within 24 hours after the 
container has been accepted at the facility site.
    For a container that is delivered to an affected facility 
containing a regulated material but is not emptied within the allowed 
24-hour period, the container must be inspected according to the 
requirements of the rule by the calendar day on which the facility 
owner or operator accepts possession of the container. For the purpose 
of compliance with subpart PP, this date of acceptance is the date of 
signature by the facility owner or operator on the manifest or shipping 
papers accompanying the container. It is allowable under subpart PP to 
have a party other than the owner or operator of the affected facility 
perform the inspection prior to the acceptance date. For example, if an 
owner or operator of an affected facility accepts a shipment of 
containers that arrives at the facility on a truck, it is allowable 
under the rule to have the shipper or transporter perform the visual 
inspection of the individual containers before or during loading of the 
containers onto the truck for transport to the affected facility. In 
this case, the party performing the inspections (e.g., the container 
shipper or transporter) needs to provide the owner or operator of the 
recipient facility with written documentation to verify that the 
containers have been inspected in accordance with the requirements of 
Sec. 63.926. Regardless of who performs the inspections, it is 
ultimately the responsibility of the owner or operator of the affected 
facility to ensure that the inspections have been performed in 
compliance with all of the applicable requirements under subpart PP.
    Section 63.926(a)(2) is amended to clarify the conditions under 
which additional visual inspections must be conducted for those 
containers, using either Container Level 1 or Container Level 2 
controls that remain at the facility for more than 1 year. When a 
container, filled or partially filled with regulated-material, remains 
unopened at the facility site for a period of 1 year or more, the 
container and its cover and closure devices must be visually inspected 
by the owner or operator initially, and thereafter, at least once every 
calendar year.
    Section 63.926(a)(3) is amended to provide additional compliance 
alternatives to owners and operators for those situations when a 
defective container is found during an inspection. The rule is amended 
to allow the owner or operator the alternatives of either emptying the 
regulated-material from the defective container or repairing the 
defective container. If the owner or operator elects to empty the 
regulated material from the defective container, the owner or operator 
must empty the defective container (i.e., meet the conditions for an 
``empty container'' as defined in the rule) and transfer the removed 
material to either: (1) a container that meets the applicable standards 
under subpart PP; or (2) to a tank, process, or treatment unit that 
meets the applicable standards under a NESHAP referencing subpart PP. 
The defective container must be emptied no later than 5 calendar days 
after detection of the defect. The emptied defective container must be 
either repaired, destroyed, or used for purposes other than management 
of regulated-material. If the owner or operator elects to repair the 
defective container, first efforts at repair of the defect must be made 
no later than 24 hours after detection, and repair must be completed as 
soon as possible but no later than 5 calendar days after detection. If 
repair of a defect cannot be completed within 5 calendar days, then the 
regulated-material must be emptied from the container and the container 
must not be used to manage regulated-material until the defect is 
repaired.

VI. Amendments to Subpart QQ--National Emission Standards for 
Surface Impoundments

    The EPA is amending 40 CFR part 63, subpart QQ, to clarify several 
definitions, to correct minor typographical and terminology errors, and 
to make the provisions of subpart QQ consistent with the technical 
amendments made to 40 CFR part 63, subpart DD, where applicable. The 
amendments to 40 CFR part 63, subpart QQ, are summarized below.

A. Definitions

    Two of the definitions in Sec. 63.941 are revised to clarify the 
EPA's intent in applying the definitions. The definition for a 
``cover'' is amended by adding examples of types of surface impoundment 
covers (e.g., a floating membrane cover placed on the surface of the 
material in the surface impoundment, an air-supported structure 
installed over the surface impoundment). The definition for a ``safety 
device'' is amended to incorporate the same change made to the 
definition for a ``safety device'' for 40 CFR part 63, subpart DD, in 
Sec. 63.681. This change is discussed in section III.B of this 
document.

B. Test Methods and Procedures

    The procedure for determination of no detectable organic emissions 
specified in Sec. 63.945 is amended to incorporate the same revisions 
and additions made to the procedure for 40 CFR part 63, subpart DD, in 
Sec. 63.694(k). The specific amendments are discussed in section III.G 
of this document.

C. Inspection and Monitoring Requirements

    The inspection and monitoring provisions for air pollution control 
equipment are amended by adding a new paragraph (d) to Sec. 63.946 
which allows alternative inspection intervals longer than 1 year when 
an owner or operator determines that performing a required inspection 
or monitoring procedure would expose a worker to dangerous, hazardous, 
or otherwise unsafe conditions. The alternative inspection interval 
provision is the same as that for 40 CFR part 63, subpart DD, in 
Sec. 63.695(f). The alternative inspection interval provision and 
related compliance requirements are discussed in section III.I of this 
document.

VII. Amendments to Subpart RR--National Emission Standards for 
Individual Drain Systems

    The EPA is amending 40 CFR part 63, subpart RR, to clarify the 
EPA's intent with regard to the types of wastewater streams to which 
air emission controls must be applied in accordance with 40 CFR part 
63, subpart RR. A definition for a ``regulated-material'' is added to 
Sec. 63.961 to mean the wastewater streams, residuals, and any other 
materials specified by the referencing

[[Page 38961]]

subpart to be managed in accordance with the standards under subpart 
RR. The definition is needed to clarify the EPA's intent that this rule 
apply to waste streams and residuals in addition to wastewater. In 
conjunction with this change, a change is made throughout subpart RR to 
replace the word ``wastewater'' with the term ``regulated material.''

VIII. Amendments to Subpart VV--National Emission Standards for 
Oil-Water Separators and Organic-Water Separators

    The EPA is amending 40 CFR part 63, subpart VV, to add a new air 
emission control alternative, to clarify several specific rule 
requirements, to correct minor typographical and terminology errors, 
and to make the provisions of subpart VV consistent with the technical 
amendments made to 40 CFR part 63, subpart DD, where applicable. The 
amendments to 40 CFR part 63, subpart VV, are summarized below.

A. Definitions

    The definition for a ``safety device'' specified in Sec. 63.1041 is 
amended to incorporate the same changes made to the definition for a 
``safety device'' for 40 CFR part 63, subpart DD, in Sec. 63.681. These 
changes are discussed in section III.B of this document.

B. Standards--Pressurized Separator

    A new section, Sec. 63.1045, is added to subpart VV which allows 
owners and operators to control air emissions from an oil-water or 
organic-water separator by using a pressurized separator that is 
operated as a closed-system. The provision requires that the 
pressurized separator be designed not to vent to the atmosphere as a 
result of compression of the vapor headspace during operation of the 
separator at its design capacity. All separator openings must be 
equipped with closure devices designed to operate with no detectable 
organic emissions as determined using the procedure specified in the 
subpart. Whenever a regulated-material is in the separator, the 
separator must be operated as a closed system that does not vent to the 
atmosphere except under emergency and maintenance conditions specified 
in the rule.

C. Test Methods and Procedures

    The procedure for determination of no detectable organic emissions 
specified in Sec. 63.1046(a) is amended to incorporate the same 
revisions and additions made to the procedure for 40 CFR part 63, 
subpart DD, in Sec. 63.694(k). The specific amendments are discussed in 
section III.G of this document.

D. Inspection and Monitoring Requirements

    The inspection and monitoring provisions for owners and operators 
that use a tank equipped with a fixed roof is amended by adding a new 
paragraph (e) to Sec. 63.1047 which allows alternative inspection 
intervals longer than 1 year when an owner or operator determines that 
performing a required inspection or monitoring procedure would expose a 
worker to dangerous, hazardous, or otherwise unsafe conditions. This 
alternative inspection interval provision is the same as that for 40 
CFR part 63, subpart DD, in Sec. 63.695(f). The alternative inspection 
interval provision and related compliance requirements are discussed in 
section III.I of this document.

IX. Administrative Requirements

A. Docket

    The docket is intended to be an organized and complete file of the 
administrative records complied by the EPA in the development of this 
rulemaking. The docket is a dynamic file because material is added 
throughout the rulemaking development. The docketing system is intended 
to allow members of the public and industries involved to readily 
identify and locate documents so that they can effectively participate 
in the rulemaking process. Along with the proposed and promulgated 
standards and their preambles, the contents of the docket, except for 
certain interagency documents, will serve as the record for judicial 
review. (See CAA section 307(d)(7)(A).) The docket for this rulemaking 
containing the information considered by the EPA in development of the 
amendments is Docket No. A-92-16. This docket is available for public 
inspection between 8:00 a.m. and 5:30 p.m., Monday through Friday, 
except for Federal holidays, at the following address: U.S. 
Environmental Protection Agency, Air and Radiation Docket and 
Information Center (MC-6102), 401 M Street SW, Washington, DC 20460; 
telephone: (202) 260-7548. The docket is located at the above address 
in Room M-1500, Waterside Mall (ground floor). A reasonable fee may be 
charged for copying.

B. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the EPA 
must determine whether the regulatory action is ``significant'' and 
therefore subject to review by the Office of Management and Budget 
(OMB) and the requirements of the Executive Order. The Executive Order 
defines ``significant regulatory action'' as one that is likely to 
result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs, or the rights and obligation of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    It has been determined that this action amending the OSWRO NESHAP 
is not a ``significant regulatory action'' under the terms of Executive 
Order 12866 and therefore not subject to OMB review.

C. Executive Order 12875: Enhancing the Intergovernmental Partnerships

    Under Executive Order 12875, the EPA may not issue a regulation 
that is not required by statute and that creates a mandate upon a 
State, local or tribal government, unless the Federal government 
provides the funds necessary to pay the direct compliance costs 
incurred by those governments or the EPA consults with those 
governments. If the EPA complies by consulting, Executive Order 12875 
requires the EPA to provide OMB a description of the extent of the 
EPA's prior consultation with representatives of affected State, local 
and tribal governments, the nature of their concerns, copies of any 
written communications from the governments, and a statement supporting 
the need to issue the regulation. In addition, Executive Order 12875 
requires the EPA to develop an effective process permitting elected 
officials and other representatives of State, local and tribal 
governments ``to provide meaningful and timely input in the development 
of regulatory proposals containing significant unfunded mandates.''
    The OSWRO NESHAP does not create a mandate on State, local, or 
tribal governments. The rule does not impose any enforceable duties on 
these entities, and State, local, and tribal governments are not 
directly impacted by this rule; i.e., they are not required to purchase 
control systems to meet the requirements of this rule. Accordingly, the 
requirements of section 1(a) of

[[Page 38962]]

Executive Order 12875 do not apply to this action.

D. Executive Order 13045: Protection of Children from Environmental 
Health Risks and Safety Risks

    Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any 
rule that (1) is determined to be ``economically significant'' as 
defined under Executive Order 12866, and (2) concerns an environmental 
health or safety risk that the EPA has reason to believe may have a 
disproportionate effect on children. If the regulatory action meets 
both criteria, the EPA must evaluate the environmental health or safety 
effects of the planned rule on children and explain why the planned 
regulation is preferable to other potentially effective and reasonably 
feasible alternatives considered by the Agency.
    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that are based on health or safety risks, such that 
the analyses required under section 5-501 of the Order has the 
potential to influence the regulation. These amendments to the OSWRO 
NESHAP are not subject to Executive Order 13045 because the OSWRO 
NESHAP is based on technology performance and not on health or safety 
risks. In addition, the amendments are not economically significant 
regulatory actions as defined by E.O. 12866.

E. Executive Order 13084: Consultations and Coordination with Indian 
Tribal Governments

    Under Executive Order 13084, the EPA may not issue a regulation 
that is not required by statute, that significantly or uniquely affects 
the communities of Indian tribal governments, and that imposes 
substantial direct compliance costs on those communities, unless the 
Federal government provides the funds necessary to pay the direct 
compliance costs incurred by the tribal governments, or the EPA 
consults with those governments. If the EPA complies by consulting, 
Executive Order 13084 requires the EPA to provide to the OMB, in a 
separately identified section of the preamble to the rule, a 
description of the extent of the EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires the EPA to 
develop an effective process permitting elected officials and other 
representatives of Indian tribal governments ``to provide meaningful 
and timely input in the development of regulatory policies on matters 
that significantly or uniquely affect their communities.''
    The OSWRO NESHAP does not significantly or uniquely affect the 
communities of Indian tribal governments. The rule does not impose any 
enforceable duties on tribal governments unless they own or operate a 
facility subject to the OSWRO NESHAP. Indian tribal governments which 
own or operate facilities subject to the OSWRO NESHAP would incur 
compliance costs; however, the EPA does not believe that there are 
many, if any, tribal governments which either own or operate such 
facilities. Accordingly, the requirements of section 3(b) of Executive 
Order 13084 do not apply to this rule.

F. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, the 
EPA generally must prepare a written statement, including a cost-
benefit analysis, for proposed and final rules with ``Federal 
mandates'' that may result in expenditures by State, local, and tribal 
governments, in the aggregate, or by the private sector, of $100 
million or more in any 1 year. Before promulgating an EPA rule for 
which a written statement is needed, section 205 of the UMRA generally 
requires the EPA to identify and consider a reasonable number of 
regulatory alternatives and adopt the least costly, most cost-effective 
or least-burdensome alternative that achieves the objectives of the 
rule. The provisions of section 205 do not apply when they are 
inconsistent with applicable law. Moreover, section 205 allows the EPA 
to adopt an alternative other than the least costly, most cost-
effective or least-burdensome alternative if the Administrator 
publishes with the final rule an explanation why that alternative was 
not adopted. Before the EPA establishes any regulatory requirements 
that may significantly or uniquely affect small governments, it must 
have developed under section 203 of the UMRA a small government agency 
plan. The plan must provide for notifying potentially affected small 
governments, enabling officials of affected small governments to have 
meaningful and timely input in the development of EPA regulatory 
proposals with significant Federal intergovernmental mandates, and 
informing, educating, and advising small governments on compliance with 
the regulatory requirements.
    The amendments to the OSWRO NESHAP will likely reduce the costs of 
complying with the rule for many affected owners and operators. These 
amendments do not increase expenditures by State, local, and tribal 
governments or the private sector. Therefore, the EPA has not prepared 
a budgetary impact statement or specifically addressed the selection of 
the least costly, most cost-effective, or least burdensome alternatives 
because these amendments are estimated to result in the expenditure by 
State and local governments, in aggregate, or by the private sector of 
less than $100 million in any 1 year. Because small governments will 
not be affected by this rule, the EPA is not required to develop a plan 
with regard to small governments. Therefore, the requirements of the 
Unfunded Mandates Act do not apply to this action.

G. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions. The EPA determined that these amendments to the OSWRO 
NESHAP do not have a significant impact on a substantial number of 
small entities. The EPA has also determined that it is not necessary to 
prepare a regulatory flexibility analysis in connection with this 
action. These amendments will not result in increased impacts to small 
entities and will result in reduced impacts in all cases.

H. Paperwork Reduction Act

    The information collection requirements of the previously 
promulgated NESHAP were submitted to and approved by the OMB. A copy of 
this Information Collection Request (ICR) document (OMB control number 
1717.02) may be obtained from Sandy Farmer, OP Regulator Information 
Division; U.S. Environmental Protection Agency, 401 M Street, SW (mail 
code 2136), Washington, DC 20460, or by calling (202) 260-2740.
    Today's amendments to the OSWRO NESHAP have no impact on the 
information collection burden estimates made previously. No additional 
certifications or filings were

[[Page 38963]]

promulgated. Therefore, the ICR has not been revised.

I. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each house of Congress and to the Comptroller General of the United 
States. The EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. These amendments 
are not a ``major rule'' as defined by 5 U.S.C. 804(2). These 
amendments will be effective July 20, 1999.

J. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, section 12(d)(15 U.S.C. 272 
note) directs the EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, business practices, etc.) that are developed or 
adopted by voluntary consensus standards bodies. Where available and 
potentially applicable voluntary consensus standards are not used by 
the EPA, the NTTAA requires the Agency to provide Congress, through 
OMB, an explanation of the reasons for not using such standards. This 
section summarizes the EPA's response to the requirements of the NTTAA 
for the test methods added to the OSWRO NESHAP as part of today's 
amendments.
    The OSWRO NESHAP involves technical standards. The amendments to 
the OSWRO NESHAP include the addition of test methods and procedures 
necessary for the determination of compliance and enforcement of air 
standards under the rule. Today's amendments increase the number of 
alternative test methods available to an owner or operator to determine 
the VOHAP concentration of an off-site material and provide for the use 
of other methods (i.e., those specified in the rule) subject to EPA 
approval. The EPA has determined that the owner or operator of an 
affected source must use the specified EPA reference methods when 
needed. While the American Society of Testing and Materials and other 
organizations have published a number of test methods and procedures 
applicable to organic content and material specifications which could 
be used to determine the flow rate and organic concentration of a 
process vent stream, these methods are not applicable to determining 
the volume, concentration, and type of air emissions from the affected 
sources. The use of these voluntary consensus standards would, 
therefore, have been impractical.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Containers, 
Hazardous air pollutants, Incorporation by reference, Individual drain 
systems, Oil-water separators, Organic-water separators, Recycling, 
Reporting and recordkeeping requirements, Surface impoundments, Tanks, 
Used oil, Used solvent, Waste management.

    Dated: July 7, 1999.
Carol W. Browner,
Administrator.

    For the reasons set forth in the preamble, title 40, chapter I, 
part 63 of the Code of Federal Regulations is amended as follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

Subpart DD--National Emission Standards for Hazardous Air 
Pollutants from Off-Site Waste and Recovery Operations

    2. Section 63.680 is amended by adding paragraph (b)(2)(viii) and 
by revising paragraphs (a)(2)(v), (b)(1)(ii), (b)(1)(iii), (b)(2)(v), 
(b)(2)(vi), (c), (d), and (e) to read as follows:


Sec. 63.680  Applicability and designation of affected sources.

    (a) * * *
    (2) * * *
    (v) A recovery operation that recycles or reprocesses used solvent 
which is an off-site material and the operation is not part of a 
chemical, petroleum, or other manufacturing process that is required to 
use air emission controls by another subpart of 40 CFR part 63 or 40 
CFR part 61.
* * * * *
    (b) * * *
    (1) * * *
    (ii) The waste, used oil, or used solvent is not produced or 
generated within the plant site, but the material is delivered, 
transferred, or otherwise moved to the plant site from a location 
outside the boundaries of the plant site; and (iii) The waste, used 
oil, or used solvent contains one or more of the hazardous air 
pollutants (HAP) listed in Table 1 of this subpart based on the 
composition of the material at the point-of-delivery, as defined in 
Sec. 63.681 of this subpart.
    (2) * * *
    (v) Waste that is transferred from a chemical manufacturing plant 
or other facility for which both of the following conditions apply to 
the waste:
    (A) The management of the waste at the facility is required either 
under part 63 subpart F--National Emission Standards for Organic 
Hazardous Air Pollutants from the Synthetic Organic Chemical 
Manufacturing Industry or under another subpart in 40 CFR part 63 to 
meet the air emission control standards for process wastewater 
specified in 40 CFR 63.132 through 63.147; and
    (B) The owner or operator of the facility from which the waste is 
transferred has complied with the provisions of 40 CFR 63.132(g)(1)(ii) 
and (g)(2).
    (vi) Waste that is transferred from a chemical manufacturing plant, 
petroleum refinery, or coke by-product recovery plant which is subject 
to 40 CFR part 61, subpart FF--National Emission Standards for Benzene 
Waste Operations, and for which both of the following conditions apply 
to the waste:
    (A) The waste is generated at a facility that is not exempted under 
the provisions of 40 CFR 61.342(a) from meeting the air emission 
control standards of 40 CFR part 61, subpart FF; and
    (B) The owner or operator of the facility from which the waste is 
transferred has complied with the provisions of 40 CFR 61.342(f)(2).
    (vii) * * *
    (viii) Hazardous waste that is stored for 10 days or less at a 
transfer facility in compliance with the provisions of 40 CFR 263.12.
    (c) Affected sources. (1) Off-site material management units. For 
each operation specified in paragraphs (a)(2)(i) through (a)(2)(vi) of 
this section that is located at the plant site, the affected source is 
the entire group of off-site material management units associated with 
the operation. An off-site material management unit is a tank, 
container, surface impoundment, oil-water separator, organic-water 
separator, or transfer system used to manage off-site material. For the 
purpose of implementing the standards under this

[[Page 38964]]

subpart, a unit that meets the definition of a tank or container but 
also is equipped with a vent that serves as a process vent for any of 
the processes listed in paragraphs (c)(2)(i) through (c)(2)(vi) of this 
section is not an off-site material management unit but instead is a 
process vent and is to be included in the appropriate affected source 
group under paragraph (c)(2) of this section. Examples of such a unit 
may include, but are not limited to, a distillate receiver vessel, a 
primary condenser, a bottoms receiver vessel, a surge control tank, a 
separator tank, and a hot well.
    (2) Process vents. For each operation specified in paragraphs 
(a)(2)(i) through (a)(2)(vi) of this section that is located at the 
plant site, the affected source is the entire group of process 
equipment associated with the process vents for the processes listed in 
paragraphs (c)(2)(i) through (c)(2)(vi) of this section.
    (i) Distillation process used for the treatment, recycling, or 
recovery of off-site material. Distillation means a process, either 
batch or continuous, separating one or more off-site material feed 
streams into two or more exit streams having different component 
concentrations from those in the feed stream or streams. The separation 
is achieved by the redistribution of the components between the liquid 
and vapor phases as they approach equilibrium within the distillation 
unit.
    (ii) Fractionation process used for the treatment, recycling, or 
recovery of off-site material. Fractionation means a liquid mixture 
separation process or method used to separate a mixture of several 
volatile components of different boiling points in successive stages, 
each stage removing from the mixture some proportion of one of the 
components.
    (iii) Thin-film evaporation process used for the treatment, 
recycling, or recovery of off-site material. Thin-film evaporation 
means a liquid mixture separation process or method that uses a heating 
surface consisting of a large diameter tube that may be either straight 
or tapered, horizontal or vertical. Liquid is spread on the tube wall 
by a rotating assembly of blades that maintain a close clearance from 
the wall or actually ride on the film of liquid on the wall.
    (iv) Solvent extraction process used for the treatment, recycling, 
or recovery of off-site material. Solvent extraction means a separation 
process or method in which a solid or a solution is contacted with a 
liquid solvent (the material and the solvent being relatively insoluble 
in each other) to preferentially dissolve and transfer one or more 
components into the solvent.
    (v) Steam stripping process used for the treatment, recycling, or 
recovery of off-site material. Steam stripping means a liquid mixture 
separation process or method in which vaporization of the volatile 
components of a liquid mixture occurs by the introduction of steam 
directly into the process.
    (vi) Gas stripping process used for the treatment, recycling, or 
recovery of off-site material. Gas stripping means a desorption process 
or method used to transfer one or more volatile components from a 
liquid mixture into a gas stream either with or without the application 
of heat to the liquid. Packed towers, spray towers, and bubble-cap, 
sieve, or valve-type plate towers are examples of the process 
configurations used for contacting the gas and a liquid.
    (3) Equipment leaks. For each operation specified in paragraphs 
(a)(2)(i) through (a)(2)(vi) of this section that is located at the 
plant site, the affected source is the entire group of equipment 
components for which each component meets all of the conditions 
specified in paragraphs (c)(3)(i) through (c)(3)(iii) of this section. 
If any one of these conditions do not apply to an equipment component, 
then that component is not part of the affected source for equipment 
leaks.
    (i) The equipment component is a pump, compressor, agitator, 
pressure relief device, sampling connection system, open-ended valve or 
line, valve, connector, or instrumentation system;
    (ii) The equipment component contains or contacts off-site material 
having a total HAP concentration equal to or greater than 10 percent by 
weight; and
    (iii) The equipment component is intended to operate for 300 hours 
or more during a calendar year in off-site material service, as defined 
in Sec. 63.681 of this subpart.
    (d) Facility-wide exemption. The owner or operator of affected 
sources subject to this subpart is exempted from the requirements of 
Secs. 63.682 through 63.699 of this subpart in situations when the 
total annual quantity of the HAP that is contained in the off-site 
material received at the plant site is less than 1 megagram per year. 
For a plant site to be exempted under the provisions of this paragraph 
(d), the owner or operator must meet the requirements in paragraphs 
(d)(1) through (d)(3) of this section.
    (1) The owner or operator must prepare an initial determination of 
the total annual HAP quantity in the off-site material received at the 
plant site. This determination is based on the total quantity of the 
HAP listed in Table 1 of this subpart as determined at the point-of-
delivery for each off-site material stream.
    (2) The owner or operator must prepare a new determination whenever 
the extent of changes to the quantity or composition of the off-site 
material received at the plant site could cause the total annual HAP 
quantity in the off-site material received at the plant site to exceed 
the limit of 1 megagram per year.
    (3) The owner or operator must maintain documentation to support 
the owner's or operator's determination of the total annual HAP 
quantity in the off-site material received at the plant site. This 
documentation must include the basis and data used for determining the 
HAP content of the off-site material.
    (e) Compliance dates. (1) Existing sources. The owner or operator 
of an affected source that commenced construction or reconstruction 
before October 13, 1994, must achieve compliance with the provisions of 
this subpart on or before the date specified in paragraph (e)(1)(i) or 
(e)(1)(ii) of this section as applicable to the affected source.
    (i) For an affected source that commenced construction or 
reconstruction before October 13, 1994 and receives off-site material 
for the first time before February 1, 2000, the owner or operator of 
this affected source must achieve compliance with the provisions of the 
subpart on or before February 1, 2000 unless an extension has been 
granted by the Administrator as provided in 40 CFR 63.6(i).
    (ii) For an affected source that commenced construction or 
reconstruction before October 13, 1994, but receives off-site material 
for the first time on or after February 1, 2000, the owner or operator 
of the affected source must achieve compliance with the provisions of 
this subpart upon the first date that the affected source begins to 
manage off-site material.
    (2) New sources. The owner or operator of an affected source for 
which construction or reconstruction commences on or after October 13, 
1994, must achieve compliance with the provisions of this subpart on or 
before July 1, 1996, or upon initial startup of operations, whichever 
date is later as provided in 40 CFR 63.6(b).
* * * * *
    3. Section 63.681 is amended by adding in alphabetical order the 
definitions of ``Flow indicator'' and ``Hazardous air pollutants,'' by 
removing the definition of ``HAP,'' and by revising the definitions of 
``Control device,'' ``Cover,'' ``Point-of-treatment,'' ``Process 
vent,'' ``Safety device,'' ``Used solvent,'' ``Volatile organic 
hazardous air pollutant concentration,'' and ``Waste stabilization 
process'' to read as follows:

[[Page 38965]]

Sec. 63.681  Definitions.

* * * * *
    Control device means equipment used for recovering, removing, 
oxidizing, or destroying organic vapors. Examples of such equipment 
include but are not limited to carbon adsorbers, condensers, vapor 
incinerators, flares, boilers, and process heaters.
    Cover means a device or system that provides a continuous barrier 
over the material managed in a off-site material management unit to 
prevent or reduce air pollutant emissions to the atmosphere. A cover 
may have openings needed for operation, inspection, sampling, 
maintenance, and repair of the unit provided that each opening is 
closed when not in use (e.g., access hatches, sampling ports). A cover 
may be a separate piece of equipment which can be detached and removed 
from the unit or a cover may be formed by structural features 
permanently integrated into the design of the unit.
* * * * *
    Flow indicator means a device that indicates whether gas is 
flowing, or whether the valve position would allow gas to flow in a 
bypass line.
* * * * *
    Hazardous air pollutants or HAP means the specific organic chemical 
compounds, isomers, and mixtures listed in Table 1 of this subpart.
* * * * *
    Off-site material service means any time when a pump, compressor, 
agitator, pressure relief device, sampling connection system, open-
ended valve or line, valve, connector, or instrumentation system 
contains or contacts off-site material.
* * * * *
    Point-of-treatment means a point after the treated material exits 
the treatment process but before the first point downstream of the 
treatment process exit where the organic constituents in the treated 
material have the potential to volatilize and be released to the 
atmosphere. For the purpose of applying this definition to this 
subpart, the first point downstream of the treatment process exit is 
not a fugitive emission point due to an equipment leak from any of the 
following equipment components: pumps, compressors, valves, connectors, 
instrumentation systems, or safety devices.
* * * * *
    Process vent means an open-ended pipe, stack, or duct through which 
a gas stream containing HAP is continuously or intermittently 
discharged to the atmosphere from any of the processes listed in 
Sec. 63.680(c)(2)(i) through (c)(2)(vi) of this section. For the 
purpose of this subpart, a process vent is none of the following: a 
pressure-relief vent or other vent that is used as a safety device (as 
defined in this section); an open-ended line or other vent that is 
subject to the equipment leak control requirements under Sec. 63.691 of 
this subpart; or a stack or other vent that is used to exhaust 
combustion products from a boiler, furnace, process heater, 
incinerator, or other combustion device.
* * * * *
    Safety device means a closure device such as a pressure relief 
valve, frangible disc, fusible plug, or any other type of device which 
functions to prevent physical damage or permanent deformation to 
equipment by venting gases or vapors during unsafe conditions resulting 
from an unplanned, accidental, or emergency event. For the purpose of 
this subpart, a safety device is not used for routine venting of gases 
or vapors from the vapor headspace underneath a cover such as during 
filling of the unit or to adjust the pressure in this vapor headspace 
in response to normal daily diurnal ambient temperature fluctuations. A 
safety device is designed to remain in a closed position during normal 
operations and open only when the internal pressure, or another 
relevant parameter, exceeds the device threshold setting applicable to 
the equipment as determined by the owner or operator based on 
manufacturer recommendations, applicable regulations, fire protection 
and prevention codes, standard engineering codes and practices, or 
other requirements for the safe handling of flammable, combustible, 
explosive, reactive, or hazardous materials.
* * * * *
    Used solvent means a mixture of aliphatic hydrocarbons or a mixture 
of one and two ring aromatic hydrocarbons that has been used as a 
solvent and as a result of such use is contaminated by physical or 
chemical impurities.
* * * * *
    Volatile organic hazardous air pollutant concentration or VOHAP 
concentration means the fraction by weight of those compounds listed in 
Table 1 of this subpart that are in an off-site material as measured 
using Method 305 in appendix A of this part and expressed in terms of 
parts per million (ppm). As an alternative to using Method 305, an 
owner or operator may determine the HAP concentration of an off-site 
material using any one of the other test methods specified in 
Sec. 63.694(b)(2)(ii) of this subpart. When a test method specified in 
Sec. 63.694(b)(2)(ii) of this subpart other than Method 305 is used to 
determine the speciated HAP concentration of an off-site material, the 
individual compound concentration may be adjusted by the corresponding 
fm305 value listed in Table 1 of this subpart to determine a 
VOHAP concentration.
* * * * *
    Waste stabilization process means any physical or chemical process 
used to either reduce the mobility of hazardous constituents in a waste 
or eliminate free liquids as determined by Test Method 9095--Paint 
Filter Liquids Test in ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods,'' EPA Publication No. SW-846, Third Edition, 
September 1986, as amended by Update I, November 15, 1992. (As an 
alternative, an owner or operator may use any more recent, updated 
version of Method 9095 approved by the EPA.) A waste stabilization 
process includes mixing the waste with binders or other materials and 
curing the resulting waste and binder mixture. Other synonymous terms 
used to refer to this process are ``waste fixation'' or ``waste 
solidification.'' A waste stabilization process does not include the 
adding of absorbent materials to the surface of a waste, without 
mixing, agitation, or subsequent curing, to absorb free liquid.
    4. Section 63.683 is revised to read as follows:


Sec. 63.683  Standards: General.

    (a) The general standards under this section apply to owners and 
operators of affected sources as designated in Sec. 63.680(c) of this 
subpart.
    (b) Off-site material management units. (1) For each off-site 
material management unit that is part of an affected source, the owner 
or operator must meet the requirements in either paragraph (b)(1)(i), 
(b)(1)(ii), or (b)(1)(iii) of this section except for those off-site 
material management units exempted under paragraph (b)(2) of this 
section.
    (i) The owner or operator controls air emissions from the off-site 
material management unit in accordance with the applicable standards 
specified in Secs. 63.685 through 63.689 of this subpart.
    (ii) The owner or operator removes or destroys HAP in the off-site 
material before placing the material in the off-site material 
management unit by treating the material in accordance with the 
standards specified in Sec. 63.684 of this subpart.
    (iii) The owner or operator determines before placing off-site 
material in the off-site material management unit that the average 
VOHAP concentration of the off-site material is less than 500 parts per 
million by weight (ppmw) at the

[[Page 38966]]

point-of-delivery. The owner or operator must perform an initial 
determination of the average VOHAP concentration of the off-site 
material using the procedures specified in Sec. 63.694(b) of this 
subpart. This initial determination must be performed either before the 
first time any portion of the off-site material stream is placed in the 
unit or by the compliance date, whichever date is later. Thereafter, 
the owner or operator must review and update, as necessary, this 
determination at least once every calendar year following the date of 
the initial determination for the off-site material stream.
    (2) An off-site material management unit is exempted from the 
requirements in paragraph (b)(1) of this section when the owner or 
operator meets one of the exemptions provided in paragraphs (b)(2)(i) 
through (b)(2)(iv) of this section as applicable to the unit.
    (i) An off-site material management unit is exempted from the 
requirements in paragraph (b)(1) of this section if the off-site 
material management unit is also subject to another subpart under 40 
CFR part 63 or 40 CFR part 61, and the owner or operator is controlling 
the HAP listed in Table 1 of this subpart that are emitted from the 
unit in compliance with the provisions specified in the other 
applicable subpart under part 61 or part 63.
    (ii) At the discretion of the owner or operator, one or a 
combination of off-site material management units may be exempted from 
the requirements in paragraph (b)(1) of this section when these units 
meet the condition that the total annual quantity of HAP contained in 
the off-site material placed in the units exempted under this paragraph 
(b)(2)(ii) is less than 1 megagram per year. For the off-site material 
management units selected by the owner or operator to be exempted from 
the requirements in paragraph (b)(1) of this section, the owner or 
operator must meet the requirements in paragraphs (b)(2)(ii)(A) and 
(b)(2)(ii)(B) of this section. An owner or operator may change the off-
site material management units selected to be exempted under this 
paragraph (b)(2)(ii) by preparing a new designation for the exempt-
units as required by paragraph (b)(2)(ii)(A) of this section and 
performing a new determination as required by paragraph (b)(2)(ii)(B) 
of this section.
    (A) The owner or operator must designate each of the off-site 
material management units selected by the owner or operator to be 
exempt under paragraph (b)(2)(ii) of this section by either submitting 
to the Administrator a written notification identifying the exempt-
units or permanently marking the exempt-units at the plant site. If an 
owner or operator chooses to prepare and submit a written notification, 
this notification must include a site plan, process diagram, or other 
appropriate documentation identifying each of the exempt-units. If an 
owner or operator chooses to permanently mark the exempt-units, each 
exempt-unit must be marked in such a manner that it can be readily 
identified as an exempt-unit from the other off-site material 
management units located at the plant site.
    (B) The owner or operator must prepare an initial determination of 
the total annual HAP quantity in the off-site material placed in the 
units exempted under this paragraph (b)(2)(ii). This determination is 
based on the total quantity of the HAP listed in Table 1 of this 
subpart as determined at the point where the off-site material is 
placed in each exempted unit. The owner or operator must perform a new 
determination whenever the extent of changes to the quantity or 
composition of the off-site material placed in the exempted units could 
cause the total annual HAP content in the off-site material to exceed 1 
megagram per year. The owner or operator must maintain documentation to 
support the most recent determination of the total annual HAP quantity. 
This documentation must include the basis and data used for determining 
the HAP content of the off-site material.
    (iii) A tank or surface impoundment is exempted from the 
requirements in paragraph (b)(1) of this section if the unit is used 
for a biological treatment process that meets the requirements in 
either paragraph (b)(2)(iii)(A) or (b)(2)(iii)(B) of this section and 
the owner or operator complies with the monitoring requirements in 
Sec. 63.684(e)(4) of this subpart.
    (A) The HAP biodegradation efficiency (Rbio) for the 
biological treatment process is equal to or greater than 95 percent. 
The HAP biodegradation efficiency (Rbio) shall be determined 
in accordance with the requirements of Sec. 63.694(h) of this subpart.
    (B) The total actual HAP mass removal rate (MRbio) for 
the off-site material treated by the biological treatment process is 
equal to or greater than the required HAP mass removal rate (RMR) for 
the off-site material. The total actual HAP mass removal rate 
(MRbio) must be determined in accordance with the 
requirements of Sec. 63.694(i) of this subpart. The required HAP mass 
removal rate (RMR) must be determined in accordance with the 
requirements of Sec. 63.694(e) of this subpart.
    (iv) An off-site material management unit is exempted from the 
requirements in paragraph (b)(1) of this section if the off-site 
material placed in the unit is a hazardous waste that meets the 
conditions specified in either paragraph (b)(2)(iv)(A) or (b)(2)(iv)(B) 
of this section.
    (A) The hazardous waste meets the numerical organic concentration 
limits, applicable to the hazardous waste, as specified in 40 CFR part 
268--Land Disposal Restrictions, listed in the table, ``Treatment 
Standards for Hazardous Waste'' in 40 CFR 268.40.
    (B) The organic hazardous constituents in the hazardous waste have 
been treated by the treatment technology established by the EPA for the 
hazardous waste in 40 CFR 268.42(a), or have been removed or destroyed 
by an equivalent method of treatment approved by the EPA under 40 CFR 
268.42(b).
    (v) A tank used for bulk feed of off-site material to a waste 
incinerator is exempted from the requirements specified in paragraph 
(b)(1) of this section if the tank meets all of the conditions 
specified in paragraphs (b)(2)(v)(A) through (b)(2)(v)(C) of this 
section.
    (A) The tank is located inside an enclosure vented to a control 
device that is designed and operated in accordance with all applicable 
requirements specified under 40 CFR part 61, subpart FF--National 
Emission Standards for Benzene Waste Operations for a facility at which 
the total annual benzene quantity from the facility waste is equal to 
or greater than 10 megagrams per year;
    (B) The enclosure and control device serving the tank were 
installed and began operation prior to July 1, 1996; and
    (C) The enclosure is designed and operated in accordance with the 
criteria for a permanent total enclosure as specified in ``Procedure 
T--Criteria for and Verification of a Permanent or Temporary Total 
Enclosure'' under 40 CFR 52.741, appendix B. The enclosure may have 
permanent or temporary openings to allow worker access; passage of 
material into or out of the enclosure by conveyor, vehicles, or other 
mechanical or electrical equipment; or to direct air flow into the 
enclosure. The owner or operator must annually perform the verification 
procedure for the enclosure as specified in Section 5.0 to ``Procedure 
T--Criteria for and Verification of a Permanent or Temporary Total 
Enclosure.''

[[Page 38967]]

    (c) Process vents. (1) For each process vent that is part of an 
affected source, the owner or operator must meet the requirements in 
either paragraph (c)(1)(i) or (c)(1)(ii) of this section except for 
those process vents exempted under paragraph (c)(2) of this section.
    (i) The owner or operator controls air emissions from the process 
vent in accordance with the standards specified in Sec. 63.690 of this 
subpart.
    (ii) The owner or operator determines before placing off-site 
material in the process equipment associated with the process vent that 
the average VOHAP concentration of the off-site material is less than 
ppmw at the point-of-delivery. The owner or operator must perform an 
initial determination of the average VOHAP concentration of the off-
site material using the procedures specified in Sec. 63.694(b) of this 
subpart before any portion of the off-site material stream is placed in 
the unit. Thereafter, the owner or operator must review and update, as 
necessary, this determination at least once every calendar year 
following the date of the initial determination for the off-site 
material stream.
    (2) A process vent is exempted from the requirements of paragraph 
(c)(1) of this section when the owner or operator meets one of the 
exemptions provided in paragraphs (c)(2)(i) through (c)(2)(iii) of this 
section.
    (i) A process vent is exempted from the requirements in paragraph 
(c)(1) of this section if the process vent is also subject to another 
subpart under part 63 or 40 CFR part 61, and the owner or operator is 
controlling the HAP listed in Table 1 of this subpart that are emitted 
from the process vent in compliance with the provisions specified in 
the other applicable subpart under part 61 or part 63.
    (ii) A process vent is exempted from the requirements specified in 
paragraph (c)(1) of this section if the owner or operator determines 
that the process vent stream flow rate is less than 0.005 cubic meters 
per minute (m3/min) at standard conditions (as defined in 40 
CFR 63.2). The process vent stream flow rate shall be determined in 
accordance with the procedures specified in Sec. 63.694(m) of this 
subpart. Documentation must be prepared by the owner or operator and 
maintained at the plant site to support the determination of the 
process vent stream flow rate. This documentation must include 
identification of each process vent exempted under this paragraph and 
the test results used to determine the process vent stream flow rate.
    (iii) A process vent is exempted from the requirements specified in 
paragraph (c)(1) of this section if the owner or operator determines 
that the process vent stream flow rate is less than 6.0 m\3\/min at 
standard conditions (as defined in 40 CFR 63.2) and the total HAP 
concentration is less than 20 ppmv. The process vent stream flow rate 
and total HAP concentration shall be determined in accordance with the 
procedures specified in Sec. 63.694(m) of this subpart. Documentation 
must be prepared by the owner or operator and maintained at the plant 
site to support the determination of the process vent stream flow rate 
and total HAP concentration. This documentation must include 
identification of each process vent exempted under this paragraph 
(c)(2)(iii) and the test results used to determine the process vent 
stream flow rate and total HAP concentration. The owner or operator 
must perform a new determination of the process vent stream flow rate 
and total HAP concentration when the extent of changes to operation of 
the unit on which the process vent is used could cause either the 
process vent stream flow rate to exceed the limit of 6.0 m3/
min or the total HAP concentration to exceed the limit of 20 ppmv.
    (d) Equipment leaks. The owner or operator must control equipment 
leaks from each equipment component that is part of the affected source 
specified in Sec. 63.680(c)(3) of this subpart by implementing leak 
detection and control measures in accordance with the standards 
specified in Sec. 63.691 of this subpart.
    5. Section 63.684 is amended by revising paragraphs (a), (b) 
introductory text, (b)(1)(ii), (b)(3) introductory text, (b)(4) 
introductory text, (b)(5), (d), (e), (f), and (g) to read as follows:


Sec. 63.684  Standards: Off-site material treatment.

    (a) The provisions of this section apply to the treatment of off-
site material to remove or destroy HAP for which Sec. 63.683(b)(1)(ii) 
of this subpart references the requirements of this section for such 
treatment.
    (b) The owner or operator shall remove or destroy the HAP contained 
in off-site material streams to be managed in the off-site material 
management unit in accordance with Sec. 63.683(b)(1)(ii) of this 
subpart using a treatment process that continuously achieves, under 
normal operations, one or more of the performance levels specified in 
paragraphs (b)(1) through (b)(5) of this section (as applicable to the 
type of treatment process) for the range of off-site material stream 
compositions and quantities expected to be treated.
    (1) * * *
    (ii) In the case when off-site material streams entering the 
treatment process are a mixture of off-site material streams having an 
average VOHAP concentration equal to or greater than 500 ppmw at the 
point-of-delivery with off-site material streams having average VOHAP 
concentrations less than 500 ppmw at the point-of-delivery, then the 
VOHAP concentration of the off-site material must be reduced to a level 
at the point-of-treatment that meets the performance level specified in 
either paragraph (b)(1)(ii)(A) or (b)(1)(ii)(B) of this section.
* * * * *
    (3) HAP reduction efficiency. For any treatment process except a 
treatment process that uses biological degradation and is performed in 
an open tank or surface impoundment, the treatment process must achieve 
the applicable performance level specified in either paragraph 
(b)(3)(i) or (b)(3)(ii) of this section.
* * * * *
    (4) Biological degradation performed in an open tank or surface 
impoundment. A treatment process using biological degradation and 
performed in an open tank or surface impoundment must achieve the 
performance level specified in either paragraph (b)(4)(i) or (b)(4)(ii) 
of this section.
* * * * *
    (5) Incineration. The treatment process must destroy the HAP 
contained in the off-site material stream using one of the combustion 
devices specified in paragraphs (b)(5)(i) through (b)(5)(iv) of this 
section.
    (i) An incinerator for which the owner or operator has been issued 
a final permit under 40 CFR part 270, and the incinerator is designed 
and operated in accordance with the requirements of 40 CFR part 264, 
subpart O--Incinerators, or
    (ii) An incinerator for which the owner or operator has certified 
compliance with the interim status requirements of 40 CFR part 265, 
subpart O--Incinerators.
    (iii) A boiler or industrial furnace for which the owner or 
operator has been issued a final permit under 40 CFR part 270, and the 
combustion unit is designed and operated in accordance with the 
requirements of 40 CFR part 266, subpart H--Hazardous Waste Burned in 
Boilers and Industrial Furnaces.
    (iv) A boiler or industrial furnace for which the owner or operator 
has certified compliance with the interim status requirements of 40 CFR 
part 266,

[[Page 38968]]

subpart H Hazardous Waste Burned in Boilers and Industrial Furnaces.
* * * * *
    (d) When the owner or operator treats the off-site material to meet 
one of the performance levels specified in paragraphs (b)(1) through 
(b)(4) of this section, the owner or operator shall demonstrate that 
the treatment process achieves the selected performance level for the 
range of expected off-site material stream compositions expected to be 
treated. An initial demonstration shall be performed as soon as 
possible but no later than 30 days after first time an owner or 
operator begins using the treatment process to manage off-site material 
streams in accordance with the requirements of either 
Sec. 63.683(b)(1)(ii) or Sec. 63.683(b)(2)(ii) of this subpart as 
applicable to the affected off-site material management unit or process 
equipment. Thereafter, the owner or operator shall review and update, 
as necessary, this demonstration at least once every calendar year 
following the date of the initial demonstration.
    (e) When the owner or operator treats the off-site material to meet 
one of the performance levels specified in paragraphs (b)(1) through 
(b)(4) of this section, the owner or operator shall ensure that the 
treatment process is achieving the applicable performance requirements 
by continuously monitoring the operation of the process when it is used 
to treat off-site material by complying with paragraphs (e)(1) through 
(e)(3) or, for biological treatment units, paragraph (e)(4) of this 
section:
    (1) A continuous monitoring system shall be installed and operated 
for each treatment that measures operating parameters appropriate for 
the treatment process technology. This system shall include a 
continuous recorder that records the measured values of the selected 
operating parameters. The monitoring equipment shall be installed, 
calibrated, and maintained in accordance with the equipment 
manufacturer's specifications or other written procedures that provide 
reasonable assurance that the monitoring equipment is operating 
properly. The continuous recorder shall be a data recording device that 
records either an instantaneous data value at least once every 15 
minutes or an average value for intervals of 15 minutes or less.
    (2) For each monitored operating parameter, the owner or operator 
shall establish a minimum operating parameter value or a maximum 
operating parameter value, as appropriate, to define the range of 
conditions at which the treatment process must be operated to 
continuously achieve the applicable performance requirements of this 
section.
    (3) When the treatment process is operating to treat off-site 
material, the owner or operator shall inspect the data recorded by the 
continuous monitoring system on a routine basis and operate the 
treatment process such that the actual value of each monitored 
operating parameter is greater than the minimum operating parameter 
value or less than the maximum operating parameter value, as 
appropriate, established for the treatment process.
    (4) When the treatment process is a biological treatment process 
that is complying with paragraph (b)(4) of this section, the owner or 
operator must establish and implement a written procedure to monitor 
the appropriate parameters that demonstrate proper operation of the 
biological treatment unit in accordance with the evaluation required in 
Sec. 63.694(h) of this subpart. The written procedure must list the 
operating parameters that will be monitored and state the frequency of 
monitoring to ensure that the biological treatment unit is operating 
between the minimum operating parameter values and maximum operating 
parameter values to establish that the biological treatment unit is 
continuously achieving the performance requirement.
    (f) The owner or operator must maintain records for each treatment 
process in accordance with the requirements of Sec. 63.696(a) of this 
subpart.
    (g) The owner or operator must prepare and submit reports for each 
treatment process in accordance with the requirements of Sec. 63.697(a) 
of this subpart.
* * * * *
    6. Section 63.685 is amended by adding paragraph (i)(3) and by 
revising paragraphs (b), (c)(2), (f)(1)(ii)(A), (g)(2)(i)(B), (h)(2), 
(h)(3), and (i) introductory text to read as follows:


Sec. 63.685  Standards: Tanks.

* * * * *
    (b) The owner or operator shall control air emissions from each 
tank subject to this section in accordance with the following 
applicable requirements:
    (1) For a tank that is part of an existing affected source but the 
tank is not used to manage off-site material having a maximum HAP vapor 
pressure kilopascal (kPa) that is equal to or greater than 76.6 kPa nor 
is the tank used for a waste stabilization process as defined in 
Sec. 63.681 of this subpart, the owner or operator shall determine 
whether the tank is required to use either Tank Level 1 controls or 
Tank Level 2 controls as specified for the tank by Table 3 of this 
subpart based on the off-site material maximum HAP vapor pressure and 
the tank's design capacity. The owner or operator shall control air 
emissions from a tank required by Table 3 to use Tank Level 1 controls 
in accordance with the requirements of paragraph (c) of this section. 
The owner or operator shall control air emissions from a tank required 
by Table 3 to use Tank Level 2 controls in accordance with the 
requirements of paragraph (d) of this section.
    (2) For a tank that is part of a new affected source but the tank 
is not used to manage off-site material having a maximum HAP vapor 
pressure that is equal to or greater than 76.6 kPa nor is the tank used 
for a waste stabilization process as defined in Sec. 63.681 of this 
subpart, the owner or operator shall determine whether the tank is 
required to use either Tank Level 1 controls or Tank Level 2 controls 
as specified for the tank by Table 4 of this subpart based on the off-
site material maximum HAP vapor pressure and the tank's design 
capacity. The owner or operator shall control air emissions from a tank 
required by Table 4 to use Tank Level 1 controls in accordance with the 
requirements of paragraph (c) of this section. The owner or operator 
shall control air emissions from a tank required by Table 4 to use Tank 
Level 2 controls in accordance with the requirements of paragraph (d) 
of this section.
    (3) For a tank that is used for a waste stabilization process, the 
owner or operator shall control air emissions from the tank by using 
Tank Level 2 controls in accordance with the requirements of paragraph 
(d) of this section.
    (4) For a tank that manages off-site material having a maximum HAP 
vapor pressure that is equal to or greater than 76.6 kPa, the owner or 
operator must control air emissions by using one of the tanks specified 
in paragraphs (b)(4)(i) through (b)(4)(iii) of this section.
    (i) A tank vented through a closed-vent system to a control device 
in accordance with the requirements specified in paragraph (g) of this 
section;
    (ii) A pressure tank designed and operated in accordance with the 
requirements specified in paragraph (h) of this section; or
    (iii) A tank located inside an enclosure that is vented through a 
closed-vent system to an enclosed combustion control device in 
accordance with the requirements specified in paragraph (i) of this 
section.

[[Page 38969]]

    (c) * * *
    (2) The owner or operator must control air emissions from the tank 
in accordance with the requirements in either paragraph (c)(2)(i), 
(c)(2)(ii), or (c)(2)(iii) of this section, as applicable to the tank.
    (i) The owner or operator controls air emissions from the tank in 
accordance with the provisions specified in subpart 00 of 40 CFR part 
63--National Emission Standards for Tanks--Level 1.
    (ii) As an alternative to meeting the requirements in paragraph 
(c)(2)(i) of this section, an owner or operator may control air 
emissions from the tank in accordance with the provisions for Tank 
Level 2 controls as specified in paragraph (d) of this section.
    (iii) As an alternative to meeting the requirements in paragraph 
(c)(2)(i) of this section when a tank is used as an interim transfer 
point to transfer off-site material from containers to another off-site 
material management unit, an owner or operator may control air 
emissions from the tank in accordance with the requirements in 
paragraphs (c)(2)(iii)(A) and (c)(2)(iii)(B) of this section. An 
example of such a tank is an in-ground tank into which organic-
contaminated debris is dumped from roll-off boxes or dump trucks, and 
then this debris is promptly transferred from the tank to a 
macroencapsulation unit by a backhoe.
    (A) During those periods of time when the material transfer 
activity is occurring, the tank may be operated without a cover.
    (B) At all other times, air emissions from the tank must be 
controlled in accordance with the provisions specified in 40 CFR part 
67, subpart 00--National Emission Standards for Tanks--Level 1.
* * * * *
    (f) * * *
    (1) * * *
    (ii) * * *
    (A) The primary seal shall be a liquid-mounted seal or a metallic 
shoe seal, as defined in Sec. 63.681 of this subpart. The total area of 
the gaps between the tank wall and the primary seal shall not exceed 
212 square centimeters (cm2) per meter of tank diameter, and the width 
of any portion of these gaps shall not exceed 3.8 centimeters (cm). If 
a metallic shoe seal is used for the primary seal, the metallic shoe 
seal shall be designed so that one end extends into the liquid in the 
tank and the other end extends a vertical distance of at least 61 
centimeters (24 inches) above the liquid surface.
* * * * *
    (g) * * *
    (2) * * *
    (i) * * *
    (B) To remove accumulated sludge or other residues from the bottom 
of the tank.
* * * * *
    (h) * * *
    (2) All tank openings shall be equipped with closure devices 
designed to operate with no detectable organic emissions as determined 
using the procedure specified in Sec. 63.694(k) of this subpart.
    (3) Whenever an off-site material is in the tank, the tank shall be 
operated as a closed system that does not vent to the atmosphere except 
under either of the following conditions as specified in paragraph 
(h)(3)(i) or (h)(3)(ii) of this section.
    (i) At those times when opening of a safety device, as defined in 
Sec. 63.681 of this subpart, is required to avoid an unsafe condition.
    (ii) At those times when purging of inerts from the tank is 
required and the purge stream is routed to a closed-vent system and 
control device designed and operated in accordance with the 
requirements of Sec. 63.693 of this subpart.
    (i) The owner or operator who elects to control air emissions by 
using an enclosure vented through a closed-vent system to an enclosed 
combustion control device shall meet the requirements specified in 
paragraphs (i)(1) through (i)(3) of this section.
* * * * *
    (3) Opening of a safety device, as defined in Sec. 63.681 of this 
subpart, is allowed at any time conditions require it to do so to avoid 
an unsafe condition.
    7. Section 63.686 is amended by revising the paragraph (b) 
introductory text and adding paragraph (b)(3) to read as follows:


Sec. 63.686  Standards: Oil-water and organic-water separators.

* * * * *
    (b) The owner or operator shall control air emissions from each 
separator subject to this section by using one of the following:
* * * * *
    (3) A pressurized separator that operates as a closed system in 
accordance with all applicable provisions specified in 40 CFR part 63, 
subpart VV--National Emission Standards for Oil-Water Separators and 
Organic-Water Separators.
    8. Section 63.687 is amended by revising the paragraph (b) 
introductory text to read as follows:


Sec. 63.687  Standards: Surface impoundments.

* * * * *
    (b) The owner or operator shall control air emissions from each 
surface impoundment subject to this section by using one of the 
following:
* * * * *
    9. Section 63.688 is amended by revising paragraphs (b) and (c) to 
read as follows:


Sec. 63.688  Standards: Containers.

* * * * *
    (b) The owner or operator shall control air emissions from each 
container subject to this section in accordance with the following 
requirements, as applicable to the container, except when the special 
provisions for waste stabilization processes specified in paragraph (c) 
of this section apply to the container.
    (1) For a container having a design capacity greater than 0.1 m\3\ 
and less than or equal to 0.46 m\3\, the owner or operator must control 
air emissions from the container in accordance with the requirements in 
either paragraph (b)(1)(i) or (b)(1)(ii) of this section.
    (i) The owner or operator controls air emissions from the container 
in accordance with the standards for Container Level 1 controls as 
specified in 40 CFR part 63, subpart PP--National Emission Standards 
for Containers.
    (ii) As an alternative to meeting the requirements in paragraph 
(b)(1)(i) of this section, an owner or operator may choose to control 
air emissions from the container in accordance with the standards for 
either Container Level 2 controls or Container Level 3 controls as 
specified in subpart PP of this part 63--National Emission Standards 
for Containers.
    (2) For a container having a design capacity greater than 0.46 m\3\ 
and the container is not in light-material service as defined in 
Sec. 63.681 of this subpart, the owner or operator must control air 
emissions from the container in accordance with the requirements in 
either paragraph (b)(1)(i) or (b)(1)(ii) of this section.
    (3) For a container having a design capacity greater than 0.46 m\3\ 
and the container is in light-material service as defined in 
Sec. 63.681 of this subpart, the owner or operator must control air 
emissions from the container in accordance with the requirements in 
either paragraph (b)(3)(i) or (b)(3)(ii) of this section.
    (i) The owner or operator controls air emissions from the container 
in accordance with the standards for Container Level 2 controls as 
specified in 40 CFR part 63, subpart PP--National Emission Standards 
for Containers.
    (ii) As an alternative to meeting the requirements in paragraph 
(b)(3)(i) of

[[Page 38970]]

this section, an owner or operator may choose to control air emissions 
from the container in accordance with the standards for Container Level 
3 controls as specified in 40 CFR part 63, subpart PP--National 
Emission Standards for Containers.
    (c) When a container subject to this subpart and having a design 
capacity greater than 0.1 m\3\ is used for treatment of an off-site 
material by a waste stabilization process as defined in Sec. 63.681 of 
this subpart, the owner or operator shall control air emissions from 
the container at those times during the process when the off-site 
material in the container is exposed to the atmosphere in accordance 
with the standards for Container Level 3 controls as specified in 40 
CFR part 63, subpart PP--National Emission Standards for Containers.
    10. Section 63.689 is amended by revising paragraphs (b), (c), (d) 
introductory text, and (d)(5) introductory text to read as follows:


Sec. 63.689  Standards: Transfer systems.

* * * * *
    (b) For each transfer system that is subject to this section and is 
an individual drain system, the owner or operator shall control air 
emissions in accordance with the standards specified in 40 CFR part 63, 
subpart RR--National Emission Standards for Individual Drain Systems.
    (c) For each transfer system that is subject to this section but is 
not an individual drain system, the owner or operator shall control air 
emissions by using one of the transfer systems specified in paragraphs 
(c)(1) through (c)(3) of this section.
    (1) A transfer system that uses covers in accordance with the 
requirements specified in paragraph (d) of this section.
    (2) A transfer system that consists of continuous hard-piping. All 
joints or seams between the pipe sections shall be permanently or semi-
permanently sealed (e.g., a welded joint between two sections of metal 
pipe or a bolted and gasketed flange).
    (3) A transfer system that is enclosed and vented through a closed-
vent system to a control device in accordance with the requirements 
specified in paragraphs (c)(3)(i) and (c)(3)(ii) of this section.
    (i) The transfer system is designed and operated such that an 
internal pressure in the vapor headspace in the enclosure is maintained 
at a level less than atmospheric pressure when the control device is 
operating, and
    (ii) The closed-vent system and control device are designed and 
operated in accordance with the requirements of Sec. 63.693 of this 
subpart.
    (d) Owners and operators controlling air emissions from a transfer 
system using covers in accordance with the provisions of paragraph 
(c)(1) of this section shall meet the requirements specified in 
paragraphs (d)(1) through (d)(6) of this section.
* * * * *
    (5) Whenever an off-site material is in the transfer system, the 
cover shall be installed with each closure device secured in the closed 
position except as specified in paragraph (d)(5)(i) or (d)(5)(ii) of 
this section.
* * * * *
    11. Section 63.690 is revised to read as follows:


Sec. 63.690  Standards: Process vents.

    (a) The provisions of this section apply to the control of air 
emissions from process vents for which Sec. 63.683(c)(1)(i) of this 
subpart references the use of this section for such air emission 
control.
    (b) The owner or operator must route the vent stream from each 
affected process vent through a closed-vent system to a control device 
that meets the standards specified in Sec. 63.693 of this subpart. For 
the purpose of complying with this paragraph (b), a primary condenser 
is not a control device; however, a second condenser or other organic 
recovery device that is operated downstream of the primary condenser is 
considered a control device.
    12. Section 63.691 is revised to read as follows:


Sec. 63.691  Standards: Equipment leaks.

    (a) The provisions of this section apply to the control of air 
emissions from equipment leaks for which Sec. 63.683(b)(3) of this 
subpart references the use of this section for such air emission 
control.
    (b) The owner or operator shall control the HAP emitted from 
equipment leaks in accordance with the applicable provisions specified 
in either paragraph (b)(1) or (b)(2) of this section.
    (1) The owner or operator controls the HAP emitted from equipment 
leaks in accordance with Sec. 61.242 through Sec. 61.247 in 40 CFR part 
61, subpart V--National Emission Standards for Equipment Leaks; or
    (2) The owner or operator controls the HAP emitted from equipment 
leaks in accordance with Sec. 63.162 through Sec. 63.182 in subpart H--
National Emission Standards for Organic Hazardous Air Pollutants from 
Equipment Leaks.
    13. Section 63.693 is revised to read as follows:


Sec. 63.693  Standards: Closed-vent systems and control devices.

    (a) The provisions of this section apply to closed-vent systems and 
control devices used to control air emissions for which another 
standard references the use of this section for such air emission 
control.
    (b) For each closed-vent system and control device used to comply 
with this section, the owner or operator shall meet the following 
requirements:
    (1) The owner or operator must use a closed-vent system that meets 
the requirements specified in paragraph (c) of this section.
    (2) The owner or operator must use a control device that meets the 
requirements specified in paragraphs (d) through (h) of this section as 
applicable to the type and design of the control device selected by the 
owner or operator to comply with the provisions of this section.
    (3) Whenever gases or vapors containing HAP are vented through a 
closed-vent system connected to a control device used to comply with 
this section, the control device must be operating except at those 
times listed in either paragraph (b)(3)(i) or (b)(3)(ii) of this 
section.
    (i) The control device may be bypassed for the purpose of 
performing planned routine maintenance of the closed-vent system or 
control device in situations when the routine maintenance cannot be 
performed during periods that the emission point vented to the control 
device is shutdown. On an annual basis, the total time that the closed-
vent system or control device is bypassed to perform routine 
maintenance shall not exceed 240 hours per each calendar year.
    (ii) The control device may be bypassed for the purpose of 
correcting a malfunction of the closed-vent system or control device. 
The owner or operator shall perform the adjustments or repairs 
necessary to correct the malfunction as soon as practicable after the 
malfunction is detected.
    (4) The owner or operator must inspect and monitor each closed-vent 
system in accordance with the requirements specified in either 
paragraph (b)(4)(i) or (b)(4)(ii) of this section.
    (i) The owner or operator inspects and monitors the closed-vent 
system in accordance with the requirements specified in Sec. 63.695(c) 
of this subpart, and complies with the applicable recordkeeping 
requirements in Sec. 63.696 of this subpart and the applicable 
reporting requirements in Sec. 63.697 of this subpart.

[[Page 38971]]

    (ii) As an alternative to meeting the requirements specified in 
paragraph (b)(4)(i) of this section, the owner or operator may choose 
to inspect and monitor the closed-vent system in accordance with the 
requirements under 40 CFR part 63, subpart H--National Emission 
Standards for Organic Hazardous Air Pollutants for Equipment Leaks as 
specified in 40 CFR 63.172(f) through (h), and complies with the 
applicable recordkeeping requirements in 40 CFR 63.181 and the 
applicable reporting requirements in 40 CFR 63.182.
    (5) The owner or operator must monitor the operation of each 
control device in accordance with the requirements specified in 
paragraphs (d) through (h) of this section as applicable to the type 
and design of the control device selected by the owner or operator to 
comply with the provisions of this section.
    (6) The owner or operator shall maintain records for each control 
device in accordance with the requirements of Sec. 63.696 of this 
subpart.
    (7) The owner or operator shall prepare and submit reports for each 
control device in accordance with the requirements of Sec. 63.697 of 
this subpart.
    (8) In the case when an owner or operator chooses to use a design 
analysis to demonstrate compliance of a control device with the 
applicable performance requirements specified in this section as 
provided for in paragraphs (d) through (g) of this section, the 
Administrator may request that the design analysis be revised or 
amended by the owner or operator to correct any deficiencies identified 
by the Administrator. If the owner or operator and the Administrator do 
not agree on the acceptability of using the design analysis (including 
any changes requested by the Administrator) to demonstrate that the 
control device achieves the applicable performance requirements, then 
the disagreement must be resolved using the results of a performance 
test conducted by the owner or operator in accordance with the 
requirements of Sec. 63.694(l) of this subpart. The Administrator may 
choose to have an authorized representative observe the performance 
test conducted by the owner or operator. Should the results of this 
performance test not agree with the determination of control device 
performance based on the design analysis, then the results of the 
performance test will be used to establish compliance with this 
subpart.
    (c) Closed-vent system requirements.
    (1) The vent stream required to be controlled shall be conveyed to 
the control device by either of the following closed-vent systems:
    (i) A closed-vent system that is designed to operate with no 
detectable organic emissions using the procedure specified in 
Sec. 63.694(k) of this subpart; or
    (ii) A closed-vent system that is designed to operate at a pressure 
below atmospheric pressure. The system shall be equipped with at least 
one pressure gage or other pressure measurement device that can be read 
from a readily accessible location to verify that negative pressure is 
being maintained in the closed-vent system when the control device is 
operating.
    (2) In situations when the closed-vent system includes bypass 
devices that could be used to divert a vent stream from the closed-vent 
system to the atmosphere at a point upstream of the control device 
inlet, each bypass device must be equipped with either a flow indicator 
as specified in paragraph (c)(2)(i) of this section or a seal or 
locking device as specified in paragraph (c)(2)(ii) of this section. 
For the purpose of complying with this paragraph (c)(2), low leg 
drains, high point bleeds, analyzer vents, open-ended valves or lines, 
or pressure relief valves needed for safety reasons are not subject to 
the requirements of this paragraph (c)(2).
    (i) If a flow indicator is used, the indicator must be installed at 
the entrance to the bypass line used to divert the vent stream from the 
closed-vent system to the atmosphere. The flow indicator must indicate 
a reading at least once every 15 minutes. The owner or operator must 
maintain records of the following information: hourly records of 
whether the flow indicator was operating and whether flow was detected 
at any time during the hour; and records of all periods when flow is 
detected or the flow indicator is not operating.
    (ii) If a seal or locking device is used, the bypass line valve 
must be secured in the non-diverting position with a car-seal or a 
lock-and-key type configuration. The seal or locking device must be 
placed on the mechanism by which the bypass device position is 
controlled (e.g., valve handle, damper lever) when the bypass device is 
in the non-diverting position such that the bypass device cannot be 
moved to the diverting position without breaking the seal or removing 
the lock. The owner or operator must visually inspect the seal or 
closure mechanism at least once every month to determine that the 
bypass line valve is maintained in the non-diverting position and the 
vent stream is not diverted through the bypass line.
    (d) Carbon adsorption control device requirements.
    (1) The carbon adsorption system must achieve the performance 
specifications in either paragraph (d)(1)(i) or (d)(1)(ii) of this 
section.
    (i) Recover 95 percent or more, on a weight-basis, of the total 
organic compounds (TOC), less methane and ethane, contained in the vent 
stream entering the carbon adsorption system; or
    (ii) Recover 95 percent or more, on a weight-basis, of the total 
HAP listed in Table 1 of this subpart contained in the vent stream 
entering the carbon adsorption system.
    (2) The owner or operator must demonstrate that the carbon 
adsorption system achieves the performance requirements in paragraph 
(d)(1) of this section by either performing a performance test as 
specified in paragraph (d)(2)(i) of this section or a design analysis 
as specified in paragraph (d)(2)(ii) of this section.
    (i) An owner or operator choosing to use a performance test to 
demonstrate compliance must conduct the test in accordance with the 
requirements of Sec. 63.694(l) of this subpart.
    (ii) An owner or operator choosing to use a design analysis to 
demonstrate compliance must include as part of this design analysis the 
information specified in either paragraph (d)(2)(ii)(A) or 
(d)(2)(ii)(B) of this section as applicable to the carbon adsorption 
system design.
    (A) For a regenerable carbon adsorption system, the design analysis 
shall address the vent stream composition, constituent concentrations, 
flow rate, relative humidity, and temperature and shall establish the 
design exhaust vent stream organic compound concentration, adsorption 
cycle time, number and capacity of carbon beds, type and working 
capacity of activated carbon used for carbon beds, design total 
regeneration steam flow over the period of each complete carbon bed 
regeneration cycle, design carbon bed temperature after regeneration, 
design carbon bed regeneration time, and design service life of the 
carbon.
    (B) For a nonregenerable carbon adsorption system (e.g., a carbon 
canister), the design analysis shall address the vent stream 
composition, constituent concentrations, flow rate, relative humidity, 
and temperature and shall establish the design exhaust vent stream 
organic compound concentration, carbon bed capacity, activated carbon 
type and working capacity, and design carbon replacement interval based 
on the total

[[Page 38972]]

carbon working capacity of the control device and emission point 
operating schedule.
    (3) The owner or operator must monitor the operation of the carbon 
adsorption system in accordance with the requirements of Sec. 63.695(e) 
of this subpart using one of the continuous monitoring systems 
specified in paragraphs (d)(3)(i) through (d)(3)(iii) of this section.
    (i) For a regenerative-type carbon adsorption system:
    (A) A continuous parameter monitoring system to measure and record 
the average total regeneration stream mass flow or volumetric flow 
during each carbon bed regeneration cycle. The integrating regenerating 
stream flow monitoring device must have an accuracy of 10 
percent; and
    (B) A continuous parameter monitoring system to measure and record 
the average carbon bed temperature for the duration of the carbon bed 
steaming cycle and to measure the actual carbon bed temperature after 
regeneration and within 15 minutes of completing the cooling cycle. The 
accuracy of the temperature monitoring device must be 1 
percent of the temperature being measured, expressed in degrees Celsius 
or 5 deg.C, whichever is greater.
    (ii) A continuous monitoring system to measure and record the daily 
average concentration level of organic compounds in the exhaust gas 
stream from the control device. The accuracy of the organic monitoring 
device must be 1 percent of the concentration being 
measured.
    (iii) A continuous monitoring system that measures other 
alternative operating parameters upon approval of the Administrator as 
specified in 40 CFR 63.8(f)(1) through (f)(5) of this part.
    (4) The owner or operator shall manage the carbon used for the 
carbon adsorption system, as follows:
    (i) Following the initial startup of the control device, all carbon 
in the control device shall be replaced with fresh carbon on a regular, 
predetermined time interval that is no longer than the carbon service 
life established for the carbon adsorption system.
    (ii) The spent carbon removed from the carbon adsorption system 
must be either regenerated, reactivated, or burned in one of the units 
specified in paragraphs (d)(4)(ii)(A) through (d)(4)(ii)(G) of this 
section.
    (A) Regenerated or reactivated in a thermal treatment unit for 
which the owner or operator has been issued a final permit under 40 CFR 
part 270 that implements the requirements of 40 CFR part 264, subpart 
X.
    (B) Regenerated or reactivated in a thermal treatment unit equipped 
with and operating air emission controls in accordance with this 
section.
    (C) Regenerated or reactivated in a thermal treatment unit equipped 
with and operating organic air emission controls in accordance with a 
national emission standard for hazardous air pollutants under another 
subpart in 40 CFR part 63 or 40 CFR part 61.
    (D) Burned in a hazardous waste incinerator for which the owner or 
operator has been issued a final permit under 40 CFR part 270 that 
implements the requirements of 40 CFR part 264, subpart O.
    (E) Burned in a hazardous waste incinerator for which the owner or 
operator has designed and operates the incinerator in accordance with 
the interim status requirements of 40 CFR part 265, subpart O.
    (F) Burned in a boiler or industrial furnace for which the owner or 
operator has been issued a final permit under 40 CFR part 270 that 
implements the requirements of 40 CFR part 266, subpart H.
    (G) Burned in a boiler or industrial furnace for which the owner or 
operator has designed and operates the unit in accordance with the 
interim status requirements of 40 CFR part 266, subpart H.
    (e) Condenser control device requirements.
    (1) The condenser must achieve the performance specifications in 
either paragraph (e)(1)(i) or (e)(1)(ii) of this section.
    (i) Recover 95 percent or more, on a weight-basis, of the total 
organic compounds (TOC), less methane and ethane, contained in the vent 
stream entering the condenser; or
    (ii) Recover 95 percent or more, on a weight-basis, of the total 
HAP, listed in Table 1 of this subpart, contained in the vent stream 
entering the condenser.
    (2) The owner or operator must demonstrate that the condenser 
achieves the performance requirements in paragraph (e)(1) of this 
section by either performing a performance test as specified in 
paragraph (e)(2)(i) of this section or a design analysis as specified 
in paragraph (e)(2)(ii) of this section.
    (i) An owner or operator choosing to use a performance tests to 
demonstrate compliance must conduct the test in accordance with the 
requirements of Sec. 63.694(l) of this subpart.
    (ii) An owner or operator choosing to use a design analysis to 
demonstrate compliance must include as part of this design analysis the 
following information: description of the vent stream composition, 
constituent concentrations, flow rate, relative humidity, and 
temperature; and specification of the design outlet organic compound 
concentration level, design average temperature of the condenser 
exhaust vent stream, and the design average temperatures of the coolant 
fluid at the condenser inlet and outlet.
    (3) The owner or operator must monitor the operation of the 
condenser in accordance with the requirements of Sec. 63.695(e) of this 
subpart using one of the continuous monitoring systems specified in 
paragraphs (e)(3)(i) through (e)(3)(iii) of this section.
    (i) A continuous parameter monitoring system to measure and record 
the daily average temperature of the exhaust gases from the control 
device. The accuracy of the temperature monitoring device shall be 
1 percent of the temperature being measured, expressed in 
degrees Celsius or 5 deg.C, whichever is greater.
    (ii) A continuous monitoring system to measure and record the daily 
average concentration of organic compounds in the exhaust vent stream 
from the control device. The accuracy of the concentration monitoring 
device shall be 1 percent of the concentration being 
measured.
    (iii) A continuous monitoring system that measures other 
alternative operating parameters upon approval of the Administrator as 
specified in 40 CFR 63.8(f)(1) through (f)(5) of this part.
    (f) Vapor incinerator control device requirements.
    (1) The vapor incinerator must achieve the performance 
specifications in either paragraph (f)(1)(i), (f)(1)(ii), or 
(f)(1)(iii) of this section.
    (i) Destroy the total organic compounds (TOC), less methane and 
ethane, contained in the vent stream entering the vapor incinerator 
either:
    (A) By 95 percent or more, on a weight-basis, or
    (B) To achieve a total incinerator outlet concentration for the 
TOC, less methane and ethane, of less than or equal to ppmv on a dry 
basis corrected to 3 percent oxygen.
    (ii) Destroy the HAP listed in Table 1 of this subpart contained in 
the vent stream entering the vapor incinerator either:
    (A) By 95 percent or more, on a total HAP weight-basis, or
    (B) To achieve a total incinerator outlet concentration for the 
HAP, listed in Table 1 of this subpart, of less than or equal to ppmv 
on a dry basis corrected to 3 percent oxygen.
    (iii) Maintain the conditions in the vapor incinerator combustion 
chamber at a residence time of 0.5 seconds or

[[Page 38973]]

longer and at a temperature of 760 deg.C or higher.
    (2) The owner or operator must demonstrate that the vapor 
incinerator achieves the performance requirements in paragraph (f)(1) 
of this section by either performing a performance test as specified in 
paragraph (f)(2)(i) of this section or a design analysis as specified 
in paragraph (f)(2)(ii) of this section.
    (i) An owner or operator choosing to use a performance test to 
demonstrate compliance must conduct the test in accordance with the 
requirements of Sec. 63.694(l) of this subpart.
    (ii) An owner or operator choosing to use a design analysis to 
demonstrate compliance must include as part of this design analysis the 
information specified in either paragraph (f)(2)(ii)(A) or 
(f)(2)(ii)(B) of this section as applicable to the vapor incinerator 
design.
    (A) For a thermal vapor incinerator, the design analysis shall 
address the vent stream composition, constituent concentrations, and 
flow rate and shall establish the design minimum and average 
temperatures in the combustion chamber and the combustion chamber 
residence time.
    (B) For a catalytic vapor incinerator, the design analysis shall 
address the vent stream composition, constituent concentrations, and 
flow rate and shall establish the design minimum and average 
temperatures across the catalyst bed inlet and outlet, and the design 
service life of the catalyst.
    (3) The owner or operator must monitor the operation of the vapor 
incinerator in accordance with the requirements of Sec. 63.695(e) of 
this subpart using one of the continuous monitoring systems specified 
in paragraphs (f)(3)(i) through (f)(3)(iv) of this section as 
applicable to the type of vapor incinerator used.
    (i) For a thermal vapor incinerator, a continuous parameter 
monitoring system to measure and record the daily average temperature 
of the exhaust gases from the control device. The accuracy of the 
temperature monitoring device must be 1 percent of the 
temperature being measured, expressed in degrees Celsius of 
0.5 deg.C, whichever is greater.
    (ii) For a catalytic vapor incinerator, a temperature monitoring 
device capable of monitoring temperature at two locations equipped with 
a continuous recorder. One temperature sensor shall be installed in the 
vent stream at the nearest feasible point to the catalyst bed inlet and 
a second temperature sensor shall be installed in the vent stream at 
the nearest feasible point to the catalyst bed outlet.
    (iii) For either type of vapor incinerator, a continuous monitoring 
system to measure and record the daily average concentration of organic 
compounds in the exhaust vent stream from the control device. The 
accuracy of the concentration monitoring device must be 1 
percent of the concentration being measured.
    (iv) For either type of vapor incinerator, a continuous monitoring 
system that measures alternative operating parameters other than those 
specified in paragraph (f)(3)(i) or (f)(3)(ii) of this section upon 
approval of the Administrator as specified in 40 CFR 63.8(f)(1) through 
(f)(5) of this part.
    (g) Boilers and process heaters control device requirements.
    (1) The boiler or process heater must achieve the performance 
specifications in either paragraph (g)(1)(i), (g)(1)(ii), (g)(1)(iii), 
(g)(1)(iv), or (g)(1)(v) of this section.
    (i) Destroy the total organic compounds (TOC), less methane and 
ethane, contained in the vent stream introduced into the flame zone of 
the boiler or process heater either:
    (A) By 95 percent or more, on a weight-basis, or
    (B) To achieve in the exhausted combustion gases a total 
concentration for the TOC, less methane and ethane, of less than or 
equal to 20 parts ppmv on a dry basis corrected to 3 percent oxygen.
    (ii) Destroy the HAP listed in Table 1 of this subpart contained in 
the vent stream entering the vapor incinerator either:
    (A) By 95 percent or more, on a total HAP weight-basis, or
    (B) To achieve in the exhausted combustion gases a total 
concentration for the HAP, listed in Table 1 of the subpart, of less 
than or equal to 20 ppmv on a dry basis corrected to 3 percent oxygen.
    (iii) Introduce the vent stream into the flame zone of the boiler 
or process heater and maintain the conditions in the combustion chamber 
at a residence time of 0.5 seconds or longer and at a temperature of 
760 deg.C or higher.
    (iv) Introduce the vent stream with the fuel that provides the 
predominate heat input to the boiler or process heater (i.e., the 
primary fuel); or
    (v) Introduce the vent stream to a boiler or process heater for 
which the owner or operator either has been issued a final permit under 
40 CFR part 270 and complies with the requirements of 40 CFR part 266, 
subpart H of this chapter; or has certified compliance with the interim 
status requirements of 40 CFR part 266, subpart H of this chapter.
    (2) The owner or operator must demonstrate that the boiler or 
process heater achieves the performance specifications in paragraph 
(g)(1) of this section chosen by the owner or operator using the 
applicable method specified in paragraph (g)(2)(i) or (g)(2)(ii) of 
this section.
    (i) If an owner or operator chooses to comply with the performance 
specifications in either paragraph (g)(1)(i), (g)(1)(ii), or 
(g)(1)(iii) of this section, the owner or operator must demonstrate 
compliance with the applicable performance specifications by either 
performing a performance test as specified in paragraph (g)(2)(i)(A) of 
this section or a design analysis as specified in paragraph 
(g)(2)(i)(B) of this section.
    (A) An owner or operator choosing to use a performance test to 
demonstrate compliance must conduct the test in accordance with the 
requirements of Sec. 63.694(l) of this subpart.
    (B) An owner or operator choosing to use a design analysis to 
demonstrate compliance must include as part of this design analysis the 
following information: description of the vent stream composition, 
constituent concentrations, and flow rate; specification of the design 
minimum and average flame zone temperatures and combustion zone 
residence time; and description of the method and location by which the 
vent stream is introduced into the flame zone.
    (ii) If an owner or operator chooses to comply with the performance 
specifications in either paragraph (g)(1)(iv) or (g)(1)(v) of this 
section, the owner or operator must demonstrate compliance by 
maintaining the records that document that the boiler or process heater 
is designed and operated in accordance with the applicable requirements 
of this section.
    (3) For a boiler or process heater complying with the performance 
specifications in either paragraph (g)(1)(i), (g)(1)(ii), or 
(g)(1)(iii) of this section, the owner or operator must monitor the 
operation of a boiler or process heater in accordance with the 
requirements of Sec. 63.695(e) of this subpart using one of the 
continuous monitoring systems specified in paragraphs (g)(3)(i) through 
(g)(3)(iii) of this section.
    (i) A continuous parameter monitoring system to measure and record 
the daily average combustion zone temperature. The accuracy of the 
temperature sensor must be 1 percent of the temperature 
being measured, expressed in degrees Celsius or 0.5 deg.C, 
whichever is greater;

[[Page 38974]]

    (ii) A continuous monitoring system to measure and record the daily 
average concentration of organic compounds in the exhaust vent stream 
from the control device. The accuracy of the concentration monitoring 
device must be 1 percent of the concentration being 
measured.
    (iii) A continuous monitoring system that measures alternative 
operating parameters other than those specified in paragraph (g)(3)(i) 
or (g)(3)(ii) of this section upon approval of the Administrator as 
specified in 40 CFR 63.8(f)(1) through (f)(5) of this part.
    (h) Flare control device requirements.
    (1) The flare must be designed and operated in accordance with the 
requirements in 40 CFR 63.11(b).
    (2) The owner or operator must demonstrate that the flare achieves 
the requirements in paragraph (h)(1) of this section by performing the 
procedures specified in paragraph (h)(2)(i) of this section. A previous 
compliance demonstration for the flare that meets all of the conditions 
specified in paragraph (h)(2)(ii) of this section may be used by an 
owner or operator to demonstrate compliance with this paragraph (h)(2).
    (i) To demonstrate that a flare achieves the requirements in 
paragraph (h)(1) of this section, the owner or operator performs all of 
the procedures specified in paragraphs (h)(2)(i)(A) through 
(h)(2)(i)(C) of this section.
    (A) The owner or operator conducts a visible emission test for the 
flare in accordance with the requirements specified in 40 CFR 
63.11(b)(4).
    (B) The owner or operator determines the net heating value of the 
gas being combusted in the flare in accordance with the requirements 
specified in 40 CFR 63.11(b)(6); and
    (C) The owner or operator determines the flare exit velocity in 
accordance with the requirements applicable to the flare design as 
specified in 40 CFR 63.11(b)(7) or 40 CFR 63.11(b)(8).
    (ii) A previous compliance demonstration for the flare may be used 
by an owner or operator to demonstrate compliance with paragraph (h)(2) 
of this section provided that all conditions for the compliance 
determination and subsequent flare operation are met as specified in 
paragraphs (h)(2)(ii)(A) and (h)(2)(ii)(B) of this section.
    (A) The owner or operator conducted the compliance determination 
using the procedures specified in paragraph (h)(2)(i) of this section.
    (B) No flare operating parameter or process changes have occurred 
since completion of the compliance determination which could affect the 
compliance determination results.
    (3) The owner or operator must monitor the operation of the flare 
using a heat sensing monitoring device (including but not limited to a 
thermocouple, ultraviolet beam sensor, or infrared sensor) that 
continuously detects the presence of a pilot flame. The owner or 
operator must record, for each 1-hour period, whether the monitor was 
continuously operating and whether a pilot flame was continuously 
present during each hour as required in Sec. 63.696(b)(3) of this 
subpart.
    14. Section 63.694 is amended by adding paragraphs (a)(12) and (m) 
and by revising paragraphs (b)(2)(ii), (b)(2)(iii), (b)(3)(i), (c), 
(e), (f), (g), (h), (i) and (k) to read as follows:


Sec. 63.694  Testing methods and procedures.

    (a) * * *
    (12) To determine process vent stream flow rate and total organic 
HAP concentration for compliance with the standards specified in 
Sec. 63.693 of this subpart, the testing methods and procedures are 
specified in paragraph (m) of this section.
    (b) * * *
    (2) * * *
    (ii) Analysis. Each collected sample must be prepared and analyzed 
in accordance with one of the following methods as applicable to the 
sampled off-site material for the purpose of measuring the HAP listed 
in Table 1 of this subpart:
    (A) Method 305 in 40 CFR part 63, appendix A.
    (B) Method 25D in 40 CFR part 60, appendix A.
    (C) Method 624 in 40 CFR part 136, appendix A. If this method is 
used to analyze one or more compounds that are not on the method's 
published list of approved compounds, the Alternative Test Procedure 
specified in 40 CFR 136.4 and 40 CFR 136.5 must be followed.
    (D) Method 625 in 40 CFR part 136, appendix A. For the purpose of 
using this method to comply with this subpart, the owner or operator 
must perform corrections to these compounds based on the ``accuracy as 
recovery'' using the factors in Table 7 of the method. If this method 
is used to analyze one or more compounds that are not on the method's 
published list of approved compounds, the Alternative Test Procedure 
specified in 40 CFR 136.4 and 40 CFR 136.5 must be followed.
    (E) Method 1624 in 40 CFR part 136, appendix A.
    (F) Method 1625 in 40 CFR part 136, appendix A.
    (G) Method 8260 in ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods,'' EPA Publication No. SW-846, Third Edition, 
September 1986, as amended by Update I, November 15, 1992. As an 
alternative, an owner or operator may use any more recent, updated 
version of Method 8260 approved by the EPA. For the purpose of using 
Method 8260 to comply with this subpart, the owner or operator must 
maintain a formal quality assurance program consistent with section 8 
of Method 8260, and this program must include the following elements 
related to measuring the concentrations of volatile compounds:
    (1) Documentation of site-specific procedures to minimize the loss 
of compounds due to volatilization, biodegradation, reaction, or 
sorption during the sample collection, storage, and preparation steps.
    (2) Documentation of specific quality assurance procedures followed 
during sampling, sample preparation, sample introduction, and analysis.
    (3) Measurement of the average accuracy and precision of the 
specific procedures, including field duplicates and field spiking of 
the off-site material source before or during sampling with compounds 
having similar chemical characteristics to the target analytes.
    (H) Method 8270 in ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods,'' EPA Publication No. SW-846, Third Edition, 
September 1986, as amended by Update I, November 15, 1992. As an 
alternative, an owner or operator may use any more recent, updated 
version of Method 8270 approved by the EPA. For the purpose of using 
Method 8270 to comply with this subpart, the owner or operator must 
maintain a formal quality assurance program consistent with Method 
8270, and this program must include the following elements related to 
measuring the concentrations of volatile compounds:
    (1) Documentation of site-specific procedures to minimize the loss 
of compounds due to volatilization, biodegradation, reaction, or 
sorption during the sample collection, storage, and preparation steps.
    (2) Documentation of specific quality assurance procedures followed 
during sampling, sample preparation, sample introduction, and analysis.
    (3) Measurement of the average accuracy and precision of the 
specific procedures, including field duplicates and field spiking of 
the off-site material source before or during sampling with compounds 
having similar chemical characteristics to the target analytes.
    (I) Any other analysis method that has been validated in accordance 
with the procedures specified in section 5.1 and

[[Page 38975]]

section 5.3 and the corresponding calculations in section 6.1 or 
section 6.3 of Method 301 in appendix A in 40 CFR part 63. The data are 
acceptable if they meet the criteria specified in section 6.1.5 or 
section 6.3.3 of Method 301. If correction is required under section 
6.3.3 of Method 301, the data are acceptable if the correction factor 
is within the range of 0.7 to 1.30. Other sections of Method 301 are 
not required.
    (iii) Calculations. The average VOHAP concentration (C) on a mass-
weighted basis shall be calculated by using the results for all samples 
analyzed in accordance with paragraph (b)(2)(ii) of this section and 
the following equation. An owner or operator using a test method that 
provides species-specific chemical concentrations may adjust the 
measured concentrations to the corresponding concentration values which 
would be obtained had the off-site material samples been analyzed using 
Method 305. To adjust these data, the measured concentration for each 
individual HAP chemical species contained in the off-site material is 
multiplied by the appropriate species-specific adjustment factor 
(fm305) listed in Table 1 of this subpart.
[GRAPHIC] [TIFF OMITTED] TR20JY99.000

Where:

C = Average VOHAP concentration of the off-site material at the point-
of-delivery on a mass-weighted basis, ppmw.
i = Individual sample ``i'' of the off-site material.
n = Total number of samples of the off-site material collected (at 
least 4) for the averaging period (not to exceed 1 year).
Qi = Mass quantity of off-site material stream represented 
by Ci, kg/hr.
QT = Total mass quantity of off-site material during the 
averaging period, kg/hr.
Ci = Measured VOHAP concentration of sample ``i'' as 
determined in accordance with the requirements of Sec. 63.694(a), ppmw.
* * * * *
    (3) * * *
    (i) Documentation shall be prepared that presents the information 
used as the basis for the owner's or operator's knowledge of the off-
site material stream's average VOHAP concentration. Examples of 
information that may be used as the basis for knowledge include: 
material balances for the source or process generating the off-site 
material stream; species-specific chemical test data for the off-site 
material stream from previous testing that are still applicable to the 
current off-site material stream; previous test data for other 
locations managing the same type of off-site material stream; or other 
knowledge based on information in documents such as manifests, shipping 
papers, or waste certification notices.
* * * * *
    (c) Determination of average VOHAP concentration of an off-site 
material stream at the point-of-treatment.
    (1) Sampling. Samples of the off-site material stream shall be 
collected at the point-of-treatment in a manner such that 
volatilization of organics contained in the sample is minimized and an 
adequately representative sample is collected and maintained for 
analysis by the selected method.
    (i) The averaging period to be used for determining the average 
VOHAP concentration for the off-site material stream on a mass-weighted 
average basis shall be designated and recorded. The averaging period 
can represent any time interval that the owner or operator determines 
is appropriate for the off-site material stream but shall not exceed 1 
year.
    (ii) A sufficient number of samples, but no less than four samples, 
shall be collected to represent the complete range of HAP compositions 
and HAP quantities that occur in the off-site material stream during 
the entire averaging period due to normal variations in the operating 
conditions for the treatment process. Examples of such normal 
variations are seasonal variations in off-site material quantity or 
fluctuations in ambient temperature.
    (iii) All samples shall be collected and handled in accordance with 
written procedures prepared by the owner or operator and documented in 
a site sampling plan. This plan shall describe the procedure by which 
representative samples of the off-site material stream are collected 
such that a minimum loss of organics occurs throughout the sample 
collection and handling process and by which sample integrity is 
maintained. A copy of the written sampling plan shall be maintained on-
site in the plant site operating records. An example of an acceptable 
sampling plan includes a plan incorporating sample collection and 
handling procedures in accordance with the requirements specified in 
``Test Methods for Evaluating Solid Waste, Physical/Chemical Methods,'' 
EPA Publication No. SW-846 or Method 25D in 40 CFR part 60, appendix A.
    (2) Analysis. Each collected sample must be prepared and analyzed 
in accordance with one of the methods specified in paragraphs 
(b)(2)(ii)(A) through (b)(2)(ii)(I) of this section, as applicable to 
the sampled off-site material, for the purpose of measuring the HAP 
listed in Table 1 of this subpart.
    (3) Calculations. The average VOHAP concentration (C) a mass-
weighted basis shall be calculated by using the results for all samples 
analyzed in accordance with paragraph (c)(2) of this section and the 
following equation. An owner or operator using a test method that 
provides species-specific chemical concentrations may adjust the 
measured concentrations to the corresponding concentration values which 
would be obtained had the off-site material samples been analyzed using 
Method 305. To adjust these data, the measured concentration for each 
individual HAP chemical species contained in the off-site material is 
multiplied by the appropriate species-specific adjustment factor 
(fm305) listed in Table 1 of this subpart.
[GRAPHIC] [TIFF OMITTED] TR20JY99.001

Where:

C = Average VOHAP concentration of the off-site material on a mass-
weighted basis, ppmw.
i = Individual sample ``i'' of the off-site material.
n = Total number of samples of the off-site material collected (at 
least 4) for the averaging period (not to exceed 1 year).
Qi = Mass quantity of off-site material stream represented 
by Ci, kg/hr.
QT = Total mass quantity of off-site material during the 
averaging period, kg/hr.
Ci = Measured VOHAP concentration of sample ``i'' as 
determined in accordance with the requirements of Sec. 63.694(a), ppmw.
* * * * *
    (e) Determination of required HAP mass removal rate (RMR).
    (1) Each individual stream containing HAP that enters the treatment 
process shall be identified.
    (2) The average VOHAP concentration at the point-of-delivery for 
each stream identified in paragraph (e)(1) of this section shall be 
determined using the test methods and procedures specified in paragraph 
(b) of this section.
    (3) For each stream identified in paragraph (e)(1) of this section 
that has an average VOHAP concentration equal to or greater than 500 
ppmw at the point-of-delivery, the average volumetric flow rate and the 
density of the off-site material stream at the point-of-delivery shall 
be determined.

[[Page 38976]]

    (4) The required HAP mass removal rate (RMR) shall be calculated by 
using the average VOHAP concentration, average volumetric flow rate, 
and density determined in paragraph (e)(3) of this section for each 
stream and the following equation:
[GRAPHIC] [TIFF OMITTED] TR20JY99.002

Where:

RMR = Required HAP mass removal rate, kg/hr.
y = Individual stream ``y'' that has a VOHAP concentration equal to or 
greater than 500 ppmw at the point-of-delivery as determined in 
Sec. 63.694(b).
n = Total number of ``y'' streams treated by process.
Vy = Average volumetric flow rate of stream ``y'' at the 
point-of-delivery, m3/hr.
ky = Density of stream ``y'', kg/m3.
Cy = Average VOHAP concentration of stream ``y'' at the 
point-of-delivery as determined in Sec. 63.694(b)(2), ppmw.

    (f) Determination of actual HAP mass removal rate (MR).
    (1) The actual HAP mass removal rate (MR) shall be determined based 
on results for a minimum of three consecutive runs. The sampling time 
for each run shall be 1 hour.
    (2) The HAP mass flow entering the process (Eb) and the 
HAP mass flow exiting the process (Ea) shall be determined 
using the test methods and procedures specified in paragraphs (g)(2) 
through (g)(4) of this section.
    (3) The actual mass removal rate shall be calculated using the HAP 
mass flow rates determined in paragraph (f)(2) of this section and the 
following equation:

MR = Eb - Ea
where:

    MR = Actual HAP mass removal rate, kg/hr.
    Eb = HAP mass flow entering process as determined in 
paragraph (f)(2) of this section, kg/hr.
    Ea = HAP mass flow exiting process as determined in 
paragraph (f)(2) of this section, kg/hr.

    (g) Determination of treatment process HAP reduction efficiency 
(R).
    (1) The HAP reduction efficiency (R) for a treatment process shall 
be determined based on results for a minimum of three consecutive runs.
    (2) Each individual stream containing HAP that enters the treatment 
process shall be identified. Each individual stream containing HAP that 
exits the treatment process shall be identified. The owner or operator 
shall prepare a sampling plan for measuring the identified streams that 
accurately reflects the retention time of the material in the process.
    (3) For each run, information shall be determined for each stream 
identified in paragraph (g)(2) of this section as specified in 
paragraphs (g)(3)(i) through (g)(3)(iii) of this section.
    (i) The mass quantity shall be determined for each stream 
identified in paragraph (g)(2) of this section as entering the process 
(Qb). The mass quantity shall be determined for each stream 
identified in paragraph (g)(2) of this section as exiting the process 
(Qa).
    (ii) The average VOHAP concentration at the point-of-delivery shall 
be determined for each stream entering the process (Cb) (as 
identified in paragraph (g)(2) of this section) using the test methods 
and procedures specified in paragraph (b) of this section.
    (iii) The average VOHAP concentration at the point-of-treatment 
shall be determined for each stream exiting the process (Ca) 
(as identified in paragraph (g)(2) of this section) using the test 
methods and procedures specified in paragraph (c) of this section.
    (4) The HAP mass flow entering the process (Eb) and the 
HAP mass flow exiting the process (Ea) shall be calculated 
using the results determined in paragraph (g)(3) of this section and 
the following equations:
[GRAPHIC] [TIFF OMITTED] TR20JY99.003

Where:

Eb = HAP mass flow entering process, kg/hr.
Ea = HAP mass flow exiting process, kg/hr.
m = Total number of runs (at least 3)
j = Individual run ``j''
Qbj = Mass quantity of material entering process during run 
``j'', kg/hr.
Qaj = Average mass quantity of material exiting process 
during run ``j'', kg/hr.
Caj = Average VOHAP concentration of material exiting 
process during run ``j'' as determined in Sec. 63.694(c), ppmw.
Cbj = Average VOHAP concentration of material entering 
process during run ``j'' as determined in Sec. 63.694(b)(2), ppmw.

    (5) The HAP reduction efficiency (R) shall be calculated using the 
HAP mass flow rates determined in paragraph (g)(4) of this section and 
the following equation:
[GRAPHIC] [TIFF OMITTED] TR20JY99.004

Where:

R = HAP reduction efficiency, percent.
Eb = HAP mass flow entering process as determined in 
paragraph (g)(4) of this section, kg/hr.
Ea = HAP mass flow exiting process as determined in 
accordance with the requirements of paragraph (g)(4) of this section, 
kg/hr.

    (h) Determination of HAP biodegradation efficiency 
(Rbio).
    (1) The fraction of HAP biodegraded (Fbio) shall be 
determined using one of the procedures specified in appendix C of this 
part 63.
    (2) The HAP biodegradation efficiency (Rbio) shall be 
calculated by using the following equation:

Rbio = Fbio  x  100

where:

Rbio = HAP biodegradation efficiency, percent.
Fbio = Fraction of HAP biodegraded as determined in 
paragraph (h)(1) of this section.

    (i) Determination of actual HAP mass removal rate 
(MRbio).
    (1) The actual HAP mass removal rate (MRbio) shall be 
determined based on results for a minimum of three consecutive runs. 
The sampling time for each run shall be 1 hour.
    (2) The HAP mass flow entering the process (Eb) shall be 
determined using the test methods and procedures specified in 
paragraphs (g)(2) through (g)(4) of this section.
    (3) The fraction of HAP biodegraded (Fbio) shall be 
determined using the procedure specified in 40 CFR part 63, appendix C 
of this part.
    (4) The actual mass removal rate shall be calculated by using the 
HAP mass

[[Page 38977]]

flow rates and fraction of HAP biodegraded determined in paragraphs 
(i)(2) and (i)(3), respectively, of this section and the following 
equation:

MRbio = Eb  x  Fbio

Where:

MRbio = Actual HAP mass removal rate, kg/hr.
Eb = HAP mass flow entering process, kg/hr.
Fbio = Fraction of HAP biodegraded.
* * * * *
    (k) Procedure for determining no detectable organic emissions for 
the purpose of complying with this subpart.
    (1) The test shall be conducted in accordance with the procedures 
specified in Method 21 of 40 CFR part 60, appendix A. Each potential 
leak interface (i.e., a location where organic vapor leakage could 
occur) on the cover and associated closure devices shall be checked. 
Potential leak interfaces that are associated with covers and closure 
devices include, but are not limited to: the interface of the cover and 
its foundation mounting; the periphery of any opening on the cover and 
its associated closure device; and the sealing seat interface on a 
spring-loaded pressure-relief valve.
    (2) The test shall be performed when the unit contains a material 
having a total organic concentration representative of the range of 
concentrations for the materials expected to be managed in the unit. 
During the test, the cover and closure devices shall be secured in the 
closed position.
    (3) The detection instrument shall meet the performance criteria of 
Method 21 of 40 CFR part 60, appendix A, except the instrument response 
factor criteria in section 3.1.2(a) of Method 21 shall be for the 
average composition of the organic constituents in the material placed 
in the unit, not for each individual organic constituent.
    (4) The detection instrument shall be calibrated before use on each 
day of its use by the procedures specified in Method 21 of 40 CFR part 
60, appendix A.
    (5) Calibration gases shall be as follows:
    (i) Zero air (less than 10 ppmv hydrocarbon in air); and
    (ii) A mixture of methane or n-hexane in air at a concentration of 
approximately, but less than, 10,000 ppmv.
    (6) An owner or operator may choose to adjust or not adjust the 
detection instrument readings to account for the background organic 
concentration level. If an owner or operator chooses to adjust the 
instrument readings for the background level, the background level 
value must be determined according to the procedures in Method 21 of 40 
CFR part 60, appendix A.
    (7) Each potential leak interface shall be checked by traversing 
the instrument probe around the potential leak interface as close to 
the interface as possible, as described in Method 21. In the case when 
the configuration of the cover or closure device prevents a complete 
traverse of the interface, all accessible portions of the interface 
shall be sampled. In the case when the configuration of the closure 
device prevents any sampling at the interface and the device is 
equipped with an enclosed extension or horn (e.g., some pressure relief 
devices), the instrument probe inlet shall be placed at approximately 
the center of the exhaust area to the atmosphere.
    (8) An owner or operator must determine if a potential leak 
interface operates with no detectable emissions using the applicable 
procedure specified in paragraph (k)(8)(i) or (k)(8)(ii) of this 
section.
    (i) If an owner or operator chooses not to adjust the detection 
instrument readings for the background organic concentration level, 
then the maximum organic concentration value measured by the detection 
instrument is compared directly to the applicable value for the 
potential leak interface as specified in paragraph (k)(9) of this 
section.
    (ii) If an owner or operator chooses to adjust the detection 
instrument readings for the background organic concentration level, the 
value of the arithmetic difference between the maximum organic 
concentration value measured by the instrument and the background 
organic concentration value as determined in paragraph (k)(6) of this 
section is compared with the applicable value for the potential leak 
interface as specified in paragraph (k)(9) of this section.
    (9) A potential leak interface is determined to operate with no 
detectable emissions using the applicable criteria specified in 
paragraphs (k)(9)(i) and (k)(9)(ii) of this section.
    (i) For a potential leak interface other than a seal around a shaft 
that passes through a cover opening, the potential leak interface is 
determined to operate with no detectable organic emissions if the 
organic concentration value determined in paragraph (k)(8) is less than 
500 ppmv.
    (ii) For a seal around a shaft that passes through a cover opening, 
the potential leak interface is determined to operate with no 
detectable organic emissions if the organic concentration value 
determined in paragraph (k)(8) is less than 10,000 ppmv.
* * * * *
    (m) Determination of process vent stream flow rate and total HAP 
concentration.
    (1) Method 1 or 1A of 40 CFR part 60, appendix A, as appropriate, 
must be used for selection of the sampling site.
    (2) No traverse site selection method is needed for vents smaller 
than 0.10 meter in diameter.
    (3) Process vent stream gas volumetric flow rate must be determined 
using Method 2, 2A, 2C, or 2D of 40 CFR part 60, appendix A, as 
appropriate.
    (4) Process vent stream total HAP concentration must be measured 
using the following procedures:
    (i) Method 18 of 40 CFR part 60, appendix A, must be used to 
measure the total HAP concentration. Alternatively, any other method or 
data that has been validated according to the protocol in Method 301 of 
appendix A of this part may be used.
    (ii) Where Method 18 of 40 CFR part 60, appendix A, is used, the 
following procedures must be used to calculate parts per million by 
volume concentration:
    (A) The minimum sampling time for each run must be 1 hour in which 
either an integrated sample or four grab samples must be taken. If grab 
sampling is used, then the samples must be taken at approximately equal 
intervals in time, such as 15 minute intervals during the run.
    (B) The total HAP concentration (CHAP) must be computed 
according to the following equation:
[GRAPHIC] [TIFF OMITTED] TR20JY99.005


Where:

CHAP = Total concentration of HAP compounds listed in Table 
1 of this subpart, dry basis, parts per million by volume.
Cji = Concentration of sample component j of the sample i, 
dry basis, parts per million by volume.
n = Number of components in the sample.
x = Number of samples in the sample run.

    15. Section 63.695 is revised to read as follows:


Sec. 63.695  Inspection and monitoring requirements.

    (a) This section specifies the inspection and monitoring procedures 
required to perform the following:

[[Page 38978]]

    (1) To inspect tank fixed roofs and floating roofs for compliance 
with the Tank Level 2 controls standards specified in Sec. 63.685 of 
this subpart, the inspection procedures are specified in paragraph (b) 
of this section.
    (2) To inspect and monitor closed-vent systems for compliance with 
the standards specified in Sec. 63.693 of this subpart, the inspection 
and monitoring procedures are specified in paragraph (c) of this 
section.
    (3) To inspect and monitor transfer system covers for compliance 
with the standards specified in Sec. 63.689(c)(1) of this subpart, the 
inspection and monitoring procedures are specified in paragraph (d) of 
this section.
    (4) To monitor control devices for compliance with the standards 
specified in Sec. 63.693 of this subpart, the monitoring procedures are 
specified in paragraph (e) of this section.
    (b) Tank Level 2 fixed roof and floating roof inspection 
requirements.
    (1) Owners and operators that use a tank equipped with an internal 
floating roof in accordance with the provisions of Sec. 63.685(e) of 
this subpart shall meet the following inspection requirements:
    (i) The floating roof and its closure devices shall be visually 
inspected by the owner or operator to check for defects that could 
result in air emissions. Defects include, but are not limited to, the 
internal floating roof is not floating on the surface of the liquid 
inside the tank; liquid has accumulated on top of the internal floating 
roof; any portion of the roof seals have detached from the roof rim; 
holes, tears, or other openings are visible in the seal fabric; the 
gaskets no longer close off the waste surfaces from the atmosphere; or 
the slotted membrane has more than 10 percent open area.
    (ii) The owner or operator shall inspect the internal floating roof 
components as follows except as provided for in paragraph (b)(1)(iii) 
of this section:
    (A) Visually inspect the internal floating roof components through 
openings on the fixed-roof (e.g., manholes and roof hatches) at least 
once every calendar year after initial fill, and
    (B) Visually inspect the internal floating roof, primary seal, 
secondary seal (if one is in service), gaskets, slotted membranes, and 
sleeve seals (if any) each time the tank is emptied and degassed and at 
least every 10 years. Prior to each inspection, the owner or operator 
shall notify the Administrator in accordance with the reporting 
requirements specified in Sec. 63.697 of this subpart.
    (iii) As an alternative to performing the inspections specified in 
paragraph (b)(1)(ii) of this section for an internal floating roof 
equipped with two continuous seals mounted one above the other, the 
owner or operator may visually inspect the internal floating roof, 
primary and secondary seals, gaskets, slotted membranes, and sleeve 
seals (if any) each time the tank is emptied and degassed and at least 
every 5 years. Prior to each inspection, the owner or operator shall 
notify the Administrator in accordance with the reporting requirements 
specified in Sec. 63.697 of this subpart.
    (iv) In the event that a defect is detected, the owner or operator 
shall repair the defect in accordance with the requirements of 
paragraph (b)(4) of this section.
    (v) The owner or operator shall maintain a record of the inspection 
in accordance with the requirements specified in Sec. 63.696 of this 
subpart.
    (2) Owners and operators that use a tank equipped with an external 
floating roof in accordance with the provisions of Sec. 63.685(f) of 
this subpart shall meet the following requirements:
    (i) The owner or operator shall measure the external floating roof 
seal gaps in accordance with the following requirements:
    (A) The owner or operator shall perform measurements of gaps 
between the tank wall and the primary seal within 60 days after initial 
operation of the tank following installation of the floating roof and, 
thereafter, at least once every 5 years. Prior to each inspection, the 
owner or operator shall notify the Administrator in accordance with the 
reporting requirements specified in Sec. 63.697 of this subpart.
    (B) The owner or operator shall perform measurements of gaps 
between the tank wall and the secondary seal within 60 days after 
initial operation of the separator following installation of the 
floating roof and, thereafter, at least once every year. Prior to each 
inspection, the owner or operator shall notify the Administrator in 
accordance with the reporting requirements specified in Sec. 63.697 of 
this subpart.
    (C) If a tank ceases to hold off-site material for a period of 1 
year or more, subsequent introduction of off-site material into the 
tank shall be considered an initial operation for the purposes of 
paragraphs (b)(2)(i)(A) and (b)(2)(i)(B) of this section.
    (D) The owner shall determine the total surface area of gaps in the 
primary seal and in the secondary seal individually using the following 
procedure.
    (1) The seal gap measurements shall be performed at one or more 
floating roof levels when the roof is floating off the roof supports.
    (2) Seal gaps, if any, shall be measured around the entire 
perimeter of the floating roof in each place where a 0.32-centimeter 
(cm) (\1/8\-inch) diameter uniform probe passes freely (without forcing 
or binding against the seal) between the seal and the wall of the tank 
and measure the circumferential distance of each such location.
    (3) For a seal gap measured under paragraph (b)(2) of this section, 
the gap surface area shall be determined by using probes of various 
widths to measure accurately the actual distance from the tank wall to 
the seal and multiplying each such width by its respective 
circumferential distance.
    (4) The total gap area shall be calculated by adding the gap 
surface areas determined for each identified gap location for the 
primary seal and the secondary seal individually, and then dividing the 
sum for each seal type by the nominal diameter of the tank. These total 
gap areas for the primary seal and secondary seal are then compared to 
the respective standards for the seal type as specified in 
Sec. 63.685(f)(1) of this subpart.
    (E) In the event that the seal gap measurements do not conform to 
the specifications in Sec. 63.685(f)(1) of this subpart, the owner or 
operator shall repair the defect in accordance with the requirements of 
paragraph (b)(4) of this section.
    (F) The owner or operator shall maintain a record of the inspection 
in accordance with the requirements specified in Sec. 63.696 of this 
subpart.
    (ii) The owner or operator shall visually inspect the external 
floating roof in accordance with the following requirements:
    (A) The floating roof and its closure devices shall be visually 
inspected by the owner or operator to check for defects that could 
result in air emissions. Defects include, but are not limited to: 
holes, tears, or other openings in the rim seal or seal fabric of the 
floating roof; a rim seal detached from the floating roof; all or a 
portion of the floating roof deck being submerged below the surface of 
the liquid in the tank; broken, cracked, or otherwise damaged seals or 
gaskets on closure devices; and broken or missing hatches, access 
covers, caps, or other closure devices.
    (B) The owner or operator shall perform the inspections following 
installation of the external floating roof and, thereafter, at least 
once every year.
    (C) In the event that a defect is detected, the owner or operator 
shall repair the defect in accordance with the

[[Page 38979]]

requirements of paragraph (b)(4) of this section.
    (D) The owner or operator shall maintain a record of the inspection 
in accordance with the requirements specified in Sec. 63.696(d) of this 
subpart.
    (3) Owners and operators that use a tank equipped with a fixed roof 
in accordance with the provisions of Sec. 63.685(g) of this subpart 
shall meet the following requirements:
    (i) The fixed roof and its closure devices shall be visually 
inspected by the owner or operator to check for defects that could 
result in air emissions. Defects include, but are not limited to, 
visible cracks, holes, or gaps in the roof sections or between the roof 
and the separator wall; broken, cracked, or otherwise damaged seals or 
gaskets on closure devices; and broken or missing hatches, access 
covers, caps, or other closure devices. In the case when a tank is 
buried partially or entirely underground, inspection is required only 
for those portions of the cover that extend to or above the ground 
surface, and those connections that are on such portions of the cover 
(e.g., fill ports, access hatches, gauge wells, etc.) and can be opened 
to the atmosphere.
    (ii) The owner or operator must perform an initial inspection 
following installation of the fixed roof. Thereafter, the owner or 
operator must perform the inspections at least once every calendar year 
except as provided for in paragraph (f) of this section.
    (iii) In the event that a defect is detected, the owner or operator 
shall repair the defect in accordance with the requirements of 
paragraph (b)(4) of this section.
    (iv) The owner or operator shall maintain a record of the 
inspection in accordance with the requirements specified in 
Sec. 63.696(e) of this subpart.
    (4) The owner or operator shall repair each defect detected during 
an inspection performed in accordance with the requirements of 
paragraph (b)(1), (b)(2), or (b)(3) of this section in the following 
manner:
    (i) The owner or operator shall within 45 calendar days of 
detecting the defect either repair the defect or empty the tank and 
remove it from service. If within this 45-day period the defect cannot 
be repaired or the tank cannot be removed from service without 
disrupting operations at the plant site, the owner or operator is 
allowed two 30-day extensions. In cases when an owner or operator 
elects to use a 30-day extension, the owner or operator shall prepare 
and maintain documentation describing the defect, explaining why 
alternative storage capacity is not available, and specify a schedule 
of actions that will ensure that the control equipment will be repaired 
or the tank emptied as soon as possible.
    (ii) When a defect is detected during an inspection of a tank that 
has been emptied and degassed, the owner or operator shall repair the 
defect before refilling the tank.
    (c) Owners and operators that use a closed-vent system in 
accordance with the provisions of Sec. 63.693 of this subpart shall 
meet the following inspection and monitoring requirements:
    (1) Each closed-vent system that is used to comply with 
Sec. 63.693(c)(1)(i) of this subpart shall be inspected and monitored 
in accordance with the following requirements:
    (i) At initial startup, the owner or operator shall monitor the 
closed-vent system components and connections using the procedures 
specified in Sec. 63.694(k) of this subpart to demonstrate that the 
closed-vent system operates with no detectable organic emissions.
    (ii) After initial startup, the owner or operator shall inspect and 
monitor the closed-vent system as follows:
    (A) Closed-vent system joints, seams, or other connections that are 
permanently or semi-permanently sealed (e.g., a welded joint between 
two sections of hard piping or a bolted and gasketed ducting flange) 
shall be visually inspected at least once per year to check for defects 
that could result in air emissions. The owner or operator shall monitor 
a component or connection using the procedures specified in 
Sec. 63.694(k) of this subpart to demonstrate that it operates with no 
detectable organic emissions following any time the component is 
repaired or replaced (e.g., a section of damaged hard piping is 
replaced with new hard piping) or the connection is unsealed (e.g., a 
flange is unbolted).
    (B) Closed-vent system components or connections other than those 
specified in paragraph (c)(1)(ii)(A) of this section, shall be 
monitored at least once per year using the procedures specified in 
Sec. 63.694(k) of this subpart to demonstrate that components or 
connections operate with no detectable organic emissions.
    (iii) In the event that a defect or leak is detected, the owner or 
operator shall repair the defect or leak in accordance with the 
requirements of paragraph (c)(3) of this section.
    (iv) The owner or operator shall maintain a record of the 
inspection and monitoring in accordance with the requirements specified 
in Sec. 63.696 of this subpart.
    (2) Each closed-vent system that is used to comply with 
Sec. 63.693(c)(1)(ii) of this subpart shall be inspected and monitored 
in accordance with the following requirements:
    (i) The closed-vent system shall be visually inspected by the owner 
or operator to check for defects that could result in air emissions. 
Defects include, but are not limited to, visible cracks, holes, or gaps 
in ductwork or piping; loose connections; or broken or missing caps or 
other closure devices.
    (ii) The owner or operator must perform an initial inspection 
following installation of the closed-vent system. Thereafter, the owner 
or operator must perform the inspections at least once every calendar 
year except as provided for in paragraph (f) of this section.
    (iii) In the event that a defect is detected, the owner or operator 
shall repair the defect in accordance with the requirements of 
paragraph (c)(3) of this section.
    (iv) The owner or operator shall maintain a record of the 
inspection in accordance with the requirements specified in Sec. 63.696 
of this subpart.
    (3) The owner or operator shall repair all detected defects as 
follows:
    (i) The owner or operator shall make first efforts at repair of the 
defect no later than 5 calendar days after detection and repair shall 
be completed as soon as possible but no later than 45 calendar days 
after detection.
    (ii) Repair of a defect may be delayed beyond 45 calendar days if 
either of the conditions specified in paragraph (c)(3)(ii)(A) or 
(c)(3)(ii)(B) occurs. In this case, the owner or operator must repair 
the defect the next time the process or unit that vents to the closed-
vent system is shutdown. Repair of the defect must be completed before 
the process or unit resumes operation.
    (A) Completion of the repair is technically infeasible without the 
shutdown of the process or unit that vents to the closed-vent system.
    (B) The owner or operator determines that the air emissions 
resulting from the repair of the defect within the specified period 
would be greater than the fugitive emissions likely to result by 
delaying the repair until the next time the process or unit that vents 
to the closed-vent system is shutdown.
    (iii) The owner or operator shall maintain a record of the defect 
repair in accordance with the requirements specified in Sec. 63.696 of 
this subpart.
    (d) Owners and operators that use a transfer system equipped with a 
cover in accordance with the provisions of Sec. 63.689(c)(1) of this 
subpart shall meet the following inspection requirements:
    (1) The cover and its closure devices shall be visually inspected 
by the owner or operator to check for defects that

[[Page 38980]]

could result in air emissions. Defects include, but are not limited to, 
visible cracks, holes, or gaps in the cover sections or between the 
cover and its mounting; broken, cracked, or otherwise damaged seals or 
gaskets on closure devices; and broken or missing hatches, access 
covers, caps, or other closure devices. In the case when a transfer 
system is buried partially or entirely underground, inspection is 
required only for those portions of the cover that extend to or above 
the ground surface, and those connections that are on such portions of 
the cover (e.g., access hatches, etc.) and can be opened to the 
atmosphere.
    (2) The owner or operator must perform an initial inspection 
following installation of the cover. Thereafter, the owner or operator 
must perform the inspections at least once every calendar year except 
as provided for in paragraph (f) of this section.
    (3) In the event that a defect is detected, the owner or operator 
shall repair the defect in accordance with the requirements of 
paragraph (d)(5) of this section.
    (4) The owner or operator shall maintain a record of the inspection 
in accordance with the requirements specified in Sec. 63.696 of this 
subpart.
    (5) The owner or operator shall repair all detected defects as 
follows:
    (i) The owner or operator shall make first efforts at repair of the 
defect no later than 5 calendar days after detection and repair shall 
be completed as soon as possible but no later than 45 calendar days 
after detection except as provided in paragraph (d)(5)(ii) of this 
section.
    (ii) Repair of a defect may be delayed beyond 45 calendar days if 
the owner or operator determines that repair of the defect requires 
emptying or temporary removal from service of the transfer system and 
no alternative transfer system is available at the site to accept the 
material normally handled by the system. In this case, the owner or 
operator shall repair the defect the next time the process or unit that 
is generating the material handled by the transfer system stops 
operation. Repair of the defect must be completed before the process or 
unit resumes operation.
    (iii) The owner or operator shall maintain a record of the defect 
repair in accordance with the requirements specified in Sec. 63.696 of 
this subpart.
    (e) Control device monitoring requirements. For each control device 
required under Sec. 63.693 of this subpart to be monitored in 
accordance with the provisions of this paragraph (e), the owner or 
operator must ensure that each control device operates properly by 
monitoring the control device in accordance with the requirements 
specified in paragraphs (e)(1) through (e)(7) of this section.
    (1) A continuous parameter monitoring system must be used to 
measure the operating parameter or parameters specified for the control 
device in Sec. 63.693(d) through Sec. 63.693(g) of this subpart as 
applicable to the type and design of the control device. The continuous 
parameter monitoring system must meet the following specifications and 
requirements:
    (i) The continuous parameter monitoring system must measure either 
an instantaneous value at least once every 15 minutes or an average 
value for intervals of 15 minutes or less and continuously record 
either:
    (A) Each measured data value; or
    (B) Each block average value for each 1-hour period or shorter 
periods calculated from all measured data values during each period. If 
values are measured more frequently than once per minute, a single 
value for each minute may be used to calculate the hourly (or shorter 
period) block average instead of all measured values.
    (ii) The monitoring system must be installed, calibrated, operated, 
and maintained in accordance with the manufacturer's specifications or 
other written procedures that provide reasonable assurance that the 
monitoring equipment is operating properly.
    (2) Using the data recorded by the monitoring system, the owner or 
operator must calculate the daily average value for each monitored 
operating parameter for each operating day. If operation of the control 
device is continuous, the operating day is a 24-hour period. If control 
device operation is not continuous, the operating day is the total 
number of hours of control device operation per 24-hour period. Valid 
data points must be available for 75 percent of the operating hours in 
an operating day to compute the daily average.
    (3) For each monitored operating parameter, the owner or operator 
must establish a minimum operating parameter value or a maximum 
operating parameter value, as appropriate, to define the range of 
conditions at which the control device must be operated to continuously 
achieve the applicable performance requirements specified in 
Sec. 63.693(b)(2) of this subpart. Each minimum or maximum operating 
parameter value must be established in accordance with the requirements 
in paragraphs (e)(3)(i) and (e)(3)(ii) of this section.
    (i) If the owner or operator conducts a performance test to 
demonstrate control device performance, then the minimum or maximum 
operating parameter value must be established based on values measured 
during the performance test and supplemented, as necessary, by the 
control device design specifications, manufacturer recommendations, or 
other applicable information.
    (ii) If the owner or operator uses a control device design analysis 
to demonstrate control device performance, then the minimum or maximum 
operating parameter value must be established based on the control 
device design analysis and supplemented, as necessary, by the control 
device manufacturer recommendations or other applicable information.
    (4) An excursion for a given control device is determined to have 
occurred when the monitoring data or lack of monitoring data result in 
any one of the criteria specified in paragraphs (e)(4)(i) through 
(e)(4)(iii) of this section being met. When multiple operating 
parameters are monitored for the same control device and during the 
same operating day more than one of these operating parameters meets an 
excursion criterion specified in paragraphs (e)(4)(i) through 
(e)(4)(iii) of this section, then a single excursion is determined to 
have occurred for the control device for that operating day.
    (i) An excursion occurs when the daily average value of a monitored 
operating parameter is less than the minimum operating parameter limit 
(or, if applicable, greater than the maximum operating parameter limit) 
established for the operating parameter in accordance with the 
requirements of paragraph (e)(3) of this section.
    (ii) An excursion occurs when the period of control device 
operation is 4 hours or greater in an operating day and the monitoring 
data are insufficient to constitute a valid hour of data for at least 
75 percent of the operating hours. Monitoring data are insufficient to 
constitute a valid hour of data if measured values are unavailable for 
any of the 15-minute periods within the hour.
    (iii) An excursion occurs when the period of control device 
operation is less than 4 hours in an operating day and more than 1 of 
the hours during the period does not constitute a valid hour of data 
due to insufficient monitoring data. Monitoring data are insufficient 
to constitute a valid hour of data if measured values are unavailable 
for any of the 15-minute periods within the hour.

[[Page 38981]]

    (5) For each excursion, except as provided for in paragraph(e)(6) 
of this section, the owner or operator shall be deemed to have failed 
to have applied control in a manner that achieves the required 
operating parameter limits. Failure to achieve the required operating 
parameter limits is a violation of this standard.
    (6) An excursion is not a violation of this standard under any one 
of the conditions specified in paragraphs (e)(6)(i) and (e)(6)(ii) of 
this section.
    (i) An excursion is not a violation nor does it count toward the 
number of excused excursions allowed under paragraph (e)(6)(ii) of this 
section when the excursion occurs during any one of the following 
periods:
    (A) During a period of startup, shutdown, or malfunction when the 
affected facility is operated during such period in accordance with the 
facility's startup, shutdown, and malfunction plan; or
    (B) During periods of non-operation of the unit or the process that 
is vented to the control device (resulting in cessation of HAP 
emissions to which the monitoring applies).
    (ii) For each control device, one excused excursion is allowed per 
semiannual period for any reason. The initial semiannual period is the 
6-month reporting period addressed by the first semiannual report 
submitted by the owner or operator in accordance with Sec. 63.697(b)(4) 
of this subpart.
    (7) Nothing in paragraphs (e)(1) through (e)(6) of this section 
shall be construed to allow or excuse a monitoring parameter excursion 
caused by any activity that violates other applicable provisions of 
this subpart.
    (f) Alternative inspection and monitoring interval. Following the 
initial inspection and monitoring of a piece of air pollution control 
equipment in accordance with the applicable provisions of this section, 
subsequent inspection and monitoring of the equipment may be performed 
at intervals longer than 1 year when an owner or operator determines 
that performing the required inspection or monitoring procedures would 
expose a worker to dangerous, hazardous, or otherwise unsafe conditions 
and the owner or operator complies with the requirements specified in 
paragraphs (f)(1) and (f)(2) of this section.
    (1) The owner or operator must prepare and maintain at the plant 
site written documentation identifying the specific air pollution 
control equipment designated as ``unsafe to inspect and monitor.'' The 
documentation must include for each piece of air pollution control 
equipment designated as such a written explanation of the reasons why 
the equipment is unsafe to inspect or monitor using the applicable 
procedures under this section.
    (2) The owner or operator must develop and implement a written plan 
and schedule to inspect and monitor the air pollution control equipment 
using the applicable procedures specified in this section during times 
when a worker can safely access the air pollution control equipment. 
The required inspections and monitoring must be performed as frequently 
as practicable but do not need to be performed more frequently than the 
periodic schedule that would be otherwise applicable to the air 
pollution control equipment under the provisions of this section. A 
copy of the written plan and schedule must be maintained at the plant 
site.
    16. Section 63.697 is amended by revising paragraphs (a) and (b) to 
read as follows:


Sec. 63.697  Reporting requirements.

    (a) Each owner or operator of an affected source subject to this 
subpart must comply with the notification requirements specified in 
paragraph (a)(1) of this section and the reporting requirements 
specified in paragraph (a)(2) of this section.
    (1) The owner or operator of an affected source must submit notices 
to the Administrator in accordance with the applicable notification 
requirements in 40 CFR 63.9 as specified in Table 2 of this subpart. 
For the purpose of this subpart, an owner or operator subject to the 
initial notification requirements under 40 CFR 63.9(b)(2) must submit 
the required notification on or before October 19, 1999.
    (2) The owner or operator of an affected source must submit reports 
to the Administrator in accordance with the applicable reporting 
requirements in 40 CFR 63.10 as specified in Table 2 of this subpart.
    (b) The owner or operator of a control device used to meet the 
requirements of Sec. 63.693 of this subpart shall submit the following 
notifications and reports to the Administrator:
    (1) A Notification of Performance Tests specified in Sec. 63.7 and 
Sec. 63.9(g) of this part,
    (2) Performance test reports specified in Sec. 63.10(d)(2) of this 
part, and
    (3) Startup, shutdown, and malfunction reports specified in 
Sec. 63.10(d)(5) of this part.
    (i) If actions taken by an owner or operator during a startup, 
shutdown, or malfunction of an affected source (including actions taken 
to correct a malfunction) are not completely consistent with the 
procedures specified in the source's startup, shutdown, and malfunction 
plan specified in Sec. 63.6(e)(3) of this part, the owner or operator 
shall state such information in the report. The startup, shutdown, or 
malfunction report shall consist of a letter, containing the name, 
title, and signature of the responsible official who is certifying its 
accuracy, that shall be submitted to the Administrator, and
    (ii) Separate startup, shutdown, or malfunction reports are not 
required if the information is included in the summary report specified 
in paragraph (b)(4) of this section.
    (4) A summary report specified in Sec. 63.10(e)(3) of this part 
shall be submitted on a semiannual basis (i.e., once every 6-month 
period). The summary report must include a description of all 
excursions as defined in Sec. 63.695(e) of this subpart that have 
occurred during the 6-month reporting period. For each excursion caused 
when the daily average value of a monitored operating parameter is less 
than the minimum operating parameter limit (or, if applicable, greater 
than the maximum operating parameter limit), the report must include 
the daily average values of the monitored parameter, the applicable 
operating parameter limit, and the date and duration of the period that 
the exceedance occurred. For each excursion caused by lack of 
monitoring data, the report must include the date and duration of 
period when the monitoring data were not collected and the reason why 
the data were not collected.
* * * * *
    17. Table 1 in Subpart DD is revised to read as follows:

    Table 1 to Subpart DD--List of Hazardous Air Pollutants (HAP) for
                               Subpart DD
------------------------------------------------------------------------
          CAS No.a                     Chemical name            fm 305
------------------------------------------------------------------------
75-07-0.....................  Acetaldehyde..................      1.000
75-05-8.....................  Acetonitrile..................      0.989
98-86-2.....................  Acetophenone..................      0.314

[[Page 38982]]

 
107-02-8....................  Acrolein......................      1.000
107-13-1....................  Acrylonitrile.................      0.999
107-05-1....................  Allyl chloride................      1.000
71-43-2.....................  Benzene (includes benzene in        1.000
                               gasoline).
98-07-7.....................  Benzotrichloride (isomers and       0.958
                               mixture).
100-44-7....................  Benzyl chloride...............      1.000
92-52-4.....................  Biphenyl......................      0.864
542-88-1....................  Bis(chloromethyl)ether b......      0.999
75-25-2.....................  Bromoform.....................      0.998
106-99-0....................  1,3-Butadiene.................      1.000
75-15-0.....................  Carbon disulfide..............      1.000
56-23-5.....................  Carbon tetrachloride..........      1.000
43-58-1.....................  Carbonyl sulfide..............      1.000
133-90-4....................  Chloramben....................      0.633
108-90-7....................  Chlorobenzene.................      1.000
67-66-3.....................  Chloroform....................      1.000
107-30-2....................  Chloromethyl methyl ether b...      1.000
126-99-8....................  Chloroprene...................      1.000
98-82-8.....................  Cumene........................      1.000
94-75-7.....................  2,4-D, salts and esters.......      0.167
334-88-3....................  Diazomethane c................      0.999
132-64-9....................  Dibenzofurans.................      0.967
96-12-8.....................  1,2-Dibromo-3-chloropropane...      1.000
106-46-7....................  1,4-Dichlorobenzene(p)........      1.000
107-06-2....................  Dichloroethane (Ethylene            1.000
                               dichloride).
111-44-4....................  Dichloroethyl ether (Bis(2-         0.757
                               chloroethyl ether).
542-75-6....................  1,3-Dichloropropene...........      1.000
79-44-7.....................  Dimethyl carbamoyl chloridec..      0.150
64-67-5.....................  Diethyl sulfate...............      0.0025
77-78-1.....................  Dimethyl sulfate..............      0.086
121-69-7....................  N,N-Dimethylaniline...........      0.0008
51-28-5.....................  2,4-Dinitrophenol.............      0.0077
121-14-2....................  2,4-Dinitrotoluene............      0.0848
123-91-1....................  1,4-Dioxane (1,4-                   0.869
                               Diethyleneoxide).
106-89-8....................  Epichlorohydrin (1-Chloro-2,3-      0.939
                               epoxypropane).
106-88-7....................  1,2-Epoxybutane...............      1.000
140-88-5....................  Ethyl acrylate................      1.000
100-41-4....................  Ethyl benzene.................      1.000
75-00-3.....................  Ethyl chloride (Chloroethane).      1.000
106-93-4....................  Ethylene dibromide                  0.999
                               (Dibromoethane).
107-06-2....................  Ethylene dichloride (1,2-           1.000
                               Dichloroethane).
151-56-4....................  Ethylene imine (Aziridine)....      0.867
75-21-8.....................  Ethylene oxide................      1.000
75-34-3.....................  Ethylidene dichloride (1,1-         1.000
                               Dichloroethane).
                              Glycol ethers d that have a       (e)
                               Henry's Law constant value
                               equal to or greater than 0.1
                               Y/X (1.8 x 10-6 atm/gm-mole/
                               m3) at 25 deg.C.
118-74-1....................  Hexachlorobenzene.............      0.97
87-68-3.....................  Hexachlorobutadiene...........      0.88
67-72-1.....................  Hexachloroethane..............      0.499
110-54-3....................  Hexane........................      1.000
78-59-1.....................  Isophorone....................      0.506
58-89-9.....................  Lindane (all isomers).........      1.000
67-56-1.....................  Methanol......................      0.855
74-83-9.....................  Methyl bromide (Bromomethane).      1.000
74-87-3.....................  Methyl chloride (Choromethane)      1.000
71-55-6.....................  Methyl chloroform (1,1,1-           1.000
                               Trichloroethane).
78-93-3.....................  Methyl ethyl ketone (2-             0.990
                               Butanone).
74-88-4.....................  Methyl iodide (Iodomethane)...      1.0001
108-10-1....................  Methyl isobutyl ketone              0.9796
                               (Hexone).
624-83-9....................  Methyl isocyanate.............      1.000
80-62-6.....................  Methyl methacrylate...........      0.916
1634-04-4...................  Methyl tert butyl ether.......      1.000
75-09-2.....................  Methylene chloride                  1.000
                               (Dichloromethane).
91-20-3.....................  Naphthalene...................      0.994
98-95-3.....................  Nitrobenzene..................      0.394
79-46-9.....................  2-Nitropropane................      0.989
82-68-8.....................  Pentachloronitrobenzene             0.839
                               (Quintobenzene).
87-86-5.....................  Pentachlorophenol.............      0.0898
75-44-5.....................  Phosgenec.....................      1.000
123-38-6....................  Propionaldehyde...............      0.999
78-87-5.....................  Propylene dichloride (1,2-          1.000
                               Dichloropropane).
75-56-9.....................  Propylene oxide...............      1.000

[[Page 38983]]

 
75-55-8.....................  1,2-Propylenimine (2-Methyl         0.945
                               aziridine).
100-42-5....................  Styrene.......................      1.000
96-09-3.....................  Styrene oxide.................      0.830
79-34-5.....................  1,1,2,2-Tetrachloroethane.....      0.999
127-18-4....................  Tetrachloroethylene                 1.000
                               (Perchloroethylene).
108-88-3....................  Toluene.......................      1.000
95-53-4.....................  o-Toluidine...................      0.152
120-82-1....................  1,2,4-Trichlorobenzene........      1.000
71-55-6.....................  1,1,1-Trichloroethane (Methyl       1.000
                               chlorform).
79-00-5.....................  1,1,2-Trichloroethane (Vinyl        1.000
                               trichloride).
79-01-6.....................  Trichloroethylene.............      1.000
95-95-4.....................  2,4,5-Trichlorophenol.........      0.108
88-06-2.....................  2,4,6-Trichlorophenol.........      0.132
121-44-8....................  Triethylamine.................      1.000
540-84-1....................  2,2,4-Trimethylpentane........      1.000
108-05-4....................  Vinyl acetate.................      1.000
593-60-2....................  Vinyl bromide.................      1.000
75-01-4.....................  Vinyl chloride................      1.000
75-35-4.....................  Vinylidene chloride (1,1-           1.000
                               Dichloroethylene).
1330-20-7...................  Xylenes (isomers and mixture).      1.000
95-47-6.....................  o-Xylenes.....................      1.000
108-38-3....................  m-Xylenes.....................      1.000
106-42-3....................  p-Xylenes.....................      1.000
------------------------------------------------------------------------
Notes:
fm 305 = Method 305 fraction measure factor.
a. CAS numbers refer to the Chemical Abstracts Services registry number
  assigned to specific compounds, isomers, or mixtures of compounds.
b. Denotes a HAP that hydrolyzes quickly in water, but the hydrolysis
  products are also HAP chemicals.
c. Denotes a HAP that may react violently with water, exercise caustic
  is an expected analyte.
d. Denotes a HAP that hydrolyzes slowly in water.
e. The fm305 factors for some of the more common glycol ethers can be
  obtained by contacting the Waste and Chemical Processes Group, Office
  of Air Quality Planning and Standards, Research Triangle Park, NC
  27711.

    18. Table 2 in Subpart DD is revised to read as follows:

 Table 2 to Subpart DD--Applicability of Paragraphs in Subpart A of This
                Part 63--General Provisions to Subpart DD
------------------------------------------------------------------------
                                    Applies to
      Subpart A reference           Subpart DD          Explanation
------------------------------------------------------------------------
63.1(a)(1)....................  Yes                .....................
63.1(a)(2)....................  Yes                .....................
63.1(a)(3)....................  Yes                .....................
63.1(a)(4)....................  No                 Subpart DD (this
                                                    table) specifies
                                                    applicability of
                                                    each paragraph in
                                                    subpart A to subpart
                                                    DD.
63.1(a)(5)-63.1(a)(9).........  No                 .....................
63.1(a)(10)...................  Yes                .....................
63.1(a)(11)...................  Yes                .....................
63.1(a)(12)...................  Yes                .....................
63.1(a)(13)...................  Yes                .....................
63.1(a)(14)...................  Yes                .....................
63.1(b)(1)....................  No                 Subpart DD specifies
                                                    its own
                                                    applicability.
63.1(b)(2)....................  Yes                .....................
63.1(b)(3)....................  No                 .....................
63.1(c)(1)....................  No                 Subpart DD explicitly
                                                    specifies
                                                    requirements that
                                                    apply.
63.1(c)(2)....................  No                 Area sources are not
                                                    subject to subpart
                                                    DD.
63.1(c)(3)....................  No                 .....................
63.1(c)(4)....................  Yes                .....................
63.1(c)(5)....................  Yes                Except that sources
                                                    are not required to
                                                    submit notifications
                                                    overridden by this
                                                    table.
63.1(d).......................  No                 .....................
63.1(e).......................  No                 .....................
63.2..........................  Yes                Sec.  63.681 of
                                                    subpart DD specifies
                                                    that if the same
                                                    term is defined in
                                                    subparts A and DD,
                                                    it shall have the
                                                    meaning given in
                                                    subpart DD.
63.3..........................  Yes                .....................
63.4(a)(1)-63.4(a)(3).........  Yes
63.4(a)(4)....................  No...............  Reserved.
63.4(a)(5)....................  Yes
63.4(b).......................  Yes

[[Page 38984]]

 
63.4(c).......................  Yes
63.5(a)(1)....................  Yes                Except replace term
                                                    ``source'' and
                                                    ``stationary
                                                    source'' in Sec.
                                                    63.5(a)(1) of
                                                    subpart A with
                                                    ``affected source.''
63.5(a)(2)....................  Yes
63.5(b)(1)....................  Yes
63.5(b)(2)....................  No                 Reserved.
63.5(b)(3)....................  Yes
63.5(b)(4)....................  Yes                Except the cross-
                                                    reference to Sec.
                                                    63.9(b) is changed
                                                    to Sec.  63.9(b)(4)
                                                    and (5). Subpart DD
                                                    overrides Sec.
                                                    63.9(b)(2) and
                                                    (b)(3).
63.5(b)(5)....................  Yes
63.5(b)(6)....................  Yes
63.5(c).......................  No                 Reserved.
63.5(d)(1)(i).................  Yes
63.5(d)(1)(ii)................  Yes
63.5(d)(1)(iii)...............  Yes
63.5(d)(2)....................  No
63.5(d)(3)....................  Yes
63.5(d)(4)....................  Yes
63.5(e).......................  Yes
63.5(f)(1)....................  Yes
63.5(f)(2)....................  Yes
63.6(a).......................  Yes
63.6(b)(1)....................  No                 Subpart DD specifies
                                                    compliance dates for
                                                    sources subject to
                                                    subpart DD.
63.6(b)(2)....................  No
63.6(b)(3)....................  Yes
63.6(b)(4)....................  No                 May apply when
                                                    standards are
                                                    proposed under
                                                    section 112(f) of
                                                    the Clean Air Act.
63.6(b)(5)....................  No...............  Sec.  63.697 of
                                                    subpart DD includes
                                                    notification
                                                    requirements.
63.6(b)(6)....................  No
63.6(b)(7)....................  No
63.6(c)(1)....................  No                 Sec.  63.680 of
                                                    subpart DD specifies
                                                    the compliance date.
63.6(c)(2)-63.6(c)(4).........  No
63.6(c)(5)....................  Yes
63.6(d).......................  No
63.6(e).......................  Yes
63.6(f)(1)....................  Yes
63.6(f)(2)(i).................  Yes
63.6(f)(2)(ii)................  Yes                Subpart DD specifies
                                                    the use of
                                                    monitoring data in
                                                    determining
                                                    compliance with
                                                    subpart DD.
63.6(f)(2)(iii) (A), (B), and   Yes
 (C).
63.6(f)(2)(iii) (D)...........  No
63.6(f)(2)(iv)................  Yes
63.6(f)(2)(v).................  Yes
63.6(f)(3)....................  Yes
63.6(g).......................  Yes
63.6(h).......................  No                 Subpart DD does not
                                                    require opacity and
                                                    visible emission
                                                    standards.
63.6(i).......................  Yes                Except for Sec.
                                                    63.6(i)(15), which
                                                    is reserved.
63.6(j).......................  Yes
63.7(a)(1)....................  No                 Subpart DD specifies
                                                    required testing and
                                                    compliance
                                                    demonstration
                                                    procedures.
63.7(a)(2)....................  Yes
63.7(a)(3)....................  Yes
63.7(b).......................  No
63.7(c).......................  No
63.7(d).......................  Yes
63.7(e)(1)....................  Yes
63.7(e)(2)....................  Yes
63.7(e)(3)....................  No                 Subpart DD specifies
                                                    test methods and
                                                    procedures.
63.7(e)(4)....................  Yes
63.7(f).......................  No                 Subpart DD specifies
                                                    applicable methods
                                                    and provides
                                                    alternatives.
63.7(g).......................  Yes
63.7(h)(1)....................  Yes
63.7(h)(2)....................  Yes
63.7(h)(3)....................  Yes
63.7(h)(4)....................  No
63.7(h)(5)....................  Yes
63.8(a).......................  No
63.8(b)(1)....................  Yes
63.8(b)(2)....................  No                 Subpart DD specifies
                                                    locations to conduct
                                                    monitoring.
63.8(b)(3)....................  Yes

[[Page 38985]]

 
63.8(c)(1)(i).................  Yes
63.8(c)(1)(ii)................  Yes
63.8(c)(1)(iii)...............  Yes
63.8(c)(2)....................  Yes
63.8(c)(3)....................  Yes
63.8(c)(4)....................  No                 Subpart DD specifies
                                                    monitoring frequency
63.8(c)(5)-63.8(c)(8).........  No
63.8(d).......................  No
63.8(e).......................  No
63.8(f)(1)....................  Yes
63.8(f)(2)....................  Yes
63.8(f)(3)....................  Yes
63.8(f)(4)(i).................  Yes
63.8(f)(4)(ii)................  Yes
63.8(f)(4)(iii)...............  No
63.8(f)(5)(i).................  Yes
63.8(f)(5)(ii)................  No
63.8(f)(5)(iii)...............  Yes
63.8(f)(6)....................  Yes
63.8(g).......................  Yes
63.9(a).......................  Yes
63.9(b)(1)(i).................  Yes
63.9(b)(1)(ii)................  No
63.9(b)(2)....................  Yes
63.9(b)(3)....................  No
63.9(b)(4)....................  Yes
63.9(b)(5)....................  Yes
63.9(c).......................  Yes
63.9(d).......................  Yes
63.9(e).......................  No
63.9(f).......................  No
63.9(g).......................  No
63.9(h).......................  Yes
63.9(i).......................  Yes
63.9(j).......................  No
63.10(a)......................  Yes
63.10(b)(1)...................  Yes
63.10(b)(2)(i)................  Yes
63.10(b)(2)(ii)...............  Yes
63.10(b)(2)(iii)..............  No
63.10(b)(2)(iv)...............  Yes
63.10(b)(2)(v)................  Yes
63.10(b)(2)(vi)-(ix)..........  Yes
63.10(b)(2)(x)................  Yes
63.10(b)(2) (xii)-(xiv).......  No
63.10(b)(3)...................  Yes
63.10(c)......................  No
63.10(d)(1)...................  No
63.10(d)(2)...................  Yes
63.10(d)(3)...................  No
63.10(d)(4)...................  Yes
63.10(d)(5)(i)................  Yes
63.10(d)(5)(ii)...............  Yes
63.10(e)......................  No
63.10(f)......................  Yes
63.11-63.15...................  Yes
------------------------------------------------------------------------
a Wherever subpart A specifies ``postmark'' dates, submittals may be
  sent by methods other than the U.S. Mail (e.g., by fax or courier).
  Submittals shall be sent by the specified dates, but a postmark is not
  required.

Subpart OO--National Emission Standards for Tanks--Level 1

    19. Section 63.901 is amended by revising the definition of 
``Safety device'' to read as follows:


Sec. 63.901  Definitions.

* * * * *
    Safety device means a closure device such as a pressure relief 
valve, frangible disc, fusible plug, or any other type of device which 
functions to prevent physical damage or permanent deformation to 
equipment by venting gases or vapors during unsafe conditions resulting 
from an unplanned, accidental, or emergency event. For the purpose of 
this subpart, a safety device is not used for routine venting of gases 
or vapors from the vapor headspace underneath a cover such as during 
filling of the unit or to adjust the pressure in this vapor headspace 
in response to normal daily diurnal

[[Page 38986]]

ambient temperature fluctuations. A safety device is designed to remain 
in a closed position during normal operations and open only when the 
internal pressure, or another relevant parameter, exceeds the device 
threshold setting applicable to the equipment as determined by the 
owner or operator based on manufacturer recommendations, applicable 
regulations, fire protection and prevention codes, standard engineering 
codes and practices, or other requirements for the safe handling of 
flammable, combustible, explosive, reactive, or hazardous materials.
* * * * *
    20. Section 63.902 is amended by revising paragraphs (a) and (b)(3) 
introductory text to read as follows:


Sec. 63.902  Standards--Tank fixed roof.

    (a) This section applies to owners and operators subject to this 
subpart and controlling air emissions from a tank using a fixed roof. 
This section does not apply to a fixed-roof tank that is also equipped 
with an internal floating roof.
    (b) * * *
    (3) Each opening in the fixed roof, and any manifold system 
associated with the fixed roof, shall be either:
* * * * *
    21. Section 63.905 is revised to read as follows:


Sec. 63.905  Test methods and procedures.

    (a) Procedure for determining no detectable organic emissions for 
the purpose of complying with this subpart.
    (1) The test shall be conducted in accordance with the procedures 
specified in Method 21 of 40 CFR part 60, appendix A. Each potential 
leak interface (i.e., a location where organic vapor leakage could 
occur) on the cover and associated closure devices shall be checked. 
Potential leak interfaces that are associated with covers and closure 
devices include, but are not limited to: the interface of the cover and 
its foundation mounting; the periphery of any opening on the cover and 
its associated closure device; and the sealing seat interface on a 
spring-loaded pressure-relief valve.
    (2) The test shall be performed when the unit contains a material 
having a total organic concentration representative of the range of 
concentrations for the materials expected to be managed in the unit. 
During the test, the cover and closure devices shall be secured in the 
closed position.
    (3) The detection instrument shall meet the performance criteria of 
Method 21 of 40 CFR part 60, appendix A, except the instrument response 
factor criteria in section 3.1.2(a) of Method 21 shall be for the 
average composition of the organic constituents in the material placed 
in the unit, not for each individual organic constituent.
    (4) The detection instrument shall be calibrated before use on each 
day of its use by the procedures specified in Method 21 of 40 CFR part 
60, appendix A.
    (5) Calibration gases shall be as follows:
    (i) Zero air (less than 10 ppmv hydrocarbon in air); and
    (ii) A mixture of methane or n-hexane in air at a concentration of 
approximately, but less than 10,000 ppmv.
    (6) An owner or operator may choose to adjust or not adjust the 
detection instrument readings to account for the background organic 
concentration level. If an owner or operator chooses to adjust the 
instrument readings for the background level, the background level 
value must be determined according to the procedures in Method 21 of 40 
CFR part 60, appendix A.
    (7) Each potential leak interface shall be checked by traversing 
the instrument probe around the potential leak interface as close to 
the interface as possible, as described in Method 21. In the case when 
the configuration of the cover or closure device prevents a complete 
traverse of the interface, all accessible portions of the interface 
shall be sampled. In the case when the configuration of the closure 
device prevents any sampling at the interface and the device is 
equipped with an enclosed extension or horn (e.g., some pressure relief 
devices), the instrument probe inlet shall be placed at approximately 
the center of the exhaust area to the atmosphere.
    (8) An owner or operator must determine if a potential leak 
interface operates with no detectable emissions using the applicable 
procedure specified in paragraph (a)(8)(i) or (a)(8)(ii) of this 
section.
    (i) If an owner or operator chooses not to adjust the detection 
instrument readings for the background organic concentration level, 
then the maximum organic concentration value measured by the detection 
instrument is compared directly to the applicable value for the 
potential leak interface as specified in paragraph (a)(9) of this 
section.
    (ii) If an owner or operator chooses to adjust the detection 
instrument readings for the background organic concentration level, the 
value of the arithmetic difference between the maximum organic 
concentration value measured by the instrument and the background 
organic concentration value as determined in paragraph (a)(6) of this 
section is compared with the applicable value for the potential leak 
interface as specified in paragraph (a)(9) of this section.
    (9) A potential leak interface is determined to operate with no 
detectable emissions using the applicable criteria specified in 
paragraphs (a)(9)(i) and (a)(9)(ii) of this section.
    (i) For a potential leak interface other than a seal around a shaft 
that passes through a cover opening, the potential leak interface is 
determined to operate with no detectable organic emissions if the 
organic concentration value determined in paragraph (a)(8) is less than 
500 ppmv.
    (ii) For a seal around a shaft that passes through a cover opening, 
the potential leak interface is determined to operate with no 
detectable organic emissions if the organic concentration value 
determined in paragraph (a)(8) is less than 10,000 ppmv.
    (b) [Reserved]
    22. Section 63.906 is amended by revising paragraphs (a)(2) and 
(b)(2), and adding paragraph (d) to read as follows:


Sec. 63.906  Inspection and monitoring requirements.

    (a) * * *
    (2) The owner or operator must perform an initial inspection 
following installation of the fixed roof. Thereafter, the owner or 
operator must perform the inspections at least once every calendar year 
except as provided for in paragraph (d) of this section.
* * * * *
    (b) * * *
    (2) Repair of a defect may be delayed beyond 45 calendar days if 
the owner or operator determines that repair of the defect requires 
emptying or temporary removal from service of the tank and no 
alternative tank capacity is available at the site to accept the 
regulated material normally managed in the tank. In this case, the 
owner or operator shall repair the defect the next time alternative 
tank capacity becomes available and the tank can be emptied or 
temporarily removed from service, as necessary to complete the repair.
* * * * *
    (d) Alternative inspection and monitoring interval. Following the 
initial inspection and monitoring of a fixed roof in accordance with 
this section, subsequent inspection and monitoring of the equipment may 
be performed at intervals longer than 1 year when an owner or operator 
determines that performing the required inspection or monitoring 
procedures would expose a worker to dangerous,

[[Page 38987]]

hazardous, or otherwise unsafe conditions and the owner or operator 
complies with the requirements specified in paragraphs (d)(1) and 
(d)(2) of this section.
    (1) The owner or operator must prepare and maintain at the plant 
site written documentation identifying the specific air pollution 
control equipment designated as ``unsafe to inspect and monitor.'' The 
documentation must include for each piece of air pollution control 
equipment designated as such a written explanation of the reasons why 
the equipment is unsafe to inspect or monitor using the applicable 
procedures under this section.
    (2) The owner or operator must develop and implement a written plan 
and schedule to inspect and monitor the air pollution control equipment 
using the applicable procedures specified in this section during times 
when a worker can safely access the air pollution control equipment. 
The required inspections and monitoring must be performed as frequently 
as practicable but do not need to be performed more frequently than the 
periodic schedule that would be otherwise applicable to the air 
pollution control equipment under the provisions of this section. A 
copy of the written plan and schedule must be maintained at the plant 
site.

Subpart PP--National Emission Standards for Containers

    23. Section 63.921 is amended by revising the definitions of 
``Empty container'' and ``Safety device'' to read as follows:


Sec. 63.921  Definitions.

* * * * *
    Empty container means a container for which either of the following 
conditions exists: the container meets the conditions for an empty 
container specified in 40 CFR 261.7(b); or all regulated-material has 
been removed from the container except for any regulated-material that 
remains on the interior surfaces of the container as clingage or in 
pools on the container bottom due to irregularities in the container.
* * * * *
    Safety device means a closure device such as a pressure relief 
valve, frangible disc, fusible plug, or any other type of device which 
functions to prevent physical damage or permanent deformation to 
equipment by venting gases or vapors during unsafe conditions resulting 
from an unplanned, accidental, or emergency event. For the purpose of 
this subpart, a safety device is not used for routine venting of gases 
or vapors from the vapor headspace underneath a cover such as during 
filling of the unit or to adjust the pressure in this vapor headspace 
in response to normal daily diurnal ambient temperature fluctuations. A 
safety device is designed to remain in a closed position during normal 
operations and open only when the internal pressure, or another 
relevant parameter, exceeds the device threshold setting applicable to 
the equipment as determined by the owner or operator based on 
manufacturer recommendations, applicable regulations, fire protection 
and prevention codes, standard engineering codes and practices, or 
other requirements for the safe handling of flammable, combustible, 
explosive, reactive, or hazardous materials.
    24. Section 63.925 is amended by revising paragraph (a) to read as 
follows:


Sec. 63.925  Test methods and procedures.

    (a) Procedures for determining no detectable organic emissions for 
the purpose of complying with this subpart.
    (1) The test shall be conducted in accordance with the procedures 
specified in Method 21 of 40 CFR part 60, appendix A. Each potential 
leak interface (i.e., a location where organic vapor leakage could 
occur) on the cover and associated closure devices shall be checked. 
Potential leak interfaces that are associated with covers and closure 
devices include, but are not limited to: the interface of the cover and 
its foundation mounting; the periphery of any opening on the cover and 
its associated closure device; and the sealing seat interface on a 
spring-loaded pressure-relief valve.
    (2) The test shall be performed when the unit contains a material 
having a total organic concentration representative of the range of 
concentrations for the materials expected to be managed in the unit. 
During the test, the cover and closure devices shall be secured in the 
closed position.
    (3) The detection instrument shall meet the performance criteria of 
Method 21 of 40 CFR part 60, appendix A, except the instrument response 
factor criteria in section 3.1.2(a) of Method 21 shall be for the 
average composition of the organic constituents in the material placed 
in the unit, not for each individual organic constituent.
    (4) The detection instrument shall be calibrated before use on each 
day of its use by the procedures specified in Method 21 of 40 CFR part 
60, appendix A.
    (5) Calibration gases shall be as follows:
    (i) Zero air (less than 10 ppmv hydrocarbon in air); and
    (ii) A mixture of methane or n-hexane in air at a concentration of 
approximately, but less than 10,000 ppmv.
    (6) An owner or operator may choose to adjust or not adjust the 
detection instrument readings to account for the background organic 
concentration level. If an owner or operator chooses to adjust the 
instrument readings for the background level, the background level 
value must be determined according to the procedures in Method 21 of 40 
CFR part 60, appendix A.
    (7) Each potential leak interface shall be checked by traversing 
the instrument probe around the potential leak interface as close to 
the interface as possible, as described in Method 21. In the case when 
the configuration of the cover or closure device prevents a complete 
traverse of the interface, all accessible portions of the interface 
shall be sampled. In the case when the configuration of the closure 
device prevents any sampling at the interface and the device is 
equipped with an enclosed extension or horn (e.g., some pressure relief 
devices), the instrument probe inlet shall be placed at approximately 
the center of the exhaust area to the atmosphere.
    (8) An owner or operator must determine if a potential leak 
interface operates with no detectable emissions using the applicable 
procedure specified in paragraph (a)(8)(i) or (a)(8)(ii) of this 
section.
    (i) If an owner or operator chooses not to adjust the detection 
instrument readings for the background organic concentration level, 
then the maximum organic concentration value measured by the detection 
instrument is compared directly to the applicable value for the 
potential leak interface as specified in paragraph (a)(9) of this 
section.
    (ii) If an owner or operator chooses to adjust the detection 
instrument readings for the background organic concentration level, the 
value of the arithmetic difference between the maximum organic 
concentration value measured by the instrument and the background 
organic concentration value as determined in paragraph (a)(6) of this 
section is compared with the applicable value for the potential leak 
interface as specified in paragraph (a)(9) of this section.
    (9) A potential leak interface is determined to operate with no 
detectable emissions using the applicable criteria specified in 
paragraphs (a)(9)(i) and (a)(9)(ii) of this section.

[[Page 38988]]

    (i) For a potential leak interface other than a seal around a shaft 
that passes through a cover opening, the potential leak interface is 
determined to operate with no detectable organic emissions if the 
organic concentration value determined in paragraph (a)(8) is less than 
500 ppmv.
    (ii) For a seal around a shaft that passes through a cover opening, 
the potential leak interface is determined to operate with no 
detectable organic emissions if the organic concentration value 
determined in paragraph (a)(8) is less than 10,000 ppmv.
* * * * *
    25. Section 63.926 is amended by revising paragraph (a) to read as 
follows:


Sec. 63.926  Inspection and monitoring requirements.

    (a) Owners and operators of containers using either Container Level 
1 or Container Level 2 controls in accordance with the provisions of 
Sec. 63.922 and Sec. 63.923 of this subpart, respectively, shall 
inspect the container and its cover and closure devices as follows:
    (1) In the case when a regulated-material already is in the 
container at the time the owner or operator first accepts possession of 
the container at the facility site and the container is not emptied 
(i.e., does not meet the conditions for an empty container as defined 
in Sec. 63.921 of this subpart) within 24 hours after the container has 
been accepted at the facility site, the container and its cover and 
closure devices shall be visually inspected by the owner or operator to 
check for visible cracks, holes, gaps, or other open spaces into the 
interior of the container when the cover and closure devices are 
secured in the closed position. This inspection of the container must 
be conducted on or before the date that the container is accepted at 
the facility (i.e., the date that the container becomes subject to the 
standards under this subpart). For the purpose of this requirement, the 
date of acceptance is the date of signature of the facility owner or 
operator on the manifest or shipping papers accompanying the container. 
If a defect is detected, the owner or operator shall repair the defect 
in accordance with the requirements of paragraph (a)(3) of this 
section.
    (2) In the case when a container filled or partially filled with 
regulated-material remains unopened at the facility site for a period 
of 1 year or more, the container and its cover and closure devices 
shall be visually inspected by the owner or operator initially and 
thereafter, at least once every calendar year, to check for visible 
cracks, holes, gaps, or other open spaces into the interior of the 
container when the cover and closure devices are secured in the closed 
position. If a defect is detected, the owner or operator shall repair 
the defect in accordance with the requirements of paragraph (a)(3) of 
this section.
    (3) When a defect is detected for the container, cover, or closure 
devices, the owner or operator must either empty the regulated-material 
from the defective container in accordance with paragraph (a)(3)(i) of 
this section or repair the defective container in accordance with 
paragraph (a)(3)(ii) of this section.
    (i) If the owner or operator elects to empty the regulated-material 
from the defective container, the owner or operator must remove the 
regulated-material from the defective container to meet the conditions 
for an empty container (as defined in Sec. 63.921 of this subpart) and 
transfer the removed regulated-material to either a container that 
meets the applicable standards under this subpart or to a tank, 
process, or treatment unit that meets the applicable standards under 
the subpart referencing this subpart. Transfer of the regulated-
material must be completed no later than 5 calendar days after 
detection of the defect. The emptied defective container must be either 
repaired, destroyed, or used for purposes other than management of 
regulated-material.
    (ii) If the owner or operator elects not to empty the regulated-
material from the defective container, the owner or operator must 
repair the defective container. First efforts at repair of the defect 
must be made no later than 24 hours after detection and repair must be 
completed as soon as possible but no later than 5 calendar days after 
detection. If repair of a defect cannot be completed within 5 calendar 
days, then the regulated-material must be emptied from the container 
and the container must not be used to manage regulated-material until 
the defect is repaired.
* * * * *

Subpart QQ--National Emission Standards for Surface Impoundments

    26. Section 63.941 is amended by revising the definitions of 
``Cover'' and ``Safety device'' to read as follows:


Sec. 63.941  Definitions.

* * * * *
    Cover means a device or system that provides a continuous barrier 
over the material managed in a surface impoundment to prevent or reduce 
air pollutant emissions to the atmosphere. A cover may have openings 
needed for operation, inspection, sampling, maintenance, and repair of 
the surface impoundment provided that each opening is closed when not 
in use (e.g., access hatches, sampling ports). Examples of a cover for 
a surface impoundment include, but are not limited to, a floating 
membrane cover placed on the surface of the material in the surface 
impoundment or an air-supported structure installed over the surface 
impoundment.
* * * * *
    Safety device means a closure device such as a pressure relief 
valve, frangible disc, fusible plug, or any other type of device which 
functions to prevent physical damage or permanent deformation to 
equipment by venting gases or vapors during unsafe conditions resulting 
from an unplanned, accidental, or emergency event. For the purpose of 
this subpart, a safety device is not used for routine venting of gases 
or vapors from the vapor headspace underneath a cover such as during 
filling of the unit or to adjust the pressure in this vapor headspace 
in response to normal daily diurnal ambient temperature fluctuations. A 
safety device is designed to remain in a closed position during normal 
operations and open only when the internal pressure, or another 
relevant parameter, exceeds the device threshold setting applicable to 
the equipment as determined by the owner or operator based on 
manufacturer recommendations, applicable regulations, fire protection 
and prevention codes, standard engineering codes and practices, or 
other requirements for the safe handling of flammable, combustible, 
explosive, reactive, or hazardous materials.
* * * * *
    27. Section 63.945 is revised to read as follows:


Sec. 63.945  Test methods and procedures.

    (a) Procedure for determining no detectable organic emissions for 
the purpose of complying with this subpart.
    (1) The test shall be conducted in accordance with the procedures 
specified in Method 21 of 40 CFR part 60, appendix A. Each potential 
leak interface (i.e., a location where organic vapor leakage could 
occur) on the cover and associated closure devices shall be checked. 
Potential leak interfaces that are associated with covers and closure 
devices include, but are not limited to the interface of the cover and 
its foundation mounting; the periphery of any opening on the cover and 
its associated closure device; and the

[[Page 38989]]

sealing seat interface on a spring-loaded pressure-relief valve.
    (2) The test shall be performed when the unit contains a material 
having a total organic concentration representative of the range of 
concentrations for the materials expected to be managed in the unit. 
During the test, the cover and closure devices shall be secured in the 
closed position.
    (3) The detection instrument shall meet the performance criteria of 
Method 21 of 40 CFR part 60, appendix A, except the instrument response 
factor criteria in section 3.1.2(a) of Method 21 shall be for the 
average composition of the organic constituents in the material placed 
in the unit, not for each individual organic constituent.
    (4) The detection instrument shall be calibrated before use on each 
day of its use by the procedures specified in Method 21 of 40 CFR part 
60, appendix A.
    (5) Calibration gases shall be as follows:
    (i) Zero air (less than 10 ppmv hydrocarbon in air); and
    (ii) A mixture of methane or n-hexane in air at a concentration of 
approximately, but less than 10,000 ppmv.
    (6) An owner or operator may choose to adjust or not adjust the 
detection instrument readings to account for the background organic 
concentration level. If an owner or operator chooses to adjust the 
instrument readings for the background level, the background level 
value must be determined according to the procedures in Method 21 of 40 
CFR part 60, appendix A.
    (7) Each potential leak interface shall be checked by traversing 
the instrument probe around the potential leak interface as close to 
the interface as possible, as described in Method 21. In the case when 
the configuration of the cover or closure device prevents a complete 
traverse of the interface, all accessible portions of the interface 
shall be sampled. In the case when the configuration of the closure 
device prevents any sampling at the interface and the device is 
equipped with an enclosed extension or horn (e.g., some pressure relief 
devices), the instrument probe inlet shall be placed at approximately 
the center of the exhaust area to the atmosphere.
    (8) An owner or operator must determine if a potential leak 
interface operates with no detectable emissions using the applicable 
procedure specified in paragraph (a)(8)(i) or (a)(8)(ii) of this 
section.
    (i) If an owner or operator chooses not to adjust the detection 
instrument readings for the background organic concentration level, 
then the maximum organic concentration value measured by the detection 
instrument is compared directly to the applicable value for the 
potential leak interface as specified in paragraph (a)(9) of this 
section.
    (ii) If an owner or operator chooses to adjust the detection 
instrument readings for the background organic concentration level, the 
value of the arithmetic difference between the maximum organic 
concentration value measured by the instrument and the background 
organic concentration value as determined in paragraph (a)(6) of this 
section is compared with the applicable value for the potential leak 
interface as specified in paragraph (a)(9) of this section.
    (9) A potential leak interface is determined to operate with no 
detectable emissions using the applicable criteria specified in 
paragraphs (a)(9)(i) and (a)(9)(ii) of this section.
    (i) For a potential leak interface other than a seal around a shaft 
that passes through a cover opening, the potential leak interface is 
determined to operate with no detectable organic emissions if the 
organic concentration value determined in paragraph (a)(8) is less than 
500 ppmv.
    (ii) For a seal around a shaft that passes through a cover opening, 
the potential leak interface is determined to operate with no 
detectable organic emissions if the organic concentration value 
determined in paragraph (a)(8) is less than 10,000 ppmv.
    (b) [Reserved]
    28. Section 63.946 is amended by adding paragraph (d) and by 
revising paragraphs (a)(2) and (b)(1)(ii) to read as follows:


Sec. 63.946  Inspection and monitoring requirements.

    (a) * * *
    (2) The owner or operator must perform an initial inspection 
following installation of the floating membrane cover. Thereafter, the 
owner or operator must perform the inspections at least once per 
calendar year except as provided for in paragraph (d) of this section.
* * * * *
    (b) * * *
    (1) * * *
    (ii) The owner or operator must perform an initial inspection 
following installation of the cover. Thereafter, the owner or operator 
must perform the inspections at least once per calendar year except as 
provide for in paragraph (d) of this section.
* * * * *
    (d) Alternative inspection and monitoring interval. Following the 
initial inspection and monitoring of a piece of air pollution control 
equipment in accordance with the applicable provisions of this section, 
subsequent inspection and monitoring of the equipment may be performed 
at intervals longer than 1 year when an owner or operator determines 
that performing the required inspection or monitoring procedures would 
expose a worker to dangerous, hazardous, or otherwise unsafe conditions 
and the owner or operator complies with the requirements specified in 
paragraphs (d)(1) and (d)(2) of this section.
    (1) The owner or operator must prepare and maintain at the plant 
site written documentation identifying the specific air pollution 
control equipment designated as ``unsafe to inspect and monitor.'' The 
documentation must include for each piece of air pollution control 
equipment designated as such a written explanation of the reasons why 
the equipment is unsafe to inspect or monitor using the applicable 
procedures under this section.
    (2) The owner or operator must develop and implement a written plan 
and schedule to inspect and monitor the air pollution control equipment 
using the applicable procedures specified in this section during times 
when a worker can safely access the air pollution control equipment. 
The required inspections and monitoring must be performed as frequently 
as practicable but do not need to be performed more frequently than the 
periodic schedule that would be otherwise applicable to the air 
pollution control equipment under the provisions of this section. A 
copy of the written plan and schedule must be maintained at the plant 
site.

Subpart RR--National Emission Standards for Individual Drain 
Systems

    29. Section 63.961 is amended by adding in alphabetical order the 
definition of ``Regulated-material'' and by revising the definitions of 
``Individual drain system,'' ``Sewer line'' and ``Waste management 
unit'' to read as follows:


Sec. 63.961  Definitions.

* * * * *
    Individual drain system means a stationary system used to convey 
regulated-material to a waste management unit or to discharge or 
disposal. The term includes hard-piping, all drains and junction boxes, 
together with their associated sewer lines and other junction boxes 
(e.g., manholes, sumps, and lift stations)

[[Page 38990]]

conveying regulated-material. For the purpose of this subpart, an 
individual drain system is not a drain and collection system that is 
designed and operated for the sole purpose of collecting rainfall 
runoff (e.g., stormwater sewer system) and is segregated from all other 
individual drain systems.
* * * * *
    Regulated-material means the wastewater streams, residuals, and any 
other materials specified by the referencing subpart to be managed in 
accordance with the standards under this subpart.
    Sewer line means a lateral, trunk line, branch line, or other 
conduit used to convey regulated-material to a downstream waste 
management unit. Sewer lines include pipes, grates, and trenches.
    Waste management unit means the equipment, structure, or device 
used to convey, store, treat, or dispose of regulated-material. 
Examples of waste management units include: wastewater tanks, surface 
impoundments, individual drain systems, and biological wastewater 
treatment units. Examples of equipment that may be waste management 
units include containers, air flotation units, oil-water separators or 
organic-water separators, or organic removal devices such as decanters, 
strippers, or thin-film evaporation units.
* * * * *
    30. Section 63.962 is amended by revising paragraph (b) to read as 
follows:


Sec. 63.962  Standards.

* * * * *
    (b) Owners and operators controlling air emissions from an 
individual drain system in accordance with paragraph (a)(1) of this 
section shall meet the following requirements:
    (1) The individual drain system shall be designed to segregate the 
organic vapors from regulated material managed in the controlled 
individual drain system from entering any other individual drain system 
that is not controlled for air emissions in accordance with the 
standards specified in this subpart.
    (2) Drain control requirements. Each drain shall be equipped with 
either a water seal or a closure device in accordance with the 
following requirements:
    (i) When a water seal is used, the water seal shall be designed 
such that either:
    (A) The outlet to the pipe discharging the regulated-material 
extends below the liquid surface in the water seal of the drain; or
    (B) A flexible shield or other device is installed which restricts 
wind motion across the open space between the outlet of the pipe 
discharging the regulated material and the drain.
    (ii) When a closure device is used (e.g., securing a cap or plug on 
a drain that is not receiving regulated-material), the closure device 
shall be designed to operate such that when the closure device is 
secured in the closed position there are no visible cracks, holes, 
gaps, or other open spaces in the closure device or between the 
perimeter of the drain opening and the closure device.
    (3) Junction box control requirements. Each junction box shall be 
equipped with controls as follows:
    (i) The junction box shall be equipped with a closure device (e.g., 
manhole cover, access hatch) that is designed to operate such that when 
the closure device is secured in the closed position there are no 
visible cracks, holes, gaps, or other open spaces in the closure device 
or between the perimeter of the junction box opening and the closure 
device.
    (ii) If the junction box is vented, the junction box shall be 
vented in accordance with the following requirements:
    (A) The junction box shall be vented through a closed vent system 
to a control device except as provided for in paragraph (b)(3)(ii)(B) 
of this section. The closed vent system and control device shall be 
designed and operated in accordance in accordance with the standards 
specified in Sec. 63.693 in subpart DD--National Emission Standards for 
Hazardous Air Pollutant Standards from Off-Site Waste and Recovery 
Operations.
    (B) As an alternative to paragraph (b)(3)(ii)(A) of this section, 
the owner or operator may vent the junction box directly to the 
atmosphere when all of the following conditions are met:
    (1) The junction box is filled and emptied by gravity flow (i.e., 
there is no pump) or is operated with no more than slight fluctuations 
in the liquid level. Large changes in the size of the junction box 
vapor headspace created by using a pump to repeatedly empty and then 
refill the junction box do not meet this condition.
    (2) The vent pipe installed on the junction box shall be at least 
90 centimeters in length and no greater than 10 centimeters in nominal 
inside diameter.
    (3) Water seals are installed at the liquid entrance(s) to or exit 
from the junction box to restrict ventilation in the individual drain 
system and between components in the individual drain system. The owner 
or operator shall demonstrate (e.g., by visual inspection or smoke 
test) upon request by the Administrator that the junction box water 
seal is properly designed and restricts ventilation.
    (4) Sewer line control requirements. Each sewer line shall not be 
open to the atmosphere and shall be covered or closed in a manner such 
that there are no visible cracks, holes, gaps, or other open spaces in 
the sewer line joints, seals, or other emission interfaces.
    (5) Operating requirements. The owner or operator shall operate the 
air emission controls required by paragraphs (b)(2) through (b)(4) of 
this section in accordance with the following requirements:
    (i) Each closure device shall be maintained in a closed position 
whenever regulated-material is in the individual drain system except 
when it is necessary to remove or open the closure device for sampling 
or removing material in the individual drain system, or for equipment 
inspection, maintenance, or repair.
    (ii) Each drain equipped with a water seal and open to the 
atmosphere shall be operated to ensure that the liquid in the water 
seal is maintained at the appropriate level. Examples of acceptable 
means for complying with this provision include but are not limited to 
using a flow-monitoring device indicating positive flow from a main to 
a branch water line supplying a trap; continuously dripping water into 
the trap using a hose; or regular visual observations.
    (iii) Each closed-vent system and the control device used to comply 
with paragraph (b)(3)(ii)(A) of this section shall be operated in 
accordance with the standards specified in 40 CFR 63.693.
    31. Section 63.964 is amended by revising paragraph (b)(2) to read 
as follows:


Sec. 63.964  Inspection and monitoring requirements.

* * * * *
    (b) * * *
    (2) Repair of a defect may be delayed beyond 15 calendar days if 
the owner or operator determines that repair of the defect requires 
emptying or temporary removal from service of the individual drain 
system and no alternative capacity is available at the facility site to 
accept the regulated-material normally managed in the individual drain 
system. In this case, the owner or operator shall repair the defect the 
next time the process or unit that is generating the regulated-material 
managed in the individual drain system stops operation. Repair of the 
defect shall be completed

[[Page 38991]]

before the process or unit resumes operation.
* * * * *
    32. Section 63.965 is amended by revising paragraph (b) to read as 
follows:


Sec. 63.965  Recordkeeping requirements.

* * * * *
    (b) Owners and operators that use a closed-vent system and a 
control device in accordance with the provisions of Sec. 63.962 of this 
subpart shall prepare and maintain the records required for the closed-
vent system and control device in accordance with the requirements of 
Sec. 63.693 in subpart DD--National Emission Standards for Hazardous 
Air Pollutant Standards from Off-Site Waste and Recovery Operations.
    33. Section 63.966 is revised to read as follows:


Sec. 63.966  Reporting requirements.

    Owners and operators that use a closed-vent system and a control 
device in accordance with the provisions of Sec. 63.962 of this subpart 
shall prepare and submit to the Administrator the reports required for 
closed-vent systems and control devices in accordance with the 
requirements of Sec. 63.693 in subpart DD--National Emission Standards 
for Hazardous Air Pollutant Standards from Off-Site Waste and Recovery 
Operations.

Subpart VV--National Emission Standards for Oil-Water Separators 
and Organic-Water Separators

    34. Section 63.1041 is amended by revising the definition of 
``Safety device'' to read as follows:


Sec. 63.1041  Definitions.

* * * * *
    Safety device means a closure device such as a pressure relief 
valve, frangible disc, fusible plug, or any other type of device which 
functions to prevent physical damage or permanent deformation to 
equipment by venting gases or vapors during unsafe conditions resulting 
from an unplanned, accidental, or emergency event. For the purpose of 
this subpart, a safety device is not used for routine venting of gases 
or vapors from the vapor headspace underneath a cover such as during 
filling of the unit or to adjust the pressure in this vapor headspace 
in response to normal daily diurnal ambient temperature fluctuations. A 
safety device is designed to remain in a closed position during normal 
operations and open only when the internal pressure, or another 
relevant parameter, exceeds the device threshold setting applicable to 
the equipment as determined by the owner or operator based on 
manufacturer recommendations, applicable regulations, fire protection 
and prevention codes, standard engineering codes and practices, or 
other requirements for the safe handling of flammable, combustible, 
explosive, reactive, or hazardous materials.
* * * * *
    35. Section 63.1045 is added to read as follows:


Sec. 63.1045  Standards--Pressurized separator.

    (a) This section applies to owners and operators controlling air 
emissions from an oil-water or organic-water separator that is 
pressurized and is operated as a closed-system.
    (b) The pressurized separator must meet the following requirements.
    (1) The separator must be designed not to vent to the atmosphere as 
a result of compression of the vapor headspace in the separator during 
operation of the separator at its design capacity.
    (2) All separator openings must be equipped with closure devices 
designed to operate with no detectable organic emissions as determined 
using the procedure specified in Sec. 63.1046(a) of this subpart.
    (3) Whenever a regulated-material is in the separator, the 
separator must be operated as a closed system that does not vent to the 
atmosphere except under either of the following conditions as specified 
in paragraph (b)(3)(i) or (b)(3)(ii) of this section.
    (i) At those times when opening of a safety device, as defined in 
Sec. 63.1041 of this subpart, is required to avoid an unsafe condition.
    (ii) At those times when purging of inerts from the separator is 
required and the purge stream is routed to a closed-vent system and 
control device designed and operated in accordance with the applicable 
requirements of Sec. 63.693 in subpart DD--National Emission Standards 
for Hazardous Air Pollutant Standards from Off-Site Waste and Recovery 
Operations.
    36. Section 63.1046 is amended by revising paragraphs (a) and 
(b)(3) to read as follows:


Sec. 63.1046  Test methods and procedures.

    (a) Procedure for determining no detectable organic emissions for 
the purpose of complying with this subpart.
    (1) The test shall be conducted in accordance with the procedures 
specified in Method 21 of 40 CFR part 60, appendix A. Each potential 
leak interface (i.e., a location where organic vapor leakage could 
occur) on the cover and associated closure devices shall be checked. 
Potential leak interfaces that are associated with covers and closure 
devices include, but are not limited to: the interface of the cover and 
its foundation mounting; the periphery of any opening on the cover and 
its associated closure device; and the sealing seat interface on a 
spring-loaded pressure-relief valve.
    (2) The test shall be performed when the unit contains a material 
having a total organic concentration representative of the range of 
concentrations for the materials expected to be managed in the unit. 
During the test, the cover and closure devices shall be secured in the 
closed position.
    (3) The detection instrument shall meet the performance criteria of 
Method 21 of 40 CFR part 60, appendix A, except the instrument response 
factor criteria in section 3.1.2(a) of Method 21 shall be for the 
average composition of the organic constituents in the material placed 
in the unit, not for each individual organic constituent.
    (4) The detection instrument shall be calibrated before use on each 
day of its use by the procedures specified in Method 21 of 40 CFR part 
60, appendix A.
    (5) Calibration gases shall be as follows:
    (i) Zero air (less than 10 ppmv hydrocarbon in air); and
    (ii) A mixture of methane or n-hexane in air at a concentration of 
approximately, but less than 10,000 ppmv.
    (6) An owner or operator may choose to adjust or not adjust the 
detection instrument readings to account for the background organic 
concentration level. If an owner or operator chooses to adjust the 
instrument readings for the background level, the background level 
value must be determined according to the procedures in Method 21 of 40 
CFR part 60, appendix A.
    (7) Each potential leak interface shall be checked by traversing 
the instrument probe around the potential leak interface as close to 
the interface as possible, as described in Method 21. In the case when 
the configuration of the cover or closure device prevents a complete 
traverse of the interface, all accessible portions of the interface 
shall be sampled. In the case when the configuration of the closure 
device prevents any sampling at the interface and the device is 
equipped with an enclosed extension or horn (e.g., some pressure relief 
devices), the instrument probe inlet shall be placed at approximately 
the center of the exhaust area to the atmosphere.

[[Page 38992]]

    (8) An owner or operator must determine if a potential leak 
interface operates with no detectable emissions using the applicable 
procedure specified in paragraph (a)(8)(i) or (a)(8)(ii) of this 
section.
    (i) If an owner or operator chooses not to adjust the detection 
instrument readings for the background organic concentration level, 
then the maximum organic concentration value measured by the detection 
instrument is compared directly to the applicable value for the 
potential leak interface as specified in paragraph (a)(9) of this 
section.
    (ii) If an owner or operator chooses to adjust the detection 
instrument readings for the background organic concentration level, the 
value of the arithmetic difference between the maximum organic 
concentration value measured by the instrument and the background 
organic concentration value as determined in paragraph (a)(6) of this 
section is compared with the applicable value for the potential leak 
interface as specified in paragraph (a)(9) of this section.
    (9) A potential leak interface is determined to operate with no 
detectable emissions using the applicable criteria specified in 
paragraphs (a)(9)(i) and (a)(9)(ii) of this section.
    (i) For a potential leak interface other than a seal around a shaft 
that passes through a cover opening, the potential leak interface is 
determined to operate with no detectable organic emissions if the 
organic concentration value determined in paragraph (a)(8) is less than 
500 ppmv.
    (ii) For a seal around a shaft that passes through a cover opening, 
the potential leak interface is determined to operate with no 
detectable organic emissions if the organic concentration value 
determined in paragraph (a)(8) is less than 10,000 ppmv.
    (b) * * *
    (3) Seal gaps, if any, shall be measured around the entire 
perimeter of the floating roof in each place where 0.32-centimeter (cm) 
(\1/8\ inch) diameter uniform probe passes freely (without forcing or 
binding against the seal) between the seal and the wall of the 
separator and measure the circumferential distance of each such 
location.
* * * * *
    37. Section 63.1047 is amended by adding paragraph (e) and by 
revising paragraphs (a)(2) and (c)(1)(ii) to read as follows:


Sec. 63.1047  Inspection and monitoring requirements.

    (a) * * *
    (2) The owner or operator must perform an initial inspection 
following installation of the fixed roof. Thereafter, the owner or 
operator must perform the inspections at least once every calendar year 
except as provided for in paragraph (e) of this section.
* * * * *
    (c) * * *
    (1) * * *
    (ii) The owner or operator must perform an initial inspection 
following installation of the fixed roof. Thereafter, the owner or 
operator must perform the inspections at least once every calendar year 
except as provided for in paragraph (e) of this section.
* * * * *
    (e) Alternative inspection interval. Following the initial 
inspection of a fixed roof in accordance with the applicable provisions 
of this section, subsequent inspection of the fixed roof may be 
performed at intervals longer than 1 year when an owner or operator 
determines that performing the required inspection would expose a 
worker to dangerous, hazardous, or otherwise unsafe conditions and the 
owner or operator complies with the requirements specified in 
paragraphs (e)(1) and (e)(2) of this section.
    (1) The owner or operator must prepare and maintain at the plant 
site written documentation identifying the specific fixed roof 
designated as ``unsafe to inspect.'' The documentation must include for 
each fixed roof designated as such a written explanation of the reasons 
why the fixed roof is unsafe to inspect using the applicable procedures 
under this section.
    (2) The owner or operator must develop and implement a written plan 
and schedule to inspect and monitor the fixed roof using the applicable 
procedures specified in this section during times when a worker can 
safely access the fixed roof. The required inspections and monitoring 
must be performed as frequently as practicable but do not need to be 
performed more frequently than the periodic schedule that would be 
otherwise applicable to the fixed roof under the provisions of this 
section. A copy of the written plan and schedule must be maintained at 
the plant site.

[FR Doc. 99-17943 Filed 7-19-99; 8:45 am]
BILLING CODE 6560-50-P