National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic Chemical Manufacturing, 73098-73122 [05-23666]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 70, Number 235 (Thursday, December 8, 2005)]
[Proposed Rules]
[Pages 73098-73122]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-23666]



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Part III





Environmental Protection Agency





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40 CFR Part 63



National Emission Standards for Hazardous Air Pollutants: Miscellaneous 
Organic Chemical Manufacturing; Proposed Rule

Federal Register / Vol. 70, No. 235 / Thursday, December 8, 2005 / 
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-OAR-2003-0121; FRL-8005-2]
RIN 2060-AM43


National Emission Standards for Hazardous Air Pollutants: 
Miscellaneous Organic Chemical Manufacturing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; amendments.

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SUMMARY: On November 10, 2003, EPA promulgated national emission 
standards for hazardous air pollutants (NESHAP) for miscellaneous 
organic chemical manufacturing. Several petitions for judicial review 
of the final rule were filed in the U.S. Court of Appeals for the 
District of Columbia Circuit. Petitioners expressed concern with 
various requirements in the final rule, including applicability of 
specific operations and processes, the leak detection and repair 
requirements for connectors, criteria to define affected wastewater 
streams requiring control, control requirements for wastewater streams 
that contain only soluble HAP (SHAP), the definition of process 
condensers, and recordkeeping requirements for Group 2 batch process 
vents. In this action, EPA proposes amendments to the final rule to 
address these issues and to correct inconsistencies that have been 
discovered during the review process.

DATES: Comments. Comments must be received on or before January 24, 
2006.
    Public Hearing. If anyone contacts EPA requesting to speak at a 
public hearing by December 19, 2005, a public hearing will be held on 
December 23, 2005.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA OAR-
2003-0121, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Agency Web site: https://www.epa.gov/edocket. EDOCKET, 
EPA's electronic public docket and comment system, will be replaced by 
an enhanced Federal-wide electronic docket management and comment 
system located at www.regulations.gov. When this occurs, you will be 
redirected to that site to access the docket and submit comments. 
Follow the on-line instructions.
     E-mail: a-and-r-docket@epa.gov.
     Fax: (202) 566-1741.
     Mail: Air and Radiation Docket and Information Center, 
EPA, Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 
20460. Please include a duplicate copy, if possible.
     Hand Delivery: Air and Radiation Docket, EPA, Room B-102, 
1301 Constitution Avenue, NW., Washington, DC 20460. Such deliveries 
are only accepted during the Docket's normal hours of operation, and 
special arrangements should be made for deliveries of boxed 
information. We request that a separate copy of each public comment 
also be sent to the contact person listed below (see FOR FURTHER 
INFORMATION CONTACT).
    Instructions: Direct your comments to Docket ID No. EPA-OAR-2003-
0121. The EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
https://www.regulations.gov including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through www.regulations.gov or e-mail. 
The www.regulations.gov Web site is an ``anonymous access'' system, 
which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through www.regulations.gov, 
your e-mail address will be automatically captured and included as part 
of the comment that is placed in the public docket and made available 
on the Internet. If you submit an electronic comment, EPA recommends 
that you include your name and other contact information in the body of 
your comment with a disk or CD-ROM you submit. If EPA cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Air and Radiation Docket, 
EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW., Washington, 
DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The telephone number for the 
Public Reading Room is (202) 566-1744, and the telephone number for the 
Air and Radiation Docket is (202) 566-1742.
    Public Hearing. If a public hearing is held, it will be held at 10 
a.m. at EPA's Environmental Research Center Auditorium, Research 
Triangle Park, North Carolina or at an alternate site nearby.

FOR FURTHER INFORMATION CONTACT: Mr. Randy McDonald, Organic Chemicals 
Group (C504-04), Emission Standards Division, U.S. EPA, Research 
Triangle Park, NC 27711; telephone number: (919) 541-5402; fax number: 
(919) 541-3470; e-mail address: mcdonald.randy@epa.gov.

SUPPLEMENTARY INFORMATION: Regulated Entities. Categories and entities 
potentially regulated by this action include:

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                                                   Examples of regulated
        Category                 NAICS *                 entities
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Industry...............  3251, 3252, 3253, 3254,  Producers of specialty
                          3255, 3256, and 3259,    organic chemicals,
                          with several             explosives, certain
                          exceptions.              polymers and resins,
                                                   and certain pesticide
                                                   intermediates.
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* North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. To determine whether your facility is regulated by this action, 
you should examine the applicability criteria in 40 CFR 63.2435. If you 
have any questions regarding the applicability of this action to a 
particular entity, consult the person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section.

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    Submitting CBI. Do not submit this information to EPA through 
www.regulations.gov or e-mail. Clearly mark the part or all of the 
information that you claim to be CBI. For CBI information on a disk or 
CD ROM that you mail to EPA, mark the outside of the disk or CD ROM as 
CBI and then identify electronically within the disk or CD ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    Public Hearing. Persons interested in presenting oral testimony or 
inquiring as to whether a hearing is to be held should contact Randy 
McDonald, Organic Chemicals Group, Emission Standards Division (Mail 
Code C504-04), U.S. EPA, Research Triangle Park, North Carolina, 27711, 
telephone number (919) 541-5402, electronic mail address 
mcdonald.randy@epa.gov, at least two days in advance of the potential 
date of the public hearing. Persons interested in attending the public 
hearing also must call Mr. Randy McDonald to verify the time, date, and 
location of the hearing. A public hearing will provide interested 
parties the opportunity to present data, views, or arguments concerning 
the proposed amendments.
    World Wide Web (WWW). In addition to being available in the docket, 
an electronic copy of the proposed rule is also available on the WWW 
through the Technology Transfer Network Web site (TTN Web). Following 
signature, a copy of the proposed rule will be posted on the TTN's 
policy and guidance page for newly proposed or promulgated rules at 
https://www.epa.gov/ttn/oarpg. The TTN provides information and 
technology exchange in various areas of air pollution control.
    Organization of This Document. The information presented in this 
preamble is organized as follows:

I. Why are we proposing amendments to subpart FFFF?
II. How are we proposing to amend the compliance dates?
    A. Existing Sources
    B. Process Changes Resulting in New Compliance Requirements
III. How are we proposing to amend the applicability requirements?
    A. Compounding and Finishing Operations in Polymer Processes
    B. Carbon Monoxide Production
    C. Boundary of a Miscellaneous Organic Chemical Manufacturing 
Process Unit That Produces a Solid Product
    D. Applicability of the MON to Coke By-Product Plants
IV. How are we proposing to amend the requirements for process 
vents?
    A. Process Condensers
    B. Requirements for HAP Metal Compounds
    C. Compliance Requirements for Process Tanks
    D. Provisions for Switching Batch Process Vents from Group 2 to 
Group 1
    E. Definition of Batch Process Vent
    F. Definitions of Continuous Process Vent and Related Terms
    G. Definition of Group 1 Continuous Process Vent
    H. Requirements for Biofilter Control Devices
    I. Emission Limit for Hydrogen Halide and Halogen HAP from 
Process Vents
V. How are we proposing to amend the requirements for wastewater 
systems?
    A. Definitions of Wastewater and Group 1 Wastewater
    B. Management Requirements for Wastewater That is Group 1 for 
Soluble HAP
    C. Discarding Materials to Water or Wastewater
    D. Compliance Requirements
    E. Definition of Wastewater
VI. How are we proposing to amend the requirements for equipment 
leaks?
VII. How are we proposing to amend the recordkeeping and reporting 
requirements?
    A. Processes with Uncontrolled Emissions Below the Thresholds 
for Control
    B. Standard and Nonstandard Batches
    C. Operating Logs
    D. Reporting Requirements for Emission Points that Change from 
Group 2 to Group 1
VIII. How are we proposing to change requirements that apply when 
requirements in subpart FFFF and another rule apply to the same 
equipment?
IX. What miscellaneous technical corrections are we proposing?
X. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act

I. Why are we proposing amendments to subpart FFFF?

    On November 10, 2003, we promulgated NESHAP for miscellaneous 
organic chemical (MON) manufacturing as subpart FFFF of 40 CFR part 63. 
Petitions for review of the MON were filed in the U.S. Court of Appeals 
for the District of Columbia Circuit by American Chemistry Council, 
Eastman Chemical Company, Clariant LSM (America), Inc., Rohm and Haas 
Company, General Electric Company, Coke Oven Environmental Task Force 
(``COETF'') and Lyondell Chemical Company (collectively 
``Petitioners'').\1\ These matters were consolidated into American 
Chemical Council, et al. v. EPA, No. 04-1004, 04-1005, 04-1008, 04-
1009, 04-1010, 04-1012, 04-1013 (D.C. Cir.). Issues raised by the 
petitioners included applicability of the final rule; leak detection 
and repair requirements for connectors; definitions of process 
condenser, continuous process vent, and Group 1 wastewater; treatment 
requirements for wastewater that is Group 1 only for SHAP; 
recordkeeping for Group 2 batch process vents; and notification 
requirements for Group 2 emission points that become Group 1 emission 
points. In early October 2005, the parties signed a settlement 
agreement. Pursuant to section 113(g) of the Clean Air Act (CAA), 
notice of the settlement was published in the Federal Register on 
October 26, 2005 (70 FR 61814).
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    \1\ The Fertilizer Institute and Arteva Specialties S.' ar.l 
also filed petitions for review but voluntarily withdrew their 
petitions.
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    Today's proposed amendments address the issues raised by 
Petitioners and include corrections and clarifications to ensure that 
the final rule is implemented as intended. Today's proposed amendments 
also provide some new compliance options, as well as new provisions 
that would reduce the burden associated with demonstrating compliance. 
For example, the use of biofilters is proposed as an option for 
complying with the 95 percent reduction emission limit for batch 
process vents, a new compliance option is proposed for wastewater that 
would allow certain waste management units in a biotreatment system to 
be uncovered if the wastewater being treated is Group 1 only for 
soluble HAP, and a new regulatory alternative for equipment leaks would 
simplify applicability by applying the same requirements to all MON 
processes and reduce the leak detection burden for connectors. We are 
also proposing revised recordkeeping requirements in 40 CFR 63.2525(e) 
for Group 2 batch process vents that would eliminate recordkeeping in 
certain situations and reduce the recordkeeping burden if non-reactive 
HAP usage is less

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than 10,000 pounds per year (lb/yr) or if emissions are less than 1,000 
lb/yr, and we are proposing to eliminate the requirement to include 
results of engineering assessments that determine emissions from batch 
operations that have hazardous air pollutant (HAP) concentrations less 
than 50 parts per million by volume (ppmv) in your precompliance 
report.

II. How are we proposing to amend the compliance dates?

A. Existing Sources

    The Miscellaneous Organic Chemical Manufacturing NESHAP promulgated 
on November 10, 2003, specifies that existing source must be in 
compliance with the NESHAP no later than November 10, 2006. 
Precompliance reports must be filed by May 10, 2006. We are proposing a 
new compliance date of May 10, 2008, because the proposed amendments 
are sufficiently far reaching and complex that an amended rule would 
effectively be a new rule warranting a new compliance date and because 
we do not anticipate finalizing the proposed amendments with sufficient 
time for parties to comply with the amended rule, which set forth 
provisions inconsistent with existing provisions.
    Section 112(a)(3) of the CAA provides that existing sources are to 
be in compliance with applicable emission standards ``as expeditiously 
as practicable, but in no event later than 3 years after the effective 
date of such standard.'' The November 10, 2003, Miscellaneous Organic 
Chemical Manufacturing NESHAP specify a compliance date 3 years from 
the issuance of that rule. Section 112(d)(6) of the CAA provides 
authority for the Administrator to revise the emission standards issued 
under CAA section 112 ``no less often than every 8 years.'' We believe 
the authority to revise the standards inherently includes the authority 
to set new compliance dates for revised rules. Congress provided us 
discretion to set a compliance date for existing sources of up to 3 
years in order to provide time for retrofitting of controls where 
necessary. Thus, due to the extensive nature of the proposed 
amendments, we are proposing a new compliance date.
    We believe that 18 months from the otherwise applicable compliance 
date will be sufficient for all sources to come into compliance with 
the proposed amendments. However, should any source be unable to meet 
that compliance date because of the need to install controls that 
cannot be installed by that date, each source may request an extension 
of up to 1 year in accordance with 40 CFR 63.6(i)(4) and (6).

B. Process Changes Resulting in New Compliance Requirements

    We are proposing to add language to 40 CFR 63.2445 to clarify when 
compliance is required after making any of the following types of 
process changes after the compliance date: Changing the status of any 
emission point from Group 2 to Group 1, increasing uncontrolled 
hydrogen halide and halogen emissions from all process vents within a 
process above 1,000 lb/yr, increasing uncontrolled HAP metals emissions 
from all process vents within a process at a new source above 150 lb/yr 
(see discussion later in this preamble regarding the change from PM HAP 
to HAP metals), or changing the status of a control device from small 
to large. A large control device is a control device that has an inlet 
HAP load equal to or greater than 10 tons per year (tpy), and a small 
control device has an inlet HAP load less than 10 tpy.
    After making any of the noted process changes, information 
presented in the notification of compliance status report demonstrating 
initial compliance must be updated according to 40 CFR 
63.2520(e)(10)(i). If the situations after any of the changes described 
above had existed on the initial compliance date, a performance test 
(or design evaluation in some cases) would have been required to 
demonstrate initial compliance. Thus, a performance test or design 
evaluation is also required to satisfy the requirements of 40 CFR 
63.2520(e)(10)(i) after one of the noted process changes, and the 
results must be included in the compliance report for the period during 
which the change occurred. Compliance reports are due 2 months after 
the end of a reporting period. This means a facility would have between 
approximately 60 and 240 days, depending on when the change occurred 
during the reporting period, to complete the performance test or design 
evaluation and include it in the applicable report. We consider 60 days 
to be insufficient, particularly for a performance test. Work on a 
design evaluation could begin before the change occurs, but a 
performance test cannot be conducted until the equipment is operating. 
We also consider the potential variability in timing among sources to 
be unreasonable. Therefore, we are proposing language in 40 CFR 63.2445 
to specify that performance tests and design evaluations must be 
conducted within 150 days after making one of the types of process 
changes listed above. This timeframe is also consistent with the amount 
of time allowed to complete these activities after the initial 
compliance date and include the results in the notification of 
compliance status report.
    Sections 63.2445(b) and (c) of the promulgated rule require 
compliance with all applicable requirements no later than the 
compliance date. If you make a process change after the compliance 
date, this requirement means you must comply with all applicable 
requirements for the changed situation beginning on the date the change 
occurs. To clarify this requirement for the types of process changes 
described above, we are proposing language in 40 CFR 63.2445 to 
explicitly state that Group 1 requirements (e.g., emission limits in 
table 2 to subpart FFFF for batch process vents) apply beginning on the 
date of a change from Group 2 to Group 1, that applicable emission 
limits in table 3 to subpart FFFF apply beginning on the date HAP 
metals or hydrogen halide and halogen HAP emissions are increased above 
applicable thresholds, and monitoring and recordkeeping requirements 
for large control devices apply beginning on the date a control device 
changes status from small to large.

III. How are we proposing to amend the applicability requirements?

    We are proposing several changes to the applicability requirements, 
particularly to clarify and add exceptions in order to make the 
regulation consistent with our intent and the data underlying the 
standards. Another change involves the boundary of a miscellaneous 
organic chemical manufacturing process unit (MCPU) that produces a 
solid product.

A. Compounding and Finishing Operations in Polymer Processes

    We are proposing to revise 40 CFR 63.2435(c)(4) to clarify the 
types of polymer finishing operations that are exempted from subpart 
FFFF. Section 63.2435(c)(4) currently exempts only fabricating 
operations (such as spinning a polymer to its end use). Another 
finishing operation (compounding of purchased resins) is exempted by 
the exemption in 40 CFR 63.2435(c)(5) for production activities 
described using the 1997 version of NAICS code 325991. These exemptions 
for finishing operations were included in the final rule due to the 
minimal potential for emissions from such operations. After reviewing 
this issue, we have determined that additional finishing operations can 
be exempted for the same reason. Thus, the proposed

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amendments to 40 CFR 63.2435(c)(4) would expand the exemption for 
finishing operations to cover activities that can be classified as 
fabricating, compounding, drawing, or extrusion operations, provided 
they do not meet certain specified conditions. For example, the 
exemption would not apply where residual monomer remains with some 
polymers and an intended purpose of the finishing operation is to 
remove the residual monomer. A finishing operation also would not be 
exempt if it involves processing with HAP solvent (e.g., if a solid 
polymer product is dissolved in a HAP solvent prior to the finishing 
operation). These changes would make the exemptions consistent with the 
exemptions in previous rules for polymer production processes such as 
40 CFR part 63, subpart JJJ.
    As noted above, spinning a polymer into its end use is given as an 
example of ``fabricating operations'' in the existing rule. To further 
exemplify the meaning of this term, the proposed amendments provide 
compressing a solid polymer into its end use as another example.
    The proposed amendments would exempt all compounding operations 
with a previously produced solid polymer, not just compounding of 
purchased resins as currently provided for in 40 CFR 63.2435(c)(5). The 
compounding operation is the same whether it is done with purchased 
resins or at the facility that produced the resins. Thus, there is no 
reason to limit the exemption to compounding of purchased resins. To 
clarify what we mean by ``compounding operations,'' the proposed 
amendments describe them as ``blending, melting, and resolidification 
of a solid polymer * * * for the purpose of incorporating additives, 
colorants, or stabilizers.''
    The proposed amendments include a new exemption for extrusion and 
drawing operations. These finishing operations are described in the 
proposed amendments as operations that ``convert[] an already produced 
solid polymer into a different shape by melting or mixing the polymer 
and then forcing it or pulling it through an orifice to create an 
extruded product.'' Note that this means some extrusion and drawing 
operations are not exempt (in addition to those operations that are 
intended to remove residual HAP monomer or involve processing with a 
HAP solvent). Specifically, extrusion and drawing operations integral 
to production of the solid polymer are part of a MCPU and are not 
exempt.

B. Carbon Monoxide Production

    While carbon monoxide (CO) is an inorganic compound,\2\ petitioners 
argued that the final rule was ambiguous whether CO production was 
covered by the MON since it is included under NAICS category 325120, 
and the MON has no exemption for CO production. While we did not intend 
to cover CO production under the MON, it is not a HAP and thus not 
subject to regulation under CAA section 112, we are proposing to 
clarify the MON by adding a new 40 CFR 63.2435(c)(7) to specifically 
exempt CO production processes.
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    \2\ Numerous government documents and technical references 
identify CO as an inorganic compound. For example, the term 
``volatile organic compounds'' is defined in 40 CFR 51.1000(s) as 
``any compound of carbon, excluding carbon monoxide * * * which 
participates in atmospheric photochemical reactions.'' The 
definition goes on to list compounds that have negligible 
photochemical reactivity. Since CO was explicitly excluded, and it 
is clearly volatile, the definition makes it clear that CO is not 
considered to be an organic compound. In addition, Hawley's 
Condensed Chemical Dictionary states that CO is classified as an 
inorganic chemical, and the physical properties of CO are listed in 
a table of inorganic compounds in the Chemical Engineers' Handbook.
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C. Boundary of a Miscellaneous Organic Chemical Manufacturing Process 
Unit That Produces a Solid Product

    A miscellaneous organic chemical manufacturing process unit is 
defined in 40 CFR 63.2550(i) of the MON as ``all equipment which 
collectively function to produce a product * * *'' The end of a process 
is the point at which product is transferred to a storage tank or a 
transfer rack because 40 CFR 63.2435(d) specifies that such equipment 
is associated with a process (i.e., not part of the process), and it 
may be part of the MCPU if it meets specified criteria. Both liquid and 
solid products may be stored or transferred to shipping containers. 
However, the definitions of ``storage tank'' and ``transfer rack'' 
explicitly refer to storage or transfer of organic liquids. Thus, it is 
not clear if storage and transfer of solid products should be subject 
to these definitions, if they are unit operations that are part of the 
process, or if they are exempt from the final rule.
    To eliminate this ambiguity, we are proposing to revise the 
definition of ``miscellaneous organic chemical manufacturing process'' 
in 40 CFR 63.2550(i) to specify the endpoint of a process that produces 
a solid product. If the product is dried, the end of the process would 
be the dryer. For a polymer production process without a dryer, the end 
of the process would be the extruder or die plate. This is consistent 
with the revisions to the exemption for polymer finishing operations 
discussed above. There would be two exceptions to these endpoints. One 
exception is if the dryer, extruder, or die plate is followed by 
blending or another operation that is designed and operated to remove 
HAP solvent or residual HAP monomer from the solid product. The second 
exception is if the dried solid is mixed with a HAP-based solvent. In 
both cases, the HAP removal operation would be the last step in the 
process.

D. Applicability of the MON to Coke By-Product Plants

    One of the petitioners requested clarification as to the 
applicability of the MON to coke by-product plants. On January 30, 
2001, EPA deleted coke by-product plants from the list of major and 
area sources of HAP required by CAA section 112(c)(1). (See 66 FR 
8220.) Consequently, 40 CFR part 63 miscellaneous achievable control 
technology (MACT) standards promulgated under CAA section 112(d), such 
as the MON, would not apply to the deleted coke by-product plant source 
category. Moreover, as EPA explained in 2001, coke by-product plants 
remain subject to the pre-existing NESHAP for benzene emissions from 
coke by-product recovery plants at 40 CFR part 61, subpart L. (See 66 
FR at 8222.) EPA is not proposing any changes to the MON in order to 
clarify this issue, as it is unnecessary to do so. Today's 
clarification is wholly consistent with EPA's previous action in 2001 
deleting the coke by-product plant source category.

IV. How are we proposing to amend the requirements for process vents?

A. Process Condensers

    We are proposing several changes to clarify the definition of 
``process condenser,'' the procedures for calculating emissions when 
process condensers are used, and related recordkeeping and reporting 
requirements. We are proposing changes to the definition because we 
have become aware of an inconsistency between the definition of that 
term as it is used in the MON and the way industry representatives 
interpreted the term when they were reporting uncontrolled emissions in 
response to our information request in 1997. The inconsistency stems 
from a difference in the interpretation of ``integral to a process.'' 
Companies considered condensers to be integral to a process if 
collected material was returned to the process or used for fuel value, 
whereas

[[Page 73102]]

we considered condensers to be integral only if they reduced the 
temperature below the bubble point or boiling point. Thus, the 
companies reported uncontrolled emissions at the outlet of more 
condensers than we realized, which means the current regulatory 
requirements do not align with the data that were used to develop the 
MACT floor. The proposed revisions would correct this misalignment by 
clarifying the term process condenser as described below.
    Section 63.2460(c)(1) of the current rule references the definition 
of process condenser in 40 CFR 63.1251 of 40 CFR part 63, subpart GGG 
(the Pharmaceuticals Production NESHAP). According to this definition, 
the primary purpose of a process condenser is to recover material as an 
integral part of a process. To clarify what is meant by the terms 
``recover'' and ``an integral part of a process,'' we are proposing to 
create a freestanding (i.e., non-cross referenced) term ``process 
condenser'' in 40 CFR 63.2550(i) of subpart FFFF. This proposed 
definition would specify that ``a primary condenser or condensers in 
series are considered to be integral to the MCPU if they are capable of 
and normally used for the purposes of recovering chemicals for fuel 
value (i.e., net positive heating value), use, reuse or for sale for 
fuel value, use, or reuse.'' The definition of process condenser in 
subpart GGG also specified that a process condenser included a 
condenser recovering condensate from a process at or above the boiling 
point, and all condensers in line prior to a vacuum source. This part 
of the definition is retained in the proposed definition for 40 CFR 
63.2550(i).
    The new language related to ``recover'' and ``integral part of a 
process'' is already used in the definition of ``recovery device'' in 
40 CFR part 63, subpart SS, that is referenced in 40 CFR part 63, 
subpart FFFF, for continuous process vents. Thus, the proposed change 
to the definition of process condenser makes it clear that the concept 
of recovering chemicals with a condenser has similar meaning regardless 
of whether the vent is associated with a batch unit operation or a 
continuous unit operation. An important point to note is that the 
proposed changes to the definition mean condensers cannot be recovery 
devices for the purpose of complying with the 95 percent reduction 
requirement specified in table 2 to subpart FFFF because any recovery 
operation makes the condenser a process condenser. Condensers that are 
not process condensers can still be control devices used alone or in 
series with other control devices to comply with either the 98 percent 
reduction or the outlet concentration option.
    We are also proposing additional changes to 40 CFR 63.2460(b) and 
(c) to clarify procedures for calculating uncontrolled emissions 
associated with process condensers. We are proposing to amend 
paragraphs (1) and (2) in 40 CFR 63.2460(b) to clarify that the 
referenced procedures for calculating uncontrolled emissions from 
heating and depressurization events for batch process vents are only 
for situations where the process vessel is not equipped with a process 
condenser. We are proposing to add a new paragraph in 40 CFR 63.2460(b) 
to provide the appropriate procedures for calculating uncontrolled 
emissions for all types of emission episodes when a process vessel is 
equipped with a process condenser.
    We are proposing to add regulatory text to 40 CFR 63.2460(c) 
specifying that you must make the determination of whether a condenser 
is a process condenser or air pollution control device as part of your 
initial compliance demonstration, and you must report the results and 
supporting rationale in your notification of compliance status report. 
This determination is made on a process basis, which means a condenser 
is either a process condenser for all gas streams from a given process, 
or it is an air pollution control device for all gas streams from the 
process. Furthermore, for nondedicated operations, this means a 
condenser may be a process condenser for some processes and an air 
pollution control device for others.
    Finally, we are proposing changes to the initial compliance 
demonstration for process condensers to be consistent with the changes 
in the definition. Section 63.2460(c)(2)(v) references the initial 
compliance demonstration procedures in 40 CFR 63.1257(d)(3)(iii)(B) for 
process condensers that are not followed by an air pollution control 
device or the air pollution control device is not in compliance with 
the alternative standard. The procedures require you to either measure 
the exhaust gas temperature and show it is less than the boiling or 
bubble point of the substances in the process vessel or perform a 
material balance around the vessel and condenser to show that at least 
99 percent of the material vaporized while boiling is condensed. To be 
consistent with the proposed definition of process condenser, we are 
also proposing to revise 40 CFR 63.2460(c)(2)(v) to specify that this 
demonstration is only required for process condensers that are used 
with boiling operations (at least part of the time), and that the 
demonstration must be performed while boiling operations are occurring.

B. Requirements for HAP Metal Compounds

    Table 3 to the final rule specifies emission limits for particulate 
matter (PM) HAP emissions from process vents at new sources, but the 
final rule does not define ``PM HAP.'' After reexamining this 
provision, we decided to propose a number of changes to table 3 and the 
corresponding compliance procedures specified in 40 CFR 63.2465(d). 
These proposed amendments focus the emission limit on metallic HAP 
compounds and clarify compliance requirements for metallic HAP.
    Our intent in setting the PM HAP emission limit in table 3 to the 
final rule was to ensure the control of metallic PM HAP emissions. 
Organic compounds that are emitted as solids are separately addressed 
by the emission limits for organic compounds (see tables 1 and 2 of 
subpart FFFF). The term PM HAP, and associated measurement and 
monitoring techniques, however, does not clearly capture this intent. 
Accordingly, to clarify this point, we are proposing a number of 
changes. First, we are proposing to revise table 3 in the rule to 
specify emission limits for ``HAP metals'' rather than ``PM HAP.'' This 
does not impact the substance of the final rule as uncontrolled HAP 
metals must still be reduced by 97 percent, identical to the reduction 
specified for PM HAP in the final rule. Second, the term ``HAP metals'' 
would be defined in 40 CFR 63.2550(i) to mean the metal portion of 
antimony compounds, arsenic compounds, beryllium compounds, cadmium 
compounds, chromium compounds, cobalt compounds, lead compounds, 
manganese compounds, nickel compounds, and selenium compounds. Third, 
the emissions threshold above which control is required would be 
changed from 400 lb/yr of PM HAP (i.e., compounds that contain metals) 
to 150 lb/yr of HAP metals. Fourth, to determine the uncontrolled 
emissions of HAP metals, we are proposing to allow the use of process 
knowledge, engineering assessments, or test data. If you do not wish to 
determine the uncontrolled emissions, we are proposing to allow you to 
designate the HAP metals emissions as greater than 150 lb/yr. Finally, 
to demonstrate initial compliance with the 97 percent reduction 
requirement for the HAP metals, we are proposing to allow the use of 
Method 29 of appendix A of 40

[[Page 73103]]

CFR part 60 as well as Method 5 of appendix A of 40 CFR part 60.
    The proposed definition of ``HAP metals'' and the revised emissions 
threshold are based on the metal portion of the compounds rather than 
the total mass of the compounds that contain metals simply to clarify 
that the threshold does not include non-HAP particulate matter. The 
revised threshold was developed using the same process that was used to 
develop the original threshold for the MACT floor. This process emitted 
400 lb/yr of manganese sulfate. Since manganese sulfate is about 36 
percent manganese by weight, the amount of manganese emitted was about 
150 lb/yr. Method 29 of appendix A of 40 CFR part 60 allows you to 
determine the quantity of each HAP metal at the inlet and outlet of the 
control device(s). However, since controls for PM would also control 
the HAP metals, a second option is to use Method 5 of appendix A of 40 
CFR part 60 to determine the quantity of PM at the inlet and outlet of 
the control device(s).

C. Compliance Requirements for Process Tanks

    As defined in 40 CFR 63.2550(i), batch process vents include 
process tanks. Table 2 to subpart FFFF requires reduction of HAP from 
batch process vents by greater than or equal to 98 percent, or 95 
percent if HAP is recovered and reused onsite. As currently written, 
however, the recovery option is restricted to situations where there is 
a closed-vent system and a recovery device. Such a system, however, is 
not the only option for preventing loss of product. Floating roof 
technology achieves 95 percent or greater reductions by preventing 
evaporation. Thus, it is a pollution prevention control technology that 
meets the intent of the 95 percent recovery option for batch process 
vents in table 2 to subpart FFFF.
    Indeed, several rules, such as the hazardous organic NESHAP (HON) 
and the new source performance standards in 40 CFR part 60, subpart Kb, 
specify that emissions from storage tanks must be reduced using an 
internal or external floating roof or by venting the emissions through 
a closed-vent system to a control device that reduces the emissions by 
at least 95 percent. To allow floating roof technology to comply with 
batch process tanks we are revising table 2 to subpart FFFF to 
reference the requirements of subpart WW of this part for any process 
tank. In addition, to make the referenced language consistent with 
process vent requirements, we propose adding regulatory text in 40 CFR 
63.2460(c) specifying that when subpart WW uses the term ``storage 
vessel,'' it means ``process tank'' for the purposes of 40 CFR 63.2460.

D. Provisions for Switching Batch Process Vents From Group 2 to Group 1

    We are proposing to add a new 40 CFR 63.2460(b)(6) to specify that 
a performance test report (or design evaluation, if emissions are 
controlled by a small control device) must be submitted in the next 
compliance report whenever you switch from Group 2 batch process vents 
to Group 1. This requirement is inherent in the existing rule because 
an initial compliance demonstration is required for Group 1 vents but 
not Group 2 vents. The proposed language simply makes more explicit 
this requirement. Also see the discussion earlier in this preamble 
regarding compliance dates for emission points that switch from Group 2 
to Group 1.
    We are also proposing to include language in the new 40 CFR 
63.2460(b)(6) to clarify the recordkeeping and reporting requirements 
associated with making a switch from Group 2 to Group 1. Section 
63.2520(e)(10)(ii)(C) currently requires a 60-day advance notification 
of any change in status from Group 2 to Group 1. The primary reason for 
this notification is that it alerts the regulatory authority to a 
situation where a performance test (or design evaluation) will be 
needed. However, we realize that certain facilities have frequent 
turnover in their batch production processes, and it can be difficult 
to predict 60 days in advance which new processes will grow to the 
point that they have Group 1 batch process vents. To minimize this 
burden, we are proposing to eliminate the advance notification 
requirement if records show the process has been in compliance with the 
10,000 lb/yr threshold for Group 2 batch process vents for at least 365 
days prior to the switch (on a rolling average). For these processes, 
we believe it will be sufficient to receive notification of the switch 
in the next compliance report. The existing requirement for a 60-day 
advance notification of a switch would still apply if the process has 
not been operated for at least one year with Group 2 batch process 
vents. See discussion later in this preamble regarding the related 
changes to the reporting requirements in 40 CFR 63.2520(e)(10).

E. Definition of Batch Process Vent

    We are proposing minor changes to clarify the threshold levels 
specified in the definition of ``batch process vent.'' Although these 
changes will not change the thresholds or the intended meaning of the 
definition, we are including a detailed explanation in this preamble of 
how to apply the thresholds to ensure that the revised language is 
interpreted as we intended. We are also proposing to make a separate 
change to reduce the burden of demonstrating whether emission streams 
exceed these thresholds and, thus, constitute batch process vents.
    Item number 8 in the definition of batch process vent specifies two 
HAP thresholds below which emission streams are not a batch process 
vent. The first threshold is 50 ppmv of HAP. This threshold applies to 
the emission stream from each individual emission episode (e.g., a 
displacement, purge, vacuum operation, etc.). If the average HAP 
concentration over the episode is less than 50 ppmv, then the emission 
stream is not a batch process vent. The second threshold is 200 lb/yr 
of HAP. This threshold applies to the collective emissions from a 
single vent (i.e., release point); including releases below the 50 ppmv 
threshold. Note that HAP concentration is not necessarily required for 
determination of the single vent emission rate. If the total HAP 
emissions for a vent are less than 200 lb/yr, then that vent is not a 
batch process vent, and none of the emission streams that discharge 
from it are subject to requirements in 40 CFR part 63, subpart FFFF. 
The vent in this determination may be for a single unit operation that 
has multiple emission episodes. On the other hand, if you connect the 
vents from multiple unit operations to a manifold and discharge 
combined emissions at one point, then the discharge point is the vent 
for the purposes of this determination. Note that the HAP in emission 
streams that are exempted by this determination (either because they 
are individually below the 50 ppmv threshold or because the total 
emissions from the vent are below the 200 lb/year threshold) do not 
need to be counted towards the 10,000 lb/yr threshold in the 
determination of whether batch process vents are Group 1 batch process 
vents.
    The following example provides a simple illustration of how to 
apply these thresholds. Consider operations in a single vessel that 
generate HAP emissions from three emission episodes: the first contains 
HAP at >50 ppmv that amounts to 180 lb/yr when summed over all of the 
batches for the process in a year, the second contains HAP at <50 ppmv 
and 20 lb/yr, and the third contains <50 ppmv and 250 lb/yr. A batch 
process vent exists for this vessel

[[Page 73104]]

because total emissions exceed 200 lb/yr and the first emission episode 
has a HAP concentration >50 ppmv. Note that only the first emission 
episode meets the definition of batch process vent. In addition, only 
the 180 lb/yr from the first emission episode must be added with 
emissions from other batch process vents to determine if total 
emissions from the process meet the 10,000 lb/yr threshold. If the 
example were changed slightly to have a manifolded vent with emissions 
from both this vessel and other operations within the process, your 
manifolded vent would be a batch process vent (regardless of the 
contribution from the other operations) because the total HAP emissions 
from the original vessel alone exceed the 200 lb/yr threshold, and an 
emission episode from the vessel exceeds 50 ppmv.
    Other proposed changes to the definition involve the procedures for 
conducting and reporting the results of an engineering assessment to 
determine the HAP concentration or mass emission rate for emission 
streams that will be exempt from control because it is determined that 
HAP is present at a concentration less than 50 ppmv or a mass emission 
rate less than 200 lb/yr. Item 8 in the current definition specifies 
that you may determine the concentration or mass emission rate using an 
engineering assessment as discussed in 40 CFR 63.1257(d)(2)(ii) of 
subpart GGG. According to the referenced provision, you could use an 
engineering assessment only if you first demonstrate that the equations 
in 40 CFR 63.1257(d)(2)(i) are not applicable. You would also have to 
provide the results and supporting information in your precompliance 
report for this finding as well as for the engineering assessment that 
you want to use.
    Since promulgation, it has been brought to our attention that many 
emission streams from batch operations in MON processes are likely to 
have HAP emissions below the specified thresholds. As a result, this 
provision is likely to impose a substantial burden on both affected 
sources and regulatory agencies. We have determined that such an 
expenditure of resources on documenting and approving procedures used 
to estimate emissions from these minor sources imposes an unreasonable 
regulatory burden relative to the additional precision potential 
achieved by using the equations in 40 CFR 63.1257(d)(2)(i).
    To minimize this burden, we are proposing changes to item 8 of the 
definition of batch process vent and to related precompliance reporting 
requirements in 40 CFR 63.2520(c)(4). One new provision in the 
definition of batch process vent would specify that you do not have to 
demonstrate that the equations in 40 CFR 63.1257(d)(2)(i) are not 
appropriate before you may use an engineering assessment, and the 
second would specify that the precompliance reporting requirements 
specified in 40 CFR 63.1257(d)(2)(ii)(E) do not apply for the purposes 
of demonstrating compliance with the applicable threshold. One of the 
proposed changes to 40 CFR 63.2520(c)(4) would eliminate the 
requirement to include data and results from an engineering assessment 
in your precompliance report if you determine the HAP concentration is 
less than 50 ppmv. We believe that this reporting requirement can be 
eliminated without compromising the regulatory agency's ability to 
determine compliance; documenting these results in your notification of 
compliance status report will be sufficient. Another proposed change to 
40 CFR 63.2520(c)(4) would eliminate the requirement to include the 
results of an engineering assessment that is based on previous test 
data in your precompliance report. Results based on test data do not 
need to be approved by the regulatory agency, and we believe that 
documenting these results in your notification of compliance status 
report will be sufficient.

F. Definitions of Continuous Process Vent and Related Terms

    In the existing rule, only air oxidation reactors, distillation 
units, and reactors can have continuous process vents because the 
definition of this term in 40 CFR 63.2550(i) references the criteria in 
40 CFR 63.107 of the HON. We are proposing to revise this definition to 
specify that it applies to any continuous unit operation for the 
purposes of 40 CFR part 63, subpart FFFF. We determined that this 
change is needed because the data we used to develop the MACT floor for 
continuous process vents was not limited to air oxidation reactors, 
distillation units, and reactors.
    We also re-examined the data to determine if any distinct class of 
continuous process vents, such as atmospheric dryers, would have a 
different MACT floor than other classes or the combined group of all 
continuous process vents. We concluded that developing separate MACT 
floors would be infeasible because data were sparse and inadequate to 
develop separate floors. However, the data we have indicates that 
several atmospheric dryers, which are not considered continuous vents 
in the current rule, have emission characteristics that are 
sufficiently similar to other continuous process vents in our database 
such that they should be included in the definition of continuous 
process vents.
    We are also proposing to add another provision to the continuous 
process vent definition to provide that the determination of whether a 
gas stream is a continuous process vent must be made at a point before 
the combination of the gas stream with any other gas streams from 
process operations. As currently written, when continuous flow gas 
streams from continuous operations are combined with other gas streams, 
40 CFR 63.107(b) would allow determination of whether the combined 
stream is a continuous process vent. This is inconsistent with our 
intent that continuous process vents and batch process vents be 
separate, distinct streams. This intent is evident in the hierarchical 
provisions in 40 CFR 63.2450(c) for determining applicable requirements 
for combined streams. The proposed change would eliminate this 
inconsistency and ensure the rule is implemented consistent with our 
intent.
    Surge control vessels are used in a process to transition from one 
operation to another. Consistent with the current definition of 
continuous process vent, the existing definition in 40 CFR part 63, 
subpart FFFF describes surge control vessels as vessels that precede 
continuous reactors, air oxidation reactors, and distillation units 
(i.e., the only operations that have continuous process vents under the 
existing rule). If the universe of continuous process vents expands as 
proposed above, then a comparable change is needed in the definition of 
surge control vessel. To maintain consistency, we are proposing to use 
the term ``continuous operations'' in place of the reference to 
reactors, air oxidation reactors, and distillation units in the 
definition of surge control vessel. The term ``continuous operation'' 
is not defined in the existing rule. However, since the final rule 
already contains a definition for the term ``batch operation,'' we are 
proposing to define a continuous operation as any MON operation that is 
not a batch operation.

G. Definition of Group 1 Continuous Process Vent

    We are proposing to revise the definition of ``Group 1 continuous 
process vent'' by adding an exemption for continuous process vents with 
a flow less than 0.005 standard cubic meter per minute, which was 
inadvertently excluded from the MON. This error occurred because rather 
than referencing the definition in 40 CFR 63.111 of the HON, we decided 
to specifically define this term in 40 CFR 63.2550(i) of subpart FFFF 
because the

[[Page 73105]]

definition is short and the key element of the definition, the total 
resource effectiveness (TRE) threshold, differs between the two rules. 
While our intent was that other elements of the definition would be the 
same as in the HON we neglected to include the flowrate threshold. The 
proposed amendment corrects this oversight.
    We believe this correction is appropriate in part because the HON 
and other NESHAP that also use the same threshold often apply to the 
same facilities that are subject to 40 CFR part 63, subpart FFFF. Thus, 
making the definitions more consistent between the rules may reduce 
both the burden on the affected sources and the potential for 
inadvertent deviations from requirements.

H. Requirements for Biofilter Control Devices

    Interest in using biofilters to control emissions is growing. 
Therefore, we are proposing to specify that biofilter control devices 
may be used to comply with the 95 percent reduction option (or outlet 
concentration limit) for batch process vents. We are also proposing to 
add a definition for biofilter in 40 CFR 63.2550(i) that is consistent 
with the definition used in subpart DDDD to part 63 (Plywood and 
Composite Wood Products NESHAP). Although biofilters are not recovery 
devices, we are proposing to allow their use for complying with the 95 
percent option because they have the ability to meet this limit and 
they have few cross media impacts.
    In addition to specifying that biofilters may be used to comply 
with the emission limit for batch process vents, we are also proposing 
initial compliance and monitoring requirements. Initial compliance 
would have to be demonstrated by conducting a performance test 
according to the procedures specified in 40 CFR 63.997. A design 
evaluation would not be allowed because we do not have information on 
the design characteristics that could be used to demonstrate proper 
operation and maximum performance of biofilters. You would also have to 
establish operating limits for either the biofilter bed temperature or 
the outlet organic concentration based on continuous monitoring 
conducted during the performance test. Extremes in temperature can slow 
or halt microbial activity. Thus, monitoring temperature helps 
determine the health of the microorganism population.
    If you elect to measure temperature, you would be allowed to place 
multiple thermocouples in representative locations throughout the 
biofilter bed and determine the average from these readings before 
determining 15-minute or more frequent averages. As for other types of 
control devices, you would be able to develop the operating limits 
based on results of a previous performance test that meets all of the 
requirements in 40 CFR 63.997 and achieves the required reduction. 
However, we are proposing to require that the operating limits be based 
only on these measurements. Engineering assessments and manufacturer's 
recommendations could not be used to supplement the test data. You 
would also be required to conduct repeat performance tests within 2 
years following each previous test and within 150 days after each 
replacement of any portion of the biofilter bed media with a different 
type of media or each replacement of more than 50 percent (by volume) 
of the biofilter bed media with the same type of media.
    Monitoring to demonstrate continuous compliance with the emission 
limit would be required for the same parameter measured during the 
performance test. The continuous parameter monitoring system (CPMS) 
monitoring and recordkeeping requirements in 40 CFR 63.996 and 40 CFR 
63.998 would apply to temperature monitors, and the continuous emission 
monitoring system (CEMS) monitoring requirements in subpart A of 40 CFR 
part 63 would apply to organic monitoring devices.

I. Emission Limit for Hydrogen Halide and Halogen HAP From Process 
Vents

    We are proposing to add a halogen atom mass flow rate emission 
limit of 0.45 kilograms per hour (kg/hr) as an alternative to the 
current emission limits that require either a 99 percent reduction or 
control to an outlet concentration limit of 20 ppmv because we 
inadvertently neglected to include it in the final rule. This control 
option is already available for hydrogen halide and halogen HAP 
emissions generated by combusting halogenated organic vent streams, and 
there is no reason not to include it for hydrogen halide and halogen 
HAP emissions from process vents. This control option also would make 
the requirements for hydrogen halide and halogen HAP consistent with 
the requirements for combusting halogenated organic vent streams. The 
amendment will allow operators with halogenated Group 1 streams also 
containing greater than 1,000 pounds per year halides to use the 0.45 
kg/yr control option for combustion devices.

V. How are we proposing to amend the requirements for wastewater 
systems?

A. Definitions of Wastewater and Group 1 Wastewater

    We are proposing several changes to the criteria for Group 1 
wastewater in 40 CFR 63.2485(c) to address inconsistencies identified 
by industry regarding concentration thresholds for partially soluble 
HAP (PSHAP compounds in table 8 to subpart FFFF) and soluble HAP (SHAP 
compounds in table 9 to subpart FFFF). We are also proposing to change 
the HAP threshold in one set of criteria for Group 1 wastewater at a 
new source due to uncertainty regarding the performance at the source 
originally identified as the best performing source.
    The three sets of criteria in the final rule are as follows:
     The total annual average concentration of compounds in 
table 8 to this subpart is greater than 50 parts per million by weight 
(ppmw), and the combined total annual average concentration of 
compounds in tables 8 and 9 to this subpart is greater than or equal to 
10,000 ppmw at any flowrate.
     The total annual average concentration of compounds in 
table 8 to this subpart is greater than 50 ppmw, the combined total 
annual average concentration of compounds in tables 8 and 9 to this 
subpart is greater than or equal to 1,000 ppmw, and the annual average 
flowrate is greater than or equal to 1 1/min.
     The total annual average concentration of compounds in 
table 8 to this subpart is less than or equal to 50 ppmw, the total 
annual average concentration of compounds in table 9 to this subpart is 
greater than or equal to 30,000 ppmw at an existing source or greater 
than or equal to 4,500 ppmw at a new source, and the total annual load 
of compounds in table 9 to this subpart is greater than or equal to 1 
tpy.
    The originally proposed wastewater provisions (67 FR 16154; April 
4, 2002) closely followed the provisions in the HON, including Group 1 
applicability determinations based on the total HAP in the wastewater 
streams. In response to comments on the proposed rule, we decided to 
develop the Group 1 criteria listed above based on SHAP and PSHAP, 
which is analogous to the approach used in the Pharmaceuticals 
Production NESHAP. By carving out streams that contain only soluble HAP 
but continuing to look at total HAP in all other streams, we created an 
inconsistency that became apparent only after promulgation of the rule. 
Specifically, a wastewater stream with less than 30,000 ppmw of SHAP 
would

[[Page 73106]]

not be Group 1 if no PSHAP was present, however, it would be Group 1 if 
there was at least 50 ppmw of PSHAP and 10,000 ppmw of total HAP. We 
are now proposing additional changes to the Group 1 criteria to more 
closely match the format used in the Pharmaceuticals Production NESHAP.
    We are proposing to make the lower concentration thresholds (i.e., 
1,000 ppmw and 10,000 ppmw) for PSHAP rather than total HAP, and to 
make the higher concentration threshold (i.e., 30,000 ppmw) for total 
HAP rather than SHAP. We are also proposing a PSHAP mass load threshold 
for the streams with at least 10,000 ppmw of PSHAP because the other 
two sets of criteria listed above and the Group 1 criteria in the 
Pharmaceuticals Production NESHAP also have minimum mass load 
thresholds. The proposed level is 200 lb/yr, which is calculated using 
10,000 ppmw and an average annual flow of 0.02 1/min.
    We are also proposing to amend the third set of criteria for Group 
1 wastewater streams by changing the total PSHAP and SHAP threshold for 
new sources from 4,500 ppmw to 30,000 ppmw. The original threshold was 
based on the lowest methanol concentration in a stream that was sent to 
a treatment unit that operated at a performance level equivalent to the 
level required in the HON; this was determined to be the best 
performing source. The stream that was determined to meet these 
conditions had a concentration of 4,500 ppmw, and it was sent to an air 
stripper (followed by incineration of the overhead gas stream). 
However, since promulgation of the final rule, questions have been 
raised about whether such a system is at least equivalent to the design 
steam stripper option in the HON (i.e., the treatment part of the MACT 
floor for wastewater at MON sources). Without actual test data for the 
specific facility, we are unable to determine that the performance of 
an air stripper system is more efficient than a design steam stripper 
for a soluble HAP like methanol. Therefore, we removed the facility 
with the 4,500 ppmw concentration from our new source analysis. The 
best performing source in the revised analysis has a wastewater stream 
with a methanol concentration of 30,000 ppmw. Therefore, we are 
proposing to use this concentration as the threshold for new sources.
    A few of the streams in our database would no longer be Group 1 
streams under the revised criteria, and a few other streams are now 
Group 1 based on a different set of criteria. The changes do not affect 
the MACT floor determinations. Overall performance of the final rule 
for the streams in our database may be reduced by the slight reduction 
in the number in Group 1 streams. However, most of the streams that are 
no longer Group 1 are at facilities that still have other Group 1 
streams that will need to be controlled, and only one of the remaining 
streams has a load over 200 lb/yr.

B. Management Requirements for Wastewater That Is Group 1 for Soluble 
HAP

    We are proposing to add an alternative compliance option in a new 
40 CFR 63.2485(n) for wastewater streams that are Group 1 for soluble 
HAP and receive biological treatment. Under the proposed option, you 
would not be required to comply with the emission suppression 
requirements (i.e., covers) for an equalization unit, neutralization 
unit, or clarifier prior to the activated sludge unit, provided you 
demonstrate that the treatment system achieves at least 90 percent 
destruction of the total PSHAP and SHAP entering the equalization unit 
(or whichever unit is first in the series of units). In addition to the 
load from streams that are Group 1 for soluble HAP, this total must 
include the PSHAP and SHAP in all Group 2 streams from MCPU that are 
sent to the biotreatment unit. If your wastewater stream is Group 1 for 
PSHAP as well as SHAP (i.e., the stream meets the criteria specified in 
40 CFR 63.2485(c)(1) or (2) as well as the criteria in 40 CFR 
63.2485(c)(3)), you may elect to meet the requirements specified in 
table 7 to subpart FFFF for the PSHAP in the stream and then comply 
with this new option for the remaining SHAP.
    To demonstrate initial compliance with this alternative, use the 
new equation 1 in 40 CFR 63.2485(n)(2) and comply with the following 
requirements. First, use the procedures specified in 40 CFR 
63