[Federal Register Volume 59, Number 224 (Tuesday, November 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-28842]


[[Page Unknown]]

[Federal Register: November 22, 1994]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-5110-9]
RIN 2060-AE02

 

National Emission Standards for Hazardous Air Pollutants for 
Source Categories: Aerospace Manufacturing and Rework; Reopening of the 
Public Comment Period

AGENCY: Environmental Protection Agency (EPA).

ACTION: Reopening of the public comment period.

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SUMMARY: On June 6, 1994, EPA proposed standards to regulate the 
emissions of certain organic hazardous air pollutants from aerospace 
manufacturing and rework facilities which are part of major sources 
under Section 112 of the Clean Air Act as amended in 1990. The period 
for receiving public comment on the proposed rule ended on September 
15, 1994. This action announces the reopening of the comment period to 
take comments on several amendments to the proposed rulemaking and 
other issues raised during the original comment period; clarification 
of the intent of a proposed requirement; and a correction of a 
typographical error.

DATES: Comments: Comments must be received on or before January 6, 
1995.

ADDRESSES: Comments: Comments should be submitted (in duplicate, if 
possible) to: Air and Radiation Docket and Information Center (6102), 
Attn: Docket No. A-92-20, U.S. Environmental Protection Agency, 401 M 
Street SW, Washington, DC 20460. Docket: All information used in the 
development of this action is contained or referenced in the preamble 
below. Docket No. A-92-20 contains the supporting information for the 
original NESHAP and is available for public inspection and copying 
between 8:30 am and 5:00 pm, Monday through Friday, at the EPA's Air 
and Radiation Docket and Information Center, Waterside Mall, Room M-
1500, 1st floor, 401 M Street SW, Washington, DC 20460, or by calling 
(202) 260-7548 or FAX (202) 260-4400. A reasonable fee may be charged 
for copying.

FOR FURTHER INFORMATION CONTACT: Ms. Mary Tom Kissell at (919) 541-
4516, Standards Development Branch, Emission Standards Division (MD-
13), U.S. Environmental Protection Agency, Research Triangle Park, NC 
27711.

SUPPLEMENTARY INFORMATION:

I. Background

    On June 6, 1994 (59 FR 29216), national emission standards for 
hazardous air pollutants for the aerospace manufacturing and rework 
source category were proposed. Since that time, the EPA has received 
information on several aspects of the proposed rule which has led to 
the amendments being proposed in this notice for the following sections 
of the proposed subpart GG of 40 CFR part 63: Secs. 63.742, 63.745, 
63.747, 63.749, 63.751, and 63.752. These sections deal with 
definitions, standards for primer and topcoat application operations, 
standards for chemical milling maskant application operations, 
compliance determinations, monitoring requirements, and recordkeeping 
requirements, respectively, for the NESHAP for aerospace manufacturing 
and rework facilities. This notice announces the reopening of the 
comment period for the aerospace NESHAP. However, only comments limited 
to the subjects listed below will be considered.
    (1) Correction of a typographical error regarding a request for 
comments for commercial exterior primers;
    (2) Proposal of a more stringent inorganic HAP emission control 
requirement for new primer and topcoat application operations and 
proposal of definition of high efficiency particulate air filter;
    (3) Proposal to eliminate the exemption for chemical milling 
maskant application operations for use with Type I chemical milling 
etchants;
    (4) Clarification of the intent of the proposed requirement for 
control devices used to control emissions from coating application 
operations;
    (5) Proposal of reduced recordkeeping requirements to encourage the 
use of a low VOC primer;
    (6) Request for comment on depainting for private, corporate, and 
small commuter aircraft;
    (7) Request for comment on use and efficiency of control devices 
for depainting operations using HAP-containing chemicals; and
    (8) Request for comment on determining the appropriate length of 
the rolling material balance period for liquid-liquid material balances 
for carbon adsorbers used as control devices for solvent recovery 
systems.
    These actions are further discussed in Part III of this preamble.
    As indicated in the preamble to the proposed rule at 59 FR 29217, 
the EPA traditionally issues a draft CTG containing recommended control 
levels for public comment. Rather than issue a separate draft CTG in 
this case, the EPA used the notice of proposed rulemaking to request 
public comment on draft best available control measures (BACM), which 
is the same as the proposed maximum achievable control technology 
(MACT) for coatings and solvents. Comments on the proposed rule and on 
the proposed amendments in this document will also be considered in 
formulating a final BACM.
    The proposed regulatory text is not included in this Federal 
Register notice, but is available in Docket No. A-92-20 or by written 
or telephone request from the Air and Radiation Docket and Information 
Center (see ADDRESSES). This notice with the proposed regulatory 
language is also available on the Technology Transfer Network (TTN), 
one of EPA's electronic bulletin boards. The TTN provides information 
and technology exchange in various areas of air pollution control. The 
service is free, except for the cost of a phone call. Dial (919) 541-
5742 for up to a 14,400 bps modem. If more information on TTN is 
needed, call the HELP line at (919) 541-5384.

II. Summary of and Rationale for Changes to the Proposed Rule and 
Request for Public Comments

A. Correction: Request for Comments on Commercial Exterior Primers

    Section II.B.2.a of the preamble to the proposed rule requested 
comments concerning whether the proposed organic HAP and VOC limits for 
commercial exterior topcoats represents demonstrated technology. This 
section should have referenced commercial exterior primers rather than 
topcoats. Consequently, the specific paragraph in this section (see 59 
FR 29224, middle column) should read as follows:

    The EPA has received information indicating that the organic HAP 
and VOC content limits for primers do not represent demonstrated 
technology for exterior commercial primers. Consequently, the EPA is 
soliciting comments on whether a separate category should be 
developed for exterior commercial primers with organic HAP and VOC 
content levels higher than the proposed levels for primers. These 
comments should provide a technical justification for a higher 
limit, including why currently available commercial primers cannot 
be used by all sources.

B. Amendment: New Source Requirements for Inorganic HAP Emissions from 
Coating Operations

    The EPA has received information that at least one facility is 
controlling inorganic HAP emissions from coating operations to a 
greater degree than that required in the proposed rule. This facility 
is using high efficiency particulate air (HEPA) filters in addition to 
the filtration methods required in the proposed rule. Consequently, the 
EPA is proposing that Sec. 63.745 require new primer and topcoat 
application operations to use HEPA filters in addition to the 
requirements specified in the rule proposed on June 6, 1994. Finally, 
the EPA is proposing that these sources keep records of documentation 
supplied by the filter manufacturer that the filter being used meets 
the HEPA filter requirements specified in the definition in Sec. 63.742 
being proposed by this notice.

C. Amendment: Inclusion of Chemical Milling Maskant Application 
Operations for Use With Type I Chemical Milling Etchants

    As proposed on June 6, 1994, the rule would apply only to those 
chemical milling maskant application operations in which Type II 
chemical milling etchants are subsequently used. This was based on 
information the EPA received showing that no facilities had implemented 
controls (either low VOC product substitutions or control devices) on 
chemical milling maskant application operations for use with Type I 
chemical milling etchants. Since proposal, the EPA has received comment 
that there is at least one chemical milling maskant application 
operation for use with Type I chemical milling etchants (which are not 
currently covered in the proposed rule) with reduced organic HAP and 
VOC content levels. The information supplied to the EPA, however, did 
not detail the applicability of this chemical milling maskant to all 
Type I etchant operations.
    The MACT floor for chemical milling maskant application operations, 
as determined by the average of the best performing 12 percent of 
sources for which the EPA had emission information, included the use of 
control devices (e.g., carbon adsorbers) as well as low organic HAP and 
VOC content chemical milling maskants. As mentioned above, the 
applicability of the low organic HAP and VOC content chemical milling 
maskant for which the EPA received comment is unknown. However, the use 
of the same control device technology as used for Type II chemical 
milling operations is applicable to Type I chemical milling operations. 
Consequently, the EPA is proposing to eliminate the exemption in 
Sec. 63.747 for chemical milling maskants used with Type I etchants and 
require them to meet the same requirements as chemical milling maskants 
for use with Type II etchants. This will allow the use of any low 
organic HAP and VOC content chemical milling maskant that meets the 160 
grams per liter (1.3 pounds per gallon) organic HAP and VOC content 
limits or the use of control devices as specified in the proposed rule.

D. Amendment: Requirement for the Capture of All Emissions by Control 
Devices

    The proposed rule required that whenever a control device is used 
to meet the emission limitations specified, the owner or operator must 
meet two provisions in order to demonstrate compliance. The first is 
that the overall control efficiency, taking into account capture and 
control efficiency, must be at least 81 percent. The second provision, 
as specified in Secs. 63.745(c)(1), 63.747(d)(1), 63.749(d)(4)(ii)(A), 
and 63.749(g)(3)(ii)(A) of the proposed rule, requires that all of the 
emissions from the respective operations be captured and controlled by 
the control device. In addition, the latter two paragraphs specify that 
all emissions must be controlled other than ``incidental emissions that 
may escape the capture system.''
    The EPA has reviewed these provisions based on comments that have 
been received concerning their enforceability. Based on this review, 
the EPA has concluded that the provision specifying an overall control 
efficiency is adequate to ensure application of MACT. The additional 
language only added confusion to the proposed rule without any added 
environmental benefit. The EPA, therefore, is deleting from the 
proposed rule the four paragraphs referenced above concerning the 
capture of all emissions from coating operations.

E. Amendment: Reduced Recordkeeping Requirements for Low Organic HAP 
and VOC Content Primer

    The EPA has received information that a low organic HAP and VOC 
content (approximately 250 grams VOC per liter (2.1 pounds per gallon) 
less water and exempt solvents) military waterborne primer has been 
qualified according to military specification MIL-P-85582A, Type I, 
Class II. While this primer may not represent demonstrated technology 
for all types of uses, the EPA wishes to encourage the use of low 
organic HAP and VOC content coatings. Consequently, the EPA is 
proposing to amend the recordkeeping requirements of Sec. 63.752 of the 
proposed rule to require that only annual purchasing records be 
maintained on the use of any primer that contains a maximum of 250 
grams organic HAP per liter (2.1 pounds per gallon) less water as 
applied and 250 grams VOC per liter (2.1 pounds per gallon) less water 
and exempt solvents as applied. This significantly reduces the 
recordkeeping from the monthly records required for coatings with 
higher organic HAP and VOC contents.

F. Request for Comments: Depainting Requirements for Private, 
Corporate, and Small Commuter Aircraft

    The EPA has received comments that the proposed standards for 
depainting do not represent demonstrated technology for private, 
corporate, and small commuter aircraft. Specifically, the commenters 
stated that depainting of these aircraft cannot be accomplished through 
the use of non-HAP chemical strippers or media blasting methods. One 
commenter also stated that the physical characteristics of the coatings 
typically used on the exterior of private and corporate aircraft cannot 
be removed by the non-HAP chemical strippers currently on the market. 
Another comment concerned the use of a control device, such as carbon 
absorbers followed by a catalytic incinerator, to reduce emissions from 
depainting operations where HAP-containing chemical strippers are used 
as an alternative means of compliance.
    In order to obtain additional and more specific information on this 
sector of the aerospace rework industry, the EPA is requesting data and 
information on the following specific issues:
    1. One commenter stated that to achieve the finish quality demanded 
by private and corporate aircraft purchasers, the aircraft 
manufacturers are using coatings that have a cross-linked polymer 
structure. According to the commenter, the structure of these coatings 
does not allow the non-HAP chemical strippers to penetrate the coating 
in order to break the bond between the coating and substrate. The EPA 
requests information on whether non-HAP chemical strippers have been 
shown to be effective on this type of coating. Commenters are requested 
to provide as many details as possible of non-HAP chemical depainting 
processes such as type and number of aircraft depainted, specific type 
of primer and topcoats removed, VOC content (as applied, less water and 
exempt solvents) of the primer and topcoat removed, and method of 
disposal of the waste stripper. Information on the cross-linked polymer 
coatings (e.g., VOC content, manufacturer) and its finish 
characteristics are also requested.
    In addition, the EPA requests comments on whether coatings other 
than cross-linked polymers can be used on private and corporate 
aircraft. Information requested includes: whether substitute coatings 
can be used to achieve similar finishes; whether these other coatings 
are easier to strip; VOC content (as applies, less water and exempt 
solvents) of these other coatings; application methods; whether 
changing coatings or not painting aircraft would affect aircraft 
safety; and the economic impacts of changing coatings or not painting 
aircraft.
    2. Another commenter focused on the thin exterior skin panels of 
private, corporate, and small commuter aircraft. The commenter said 
that since weight is a critical parameter for these aircraft, very thin 
exterior skin panels, that are very susceptible to damage from blast 
depainting methods, are typically used. The commenter states that as a 
consequence, no rework facilities are currently using blast depainting 
methods on these aircraft.
    Information on this topic is requested from any facility that has 
evaluated or is currently using any blast depainting method or non-
chemical means to remove coatings from the exterior of private, 
corporate, or small commuter aircraft. Specifically, the information 
should document both successful and unsuccessful applications of blast 
or mechanical depainting methods for these aircraft, or any other 
aircraft with similarly thin exterior skin panels. Any information on 
the generation and control of emissions from blast or mechanical 
depainting operations (of any type of aircraft) would also be 
beneficial.

G. Request for Comment: Control Devices for Depainting Operations Using 
HAP-Containing Chemicals

    Another commenter recommended that conventional chemical strippers 
(containing HAPs) be allowed when emissions are reduced through the use 
of a control device. The commenter stated that a combination of a 
carbon adsorber and catalytic incinerator can achieve greater than 99 
percent removal efficiency, and would be essentially equal to the 
depainting standard of no HAP emissions.
    Information submitted on this topic should address the feasibility 
of installing such a control system, including cost and ability to 
achieve greater than 99 percent removal efficiency on a dilute 
airstream. Also, since some portion of the volatile HAP content of 
conventional strippers will be retained in the waste sludge produced 
from the operation, commenters should detail the ultimate fate of 
emissions from the volatile HAPs in the waste stream. For example, a 
conventional waste treatment system may aerate the waste stream as an 
initial processing step, emitting the volatile HAPs at that point. 
However, other waste treatment methods may destroy HAPs before the 
aeration step. Comments are also requested on whether a standard 
allowing the use of control devices to reduce emissions from depainting 
operations should apply only to the depainting of private, corporate, 
and small commuter aircraft, or if it should apply to military and 
commercial aircraft as well.

H. Request for Comment: Appropriate Length of Rolling Material Balance 
Period for Liquid-Liquid Material Balances for Carbon Adsorbers Used as 
Control Devices on Solvent Recovery Systems

    The EPA proposed Method 309, ``Method to Determine Length of 
Rolling Period for Liquid/Liquid Material Balance Method'' to determine 
the length of the rolling material balance period for the liquid-liquid 
material balance for carbon adsorbers used as control devices on 
solvent recovery systems. Several comments have been received 
concerning whether Method 309 is the most appropriate method for the 
aerospace industry in all instances. Therefore, the EPA is requesting 
comment on alternatives to Method 309. Information in support of 
alternatives to Method 309 should include how the length of the balance 
period is determined; discussions of operations that make an alternate 
determination of length appropriate; discussions concerning how 
compliance is indicated and ensured with the alternative determination; 
whether the alternative determination has been approved by state or 
local air pollution agencies in permits or other documents; and why 
Method 309 does not allow for the alternative determination.

III. Administrative Requirements

A. Paperwork Reduction Act

    The changes detailed in this notice will have the following effects 
on the information collection burden (recordkeeping, reporting, and 
monitoring requirements) of the proposed rule:
    (1) The request for comments concerning commercial exterior primers 
does not affect the information collection burden of the proposed rule;
    (2) New sources would be required to use HEPA filter and to 
maintain records documenting that the filters used meet the 
requirements of HEPA filters, but this would not significantly increase 
the recordkeeping burden;
    (3) The inclusion of Type I chemical milling maskants would require 
the same recordkeeping and reporting requirements as specified for Type 
II chemical milling maskants. Since the EPA has no information on which 
to base an estimate of the number of facilities currently using Type I 
chemical milling etchants, the magnitude of the effect on the 
information collection burden cannot be made;
    (4) The deletion of the requirement to capture and control all of 
the emissions from coating operations does not affect the information 
collection burden of the proposed rule; and
    (5) Reducing the recordkeeping requirements for low organic HAP and 
VOC content primers will result in a decrease in the information 
collection requirements for those facilities that use these primers. 
However, the EPA has no information on which to base an estimate of the 
number of facilities that will use the low organic HAP and VOC content 
primers. Therefore, the magnitude of the effect on the information 
collection request burden cannot be made.
    Even though the effect on the information collection burden cannot 
be completely quantified, the EPA believes that it will not 
significantly change. Therefore, the Information Collection Request 
document developed for the proposed rule has not been revised.

B. Executive Order 12866 Review

    This rule was classified as ``non-significant'' under Executive 
Order 12866 and, therefore, was not reviewed by the Office of 
Management and Budget.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Reporting and recordkeeping requirements.

    Dated: November 14, 1994.
Mary D. Nichols,
Assistant Administrator for Air and Radiation.
[FR Doc. 94-28842 Filed 11-21-94; 8:45 am]
BILLING CODE 6560-50-P