# National Emission Standards for Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks

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URL: https://www.frixlaw.com/law-library/documents/fr%3A95-65

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** January 25, 1995
- **Citation:** 60 FR 4948

## Text

SUMMARY: Pursuant to section 112 of the Clean Air Act as amended in
1990 (the Act), this action promulgates final standards that limit the
discharge of chromium compound air emissions from existing and new hard
chromium electroplating, decorative chromium electroplating, and
chromium anodizing tanks at major and area sources. Chromium compounds
are among the 189 hazardous air pollutants (HAP) listed for regulation
under section 112 of the Act. Hard and decorative chromium
electroplating and chromium anodizing tanks have been identified by the
EPA as significant emitters of chromium compounds to the atmosphere.
The purpose of the final rule is to reduce chromium compound air
emissions from the source categories identified above. All affected
sources must limit emissions to the level of the maximum achievable
control technology (MACT). The EPA is also finalizing Methods 306,
306A, and 306B with these standards.

DATES: Effective Date: January 25, 1995.
Incorporation by Reference. The incorporation by reference of
certain publications in this standard is approved by the Director of
the Office of the Federal Register as of January 25, 1995.
Judicial Review. Under section 307(b)(1) of the Act, judicial
review of national emission standards for hazardous air pollutants
(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
Act, the requirements that are the subject of today's notice may not be
challenged later in civil or criminal proceedings brought by the EPA to
enforce these requirements.

ADDRESSES: Docket. Docket No. A-88-02, containing information
considered by the EPA in developing the promulgated NESHAP for hard and
decorative chromium electroplating and chromium anodizing tanks is
available for public inspection and copying between 8 a.m. and 5:30
p.m., Monday through Friday, except for Federal holidays, at the EPA's
Air and Radiation Docket and Information Center, Room M1500, U. S.
Environmental Protection Agency, 401 M Street, SW., Washington, DC
20460; telephone (202) 260-7548. A reasonable fee may be charged for
copying.
Background Information Document. A background information document
(BID) for the promulgated NESHAP may be obtained from the docket; the
U. S. EPA Library (MD-35), Research Triangle Park, North Carolina
27711, telephone (919) 541-2777; or from National Technical Information
Services, 5285 Port Royal Road, Springfield, Virginia 22161, telephone
(703) 487-4650. Please refer to ``Chromium Emissions from Chromium
Electroplating and Chromic Acid Anodizing Operations--Background
Information for Promulgated Standards'' (EPA-453/R-94-082b). The BID
contains a summary of the public comments made on the proposed
standards and EPA responses to the comments.

FOR FURTHER INFORMATION CONTACT: Mr. Lalit Banker of the Emission
Standards Division (MD-13), U. S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711; telephone (919) 541-5420.

SUPPLEMENTARY INFORMATION: The information presented in this preamble
is organized as follows:

I. Background
II. Summary
A. Summary of Promulgated Standards
B. Summary of Major Changes Since Proposal
III. Summary of Environmental, Energy, Cost, and Economic Impacts
A. Environmental and Energy Impacts
B. Cost Impacts
C. Economic Impacts
IV. Public Participation
V. Significant Comments and Responses
A. Selection of Source Categories and Pollutants to be Regulated
B. Selection of MACT/GACT Approach
C. Selection of MACT for Hard Chromium Electroplating Tanks
D. Selection of MACT for Decorative Chromium Electroplating and
Chromium Anodizing Tanks
E. Selection of the Format of the Standard
F. Selection of the Emission Limits
G. Selection of Compliance Dates
H. Selection of Monitoring Requirements
I. Selection of Test Methods
J. Selection of Reporting and Recordkeeping Requirements
K. Operating Permit Program
VI. Administrative Requirements
A. Docket
B. Executive Order 12866
C. Paperwork Reduction Act
D. Regulatory Flexibility Act
E. Miscellaneous

I. Background

Section 112(b) of the Act lists 189 HAP and requires the EPA to
establish national emission standards for all major sources and some
area sources of those HAP. Among the listed pollutants are chromium
compounds. On July 16, 1992 (57 FR 31576), the EPA published a list of
major and area sources for which NESHAP are to be promulgated and on
December 3, 1993 (58 FR 83941), the EPA published a schedule for
promulgation of those standards. The hard and decorative chromium
electroplating and chromium anodizing source categories are included in
the list of major and area sources for which the EPA is to establish
national emission standards by November 1994.
This NESHAP was proposed in the Federal Register on December 16,
1993 (58 FR 65768). A public hearing on this rule was conducted on
January 20, 1994. In addition, 62 letters commenting on the proposed
rule were received during the public comment period, and 3 late
comments were received.

II. Summary

A. Summary of Promulgated Standards

The final rule applies to major and area sources performing hard
chromium electroplating, decorative chromium electroplating, and
chromium anodizing. The affected source is each chromium electroplating
or chromium anodizing tank. The emission limitations for each of these
source categories are summarized in Table 1. These emission limitations
apply only during tank operation, including periods of startup and
shutdown. The emission limitation for all new hard chromium
electroplating tanks, and for existing hard chromium electroplating
tanks that are located at large, hard chromium electroplating
facilities is based on the use of a composite mesh-pad system. The
emission limitation for existing hard chromium electroplating tanks
located at small, hard chromium electroplating facilities is based on
the use of a packed-bed scrubber. For all existing and new sources
performing decorative chromium electroplating and all existing and new
sources performing chromium anodizing, the standard is based on the use
of fume suppressants. Even though these technologies formed the bases
for the standards, any technology can be used as long as it is
demonstrated to meet the prescribed emission limitation. All area and
major sources must limit emissions to the level of the maximum
achievable control technology (MACT).

[[Page 4949]]
Table 1.--Standards for Chromium Electroplating and Chromium Anodizing Tanks Based on MACT
--------------------------------------------------------------------------------------------------------------------------------------------------------
Emission limitations
Type of tank ---------------------------------------------------------------------------------------------------------------------------
Small Large
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hard Chromium Plating Tanks
--------------------------------------------------------------------------------------------------------------------------------------------------------
All existing tanks.......... 0.03 mg/dcsm (1.3 x 10-5 gr/dscf)........................... 0.015 mg/dscm (6.6 x 10-6 gr/dscf)
All new tanks............... 0.015 mg/dcsm (6.6 x 10-6 gr/dscf).......................... 0.015 mg/dscm (6.6 x 10-6 gr/dscf)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Decorative Chromium Plating Tanks Using a Chromic Acid Bath

--------------------------------------------------------------------------------------------------------------------------------------------------------
All new and existing tanks..
(1) 0.01 mg/dscma(4.4 x 10-6
gr/dscf)

--------------------------------------------------------------------------------------------------------------------------------------------------------
Chromium Anodizing Tanks

--------------------------------------------------------------------------------------------------------------------------------------------------------
All new and existing tanks..
(1) 0.01 mg/dscma(4.4 x 10-6
gr/dscf)
--------------------------------------------------------------------------------------------------------------------------------------------------------
aIn accordance with Sec. 63.342(d)(2), owners or operators using a fume suppressant containing a wetting agent as a control technique can meet an
alternate emission limitation of 45 dynes/cm (3.1 x 10-3 lbf/ft).

Owners and operators of all affected sources are also subject to
work practice standards, which require them to complete an operation
and maintenance (O&M) plan that contains the minimum elements of
Sec. 63.342(f)(3) and Table 2.

Table 2.--Summary of Work Practice Standards
------------------------------------------------------------------------
Control technique Work practice standards Frequency
------------------------------------------------------------------------
Composite mesh-pad 1. Visually inspect device 1. 1/quarter.
(CMP) system. to ensure there is proper
drainage, no chromic acid
buildup on the pads, and
no evidence of chemical
attack on the structural
integrity of the device.
2. Visually inspect back 2. 1/quarter.
portion of the mesh pad
closet to the fan to
ensure there is no
breakthrough of chromic
acid mist.
3. Visually inspect 3. 1/quarter.
ductwork from tank or
tanks to the control
device to ensure there
are no leaks.
4. Perform washdown of the 4. Per manufacturer.
composite mesh-pads in
accordance with
manufacturers
recommendations.
Packed-bed scrubber 1. Visually inspect device 1. 1/quarter.
(PBS). to ensure there is proper
drainage, no chromic acid
buildup on the packed
beds, and no evidence of
chemical attack on the
structural integrity of
the device.
2. Visually inspect back 2. 1/quarter.
portion of the chevron
blade mist eliminator to
ensure that it is dry and
there is no breakthrough
of chromic acid mist.
3. Same as number 3 above. 3. 1/quarter.
4. Add fresh makeup water 4. Whenever makeup is
to the top of the packed added.
beda,b.
PBS/CMP system....... 1. Same as for CMP system. 1. 1/quarter.
2. Same as for CMP system. 2. 1/quarter.
3. Same as for CMP system. 3. 1/quarter.
4. Same as for CMP system. 4. Per manufacturer.
Fiber-bed mist 1. Visually inspect fiber- 1. 1/quarter.
eliminatorc. bed unit and prefiltering
device to ensure there is
proper drainage, no
chromic acid buildup in
the units, and no
evidence of chemical
attack on the structural
integrity of the devices.
2. Visually inspect 2. 1/quarter.
ductwork from tank or
tanks to the control
device to ensure there
are no leaks.
3. Perform washdown of 3. Per manufacturer.
fiber elements in
accordance with
manufacturers
recommendations.
Air pollution control To be proposed by the To be proposed by the
device (APCD) not source for approval by source for approval
listed in rule. the Administrator. by the
Administrator.

------------------------------------------------------------------------
Monitoring Equipment

------------------------------------------------------------------------
Pitot tube........... Backflush with water, or 1/quarter.
remove from the duct and
rinse with fresh water.
Replace in the duct and
rotate 180 degrees to
ensure that the same zero
reading is obtained.
Check pitot tube ends for
damage. Replace pitot
tube if cracked or
fatigued.
Stalagmometer........ Follow manufacturers
recommendations.
------------------------------------------------------------------------
aIf greater than 50 percent of the scrubber water is drained (e.g., for
maintenance purposes), makeup water may be added to the scrubber
basin.
bFor horizontal-flow scrubbers, top is defined as the section of the
unit directly above the packing media such that the makeup water would
flow perpendicular to the air flow through the packing. For vertical-
flow units, the top is defined as the area downstream of the packing
material such that the makeup water would flow countercurrent to the
air flow through the unit.
cWork practice standards for the control device installed upstream of
the fiber-bed mist eliminator to prevent plugging do not apply as long
as the work practice standards for the fiber-bed unit are followed.

[[Page 4950]]

All existing sources performing hard chromium electroplating and
chromium anodizing must comply with the emission limitations within 2
years of January 25, 1995. All existing sources performing decorative
chromium electroplating must comply with the emission limitations
within 1 year of January 25, 1995. All new and reconstructed sources
must comply immediately upon startup.
Sources must demonstrate initial compliance with the prescribed
emission limitation in accordance with Secs. 63.343(b) and 63.344.
Continuous compliance is demonstrated through the monitoring required
by Sec. 64.343(c), as summarized in Table 3. As indicated in this
table, the type of compliance monitoring performed is based on the type
of control technique used to comply with the emission limitation, not
the type of source being controlled.

Table 3.--Summary of Monitoring Requirements
----------------------------------------------------------------------------------------------------------------
Parameter(s) for compliance Frequency of compliance
Control technique Initial compliance test monitoring monitoring
----------------------------------------------------------------------------------------------------------------
Composite mesh-pad (CMP) Yes...................... Pressure drop across the unit. 1/day.
system.
Packed-bed scrubber (PSB) Yes...................... Velocity pressure at the inlet 1/day.
of the control system and
pressure drop across the unit.
PBS/CMP system........... Yes...................... Pressure drop across the unit. 1/day
Fiber-bed mist eliminator Yes...................... Pressure drop across the fiber- 1/day.
bed mist eliminator and the
pressure drop across the
upstream control device used
to prevent plugging.
Wetting agent-type fume Yes (Unless the criteria Surface tension............... Once every 4 hours.a
suppressant. of Sec. 63.343(b)(2) are
met).
Foam blankets............ Yes...................... Foam thickness................ Once per hour.a
Air pollution control Yes...................... To be proposed by the source N/A.
device (APCD) not listed for approval by Administrator.
in rule.
----------------------------------------------------------------------------------------------------------------
aFrequency can be decreased according to Sec. 63.343 (c)(5)(ii) and (c)(6)(ii) of subpart N.

Owners or operators of affected sources are required to keep the
records required by Sec. 63.346 to document compliance with these
standards. Records include those associated with the work practice
standards, performance test results, compliance monitoring data,
duration of exceedances, and records to support a Federally-enforceable
limit on facility size. Reports must also be periodically submitted.
Table 4 summarizes the reports to be submitted and the reporting
timeframes.

Table 4.--Summary of Reporting Requirements
------------------------------------------------------------------------
Section in Subpart N Description Timeframe for submittal
------------------------------------------------------------------------
Sec. 63.345(b)....... Notification of Depends on when source
construction or was constructed--see
reconstruction. Sec. 63.345(b)(5).
Sec. 63.347(c)(1).... Initial notification.... 180 days after the
effective date.
Sec. 63.347(c)(2).... --Notification of when --Within 30 days of
construction commenced. commencement for
sources built after
effective date, or
with notification
required by Sec.
63.345(b) if built
prior to effective
date.
--Notification of actual --Within 30 days of
startup. startup.
Sec. 63.347(d)....... Notification of At least 60 days prior
performance test. to test.
Sec. 63.347(e)....... Notification of Within 90 days of
compliance status. performance test (if a
test is conducted) or
within 30 days of
compliance date.
Sec. 63.347(f)....... Notification of Within 90 days of
performance test performance test.
results.
Sec. 63.347(g)....... Compliance status 2 times/yr, or 4 times/
reports for major yr if exceedances
sources. occur or if requested
by Administrator.
Sec. 63.347(h)....... Compliance status Complete once/yr and
reports for area maintain on site, or 2
sources. times/yr if
exceedances occur or
if requested by
Administrator.
Sec. 63.347(i)....... --Initial notification --Within 180 days of
for users of TVC baths. effective date.
--Notification of --Within 30 days of
compliance status for compliance date.
users of TVC baths.
--Notification of --Within 30 days of
process change. process change.
------------------------------------------------------------------------

B. Summary of Major Changes Since Proposal

In response to public comments received and additional analyses
performed by the EPA, the following changes have been made to the final
rule since proposal:
1. The emission limits associated with the control technologies
that form the bases for the standards have been revised. The emission
limit based on the use of a composite mesh-pad system is 0.015
milligrams of total chromium per dry standard cubic meter (mg/dscm) of
exhaust air. The emission limit based on the use of a fume suppressant
is 0.01 mg/dscm. The emission limit based on the use of a packed-bed
scrubber is unchanged (0.03 mg/dscm).

[[Page 4951]]
Table 3.--Summary of Monitoring Requirements
----------------------------------------------------------------------------------------------------------------
Parameter(s) for compliance Frequency of compliance
Control technique Initial compliance test monitoring monitoring
----------------------------------------------------------------------------------------------------------------
Composite mesh-pad (CMP) Yes...................... Pressure drop across the unit 1/day.
system.
Packed-bed scrubber (PBS) Yes...................... Velocity pressure at the 1/day.
inlet of the control system
and pressure drop across the
unit.
PBS/CMP system........... Yes...................... Pressure drop across the unit 1/day.
Fiber-bed mist eliminator Yes...................... Pressure drop across the 1/day.
fiber-bed mist eliminator
and the pressure drop across
the upstream control device
used to prevent plugging.
Wetting agent-type fume Yes (Unless the criteria Surface tension.............. Once every 4 hours.a
suppressant. of Sec. 63.343(b)(2) are
met).
Foam blankets............ Yes...................... Foam thickness............... Once per hour.a
Air pollution control Yes...................... To be proposed by the source N/A
device (APCD) not listed for approval by
in rule. Administrator.
----------------------------------------------------------------------------------------------------------------
aFrequency can be decreased according to Sec. 63.343 (c)(5)(ii) and (c)(6)(ii) of subpart N.

Table 4.--Summary of Reporting Requirements
------------------------------------------------------------------------
Section in subpart
N Description Timeframe for submittal
------------------------------------------------------------------------
Sec. 63.345(b).... Notification of Depends on when source was
construction or constructed--see Sec.
reconstruction. 63.345(b)(5).
Sec. 63.347(c)(1). Initial notification... 180 days after the
effective date.
Sec. 63.347(c)(2). --Notification of when --Within 30 days of
construction commenced. commencement for sources
built after effective
date, or with notification
required by Sec. 63.345(b)
if built prior to
effective date.
--Notification of --Within 30 days of
actual startup. startup.
Sec. 63.347(d).... Notification of At least 60 days prior to
performance test. test.
Sec. 63.347(e).... Notification of Within 90 days of
compliance status. performance test (if a
test is conducted) or
within 30 days of
compliance date.
Sec. 63.347(f).... Notification of Within 90 days of
performance test performance test.
results.
Sec. 63.347(g).... Compliance status 2 times/yr, or 4 times/yr
reports for major if exceedances occur or if
sources. requested by
Administrator.
Sec. 63.347(h).... Compliance status Complete once/yr and
reports for area maintain on site, or 2
sources. times/yr if exceedances
occur or if requested by
Administrator.
Sec. 63.347(i).... --Initial notification --Within 180 days of
for users of TVC baths. effective date.
--Notification of --Within 30 days of
compliance status for compliance date.
users of TVC baths.
--Notification of --Within 30 days of process
process change. change.
------------------------------------------------------------------------

2. Owners or operators of decorative chromium electroplating tanks
using a trivalent chromium process that incorporates a wetting agent
are required only to submit the notifications required by
Sec. 63.347(i) with subsequent notifications required if the process is
changed or replaced.
3. Existing sources performing hard chromium electroplating and
chromium anodizing must comply with the standard within 2 years after
January 25, 1995. Existing sources performing decorative chromium
electroplating must comply with the standard within 1 year after
January 25, 1995.
4. The monitoring, reporting, and recordkeeping requirements for
affected sources have been reduced to the extent possible while still
allowing the EPA to determine the compliance status on a continuous
basis. Special consideration has been given to area sources.
5. Table 1 of subpart N clarifies which sections of the General
Provisions apply to sources subject to subpart N and which sections do
not.
The rationale for the above changes is discussed in detail in
section V of this preamble, which summarizes the major comments
received on the proposed rule and the EPA's response to these comments.
This section also discusses major comments that were received but that
did not result in changes to the final rule.

III. Summary of Environmental, Energy, Cost, and Economic Impacts

A. Environmental and Energy Impacts

The environmental and energy impacts for the sources covered by
this rulemaking are unchanged from proposal because the bases of the
MACT standards have not changed.

B. Cost Impacts

The annualized cost of control for the sources covered by this
rulemaking remain unchanged from proposal because the bases of the MACT
standards have not changed.
The monitoring, reporting, and recordkeeping burden in the final
rule has decreased from the proposed requirements. Likewise, the costs
of monitoring, reporting, and recordkeeping have also decreased. The
on-going, annual cost of the final monitoring, reporting, and
recordkeeping is approximately 160,000 hours for hard chromium
electroplaters, 29,000 hours for decorative chromium electroplaters
using a trivalent chromium plating process, 260,000 hours for other
decorative chromium electroplaters, and 70,000 hours for chromium
anodizers. Nationwide annual costs for these source categories are $3.5
million for hard chromium electroplaters, $640,000 for decorative
chromium electroplaters using a trivalent chromium plating process,
$5.8 million for other decorative chromium electroplaters, and $1.6
million for chromium anodizers. These numbers [[Page 4952]] are reduced
from the nationwide annual costs associated with monitoring, reporting,
and recordkeeping in the proposed rule of $8.6 million for hard
chromium electroplaters, $1.6 million for decorative chromium
electroplaters using a trivalent chromium plating process, $14 million
for other decorative chromium electroplaters, and $3.8 million for
chromium anodizers.

C. Economic Impacts

The economic impacts for the sources covered by this rulemaking are
unchanged from proposal because the basis of the MACT standards have
not changed.

IV. Public Participation

Prior to proposal of the chromium electroplating and anodizing
rule, meetings of the National Air Pollution Control Techniques
Advisory Committee (NAPCTAC) were held on January 30 and November 19,
1991. These meetings were open to the public, and each attendee was
given an opportunity to comment on the draft rule.
The proposed rule was published in the Federal Register on December
16, 1993 (58 FR 65768). The preamble to the proposal discussed the
availability of the proposal BID (Chromium Electroplating NESHAP--
Background Information for Proposed Standards (Volume I: EPA-453/R-93-
030a and Volume II: EPA-453/R-93-030b)), which describes in detail the
regulatory alternatives considered and the impacts associated with
those alternatives. Public comments were solicited at the time of
proposal, and copies of the proposal BID were made available to
interested parties.
The public comment period officially ended on March 14, 1994. A
public hearing was held on January 20, 1994. In addition, 62 comment
letters were received during the public comment period; 3 late comments
were also received. The comments were carefully considered, and where
determined to be appropriate by the Administrator, changes were made in
the final rule.

V. Significant Comments and Responses

Comments on the proposed rule were received from industry,
environmental groups, and State and local regulatory agencies. A
detailed discussion of these comments and responses can be found in the
promulgation BID (see ADDRESSES section). The summary of comments and
responses in the promulgation BID serves as the basis for the revisions
that have been made to the rule between proposal and promulgation.

A. Selection of Source Categories and Pollutants To Be Regulated

Six commenters said that maximum cumulative potential rectifier
capacity was an inappropriate parameter for determining facility size.
Sources may have excess rectifier capacity to handle atypical
applications, for safety purposes, or for other reasons, but may
routinely operate at a significantly lower rectifier output. Several
commenters urged the EPA to consider alternatives to the maximum
potential rectifier capacity specified, such as actual annual ampere-
hour usage, raising the maximum potential ampere-hour limit for small
sources to 100 million amp-hr/yr, allowing sources to multiply the
maximum potential rectifier capacity by 0.75 to account for oversizing,
or allowing sources to accept Federally-enforceable limits on their
rectifier capacity that would allow them to be categorized as ``small''
facilities.
Although the cutoff between small and large hard chromium
electroplating facilities has not been changed, the EPA has included
two provisions in the final rule to allow sources to use actual
rectifier capacity or to limit their potential rectifier capacity. The
first provision is available to facilities whose production records
show that the previous annual, actual rectifier capacity was less than
60 million amp-hr/yr. Under this provision, hard chromium
electroplating facilities may determine their size by using actual
cumulative rectifier capacity in lieu of the maximum potential capacity
if nonresettable, amp-hr meters are used on affected tanks. The final
rule (Sec. 63.346(b)(12) and Sec. 63.347(c)(1)(vi)) requires that
records of amp-hr usage be kept.
The final rule also allows all sources performing hard chromium
electroplating to establish Federally-enforceable limits on their
rectifier capacity to allow facilities to comply with the standards for
small, hard chromium electroplating tanks, even if those facilities
have potential rectifier capacities that exceed the 60 million amp-hr/
yr cutoff. A Federally-enforceable limit is obtained through the title
V permit that is required by Sec. 63.340(e) of the final rule. Records
are required in accordance with Sec. 63.346(b)(12) and
Sec. 63.347(c)(1)(viii) to document that the Federally-enforceable
limit is being maintained.
The final rule has also been clarified to state that only the
rectifiers associated with hard chromium electroplating should be used
to determine maximum cumulative potential rectifier capacity.
Comments were received regarding other processes conducted by this
source category that were not identified in the process description.
One commenter pointed out a distinction among decorative chromium
electroplating processes: Black chromium and white chromium. The
commenter stated that black chromium electroplating is more like hard
chromium electroplating in terms of process parameters, and the
commenter recommended that black chromium electroplating be subject to
the same requirements as hard chromium electroplating processes. Other
commenters noted that the proposed rule did not cover a hard chromium
electroplating method that uses lower amperage and a longer
electroplating time (less amperage per square foot than decorative
electroplating process) such that emissions are lower.
In the final rule, the definitions of hard chromium electroplating,
decorative chromium electroplating, and chromium anodizing have been
expanded, and are now expressed in terms of process parameters as well
as by function. Regardless of what name a facility has assigned to its
process, for the purposes of the regulation, the process will be
regulated according to its function, bath operating parameters, and
desired plating characteristics. Therefore, black decorative chromium
electroplaters would likely be subject to the standards for hard
chromium electroplaters based on plating characteristics. The EPA will
provide States with additional guidance on these types of applicability
issues in the enabling document.
The commenters that use a low-amperage electroplating process were
concerned that such a process would not be allowed by the rule, even
though emissions from this process are low. Although the process does
differ from other hard chromium electroplating processes in that a
lower amperage is used, the rule does not preclude the use of this
process or any other technique to meet the applicable emission
limitation. The rule does require that the technique be demonstrated
through performance testing conducted in accordance with the test
methods and procedures identified in the final rule, and that
compliance monitoring be conducted to determine continuous compliance.

B. Selection of MACT/GACT Approach

Ten commenters questioned the Agency's decision to regulate area
sources with MACT. A number of these commenters disagreed that the
chromium compound toxicity data alone was justification for regulating
[[Page 4953]] area sources as stringently as major sources. Other
commenters stated that the costs to area sources regulated with MACT
was unduly burdensome, particularly if those sources would be subject
to title V. Two commenters suggested that the EPA apply GACT standards
to small facilities to allow the Agency to focus its resources on
facilities posing the greatest impact, or establish a threshold below
which sources would be subject to GACT. Another commenter questioned
the EPA's decision to apply MACT to area sources on the grounds that
the Act does not intend a residual risk analysis for area sources. This
commenter noted that it was important to have separate standards for
area sources even if GACT was as stringent as MACT to preserve the
intent of section 112(d).
In determining whether to apply MACT or GACT to the area sources in
this source category, the EPA considered the toxicity of chromium
compounds emitted from such sources and the availability of controls.
The EPA has concluded that MACT should be applied to all area sources
in all source categories. The basis for this decision is the toxicity
of chromium compounds. The potency of hexavalent chromium, which is
categorized as a Group A carcinogen, is well documented, and at least
three epidemiological studies have shown a strong association between
lung cancer and occupational exposures to mixtures of trivalent and
hexavalent chromium. Therefore, the Agency has concluded that all
chromium compounds emitted to the air should be considered toxic until
adequate data are available to determine otherwise.
In selecting MACT over GACT for all area sources, the EPA also
evaluated the availability of control technologies and the cost of
compliance for area sources. The control technologies that form the
bases for MACT are widely available.
Although Sec. 112(d)(5) of the Act does allow an alternative
standard for area sources, the EPA interprets this paragraph as
authorizing the Administrator to establish GACT standard for area
sources when the imposition of MACT is determined to be unreasonable.
For the source categories subject to subpart N, the Agency considers it
reasonable to apply MACT to area sources.

C. Selection of MACT for Hard Chromium Electroplating Tanks

1. Selection of the MACT Floor
Four commenters suggested that the MACT floor for new hard chromium
electroplating tanks should be based on the use of a fiber-bed mist
eliminator (FBME) because this is the best technology in use.
The EPA has gathered additional information since proposal in
response to public comments received. Based on this information, a
total of five facilities are known to be using FBME to control chromium
emissions from affected hard chromium electroplating and chromium
anodizing tanks. These five facilities represent different sizes of
hard chromium electroplating and chromium anodizing operations.
Emission test data were obtained from four of the five facilities
using FBME (see Item No. IV-B-01 of Docket A-88-02). The emission test
data available from one facility were incomplete and could not be used
to assess the performance of fiber-bed units. The test results from the
other facilities were adequate to evaluate the performance of FBME.
However, after a thorough evaluation, it was determined that the
limited data are not sufficient to establish an emission limit which
must be met on a continuous long-term basis. In one case, the data were
inadequate because only a single traverse was made when two should have
been performed. In the other cases, the quantity of emissions captured
during sampling was too small to meet Agency guidelines on minimum
quantification levels. These data, therefore, must be treated as
qualitative rather than quantitative results and may not be used to
establish achievable emission limits. Based on this qualitative
assessment, it appears that FBME offer excellent control potential.
In evaluating control technologies, the Agency also must consider
the sustainability of any performance level. The EPA is concerned with
the long-term performance of these systems because of the tendency of
the fiber beds to plug. In other contexts, most vendors of FBME systems
do not recommend their use as primary pollution control systems.
Rather, they recommend that coarse prefiltering be provided upstream of
the fiber beds to prevent plugging. The prefiltering devices range from
a series of mesh pads to a complete packed-bed scrubber unit. At
present, there are no long-term data available to assess any actual
deterioration or operational problems associated with FBME. Fiber-bed
mist eliminators to control chromium electroplating and anodizing tanks
have only recently been installed as a result of local air district
requirements; therefore, it is unlikely that any long-term data are
available.
Because of the uncertainties in both the measured FBME performance
data and the potential long-term variability of the system performance,
the Administrator cannot at this time determine that a more stringent
emission limit could be achieved based on the application of FBME
technology for new hard chromium plating or chromium anodizing
operations. Therefore, the final MACT performance level of new hard
chromium electroplating and chromium anodizing tanks is unchanged from
the proposal. However, the limited data do suggest that FBME systems
can achieve the emission limits established for composite mesh-pad
systems and fume suppressants. Because this standard is a performance
standard, the use of a specific technology is not mandatory; therefore,
any system that meets or exceeds the required performance level may be
used.
In order to facilitate the use of FBME to achieve compliance with
the standard, monitoring provisions have been included in the final
rule for use with FBME. (See discussion in section V.H.) The test
methods in the proposed rule are suitable for demonstrating compliance
with the standard regardless of the control technology employed.
2. Regulatory Alternatives Considered
Eight commenters suggested that the EPA was too limiting in the
regulatory alternatives for hard chromium electroplating operations.
These commenters believed that the EPA should allow sources in this
subcategory to use fume suppressants to comply with the standard,
instead of locking sources into a control technology, such as packed-
bed scrubbers. Four of the commenters also proposed that the EPA allow
new and existing hard chromium electroplating operations the option of
meeting the same surface tension limit allowed for decorative chromium
electroplating operations that use a wetting agent-type fume
suppressant.
The EPA has selected an emission limit format to provide sources
with the flexibility to choose the emission control strategy best
suited to their facility. The regulation only requires that any
strategy selected meet the emission limits set out in the rule. As
such, hard chromium electroplating sources can use fume suppressants to
achieve compliance with the standard, as long as initial compliance
testing demonstrates that the emission limit stipulated in the standard
is being achieved. As discussed later in this preamble, however, on-
going compliance monitoring is control-technique specific. As such, the
owner or operator of any source that uses a fume suppressant to comply
with an emission limitation shall monitor surface tension or foam
blanket [[Page 4954]] thickness, as appropriate, to demonstrate
continuous compliance.
3. Selection of MACT
Several commenters remarked that the standard for existing hard
chromium electroplaters is inappropriate. Nine commenters stated that
the standard was too stringent for large, hard chromium electroplaters;
small, hard chromium electroplaters; or both. The arguments against
regulating existing hard chromium electroplaters as stringently as that
proposed were primarily that the costs associated with the standard
were unduly burdensome and did not justify the resulting environmental
benefit, and the emission concentration limits specified in the
proposed rule were not consistently achievable using the control
devices upon which the standards are based.
Five commenters, on the other hand, indicated that the standard for
small, hard chromium electroplaters was too lenient. The arguments
presented by the commenters who supported a more stringent standard for
small, hard chromium electroplaters were that the residual risk
associated with emissions from these sources warranted more stringent
controls, the Agency's interpretation of the MACT floor was flawed
(i.e.; should be based on a straight average, not a median); and the
control efficiency for packed-bed scrubbers is overstated, as are the
cost impacts for a standard based on the use of composite mesh-pad
systems.
In setting an emission standard, the Act directs the Administrator
to take into account costs, nonair quality health and environmental
impacts, and energy requirements. To fulfill this requirement for
existing hard chromium electroplating sources, the EPA evaluated the
cost, impact, and benefit of a standard based on the use of a packed-
bed scrubber as well as a standard based on the use of a composite
mesh-pad system. The Agency's estimate of the incremental cost
effectiveness of requiring all sources to meet a standard based on
composite mesh-pad systems compared to one based on packed-bed
scrubbers is approximately $3.7 million per Megagram of chromium
controlled ($/Mg) for large sources and $10.7 million/Mg for small
sources.
Based on the EPA's economic analysis, a standard based on the use
of composite mesh-pad systems by all sources would not cause adverse
economic effects on large sources that currently use packed-bed
scrubbers. Due to economies of scale, the economic impacts on larger
facilities are consistently less than those on small facilities. As a
result, larger facilities will have a greater ability to pass on
control costs. Although these costs may seem high, the EPA believes the
toxicity of chromium justifies these costs. In consideration of the
potential adverse impacts to small sources, the final rule requires a
less stringent standard for small sources than large sources, which is
based on the use of packed-bed scrubbers rather than composite mesh-pad
systems. [See Chapter 5 of the New Technology Document (``Technical
Assessment of New Emission Control Technologies Used in the Hard
Chromium Electroplating Industry;'' EPA-453/R-93-031) for a detailed
discussion of EPA's economic analysis for these systems.]
The EPA considers the emission limitation based on the use of
composite mesh-pad systems to be representative of and consistently
achievable with well-maintained units. No data were submitted to
support an alternate emission limitation. (For further discussion of
the emission limitations, see section V.F.)
Regarding the comments that the proposed standard for small, hard
electroplaters was too lenient, the Agency believes that the MACT floor
is properly based on the use of packed-bed scrubbers for this source
category. The EPA promulgated a final rule on June 6, 1994 (57 FR
29196) that presents the Agency's interpretation of section 112(d)(A)
of the Act regarding the basis for the MACT floor. Under this
interpretation, the Agency considers the emission limitations achieved
by the best performing 12 percent of existing sources and arrives at
the MACT floor by selecting the median of the values, rather than a
straight average. This interpretation was followed in establishing the
MACT floor for small, hard chromium electroplaters. The Agency
considers any discussion of the risk remaining from small, hard
chromium electroplaters to be premature at this time.
In accordance with section 112(f) of the Act, if a significant
residual risk from small, hard chromium electroplating operations
regulated by MACT is found, the Agency is required to promulgate
standards to mitigate that risk. The EPA recognizes the potential
hazards of chromium emissions from small sources and has chosen to
regulate area sources with MACT rather than GACT. The EPA also
considers its cost and impact analysis for small, hard chromium
electroplaters to be sound. The EPA estimated retrofit costs based on
information from vendors who supply the equipment to the industry, and
therefore estimates are representative of the control costs incurred by
affected sources. The EPA considers the efficiency assigned to packed-
bed scrubbers for purposes of calculating impacts to be representative
of that achieved by well-maintained and well-operated units controlling
emissions from hard chromium electroplating tanks. As with comments on
the emission limit based on composite mesh-pad systems, no data
supporting alternate emission limits for a standard based on packed-bed
scrubbers were submitted.

D. Selection of MACT for Decorative Chromium Electroplating and
Chromium Anodizing Tanks

1. Regulation of the Trivalent Chromium Plating Process
Eleven commenters disagreed that decorative chromium electroplating
tanks that use a trivalent chromium process should be regulated by the
proposed rule. Many of the commenters felt that the EPA had
insufficient data to conclude that the risk associated with this
process warranted regulation of those sources. Four commenters found
fault with the EPA's supporting data and noted that the level of
hexavalent chromium in a trivalent chromium bath that corresponds to
the EPA's estimate of hexavalent emissions from that bath would far
exceed that level of hexavalent chromium that would destroy the
trivalent bath. Three other commenters stated that use of the trivalent
chromium process should be encouraged by the EPA, because trivalent
processes result in less total chromium in process wastewater and less
sludge generation. One of the commenters suggested regulating trivalent
chromium electroplating processes under GACT to eliminate some of the
burden associated with the reporting, recordkeeping, and monitoring
requirements specified in the proposed rule.
Twelve commenters responded to the EPA's request for comment on
whether the trivalent chromium electroplating process should be
required for new sources. The majority of these commenters did not
think that this should be a requirement because the process was not
technically feasible for the full range of decorative chromium
electroplating operations. Two commenters pointed out inconsistencies
in the EPA's reasoning; the EPA can only require trivalent chromium
baths if it recognizes the difference in toxicity between hexavalent
and trivalent chromium.
The EPA has reconsidered the technical basis for regulating tanks
[[Page 4955]] using the trivalent chromium electroplating process and
the feasibility of requiring such a process for new sources. During
development of the proposed standards, the EPA evaluated the trivalent
chromium electroplating process as a pollution prevention alternative.
Chromic acid is not present in the plating solution in the trivalent
chromium processes, and hexavalent chromium is regarded as a bath
contaminant in these processes. In addition, all of the trivalent
chromium plating solutions with which EPA is familiar contain a wetting
agent as an inherent bath component. That is, the wetting agent is part
of the plating solution purchased from the vendor; it is not added
separately by the end user.
With a trivalent chromium plating process, the potential emissions
of chromium in any form are much lower because the concentration of
total chromium in trivalent chromium baths is approximately four times
lower than the total chromium concentration in chromic acid baths.
Trivalent chromium processes greatly reduce emissions of the most
potent form of chromium (hexavalent), and significantly lower emissions
of chromium in other forms. In addition to reduction of air emissions,
the use of trivalent chromium processes results in lower chromium
concentrations in process wastewaters and, consequently, reduces the
amount of sludge generated. Based on a source test conducted by the
EPA, total chromium emissions from a trivalent chromium bath are
approximately 99 percent less than those from a traditional,
uncontrolled decorative hexavalent chromium bath. Hexavalent chromium
emissions from a trivalent chromium bath were found to be approximately
equivalent to those emitted from a decorative hexavalent chromium bath
controlled by adding a wetting agent.
Although chromium emissions from the trivalent chromium process
were low, the EPA had not anticipated the presence of hexavalent
chromium in emissions from the trivalent electroplating process nor the
level of total chromium emissions. Given that the Act lists all forms
of chromium on the HAP list, the EPA considered the trivalent chromium
electroplating process as a source of chromium emissions as well as an
emission control alternative for the chromic acid electroplating
process. Based on the emission test results, a decorative hexavalent
chromium bath controlled by adding a wetting agent had equivalent
hexavalent chromium emissions and less total chromium emissions than a
trivalent chromium plating bath. (As previously stated, for trivalent
chromium baths, the wetting agent is inherent to the solution; it does
not need to be added by the user.) In addition, the trivalent chromium
process may not be technically feasible for all decorative chromium
electroplating applications. Therefore, the final rule does not require
the use of a trivalent chromium electroplating process for either
existing or new decorative chromium electroplating tanks.
The EPA has decided to regulate sources that use trivalent chromium
baths in the final rule. It is not clear whether the EPA data
accurately reflect emissions from the trivalent chromium electroplating
process, or if the analytical integrity of the data is suspect. In
light of the ambiguity of the air emissions data, and given the other
environmental benefits from the trivalent chromium process, the EPA has
decided to regulate these baths differently from hexavalent chromium
electroplating baths.
The final rule requires users of trivalent chromium baths to submit
an initial notification and a notification of compliance status
certifying that a trivalent chromium bath is being used and identifying
the bath components (specifically, the wetting agent). Subsequent
notifications are required only if the process is changed, or if a new
trivalent chromium process is introduced. Users of trivalent chromium
baths must also keep records of bath chemicals purchased so the EPA can
be assured that the bath contains a wetting agent. These notification
and recordkeeping requirements apply only to those trivalent chromium
baths that incorporate a wetting agent. The EPA has evaluated baths
with this characteristic and found them to have the environmental
benefits discussed above. Although such baths are not known to exist,
the EPA has chosen to regulate trivalent chromium baths that do not
incorporate a wetting agent in the same manner as decorative chromium
baths using a chromic acid solution. The EPA believes that this will
discourage the use of a trivalent chromium bath that does not have a
wetting agent as an inherent bath component.
2. Selection of MACT for Decorative Chromium Electroplating Tanks
Three commenters suggested that the proposed emission limit of
0.003 mg/dscm for decorative chromium electroplaters using hexavalent
chromium baths was too stringent. Two commenters did not think that a
source using either a fume suppressant or a fume suppressant in
conjunction with a packed-bed scrubber could consistently meet a limit
of 0.003 mg/dscm.
In response to the comments received at proposal, the EPA has
reconsidered the basis for the emission limit of 0.003 mg/dscm for
decorative chromium electroplating and chromium anodizing tanks. As
stated in the preamble to the proposed rule, this emission limit was
based on tests of a decorative chromium electroplating tank in which a
combination wetting agent/foam blanket was used to control emissions.
Tests had also been conducted on a decorative chromium electroplating
tank using only a foam blanket for control. The chromium emission data
for all types of fume suppressants ranged from 0.001 to 0.007 mg/dscm,
with the wetting agent/foam blanket data ranging from 0.001 to 0.003
mg/dscm and the foam blanket data ranging from 0.003 to 0.007 mg/dscm.
In evaluating whether the proposed emission limit of 0.003 mg/dscm
should be revised in the final rule, the EPA reassessed the effect the
test methods may have had on the emission data obtained. The analytical
method used for the fume suppressant test was colorimetric
spectroscopy. As more efficient control technologies (such as composite
mesh-pad systems) were developed, a more sensitive analytical method
was needed to measure the lower concentrations of chromium being
emitted. Therefore, the more sensitive ion chromatography method was
used in the later phases of emission testing for these standards
involving add-on control devices.
By using the less sensitive colorimetric analytical method, it is
unclear whether the variation found between the two types of fume
suppressants was due to a performance difference in the fume
suppressants or was an artifact of the analytical method used. The fact
that there is overlap between the foam blanket and wetting agent/foam
blanket data further indicates that this could be the case. (Both were
able to achieve a limit of 0.003 mg/dscm in one instance.) Therefore,
the EPA has concluded that the emission limit in the final rule should
be based on the performance of both foam blankets and wetting agents.
Accordingly, the emission limit selected for decorative chromium
electroplating and chromium anodizing tanks in the final rule is 0.01
mg/dscm. This emission limit was selected by applying a safety factor
to the highest measured data point (0.007 mg/dscm) to account for
variations in sampling and analytical procedures. The selection of this
emission limit is consistent with the methodology used to select
emission limits based on other control [[Page 4956]] techniques, as is
further discussed in section V.F.
3. Selection of MACT Floor/MACT for Chromium Anodizing Tanks
Three commenters questioned the MACT floor established by the EPA
for sources performing chromium anodizing. The commenters stated that
it did not appear that the EPA had sufficient data to perform a MACT
floor analysis for these sources. Commenters stated that chromium
anodizers and decorative chromium electroplaters that cannot use fume
suppressants should be considered separately, and the MACT floor for
such sources should be based on packed-bed scrubbers. Also, according
to six commenters, the standard for chromium anodizing tanks is not
achievable in all situations, especially when an add-on control device
is used in lieu of fume suppressants. One commenter stated that unless
the standard for chromium anodizing tanks controlled with add-on
control devices is set at 0.03 mg/dscm, sources will have to use an
add-on control device followed by a fiber-bed mist eliminator to
achieve the emission limit.
The MACT floor for chromium anodizing sources was based on
information available to the EPA on the source category. Information on
the industry was obtained through survey questionnaires to both
industry representatives and control system vendors, site visit
reports, and available emission data. Although information was not
available from all sources in the category, the EPA believes the
information was sufficient to satisfy the requirements of section
112(d)(3) of the Act. The survey responses, which included some
aerospace facilities, indicated that fume suppressants were the control
technique used predominantly in the industry. Section 112(d)(3) of the
Act prohibits the EPA from establishing a standard that is any less
stringent than the MACT floor for a category or subcategory of sources.
No technical reason was provided by industry, nor is one known to the
EPA, for creating a separate subcategory of sources for which fume
suppressants are not technically feasible. Thus, all new and existing
sources performing chromium anodizing must meet either an emission
limit of 0.01 mg/dscm or maintain the surface tension specified in the
rule. The EPA believes that the revised chromium emission limit of 0.01
mg/dscm for chromium anodizing tanks in the final rule is achievable by
sources using add-on control technology. Alternatively, the EPA
believes that the compliance timeframe for existing sources performing
chromium anodizing in the final rule (2 years) will allow these sources
to further investigate the feasibility of using fume suppressants.

E. Selection of the Format of the Standard

Seven commenters stated that the format of the standard should be
expressed as a process emission rate in milligrams of chromium emitted
per amp-hour of operation (mg/amp-hr), which would be consistent with
California rules, rather than as an emission concentration (mg/dscm).
According to the commenters, concentration-based standards are flawed
because they can be circumvented by dilution, concentration can vary
from system to system, and source test data indicate that outlet
concentrations vary widely for different inlet conditions. Several
commenters also pointed out that emissions should be correlated to
production rates because chromium emissions increase proportionately
with increased current. Two other commenters suggested that the final
rule specify acceptable process emission rates to avoid an equivalency
evaluation.
Based on the Agency's evaluation, the available test data indicate
that a process emission rate format will not ensure consistent
compliance with the control level required by the standard. The
concentration data collected by the EPA for the composite mesh-pad and
packed-bed scrubber systems do not overlap; that is, composite mesh-pad
systems consistently outperform packed-bed scrubbers. The process
emission rate data, on the other hand do overlap; even though composite
mesh-pad systems are a superior technology to packed-bed scrubbers,
both sometimes achieve the same process emission rate. This occurs
because two sources can be using the same control technology and
achieving the same outlet emissions concentration, but the one with the
higher current loading will have a lower process emission rate.
Commenters contend that this is reasonable because the production rate,
as measured in ampere-hours, is related to emissions. However, the
amount of current supplied to the tank is an indicator of the amount of
uncontrolled emissions from the tank, not the controlled emission level
from the tank. Because of the differences in process emission rate-
based and concentration-based standards, and the source-specific nature
of process emission rate standards, the EPA cannot cite an equivalent
process emission rate in the final rule.
Regarding the issue of circumvention of the standard through
dilution of the emission stream, the EPA believes that dilution of the
gas stream can be determined by reviewing test and permit data for a
facility. The outlet air flow rate measured during testing should
approximate the design air flow rate for the control system reported on
the permit application. If the two values differ significantly, then an
inspection of the control system can be made to determine if dilution
air is being introduced. It is also possible for a facility to dilute
the inlet gas stream to the control device by designing a system to
ventilate the electroplating tanks at air flow rates substantially
above those required for adequate ventilation. However, the increased
installation and maintenance costs associated with such a system would
outweigh the costs of complying with the standard without dilution.
Further, Sec. 63.4(b) of the General Provisions expressly prohibits
dilution as a means to comply with an emission limit. Therefore,
concerns of dilution of the air stream were not considered to outweigh
the benefits of a concentration-based format for the standard.
Eight commenters disagreed with the EPA's decision to base the
standard on emissions of total chromium rather than on emissions of
hexavalent chromium. Two commenters suggested allowing sources to
demonstrate compliance by testing for hexavalent chromium in lieu of
total chromium.
The EPA decided to base the standard on total chromium because the
HAP list identifies all chromium compounds, not just hexavalent
chromium compounds. In addition, based on testing conducted by the EPA
for these source categories, the available test data indicate that
hexavalent and total chromium levels in the emission stream were
essentially the same for chromic acid baths (varying within
10 percent in most instances). Because the EPA data base is
mainly comprised of data measured as hexavalent chromium, the final
rule does allow all sources using chromic acid baths to demonstrate
compliance by measuring either hexavalent or total chromium for all
sources.

F. Selection of the Emission Limits

Many commenters stated that the emission limit based on the use of
composite mesh-pad systems should be changed. Three commenters
suggested lowering the emission limit that is based on the use of
composite mesh-pad systems, stating that the EPA did not test the best
systems available, and suggested levels ranging from 0.001 mg/dscm to
0.009 mg/dscm. Other [[Page 4957]] commenters stated that the proposed
limit based on composite mesh-pad systems (0.013 mg/dscm) was too low.
Five commenters stated that the proposed emission limit for packed-bed
scrubbers was also too high, noting that some units tested by the EPA
did not achieve this limit.
The proposed emission limit of 0.013 mg/dscm for large hard
chromium electroplaters was based on tests that the EPA conducted on
actual control devices operating under normal process conditions. Lower
limits than the one selected for large sources were measured from these
devices, but the EPA based the emission limit on the highest measured
data point and believes that this limit is consistently achievable.
Regarding the emission limit based on packed-bed scrubbers, the EPA did
test some packed-bed scrubber systems that were not achieving the level
of 0.03 mg/dscm required by the proposed standard. However, these
devices were not optimized to achieve the higher removal efficiencies.
Specifically, when scrubbers were operated with periodic or continuous
washdown in which fresh water was supplied as makeup to the top of the
bed, a limit of at least 0.03 mg/dscm was achieved. The final rule
includes work practice standards that require the use of fresh water
added to the top of the packed bed whenever makeup additions occur.
Thus, packed-bed scrubbers that are operated in accordance with the
requirements of the rule should be able to achieve a limit of 0.03 mg/
dscm. The EPA does not think it is appropriate to substantially change
the emission limits based on the use of composite mesh-pad systems or
packed-bed scrubbers; the commenters did not provide data that
supported their claim that different emission limits are more
appropriate.
As discussed previously, the emission limit for decorative chromium
electroplating tanks and chromium anodizing tanks has been changed to
0.01 mg/dscm in the final rule by applying a safety factor to the
highest data point (0.007 mg/dscm) in the fume suppressant data base.
Similarly, the emission limit that is based on packed-bed scrubbers is
based on rounding the highest value (0.028 mg/dscm) in the packed-bed
scrubber data base to 0.03 mg/dscm to incorporate a safety factor.
Therefore, in the final rule, the emission limit that is based on the
use of composite mesh-pad systems (0.013 mg/dscm) has been adjusted to
0.015 mg/dscm by applying a safety factor to the highest value (0.013
mg/dscm) in the data base to ensure that the limit is achievable on a
consistent basis.

G. Selection of Compliance Dates

Several commenters stated that the proposed compliance dates for
affected existing sources did not allow sufficient time to achieve
compliance with the proposed rule. The majority of these commenters
suggested compliance timeframes of 2 to 3 years. According to the
commenters, the compliance period specified in the proposed rule did
not allow enough time to inform and educate affected owners and
operators; acquire capital; conduct research and test systems;
identify, purchase, and install control equipment; develop startup,
shutdown, and malfunction plans; train staff; build inventories; and
establish reporting and recordkeeping systems.
The Agency agrees with the commenters that the compliance
timeframes for affected sources should be increased. The EPA recognizes
that some of the facilities within all of the source categories will
have to investigate the technical feasibility of installing control
devices or using other technologies at their facility to meet the
standards. Also, many area sources are not yet aware that a rule is to
be promulgated for their industry, and time is needed for them to be
made aware of the requirements of this rule. Therefore, the EPA has
extended the compliance date to 1 year after the promulgation date for
existing decorative chromium electroplaters and 2 years after the
promulgation date for existing hard chromium electroplaters and
chromium anodizers. The EPA believes that the 1 year timeframe for
decorative chromium electroplaters is sufficient because, based on the
EPA's survey data, 80 percent of existing sources already use fume
suppressants and very few will need to install add-on air pollution
control devices. The EPA thinks that the compliance timeframes in the
final rule will address commenters concerns and still ensure
implementation of controls in a timely fashion. Due to the toxicity of
chromium compounds and the importance of controlling chromium emissions
to protect human health and the environment, the Agency decided against
a compliance time longer than 2 years for any of the source categories
affected.
To accommodate sources that cannot comply with the standard by the
compliance date, Sec. 63.6(i) of the General Provisions and
Sec. 63.343(a)(6) of subpart N allows a source to request a 1-year
compliance extension, which must be submitted 6 months in advance of
the compliance date identified in the regulation. This extension
combined with the compliance timeframes in the proposed rule could
provide a total of 2 years for compliance for decorative chromium
electroplaters and 3 years for compliance for hard chromium
electroplaters and chromium anodizers.

H. Selection of Monitoring Requirements

Section 114(a)(3) of the Act requires enhanced monitoring and
compliance certification of all major stationary sources. The annual
compliance certifications certify whether compliance has been
continuous or intermittent. Enhanced monitoring shall be capable of
detecting deviations from each applicable emission limit or standard
with sufficient representativeness, accuracy, precision, reliability,
frequency, and timeliness to determine if compliance is continuous
during a reporting period. The monitoring in this regulation satisfies
the requirements of enhanced monitoring.
1. Compliance Monitoring for Add-on Air Pollution Control Devices
Eleven comments addressed the suitability of measuring gas velocity
to demonstrate on-going compliance when add-on air pollution control
devices are used to comply with an emission limit. The commenters
stated that measuring gas velocity is very complicated, redundant with
measuring pressure drop, and not indicative of control device
performance. Two commenters pointed out that no suitable testing point
may be accessible, and a permanent measurement device may be fouled by
chromic acid.
Several commenters remarked on the requirement for measuring
chromium concentration in the scrubber water. Four of these commenters
stated that there is no obvious relationship between scrubber water
chromium concentration and scrubber performance. Other commenters
indicated that measurement of chromium concentration in scrubber water
with a hydrometer is not accurate.
In revising the proposed rule, the EPA recognizes that the
measurement of gas velocity could be burdensome and that other control
system parameters could potentially be used to determine on-going
compliance. Therefore, in the final rule, sources using composite mesh-
pad systems are required to monitor pressure drop across the device for
compliance purposes. Based on information gathered by the EPA, pressure
drop is directly related to composite mesh-pad system performance,
measurement of pressure drop is straightforward, and some users of
composite mesh-pad systems are currently monitoring pressure drop. The
[[Page 4958]] EPA believes that this change makes the rule more
flexible for regulated sources, while still ensuring that the EPA has a
mechanism for determining compliance with the emission limits at any
given time.
The final rule requires sources that use a packed-bed scrubber to
meet the emission limit must measure the velocity pressure at the inlet
to the control system as well as the pressure drop across the device.
The relationship between pressure drop and packed-bed scrubber
performance is less reliable than the relationship between pressure
drop and composite mesh-pad system performance because of the lower
pressure drop in packed-bed scrubbers. Therefore, the EPA also requires
sources using packed-bed scrubbers to monitor the velocity pressure at
the inlet to the control device. This requirement will ensure that the
gas velocity through the control system is maintained in accordance
with vendor recommendations and, along with the pressure drop
monitoring, will ensure that the control system is properly operating.
The requirement that sources using packed-bed scrubbers monitor the
chromium concentration in the scrubber water has been eliminated,
because the EPA concluded that monitoring of the velocity pressure at
the control device inlet and the pressure drop across the device was
sufficient to demonstrate compliance with the emission limits when
packed-bed scrubbers are used.
Compliance monitoring requirements for fiber-bed mist eliminators
have been added in the final rule because these devices could likely be
used to meet the emission limitations, and some fiber-bed mist
eliminators are known to be in use. Sources that use a fiber-bed mist
eliminator to meet the emission limit must measure the pressure drop
across the fiber-bed unit, as well as the pressure drop across the
control device upstream of the fiber-bed unit that is in place to
prevent plugging.
As discussed above, several changes have been made to the
monitoring requirements specified in the proposed rule based on the
EPA's review of comments received on the proposed rule and further
investigation of which process parameters relate best to proper
performance of the control systems. The final compliance monitoring
requirements are found in Sec. 63.343(c) of the final rule.
2. Work Practice Standards for Add-on Air Pollution Control Devices
In the proposed rule, Operation and Maintenance (O&M) requirements
for add-on air pollution control devices consisted of adding makeup
water to packed-bed scrubbers, requiring washdown of composite mesh
pads, and various inspections for both types of control devices. The
majority of comments focused on the requirements associated with makeup
water for packed beds and washdown for composite mesh pads. Several
commenters suggested alternatives for the requirements for adding
makeup water to packed-bed scrubbers. The commenters disagreed that
makeup water can or should be added to the top of the scrubber. Others
questioned the need to use fresh water in scrubbers and composite mesh
pads because doing so increased wastewater flows. Other commenters
requested that the final rule define the term ``fresh water.''
In the final rule, the O&M requirements have been replaced with
work practice standards that address O&M practices [Sec. 63.342(f)].
The final rule continues to require sources using packed-bed scrubbers
to meet an emission limit and ensure that all makeup water is fresh and
supplied to the unit at the top of the packed bed. The EPA considers
this requirement essential to meeting the prescribed emission limit.
During source testing conducted by the EPA to establish the performance
level of packed-bed scrubbers, it was noted that a system equipped with
an overhead spray system that periodically cleaned the packing with
fresh water performed much better than a system without such cleaning.
Based on those results, the EPA believes that without the requirement
that makeup water be fresh and added to the top of the packed bed,
scrubbers will not continuously meet the required emission limit even
if the scrubber met the limit during the initial performance test and
is operated within the appropriate ranges of pressure drop and velocity
pressure. For clarification, the term fresh water is defined in the
final rule.
There were 11 comments on the washdown requirements for composite
mesh-pad systems. Several of these commenters indicated that the
specified washdown frequency was either impractical, infeasible, or
unnecessary. Seven commenters suggested washdown requirements for
composite mesh-pad systems be site-specific, as recommended by vendors,
or apply only if pressure drop determinations indicate the potential
presence of chromic acid buildup. Two commenters indicated that the
washdown water will likely exceed the quantity of water that can be
recycled, thus resulting in a wastewater stream that needs to be
treated.
In the final rule, the EPA has revised the requirement that sources
complying with an emission limit by using a composite mesh-pad system
perform washdown of the pads. The EPA believes that washdown is an
essential part of composite mesh-pad system operation; if proper system
maintenance such as washdown does not occur, there will be a decline in
system performance. However, instead of specifying a washdown
frequency, the revised rule specifies that washdown be conducted in
accordance with manufacturers' recommendations as part of a facility's
O&M plan. The EPA recognizes that vendor designs for these systems vary
significantly, and the requirements for washdown are based on the
design of the unit and the operation of the plating tanks. The
frequency of washdown is dependent upon the position of the pad in the
control unit. Pads located in the front portions of the unit are
exposed to higher chromium concentrations and, therefore, require
washdowns more frequently than those located in the back of the unit.
Washdown practices recommended by manufacturers vary from continuous in
some cases to a maximum of once every 1 to 2 weeks.
The EPA has also added work practice standards for fiber-bed mist
eliminators in the final rule because these control devices are likely
to meet the emission limitations, and are known to be in use by sources
affected by these standards. The work practice standards identified for
fiber-bed mist eliminators are analogous to those identified for the
composite mesh-pad system. Washdown requirements for fiber-bed units
will depend on the efficiency of the prefiltering device and the
operation of the plating tanks. Fiber-bed units installed downstream of
more efficient prefiltering systems, such as packed-bed scrubbers, will
require less frequent washdown than those using a less effective
prefiltering device because of the lower inlet loading to the unit.
Most vendors of fiber-bed units recommended monitoring of the pressure
drop as a means of gauging when the unit needs to be washed down. If an
increase in pressure drop is observed, then the unit will be washed
down to remove any chromium built up on the fiber elements.
3. Frequency of Monitoring for Add-on Air Pollution Control Devices
Fourteen commenters indicated that the daily monitoring of add-on
air pollution control devices is unnecessary, particularly for small
sources, and suggested that at least some of the monitoring be required
on only a weekly, monthly, or quarterly basis. [[Page 4959]] Other
commenters suggested that monitoring be tied to production rate, that
monitoring be conducted only on days when electroplating is taking
place, or that monitoring requirements be reduced after the source has
been in compliance for 6 months. Commenters also requested that
monitoring be required only during tank operation, and that tank
operation be defined. Several commenters disagreed with the proposed
inspection frequency because of increased exposure hazards to persons
conducting the inspections or of anticipated down-time due to the
inaccessibility of control systems.
In response to these comments and to minimize the burden on
regulated sources, the EPA has reduced the burden associated with the
compliance monitoring and work practice standards in the final rule.
The final rule continues to require daily monitoring of pressure drop
and velocity pressure for compliance, but the monitoring procedures
specified in the rule are the minimum required to determine continuous
compliance. Once the monitoring devices are in place, the only labor
required is that needed to read the gauges. The frequency of
inspections for compliance with the work practice standards has also
been reduced or revised. In the final rule, the frequency of
inspections has been reduced from monthly or daily to once every 3
months. The EPA believes that the inspections are still necessary to
ensure that system degradation is not occurring over time, because
gradual degradation may not be apparent from compliance monitoring
alone. Some commenters noted that their systems were not accessible for
inspection, or that the inspection would result in extended downtime.
The compliance timeframes in the final rule should allow sources
sufficient time to retrofit their systems to facilitate inspections,
and the negative effects of any downtime are minimized by the reduced
inspection frequency.
The final rule also has been clarified so that monitoring
requirements apply only during tank operation; tank operation is
defined in Sec. 63.341.
4. Compliance Monitoring Associated With Fume Suppressants
Regarding the use of wetting agent-type fume suppressants, seven
commenters indicated that the requirement for maintaining surface
tension below 40 dynes/cm for chromic acid baths is inappropriate. The
reasons provided by the commenters were that a surface tension standard
may not be prudent to demonstrate compliance, a direct correlation
between exceedance of parameters and emission limits has not been
established, and the rule should allow sources to set their own
compliance value for surface tension. Other commenters noted that the
specified limit was either too low or was not consistent with
manufacturers' recommendations.
Based on data collected by the EPA, the performance of an
electroplating bath controlled with a wetting agent-type fume
suppressant can be determined by the surface tension of the bath.
Therefore, the EPA believes that there is a direct link between surface
tension and emissions. The EPA also believes that it is necessary and
appropriate to set a default value for surface tension in the rule.
Based on the EPA's experience, many decorative chromium electroplating
tanks are not ventilated, making source testing impossible without
considerable retrofitting.
The EPA has increased the default surface tension limit from the
proposed 40 dynes/cm to 45 dynes/cm based on information received
during the comment period. However, if a facility believes that a
different surface tension value is appropriate, the rule allows a
source to conduct a performance test concurrently with surface tension
monitoring to establish the maximum surface tension that corresponds to
compliance with the emission limits. The source would subsequently
monitor surface tension, with an exceedance occurring if the surface
tension of the bath exceeded the value measured during the performance
test.
Regarding foam blanket-type fume suppressants, several commenters
were concerned about the technique for measuring foam blanket thickness
and the potential hazards associated with this measurement. Another
commenter stated that the stack testing requirement is unreasonable due
to its excessive cost.
The EPA does not believe that it is necessary to specify a
procedure because it is simply a depth measurement. Specifying a
technique may also hinder the development of site-specific techniques
to reduce worker exposure. The EPA believes that wetting agents are
safer than foam blankets because foam blankets present a potential
safety hazard. The foam traps the hydrogen gas and chromic acid mist in
the foam layer; if these gases build up and a spark is generated, a
hydrogen explosion will result. As a means of encouraging wetting agent
use over foam blankets, sources using wetting agents do not have to
conduct a performance test unless they want to set a surface tension
limit other than the default value of 45 dynes/cm. The EPA believes
that the compliance timeframes in the final rule will allow sources
that currently use foam blankets the opportunity to explore the use of
wetting agents. Sources that wish to continue using foam blankets will
be required to conduct a performance test.
5. Frequency of Monitoring Associated With Fume Suppressants
There were over 20 comments related to the frequency of monitoring
surface tension. Several of these commenters made recommendations for
alternate monitoring schedules, ranging from daily to monthly
monitoring, in place of the 4-hour schedule. Among the reasons cited
for decreasing the surface tension monitoring frequency were that
surface tension does not change on a daily or weekly basis, measuring
surface tension is very time-consuming and could require someone full-
time if there were multiple tanks, and frequent monitoring results in
increased worker exposure.
Thirteen commenters provided remarks regarding the burden of hourly
testing for sources using foam blankets. The commenters noted that foam
blankets that are used according to manufacturer's instructions are
designed to last 24 hours provided the air is not agitated at the
surface near the anodes and freeboard height is adequate. Therefore,
visual observation is adequate for determining foam blanket
effectiveness. Other commenters stated that the excessive monitoring
requirements for foam blankets discourage their use, yet several States
recommend or require foam blankets with less testing and recordkeeping
than that proposed by the EPA.
In response to comments and some data received, the EPA recognizes
that the 4-hour surface tension monitoring frequency specified in the
proposed rule may be burdensome, and in some cases, unnecessary. The
EPA has insufficient data, however, to establish the monitoring
frequency that is appropriate for each mode of bath operation.
Therefore, the final rule allows a decrease in monitoring frequency if
no exceedances occur. Section 63.343(c)(5)(ii)(B) specifies that the
surface tension be measured once every 4-hours of tank operation for
the first 40 hours of tank operation after the compliance date. If no
exceedances occur, monitoring can occur once every 8 hours of tank
operation. Once there are again no exceedances during 40 hours of tank
operation, surface tension measurement may be conducted once every 40
hours of tank operation on an on-going basis, until an exceedance
occurs. Once an exceedance of the [[Page 4960]] standard occurs or the
electroplating solution is changed out, the original monitoring
schedule must be resumed.
Likewise, the final rule contains allowances to decrease the
frequency of monitoring foam blanket thickness. The proposed hourly
frequency is based on the EPA's experience that foam blankets can
deplete quickly and must be closely monitored. The final rule is
unchanged in that sources using a foam blanket must conduct a
performance test, and the initial monitoring frequency is once per
hour. However, as with wetting agents, the final rule allows a decrease
in monitoring frequency if no exceedances occur. Section
63.343(c)(6)(ii)(B) specifies that the foam blanket thickness be
measured once every hour of tank operation for the first 40 hours of
tank operation after the compliance date. If no exceedances occur, the
time between monitoring may be increased to once every 4 hours of tank
operation. Once there are no exceedances during 40 hours of tank
operation, foam blanket thickness measurement may be conducted once
every 8 hours of tank operation on an on-going basis. As with wetting
agents, if there is an exceedance or if the electroplating bath is
changed out, the original monitoring schedule must be resumed.
I. Selection of Test Methods
Three commenters requested that CARB Method 425 be evaluated for
equivalency, and if determined to be equivalent, be identified as such
in the rule. These commenters also stated that sources that have
performed this test should not have to retest. Four commenters asked
whether retesting will be required if sources have conducted
performance tests previously using 306, 306A, or an equivalent test
method.
Section 63.344(c)(2) identifies the conditions under which the CARB
Method 425 is considered equivalent. Basically, the acceptability of
this test method will depend upon the analysis rather than the sampling
train or sampling procedure. Regarding the issue of whether retesting
is required, Sec. 63.344(b) of the final rule outlines the criteria
that must be met for a previous source test to be acceptable.
Two commenters requested that the rule provide guidance on how to
verify compliance when both chromium anodizing and hard chromium
electroplating tanks are vented to a common control device. Three
commenters pointed out that the regulation does not account for the
situation in which chromium electroplating sources share a ventilation
system with nonchromium sources that could introduce dilution air.
Three commenters noted that it is extremely difficult to reconfigure
some existing systems in such a way that only the emissions from
chromium electroplating or anodizing are tested.
There are basically two situations involving multiple tanks
manifolded to one control system: (1) The multiple tanks include a
chromium electroplating or chromium anodizing tank among other tanks
not affected by the rule; or (2) the multiple tanks include chromium
tanks performing different operations (e.g., electroplating and
anodizing) or hard chromium tanks subject to different emission limits
(e.g., a new tank and an existing small tank), which may or may not be
controlled with nonaffected sources. Section 63.344(e) of the final
rule includes compliance provisions for both of these situations.
J. Selection of Reporting and Recordkeeping Requirements
Several commenters stated that the frequency of recordkeeping and
reporting outlined in the proposed rule was overly burdensome and
suggested several alternatives. Seven commenters stated that the types
of recordkeeping required by the rule are inappropriate. In general,
the commenters remarked that records, such as the amount of chemicals
used and purchased and the amount of fume suppressant material added do
not indicate compliance. Two commenters stated that recordkeeping
requirements be limited to only surface tension measurements because
that measurement is the basis of compliance. One commenter indicated
there is no environmental benefit to keeping records of gas velocities,
pressure drops, washdown conditions, and scrubber water chromium
concentrations. Two commenters stated that maintaining records at a
facility for 5 years is excessive; a more appropriate length of time
would be 3 years. One commenter suggested a minimum of 2 years.
Two commenters suggested that the reporting schedule be replaced
with a requirement that the source submit an annual certification that
necessary control parameters have been met, consistent with the annual
certification requirements of title V. Another commenter indicated that
sources should not be required to submit compliance reports if the
source's permitting agency inspects the onsite records annually.
Finally, one commenter suggested that the rule allow a reduced
reporting frequency after 2 years if sources do not experience
exceedances of any State or Federal emission standards.
Seven commenters stated that the costs associated with the
monitoring and recordkeeping constituted an unnecessary burden to both
large and small facilities. These commenters also noted that the EPA
underestimated the costs associated with monitoring, reporting, and
recordkeeping. Two of the commenters stated that small businesses do
not have the resources to keep extensive records. Another commenter
pointed out that the EPA has recognized differences in large and small
facilities in selecting MACT emission standards and should also
recognize differences between large and small facilities in selecting
reporting, recordkeeping, and permitting requirements.
To respond to comments received and to reduce the burden on the
many area sources that will be subject to these standards, the
monitoring, reporting, and recordkeeping requirements have been reduced
in the final rule to the extent possible while still providing the EPA
with the ability to determine a source's continuous compliance status.
The recordkeeping requirements are contained in Sec. 63.346 of the
final rule. The EPA concurs that the records required to be kept should
correspond specifically to that which is required to demonstrate
compliance. As such, recordkeeping associated with fume suppressants
requires only that sources maintain records of the date and time of
surface tension or foam blanket thickness measurements, as appropriate,
the value measured, and the date and time of additions of fume
suppressant to the bath. Likewise, the recordkeeping associated with
the add-on air pollution control devices is reduced to the extent that
the monitoring requirements have been reduced. Sources will have to
keep records of pressure drop and velocity pressure, as appropriate, as
well as records to document adherence with the O&M plan required by
Sec. 63.342(f)(3).
The final rule is unchanged from proposal in that it requires that
owners or operators of affected sources maintain records for a period
of 5 years following each occurrence, measurement, maintenance,
corrective action, report, or record. This requirement is consistent
with the General Provisions and with the title V permit program. The
EPA believes retention of records for 5 years allows the EPA to
establish a source's history and pattern of compliance for purposes of
determining the appropriate level of enforcement action.
The final rule also requires submission of on-going compliance
status reports to document whether a [[Page 4961]] source has been in
continuous compliance with the standards. The final rule contains
different reporting schedules for major and area sources. Major sources
are required to submit on-going compliance status reports semiannually,
unless an exceedance occurs, at which time quarterly reports would be
required. This change is analogous to the requirements of the final
General Provisions, which had only been proposed at the time of this
proposed rulemaking.
In an effort to reduce the burden on area sources, the final rule
allows area sources to complete an annual compliance report, and allows
the source to maintain the report on site, to be made available to the
Administrator or permitting authority upon request. The EPA recognizes
that many permitting authorities may not be equipped to handle reports
from area sources, and that these sources may not be the sources of
primary concern to the authority. However, the requirements in the
final rule do not alleviate affected area sources from complying with
the reporting requirements of State or Federal operating permit
programs under title V. The rule does require that area sources submit
reports semiannually if exceedances occur, or if required by the
Administrator or permitting authority.
Sources using a trivalent chromium bath are only required to keep
records of the bath ingredients purchased. These sources must submit an
initial notification and notification of compliance status, but are not
required to submit on-going compliance status reports.
As a result of the reduced monitoring, reporting, and recordkeeping
in the final rule compared to the proposed rule, the costs of these
activities have also been reduced. A comparison of the cost of the
monitoring, reporting, and recordkeeping associated with the final and
proposed rules was presented in section III.B of this preamble for each
of the regulated source categories.
One commenter requested that the rule clearly state which sections
of the General Provisions apply to chromium electroplating sources and
which do not apply. To eliminate confusion concerning the applicability
of the General Provisions to this source category, Table 1 of subpart N
lists which of the General Provisions to part 63 apply and which do not
apply to affected sources.

K. Operating Permit Program

Eleven commenters stated that area sources should not be required
to obtain title V operating permits because the costs for area sources
to obtain title V permits would be overly burdensome, and the emissions
from these sources may be insignificant. Three of these commenters
suggested that the rule explicitly state that a permit is required only
for applicable emissions units at nonmajor sources. Two commenters
asked that a general permit be included in the final rule to reduce the
burden for small facilities. Another commenter stated that a title V
permit is not necessary because existing requirements are enforceable
through State and local permits. This commenter and one other commenter
pointed out that because area sources are not likely to be subject to
multiple MACT standards or to employ emissions averaging and complex
alternate operating scenarios, title V permits do not benefit the area
sources.
Two commenters stated that in preparing their title V permit
programs, States did not anticipate a need for emission-unit specific
permits at nonmajor sources, and inclusion of nonmajor sources under
title V will require that many local agencies revise their permit
programs. Two other commenters stated that States will not have the
resources for completing title V permits for area sources; some states
have exempted nonmajor sources from their permitting programs until the
nonmajor source permitting rule is promulgated in the late 1990's.
The EPA believes that requiring all sources that are subject to the
standards, including area sources, to obtain title V operating permits
is important because of the toxicity of chromium compounds and the
close proximity of many of these sources to residential areas. The EPA
believes that permitting area sources will not be overly burdensome to
permitting authorities and affected sources for the reasons given
below.
First, many States are already permitting these sources under their
State permit programs. The preamble to the final part 70 rule states
that ``some nonmajor sources would already be permitted at the State
level, and therefore would have some experience with the permitting
process and completing permit applications.'' Therefore, a State would
have little reason to defer title V permitting of sources that already
have State operating permits. Second, the burden may be reduced
significantly by issuing general permits to these sources. According to
the preamble to the final part 70 rule, general permits ``* * * provide
an alternative means for permitting sources for which the procedures of
the normal permitting process would be overly burdensome, such as area
sources under section 112* * *'' Under this option, States would
develop a single general permit for this source category and issue it
to individual sources; or alternatively, a letter or certification may
be used. The burden would also be reduced by using general permits
because public participation and the EPA and affected State review is
only necessary when the initial general permit is drafted and issued.
When subsequent general permits are issued to individual sources, these
activities are not required. Finally, States are developing small
business assistance programs (SBAP's) to assist these types of sources
with the permitting process that will be funded using the annual fees
collected from permitted sources. Small businesses may also be eligible
for reduced permitting fees. Also, the EPA is developing a guidance
document, scheduled to be completed by January 1995, which will include
sample forms for monitoring, recordkeeping, and reporting requirements,
and a simplified general operating permit.
Under title V, sources must include information on all emission
points (except those considered insignificant under the State or local
permit program) in their permit application. However, only these
emission points that are subject to regulation will be addressed in the
permit.

VI. Administrative Requirements

A. Docket

The docket for this rulemaking is A-88-02. The docket is an
organized and complete file of all the information submitted to or
otherwise considered by the EPA in the development of this rulemaking.
The principal purposes of the docket are: (1) To allow interested
parties a means to identify and locate documents so that they can
effectively participate in the rulemaking process; and (2) to serve as
the record in case of judicial review (except for interagency review
materials) [section 307(d)(7)(A) of the Act]. The docket is available
for public inspection at the EPA's Air and Radiation Docket and
Information Center, the location of which is given in the ADDRESSES
section of this notice.

B. Executive Order 12866

Under Executive Order 12866 [58 FR 51735 (October 4, 1993)], the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may: [[Page 4962]]
(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 obligations 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.
Pursuant to the terms of the Executive Order 12866, the Office of
Management and Budget (OMB) has notified the EPA that this action is a
``significant regulatory action'' within the meaning of the Executive
Order. For this reason, this action was sent to OMB for review. Changes
made in response to OMB suggestions or recommendations will be
documented in the public record.

C. Paperwork Reduction Act

Information collection requirements associated with this rule have
been approved by OMB under the provisions of the Paperwork Reduction
Act of 1980, 44 U.S.C. 3501 et seq., and have been assigned OMB control
number 2060-0327. An Information Collection Request (ICR) document has
been prepared by the EPA (ICR No. 1611.02) to reflect the changed
information requirements of the final rule and has been submitted to
OMB for review. A copy may be obtained from Sandy Farmer, Information
Policy Branch, EPA, 401 M Street, SW. (2136), Washington, DC 20460, or
by calling (202) 260-2740.
The public reporting burden for this collection of information is
estimated to average 34 hours per respondent in the first year, 117
hours per respondent in the second year, and 297 hours per respondent
in the third year. This estimate includes the time required for
reviewing instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. The burden is greatest in the second and
third years because this is when performance tests will be conducted.
An on-going burden of 104 hours per respondent is representative of the
burden following the third year.
Send comments regarding the burden estimate or any other aspect of
this collection of information, including suggestions for reducing this
burden, to Chief, Information Policy Branch, EPA, 401 M Street, SW.
(2136), Washington, DC 20460; and to the Office of Information and
Regulatory Affairs, Office of Management and Budget, Washington, DC
20503, marked ``Attention: Desk Officer for EPA.''

D. Regulatory Flexibility Act

The Regulatory Flexibility Act of 1980 (5 U.S.C. 601 et seq.)
requires that a Regulatory Flexibility Analysis be performed for all
rules that have ``significant impact on a substantial number of small
entities.'' If a preliminary analysis indicates that a proposed
regulation would have a significant economic impact on 20 percent or
more of small entities, then a regulatory flexibility analysis must be
prepared.
Present Regulatory Flexibility Act guidelines define an economic
impact as significant if it meets one of the following criteria:
(1) Compliance increases annual production costs by more than 5
percent, assuming costs are passed on to consumers;
(2) Compliance costs as a percentage of sales for small entities
are at least 10 percent more than compliance costs as a percentage of
sales for large entities;
(3) Capital costs of compliance represent a ``significant'' portion
of capital available to small entities, considering internal cash flow
plus external financial capabilities; or
(4) Regulatory requirements are likely to result in closures of
small entities.
Using the Small Business Administration's definition of a small
business for SIC Code 3471 of less than 500 employees, it has been
determined that none of the above criteria are triggered. In the hard
chromium electroplating source category, the number of small businesses
is estimated to be 1,170. None of the regulatory alternatives
considered will significantly impact 20 percent of this operation. For
example, the estimated number of closures is approximated as less than
5 percent. Likewise, the standards for decorative chromium
electroplaters and chromium anodizers would not cause any of the above
criteria to be triggered.
Pursuant to the provisions of 5 U.S.C. 605(b), I hereby certify
that this rule will not have a significant economic impact on a
substantial number of small business entities because the number of
small business entities that would be affected is not significant.

E. Miscellaneous

In accordance with section 117 of the Act, publication of this
promulgated rule was preceded by consultation with appropriate advisory
committees, independent experts, and Federal departments and agencies.
This regulation will be reviewed 8 years from the date of
promulgation. This review will include an assessment of such factors as
evaluation of the residual health risks, any overlap with other
programs, the existence of alternative methods, enforceability,
improvements in emission control technology and health data, and the
recordkeeping and reporting requirements.

List of Subjects in 40 CFR Parts 9 and 63

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

Dated: November 22, 1994.
Carol M. Browner,
Administrator.

For the reasons set out in the preamble, title 40, Chapter I of the
Code of Federal Regulations is amended as set forth below.

PART 9--[AMENDED]

1. The authority citation for part 9 continues to read as follows:

Authority: 7 U.S.C. 135 et seq., 1235-136y; 15 U.S.C. 2001,
2003, 2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C.
9701; 33 U.S.C. 1251 et seq., 1311, 1313d, 1314, 1321, 1326, 1330,
1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR, 1971-
1975; Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-
1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3,
300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-
9657, 11023, 11048.

2. Section 9.1 is amended by adding a new entry to the table under
the indicated heading in numerical order to read as follows:

Sec. 9.1 OMB approvals under the Paperwork Reduction Act.

* * * * *

------------------------------------------------------------------------
OMB control
40 CFR citation No.
------------------------------------------------------------------------

* * * * *
National Emission Standards for Hazardous Air Pollutants
for Source Categories:

* * * * *
63.345-63.347.............................................. 2060-0327

* * * * *
------------------------------------------------------------------------

[[Page 4963]] PART 63--[AMENDED]

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

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

2. Section 63.14 is amended by adding paragraphs (b) (4) and (5) to
read as follows:

Sec. 63.14 Incorporation by reference.

* * * * *
(b) * * *
(4) ASTM D 1193-77, Standard Specification for Reagent Water, IBR
approved for Method 306, section 4.1.1 and section 4.4.2, of appendix A
to part 63.
(5) ASTM D 1331-89, Standard Test Methods for Surface and
Interfacial Tension of Solutions of Surface Active Agents, IBR approved
for Method 306B, section 2.2, section 3.1, and section 4.2, of appendix
A to part 63.
* * * * *
3. By adding a new subpart N to read as follows:
Subpart N--National Emission Standards for Chromium Emissions From Hard
and Decorative Chromium Electroplating and Chromium Anodizing Tanks
Sec.
63.340 Applicability and designation of sources.
63.341 Definitions and nomenclature.
63.342 Standards.
63.343 Compliance provisions.
63.344 Performance test requirements and test methods.
63.345 Provisions for new and reconstructed sources.
63.346 Recordkeeping requirements.
63.347 Reporting requirements.

Table 1 to Subpart N of Part 63--General Provisions Applicability to
Subpart N

Subpart N--National Emission Standards for Chromium Emissions From
Hard and Decorative Chromium Electroplating and Chromium Anodizing
Tanks

Sec. 63.340 Applicability and designation of sources.

(a) The affected source to which the provisions of this subpart
apply is each chromium electroplating or chromium anodizing tank at
facilities performing hard chromium electroplating, decorative chromium
electroplating, or chromium anodizing.
(b) Owners or operators of affected sources subject to the
provisions of this subpart must also comply with the requirements of
subpart A of this part, according to the applicability of subpart A of
this part to such sources, as identified in Table 1 of this subpart.
(c) Process tanks associated with a chromium electroplating or
chromium anodizing process, but in which neither chromium
electroplating nor chromium anodizing is taking place, are not subject
to the provisions of this subpart. Examples of such tanks include, but
are not limited to, rinse tanks, etching tanks, and cleaning tanks.
Likewise, tanks that contain a chromium solution, but in which no
electrolytic process occurs, are not subject to this subpart. An
example of such a tank is a chrome conversion coating tank where no
electrical current is applied.
(d) Affected sources in which research and laboratory operations
are performed are exempt from the provisions of this subpart when such
operations are taking place.
(e) The owner or operator of an affected source subject to the
requirements of this subpart is required to obtain a title V permit
from the permitting authority in which the affected source is located.

Sec. 63.341 Definitions and nomenclature.

(a) Definitions. Terms used in this subpart are defined in the Act,
in subpart A of this part, or in this section. For the purposes of
subpart N of this part, if the same term is defined in subpart A of
this part and in this section, it shall have the meaning given in this
section.
Add-on air pollution control device means equipment installed in
the ventilation system of chromium electroplating and anodizing tanks
for the purposes of collecting and containing chromium emissions from
the tank(s).
Air pollution control technique means any method, such as an add-on
air pollution control device or a chemical fume suppressant, that is
used to reduce chromium emissions from chromium electroplating and
chromium anodizing tanks.
Base metal means the metal or metal alloy that comprises the
workpiece.
Bath component means the trade or brand name of each component(s)
in trivalent chromium plating baths. For trivalent chromium baths, the
bath composition is proprietary in most cases. Therefore, the trade or
brand name for each component(s) can be used; however, the chemical
name of the wetting agent contained in that component must be
identified.
Chemical fume suppressant means any chemical agent that reduces or
suppresses fumes or mists at the surface of an electroplating or
anodizing bath; another term for fume suppressant is mist suppressant.
Chromic acid means the common name for chromium anhydride
(CrO3).
Chromium anodizing means the electrolytic process by which an oxide
layer is produced on the surface of a base metal for functional
purposes (e.g., corrosion resistance or electrical insulation) using a
chromic acid solution. In chromium anodizing, the part to be anodized
acts as the anode in the electrical circuit, and the chromic acid
solution, with a concentration typically ranging from 50 to 100 grams
per liter (g/L), serves as the electrolyte.
Chromium electroplating or chromium anodizing tank means the
receptacle or container in which hard or decorative chromium
electroplating or chromium anodizing occurs.
Composite mesh-pad system means an add-on air pollution control
device typically consisting of several mesh-pad stages. The purpose of
the first stage is to remove large particles. Smaller particles are
removed in the second stage, which consists of the composite mesh pad.
A final stage may remove any reentrained particles not collected by the
composite mesh pad.
Decorative chromium electroplating means the process by which a
thin layer of chromium (typically 0.003 to 2.5 microns) is
electrodeposited on a base metal, plastic, or undercoating to provide a
bright surface with wear and tarnish resistance. In this process, the
part(s) serves as the cathode in the electrolytic cell and the solution
serves as the electrolyte. Typical current density applied during this
process ranges from 540 to 2,400 Amperes per square meter (A/m2)
for total plating times ranging between 0.5 to 5 minutes.
Electroplating or anodizing bath means the electrolytic solution
used as the conducting medium in which the flow of current is
accompanied by movement of metal ions for the purposes of
electroplating metal out of the solution onto a workpiece or for
oxidizing the base material.
Emission limitation means, for the purposes of this subpart, the
concentration of total chromium allowed to be emitted expressed in
milligrams per dry standard cubic meter (mg/dscm), or the allowable
surface tension expressed in dynes per centimeter (dynes/cm).
Facility means the major or area source at which chromium
electroplating or chromium anodizing is performed.
Fiber-bed mist eliminator means an add-on air pollution control
device that removes contaminants from a gas stream through the
mechanisms of inertial impaction and Brownian diffusion. These devices
are typically installed downstream of another control device, which
serves to prevent plugging, and [[Page 4964]] consist of one or more
fiber beds. Each bed consists of a hollow cylinder formed from two
concentric screens; the fiber between the screens may be fabricated
from glass, ceramic plastic, or metal.
Foam blanket means the type of chemical fume suppressant that
generates a layer of foam across the surface of a solution when current
is applied to that solution.
Fresh water means water, such as tap water, that has not been
previously used in a process operation or, if the water has been
recycled from a process operation, it has been treated and meets the
effluent guidelines for chromium wastewater.
Hard chromium electroplating or industrial chromium electroplating
means a process by which a thick layer of chromium (typically 1.3 to
760 microns) is electrodeposited on a base material to provide a
surface with functional properties such as wear resistance, a low
coefficient of friction, hardness, and corrosion resistance. In this
process, the part serves as the cathode in the electrolytic cell and
the solution serves as the electrolyte. Hard chromium electroplating
process is performed at current densities typically ranging from 1,600
to 6,500 A/m2 for total plating times ranging from 20 minutes to
36 hours depending upon the desired plate thickness.
Hexavalent chromium means the form of chromium in a valence state
of +6.
Large, hard chromium electroplating facility means a facility that
performs hard chromium electroplating and has a maximum cumulative
potential rectifier capacity greater than or equal to 60 million
ampere-hours per year (amp-hr/yr).
Maximum cumulative potential rectifier capacity means the summation
of the total installed rectifier capacity associated with the hard
chromium electroplating tanks at a facility, expressed in amperes,
multiplied by the maximum potential operating schedule of 8,400 hours
per year and 0.7, which assumes that electrodes are energized 70
percent of the total operating time. The maximum potential operating
schedule is based on operating 24 hours per day, 7 days per week, 50
weeks per year.
Operating parameter value means a minimum or maximum value
established for a control device or process parameter which, if
achieved by itself or in combination with one or more other operating
parameter values, determines that an owner or operator is in continual
compliance with the applicable emission limitation or standard.
Packed-bed scrubber means an add-on air pollution control device
consisting of a single or double packed bed that contains packing media
on which the chromic acid droplets impinge. The packed-bed section of
the scrubber is followed by a mist eliminator to remove any water
entrained from the packed-bed section.
Research or laboratory operation means an operation whose primary
purpose is for research and development of new processes and products,
that is conducted under the close supervision of technically trained
personnel, and that is not involved in the manufacture of products for
commercial sale in commerce, except in a de minimis manner.
Small, hard chromium electroplating facility means a facility that
performs hard chromium electroplating and has a maximum cumulative
potential rectifier capacity less than 60 million amp-hr/yr.
Stalagmometer means a device used to measure the surface tension of
a solution.
Surface tension means the property, due to molecular forces, that
exists in the surface film of all liquids and tends to prevent liquid
from spreading.
Tank operation means the time in which current and/or voltage is
being applied to a chromium electroplating tank or a chromium anodizing
tank.
Tensiometer means a device used to measure the surface tension of a
solution.
Trivalent chromium means the form of chromium in a valence state of
+3.
Trivalent chromium process means the process used for
electrodeposition of a thin layer of chromium onto a base material
using a trivalent chromium solution instead of a chromic acid solution.
Wetting agent means the type of chemical fume suppressant that
reduces the surface tension of a liquid.
(b) Nomenclature. The nomenclature used in this subpart has the
following meaning:
(1) AMR=the allowable mass emission rate from each type of affected
source subject to the same emission limitation in milligrams per hour
(mg/hr).
(2) AMRsys=the allowable mass emission rate from affected
sources controlled by an add-on air pollution control device
controlling emissions from multiple sources in mg/hr.
(3) EL=the applicable emission limitation from Sec. 63.342 in
milligrams per dry standard cubic meter (mg/dscm).
(4) IAtotal=the sum of all inlet duct areas from both affected
and nonaffected sources in meters squared.
(5) IDAi=the total inlet area for all ducts associated with
affected sources in meters squared.
(6) IDAi,a=the total inlet duct area for all ducts conveying
chromic acid from each type of affected source performing the same
operation, or each type of affected source subject to the same emission
limitation in meters squared.
(7) VR=the total of ventilation rates for each type of affected
source subject to the same emission limitation in dry standard cubic
meters per minute (dscm/min).
(8) VRinlet=the total ventilation rate from all inlet ducts
associated with affected sources in dscm/min.
(9) VRinlet,a=the total ventilation rate from all inlet ducts
conveying chromic acid from each type of affected source performing the
same operation, or each type of affected source subject to the same
emission limitation in dscm/min.
(10) VRtot=the average total ventilation rate for the three
test runs as determined at the outlet by means of the Method 306 in
appendix A of this part testing in dscm/min.

Sec. 63.342 Standards.

(a) Each owner or operator of an affected source subject to the
provisions of this subpart shall comply with these requirements on and
after the compliance dates specified in Sec. 63.343(a). All affected
sources are regulated by applying maximum achievable control
technology.
(b) Applicability of emission limits. (1) The emission limitations
in this section apply only during tank operation, and also apply during
periods of startup and shutdown as these are routine occurrences for
affected sources subject to this subpart. The emission limitations do
not apply during periods of malfunction, but the work practice
standards that address operation and maintenance and that are required
by paragraph (f) of this section must be followed during malfunctions.
(2) If an owner or operator is controlling a group of tanks with a
common add-on air pollution control device, the emission limitations of
paragraphs (c), (d), and (e) of this section apply whenever any one
affected source is operated. The emission limitation that applies to
the group of affected sources is:
(i) The emission limitation identified in paragraphs (c), (d), and
(e) of this section if the affected sources are performing the same
type of operation (e.g., hard chromium electroplating), are subject to
the same emission limitation, and are not controlled by an add-on air
pollution control device also controlling nonaffected
sources; [[Page 4965]]
(ii) The emission limitation calculated according to
Sec. 63.344(e)(3) if affected sources are performing the same type of
operation, are subject to the same emission limitation, and are
controlled with an add-on air pollution control device that is also
controlling nonaffected sources; and
(iii) The emission limitation calculated according to
Sec. 63.344(e)(4) if affected sources are performing different types of
operations, or affected sources are performing the same operations but
subject to different emission limitations, and are controlled with an
add-on air pollution control device that may also be controlling
emissions from nonaffected sources.
(c)(1) Standards for hard chromium electroplating tanks. During
tank operation, each owner or operator of an existing, new, or
reconstructed affected source shall control chromium emissions
discharged to the atmosphere from that affected source by not allowing
the concentration of total chromium in the exhaust gas stream
discharged to the atmosphere to exceed:
(i) 0.015 milligrams of total chromium per dry standard cubic meter
(mg/dscm) of ventilation air (6.6 x 10-6 grains per dry standard
cubic foot [gr/dscf]); or
(ii) 0.03 mg/dscm (1.3 x 10-5 gr/dscf) if the hard chromium
electroplating tank is an existing affected source and is located at a
small, hard chromium electroplating facility.
(2)(i) An owner or operator may demonstrate the size of a hard
chromium electroplating facility through the definitions in
Sec. 63.341(a). Alternatively, an owner or operator of a facility with
a maximum cumulative potential rectifier capacity of 60 million amp-hr/
yr or more may be considered small if the actual cumulative rectifier
capacity is less than 60 million amp-hr/yr as demonstrated using the
following procedures:
(A) If records show that the facility's previous annual actual
rectifier capacity was less than 60 million amp-hr/yr, by using
nonresettable ampere-hr meters and keeping monthly records of

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A95-65. Public record. Not legal advice.