[Federal Register Volume 60, Number 16 (Wednesday, January 25, 1995)]
[Rules and Regulations]
[Pages 4948-4993]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-65]




[[Page 4947]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 9 and 63



National Emission Standards for Chromium Emissions From Hard and 
Decorative Chromium Electroplating and Chromium Anodizing Tanks; Final 
Rule

Federal Register / Vol. 60, No. 16 / Wednesday, January 25, 1995 / 
Rules and Regulations 
[[Page 4948]] 

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9 and 63

[AD-FRL-5115-7]
RIN 2060-AC14


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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

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<SUP>-5 gr/dscf)...........................  0.015 mg/dscm (6.6 x 10<SUP>-6 gr/dscf)                          
All new tanks...............  0.015 mg/dcsm (6.6 x 10<SUP>-6 gr/dscf)..........................  0.015 mg/dscm (6.6 x 10<SUP>-6 gr/dscf)                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Decorative Chromium Plating Tanks Using a Chromic Acid Bath                                              
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
All new and existing tanks..                                                                                                                            
(1) 0.01 mg/dscm<SUP>a(4.4 x 10<SUP>-6                                                                                                                            
 gr/dscf)                                                                                                                                               
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Chromium Anodizing Tanks                                                                
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
All new and existing tanks..                                                                                                                            
(1) 0.01 mg/dscm<SUP>a(4.4 x 10<SUP>-6                                                                                                                            
 gr/dscf)                                                                                                                                               
--------------------------------------------------------------------------------------------------------------------------------------------------------
<SUP>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<SUP>-3 lb<INF>f/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.              
                        bed<SUP>a,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.        
 eliminator<SUP>c.           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.                                
------------------------------------------------------------------------
<SUP>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.                                                                
<SUP>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.                                            
<SUP>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.<SUP>a      
 suppressant.               of Sec. 63.343(b)(2) are                                                            
                            met).                                                                               
Foam blankets............  Yes......................  Foam thickness................  Once per hour.<SUP>a           
Air pollution control      Yes......................  To be proposed by the source    N/A.                      
 device (APCD) not listed                              for approval by Administrator.                           
 in rule.                                                                                                       
----------------------------------------------------------------------------------------------------------------
<SUP>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.<SUP>a       
 suppressant.               of Sec. 63.343(b)(2) are                                                            
                            met).                                                                               
Foam blankets............  Yes......................  Foam thickness...............  Once per hour.<SUP>a            
Air pollution control      Yes......................  To be proposed by the source   N/A                        
 device (APCD) not listed                              for approval by                                          
 in rule.                                              Administrator.                                           
----------------------------------------------------------------------------------------------------------------
<SUP>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 
<plus-minus>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 
(CrO<INF>3).
    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/m<SUP>2) 
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/m<SUP>2 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) AMR<INF>sys=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) IA<INF>total=the sum of all inlet duct areas from both affected 
and nonaffected sources in meters squared.
    (5) IDA<INF>i=the total inlet area for all ducts associated with 
affected sources in meters squared.
    (6) IDA<INF>i,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) VR<INF>inlet=the total ventilation rate from all inlet ducts 
associated with affected sources in dscm/min.
    (9) VR<INF>inlet,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) VR<INF>tot=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<SUP>-6 grains per dry standard 
cubic foot [gr/dscf]); or
    (ii) 0.03 mg/dscm (1.3 x 10<SUP>-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 actual 
ampere-hr usage for each 12-month rolling period following the 
compliance date in accordance with Sec. 63.346(b)(12). The actual 
cumulative rectifier capacity for the previous 12-month rolling period 
shall be tabulated monthly by adding the capacity for the current month 
to the capacities for the previous 11 months; or
    (B) By accepting a Federally-enforceable limit on the maximum 
cumulative potential rectifier capacity of a hard chromium 
electroplating facility through the title V permit required by 
Sec. 63.340(e), and by maintaining monthly records in accordance with 
Sec. 63.346(b)(12) to demonstrate that the limit has not been exceeded. 
The actual cumulative rectifier capacity for the previous 12-month 
rolling period shall be tabulated monthly by adding the capacity for 
the current month to the capacities for the previous 11 months.
    (ii) Once the monthly records required to be kept by 
Sec. 63.346(b)(12) and by this paragraph show that the actual 
cumulative rectifier capacity over the previous 12-month rolling period 
corresponds to the large designation, the owner or operator is subject 
to the emission limitation identified in paragraph (c)(1)(i) of this 
section, in accordance with the compliance schedule of 
Sec. 63.343(a)(5).
    (d) Standards for decorative chromium electroplating tanks using a 
chromic acid bath and chromium anodizing 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 either:
    (1) Not allowing the concentration of total chromium in the exhaust 
gas stream discharged to the atmosphere to exceed 0.01 mg/dscm 
(4.4 x 10<SUP>-6 gr/dscf); or
    (2) If a chemical fume suppressant containing a wetting agent is 
used, by not allowing the surface tension of the electroplating or 
anodizing bath contained within the affected source to exceed 45 dynes 
per centimeter (dynes/cm) (3.1 x 10<SUP>-3 pound-force per foot 
[lb<INF>f/ft]) at any time during operation of the tank.
    (e) Standards for decorative chromium electroplating tanks using a 
trivalent chromium bath. (1) Each owner or operator of an existing, 
new, or reconstructed decorative chromium electroplating tank that uses 
a trivalent chromium bath that incorporates a wetting agent as a bath 
ingredient is subject to the recordkeeping and reporting requirements 
of Secs. 63.346(b)(14) and 63.347(i), but are not subject to the work 
practice requirements of paragraph (f) of this section, or the 
continuous compliance monitoring requirements in Sec. 63.343(c). The 
wetting agent must be an ingredient in the trivalent chromium bath 
components purchased from vendors.
    (2) Each owner or operator of an existing, new, or reconstructed 
decorative chromium electroplating tank that uses a trivalent chromium 
bath that does not incorporate a wetting agent as a bath ingredient is 
subject to the standards of paragraph (d) of this section.
    (3) Each owner or operator of existing, new, or reconstructed 
decorative chromium electroplating tank that had been using a trivalent 
chromium bath that incorporates a wetting agent and ceases using this 
type of bath must fulfill the reporting requirements of 
Sec. 63.347(i)(3) and comply with the applicable emission limitation 
within the timeframe specified in Sec. 63.343(a)(7).
    (f) Work practice standards. The work practice standards of this 
section address operation and maintenance practices. All owners or 
operators subject to the standards in paragraphs (c) and (d) of this 
section are subject to these work practice standards.
    (1)(i) At all times, including periods of startup, shutdown, and 
malfunction, owners or operators shall operate and maintain any 
affected source, including associated air pollution control devices and 
monitoring equipment, in a manner consistent with good air pollution 
control practices, consistent with the operation and maintenance plan 
required by paragraph (f)(3) of this section.
    (ii) Malfunctions shall be corrected as soon as practicable after 
their occurrence in accordance with the operation and maintenance plan 
required by paragraph (f)(3) of this section.
    (iii) Operation and maintenance requirements established pursuant 
to section 112 of the Act are enforceable independent of emissions 
limitations or other requirements in relevant standards.
    (2)(i) Determination of whether acceptable operation and 
maintenance procedures are being used will be based on information 
available to the Administrator, which may include, but is not limited 
to, monitoring results; review of the operation and maintenance plan, 
procedures, and records; and inspection of the source.
    (ii) Based on the results of a determination made under paragraph 
(f)(2)(i) of this section, the Administrator may require that an owner 
or operator of an affected source make changes to the operation and 
maintenance plan required by paragraph (f)(3) of this section for that 
source. Revisions may be required if the Administrator finds that the 
plan:
    (A) Does not address a malfunction that has occurred;
    (B) Fails to provide for the operation of the affected source, the 
air pollution control techniques, or the control system and process 
monitoring equipment during a malfunction in a manner consistent with 
good air pollution control practices; or [[Page 4966]] 
    (C) Does not provide adequate procedures for correcting 
malfunctioning process equipment, air pollution control techniques, or 
monitoring equipment as quickly as practicable.
    (3) Operation and maintenance plan. (i) The owner or operator of an 
affected source subject to the work practices of paragraph (f) of this 
section shall prepare an operation and maintenance plan to be 
implemented no later than the compliance date. The plan shall be 
incorporated by reference into the source's title V permit and shall 
include the following elements:
    (A) The plan shall specify the operation and maintenance criteria 
for the affected source, the add-on air pollution control device (if 
such a device is used to comply with the emission limits), and the 
process and control system monitoring equipment, and shall include a 
standardized checklist to document the operation and maintenance of 
this equipment;
    (B) For sources using an add-on air pollution control device or 
monitoring equipment to comply with this subpart, the plan shall 
incorporate the work practice standards for that device or monitoring 
equipment, as identified in Table 1 of this section, if the specific 
equipment used is identified in Table 1 of this section;
    (C) If the specific equipment used is not identified in Table 1 of 
this section, the plan shall incorporate proposed work practice 
standards. These proposed work practice standards shall be submitted to 
the Administrator for approval as part of the submittal required under 
Sec. 63.343(d);
    (D) The plan shall specify procedures to be followed to ensure that 
equipment or process malfunctions due to poor maintenance or other 
preventable conditions do not occur; and
    (E) The plan shall include a systematic procedure for identifying 
malfunctions of process equipment, add-on air pollution control 
devices, and process and control system monitoring equipment and for 
implementing corrective actions to address such malfunctions.
    (ii) If the operation and maintenance plan fails to address or 
inadequately addresses an event that meets the characteristics of a 
malfunction at the time the plan is initially developed, the owner or 
operator shall revise the operation and maintenance plan within 45 days 
after such an event occurs. The revised plan shall include procedures 
for operating and maintaining the process equipment, add-on air 
pollution control device, or monitoring equipment during similar 
malfunction events, and a program for corrective action for such 
events.
    (iii) Recordkeeping associated with the operation and maintenance 
plan is identified in Sec. 63.346(b). Reporting associated with the 
operation and maintenance plan is identified in Sec. 63.347 (g) and (h) 
and paragraph (f)(3)(iv) of this section.
    (iv) If actions taken by the owner or operator during periods of 
malfunction are inconsistent with the procedures specified in the 
operation and maintenance plan required by paragraph (f)(3)(i) of this 
section, the owner or operator shall record the actions taken for that 
event and shall report such actions within 2 working days after 
commencing actions inconsistent with the plan. This report shall be 
followed by a letter within 7 working days after the end of the event, 
unless the owner or operator makes alternative reporting arrangements, 
in advance, with the Administrator.
    (v) The owner or operator shall keep the written operation and 
maintenance plan on record after it is developed to be made available 
for inspection, upon request, by the Administrator for the life of the 
affected source or until the source is no longer subject to the 
provisions of this subpart. In addition, if the operation and 
maintenance plan is revised, the owner or operator shall keep previous 
(i.e., superseded) versions of the operation and maintenance plan on 
record to be made available for inspection, upon request, by the 
Administrator for a period of 5 years after each revision to the plan.
    (vi) To satisfy the requirements of paragraph (f)(3) of this 
section, the owner or operator may use applicable standard operating 
procedure (SOP) manuals, Occupational Safety and Health Administration 
(OSHA) plans, or other existing plans, provided the alternative plans 
meet the requirements of this section.
    (g) The standards in this section that apply to chromic acid baths 
shall not be met by using a reducing agent to change the form of 
chromium from hexavalent to trivalent.


Sec. 63.343  Compliance provisions.

    (a) Compliance dates. (1) The owner or operator of an existing 
affected source shall comply with the emission limitations in 
Sec. 63.342 as follows:
    (i) No later than 1 year after January 25, 1995, if the affected 
source is a decorative chromium electroplating tank; and
    (ii) No later than 2 years after January 25, 1995, if the affected 
source is a hard chromium electroplating tank or a chromium anodizing 
tank.
    (2) The owner or operator of a new or reconstructed affected source 
that has an initial startup after January 25, 1995, shall comply 
immediately upon startup of the source. The owner or operator of a new 
or reconstructed affected source that has an initial startup after 
December 16, 1993 but before January 25, 1995, shall follow the 
compliance schedule of Sec. 63.6(b) (3) and (4).

                           Table 1 to Sec. 63.342.--Summary of Work Practice Standards                          
----------------------------------------------------------------------------------------------------------------
    Control technique                      Work practice standards                            Frequency         
----------------------------------------------------------------------------------------------------------------
Composite mesh-pad (CMP)   1. Visually inspect device to ensure there is proper     1. 1/quarter.               
 system.                    drainage, no chronic acid buildup on the pads, and no                               
                            evidence of chemical attack on the structural                                       
                            integrity of the device.                                                            
                           2. Visually inspect back portion of the mesh pad         2. 1/quarter.               
                            closest to the fan to ensure there is no breakthrough                               
                            of chromic acid mist.                                                               
                           3. Visually inspect ductwork from tank to the control    3. 1/quarter.               
                            device to ensure there are no leaks.                                                
                           4. Perform washdown of the composite mesh-pads in        4. Per manufacturer.        
                            accordance with manufacturers recommendations.                                      
Packed-bed scrubber (PSB)  1. Visually inspect device to ensure there is proper     1. 1/quarter.               
                            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 portion of the chevron blade    2. 1/quarter.               
                            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.               
[[Page 4967]]                                                                                                   
                                                                                                                
                           4. Add fresh makeup water to the top of the packed bed   4. Whenever makeup is added.
                            <SUP>a,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-bed unit and prefiltering      1. 1/quarter.               
 eliminator<SUP>c.               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 ductwork from tank or tanks to the   2. 1/quarter.               
                            control device to ensure there are no leaks.                                        
                           3. Perform washdown of fiber elements in accordance      3. Per manufacturer.        
                            with manufacturers recommendations.                                                 
Air pollution control      To be proposed by the source for approval by the         To be proposed by the source
 device (APCD) not listed   Administrator.                                           for approval by the        
 in rule.                                                                            Administrator.             
                                                                                                                
----------------------------------------------------------------------------------------------------------------
                                              Monitoring Equipment                                              
                                                                                                                
----------------------------------------------------------------------------------------------------------------
Pitot tube...............  Backflush with water, or remove from the duct and rinse  1/quarter.                  
                            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...................  ............................
----------------------------------------------------------------------------------------------------------------
<SUP>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.                                                                               
<SUP>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.                                                              
<SUP>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.             

    (3) The owner or operator of an existing area source that increases 
actual or potential emissions of hazardous air pollutants such that the 
area source becomes a major source must comply with the provisions for 
existing major sources, including the reporting provisions of 
Sec. 63.347(g), immediately upon becoming a major source.
    (4) The owner or operator of a new area source (i.e., an area 
source for which construction or reconstruction was commenced after 
December 16, 1993) that increases actual or potential emissions of 
hazardous air pollutants such that the area source becomes a major 
source must comply with the provisions for new major sources, 
immediately upon becoming a major source.
    (5) An owner or operator of an existing hard chromium 
electroplating tank or tanks located at a small, hard chromium 
electroplating facility that increases its maximum cumulative potential 
rectifier capacity, or its actual cumulative rectifier capacity, such 
that the facility becomes a large, hard chromium electroplating 
facility must comply with the requirements of Sec. 63.342(c)(1)(i) for 
all hard chromium electroplating tanks at the facility no later than 1 
year after the month in which monthly records required by 
Secs. 63.342(c)(2) and 63.346(b)(12) show that the large designation is 
met.
    (6) Request for an extension of compliance. An owner or operator of 
an affected source or sources that requests an extension of compliance 
shall do so in accordance with this paragraph and the applicable 
paragraphs of Sec. 63.6(i). When the owner or operator is requesting 
the extension for more than one affected source located at the 
facility, then only one request may be submitted for all affected 
sources at the facility.
    (i) The owner or operator of an existing affected source who is 
unable to comply with a relevant standard under this subpart may 
request that the Administrator (or a State, when the State has an 
approved part 70 permit program and the source is required to obtain a 
part 70 permit under that program, or a State, when the State has been 
delegated the authority to implement and enforce the emission standard 
for that source) grant an extension allowing the owner or operator up 
to 1 additional year to comply with the standard for the affected 
source. The owner or operator of an affected source who has requested 
an extension of compliance under this paragraph and is otherwise 
required to obtain a title V permit for the source shall apply for such 
permit or apply to have the title V permit revised to incorporate the 
conditions of the extension of compliance. The conditions of an 
extension of compliance granted under this paragraph will be 
incorporated into the owner or operator's title V permit for the 
affected source(s) according to the provisions of 40 CFR part 70 or 40 
CFR part 71, whichever is applicable.
    (ii) Any request under this paragraph for an extension of 
compliance with a relevant standard shall be submitted in writing to 
the appropriate authority not later than 6 months before the affected 
source's compliance date as specified in this section.
    (7) An owner or operator of a decorative chromium electroplating 
tank that uses a trivalent chromium bath that incorporates a wetting 
agent, and that ceases using the trivalent chromium process, must 
comply with the emission limitation now applicable to the tank within 1 
year of switching bath operation.
    (b) Methods to demonstrate initial compliance. (1) Except as 
provided in paragraphs (b)(2) and (b)(3) of this section, an owner or 
operator of an affected source subject to the requirements of this 
subpart is required to conduct an initial performance test as required 
under Sec. 63.7, using the [[Page 4968]] procedures and test methods 
listed in Sec. 63.7 and Sec. 63.344.
    (2) If the owner or operator of an affected source meets all of the 
following criteria, an initial performance test is not required to be 
conducted under this subpart:
    (i) The affected source is a decorative chromium electroplating 
tank or a chromium anodizing tank; and
    (ii) A wetting agent is used in the plating or anodizing bath to 
inhibit chromium emissions from the affected source; and
    (iii) The owner or operator complies with the applicable surface 
tension limit of Sec. 63.342(d)(2) as demonstrated through the 
continuous compliance monitoring required by paragraph (c)(5)(ii) of 
this section.
    (3) If the affected source is a decorative chromium electroplating 
tank using a trivalent chromium bath, and the owner or operator is 
subject to the provisions of Sec. 63.342(e), an initial performance 
test is not required to be conducted under this subpart.
    (c) Monitoring to demonstrate continuous compliance. The owner or 
operator of an affected source subject to the emission limitations of 
this subpart shall conduct monitoring according to the type of air 
pollution control technique that is used to comply with the emission 
limitation. The monitoring required to demonstrate continuous 
compliance with the emission limitations is identified in this section 
for the air pollution control techniques expected to be used by the 
owners or operators of affected sources.
    (1) Composite mesh-pad systems. (i) During the initial performance 
test, the owner or operator of an affected source, or a group of 
affected sources under common control, complying with the emission 
limitations in Sec. 63.342 through the use of a composite mesh-pad 
system shall determine the outlet chromium concentration using the test 
methods and procedures in Sec. 63.344(c), and shall establish as a 
site-specific operating parameter the pressure drop across the system, 
setting the value that corresponds to compliance with the applicable 
emission limitation, using the procedures in Sec. 63.344(d)(5). An 
owner or operator may conduct multiple performance tests to establish a 
range of compliant pressure drop values, or may set as the compliant 
value the average pressure drop measured over the three test runs of 
one performance test and accept <plus-minus>1 inch of water column from 
this value as the compliant range.
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec. 63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the pressure drop across the composite mesh-
pad system once each day that any affected source is operating. To be 
in compliance with the standards, the composite mesh-pad system shall 
be operated within <plus-minus>1 inch of water column of the pressure 
drop value established during the initial performance test, or shall be 
operated within the range of compliant values for pressure drop 
established during multiple performance tests.
    (2) Packed-bed scrubber systems. (i) During the initial performance 
test, the owner or operator of an affected source, or group of affected 
sources under common control, complying with the emission limitations 
in Sec. 63.342 through the use of a packed-bed scrubber system shall 
determine the outlet chromium concentration using the procedures in 
Sec. 63.344(c), and shall establish as site-specific operating 
parameters the pressure drop across the system and the velocity 
pressure at the common inlet of the control device, setting the value 
that corresponds to compliance with the applicable emission limitation 
using the procedures in Sec. 63.344(d) (4) and (5). An owner or 
operator may conduct multiple performance tests to establish a range of 
compliant operating parameter values. Alternatively, the owner or 
operator may set as the compliant value the average pressure drop and 
inlet velocity pressure measured over the three test runs of one 
performance test, and accept <plus-minus>1 inch of water column from 
the pressure drop value and <plus-minus>10 percent from the velocity 
pressure value as the compliant range.
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec. 63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the velocity pressure at the inlet to the 
packed-bed scrubber and the pressure drop across the scrubber system 
once each day that any affected source is operating. To be in 
compliance with the standards, the scrubber system shall be operated 
within <plus-minus>10 percent of the velocity pressure value 
established during the initial performance test, and within 
<plus-minus>1 inch of water column of the pressure drop value 
established during the initial performance test, or within the range of 
compliant operating parameter values established during multiple 
performance tests.
    (3) Packed-bed scrubber/composite mesh-pad system. The owner or 
operator of an affected source, or group of affected sources under 
common control, that uses a packed-bed scrubber in conjunction with a 
composite mesh-pad system to meet the emission limitations of 
Sec. 63.342 shall comply with the monitoring requirements for composite 
mesh-pad systems as identified in paragraph (c)(1) of this section.
    (4) Fiber-bed mist eliminator. (i) During the initial performance 
test, the owner or operator of an affected source, or group of affected 
sources under common control, complying with the emission limitations 
in Sec. 63.342 through the use of a fiber-bed mist eliminator shall 
determine the outlet chromium concentration using the procedures in 
Sec. 63.344(c), and shall establish as a site-specific operating 
parameter the pressure drop across the fiber-bed mist eliminator and 
the pressure drop across the control device installed upstream of the 
fiber bed to prevent plugging, setting the value that corresponds to 
compliance with the applicable emission limitation using the procedures 
in Sec. 63.344(d)(5). An owner or operator may conduct multiple 
performance tests to establish a range of compliant pressure drop 
values, or may set as the compliant value the average pressure drop 
measured over the three test runs of one performance test and accept 
<plus-minus>1 inch of water column from this value as the compliant 
range.
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec. 63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the pressure drop across the fiber-bed mist 
eliminator, and the control device installed upstream of the fiber bed 
to prevent plugging, once each day that any affected source is 
operating. To be in compliance with the standards, the fiber-bed mist 
eliminator and the upstream control device shall be operated within 
<plus-minus>1 inch of water column of the pressure drop value 
established during the initial performance test, or shall be operated 
within the range of compliant values for pressure drop established 
during multiple performance tests.
    (5) Wetting agent-type or combination wetting agent-type/foam 
blanket fume suppressants. (i) During the initial performance test, the 
owner or operator of an affected source complying with the emission 
limitations in Sec. 63.342 through the use of a wetting agent in the 
electroplating or anodizing bath shall determine the outlet chromium 
concentration using the procedures in Sec. 63.344(c). The owner or 
operator shall establish as the site-specific operating parameter the 
surface tension of the bath using Method 306B, appendix A of 
[[Page 4969]] this part, setting the maximum value that corresponds to 
compliance with the applicable emission limitation. In lieu of 
establishing the maximum surface tension during the performance test, 
the owner or operator may accept 45 dynes/cm as the maximum surface 
tension value that corresponds to compliance with the applicable 
emission limitation. However, the owner or operator is exempt from 
conducting a performance test only if the criteria of paragraph (b)(2) 
of this section are met.
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec. 63.7, the owner or operator of an 
affected source shall monitor the surface tension of the electroplating 
or anodizing bath. Operation of the affected source at a surface 
tension greater than the value established during the performance test, 
or greater than 45 dynes/cm if the owner or operator is using this 
value in accordance with paragraph (c)(5)(i) of this section, shall 
constitute noncompliance with the standards. The surface tension shall 
be monitored according to the following schedule:
    (A) The surface tension shall be measured once every 4 hours during 
operation of the tank with a stalagmometer or a tensiometer as 
specified in Method 306B, appendix A of this part.
    (B) The time between monitoring can be increased if there have been 
no exceedances. The surface tension shall be measured once every 4 
hours of tank operation for the first 40 hours of tank operation after 
the compliance date. Once there are no exceedances during 40 hours of 
tank operation, surface tension measurement may be conducted once every 
8 hours of tank operation. Once there are no exceedances during 40 
hours of tank operation, surface tension measurement may be conducted 
once every 40 hours of tank operation on an ongoing basis, until an 
exceedance occurs. The minimum frequency of monitoring allowed by this 
subpart is once every 40 hours of tank operation.
    (C) Once an exceedance occurs as indicated through surface tension 
monitoring, the original monitoring schedule of once every 4 hours must 
be resumed. A subsequent decrease in frequency shall follow the 
schedule laid out in paragraph (c)(5)(ii)(B) of this section. For 
example, if an owner or operator had been monitoring an affected source 
once every 40 hours and an exceedance occurs, subsequent monitoring 
would take place once every 4 hours of tank operation. Once an 
exceedance does not occur for 40 hours of tank operation, monitoring 
can occur once every 8 hours of tank operation. Once an exceedance does 
not occur for 40 hours of tank operation on this schedule, monitoring 
can occur once every 40 hours of tank operation.
    (iii) Once a bath solution is drained from the affected tank and a 
new solution added, the original monitoring schedule of once every 4 
hours must be resumed, with a decrease in monitoring frequency allowed 
following the procedures of paragraphs (c)(5)(ii) (B) and (C) of this 
section.
    (6) Foam blanket-type fume suppressants. (i) During the initial 
performance test, the owner or operator of an affected source complying 
with the emission limitations in Sec. 63.342 through the use of a foam 
blanket in the electroplating or anodizing bath shall determine the 
outlet chromium concentration using the procedures in Sec. 63.344(c), 
and shall establish as the site-specific operating parameter the 
thickness of the foam blanket, setting the minimum thickness that 
corresponds to compliance with the applicable emission limitation. In 
lieu of establishing the minimum foam blanket thickness during the 
performance test, the owner or operator may accept 2.54 centimeters (1 
inch) as the minimum foam blanket thickness that corresponds to 
compliance with the applicable emission limitation. All foam blanket 
measurements must be taken in close proximity to the workpiece or 
cathode area in the plating tank(s).
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec. 63.7, the owner or operator of an 
affected source shall monitor the foam blanket thickness of the 
electroplating or anodizing bath. Operation of the affected source at a 
foam blanket thickness less than the value established during the 
performance test, or less than 2.54 cm (1 inch) if the owner or 
operator is using this value in accordance with paragraph (c)(6)(i) of 
this section, shall constitute noncompliance with the standards. The 
foam blanket thickness shall be measured according to the following 
schedule:
    (A) The foam blanket thickness shall be measured once every 1 hour 
of tank operation.
    (B) The time between monitoring can be increased if there have been 
no exceedances. The foam blanket thickness shall be measured once every 
hour of tank operation for the first 40 hours of tank operation after 
the compliance date. Once there are no exceedances for 40 hours of tank 
operation, foam blanket thickness measurement may be conducted 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 ongoing basis, 
until an exceedance occurs. The minimum frequency of monitoring allowed 
by this subpart is once per 8 hours of tank operation.
    (C) Once an exceedance occurs as indicated through foam blanket 
thickness monitoring, the original monitoring schedule of once every 
hour must be resumed. A subsequent decrease in frequency shall follow 
the schedule laid out in paragraph (c)(6)(ii)(B) of this section. For 
example, if an owner or operator had been monitoring an affected source 
once every 8 hours and an exceedance occurs, subsequent monitoring 
would take place once every hour of tank operation. Once an exceedance 
does not occur for 40 hours of tank operation, monitoring can occur 
once every 4 hours of tank operation. Once an exceedance does not occur 
for 40 hours of tank operation on this schedule, monitoring can occur 
once every 8 hours of tank operation.
    (iii) Once a bath solution is drained from the affected tank and a 
new solution added, the original monitoring schedule of once every hour 
must be resumed, with a decrease in monitoring frequency allowed 
following the procedures of paragraphs (c)(6)(ii) (B) and (C) of this 
section.
    (7) Fume suppressant/add-on control device. (i) If the owner or 
operator of an affected source uses both a fume suppressant and add-on 
control device and both are needed to comply with the applicable 
emission limit, monitoring requirements as identified in paragraphs (c) 
(1) through (6) of this section, and the work practice standards of 
Table 1 of Sec. 63.342, apply for each of the control techniques used.
    (ii) If the owner or operator of an affected source uses both a 
fume suppressant and add-on control device, but only one of these 
techniques is needed to comply with the applicable emission limit, 
monitoring requirements as identified in paragraphs (c) (1) through (6) 
of this section, and work practice standards of Table 1 of Sec. 63.342, 
apply only for the control technique used to achieve compliance.
    (8) Use of an alternative monitoring method. (i) Requests and 
approvals of alternative monitoring methods shall be considered in 
accordance with Sec. 63.8(f)(1), (f)(3), (f)(4), and (f)(5).
    (ii) After receipt and consideration of an application for an 
alternative monitoring method, the Administrator may approve 
alternatives to any [[Page 4970]] monitoring methods or procedures of 
this subpart including, but not limited to, the following:
    (A) Alternative monitoring requirements when installation or use of 
monitoring devices specified in this subpart would not provide accurate 
measurements due to interferences caused by substances within the 
effluent gases; or
    (B) Alternative locations for installing monitoring devices when 
the owner or operator can demonstrate that installation at alternate 
locations will enable accurate and representative measurements.
    (d) An owner or operator who uses an air pollution control device 
not listed in this section shall submit a description of the device, 
test results collected in accordance with Sec. 63.344(c) verifying the 
performance of the device for reducing chromium emissions to the 
atmosphere to the level required by this subpart, a copy of the 
operation and maintenance plan referenced in Sec. 63.342(f) including 
proposed work practice standards, and appropriate operating parameters 
that will be monitored to establish continuous compliance with the 
standards. The monitoring plan submitted identifying the continuous 
compliance monitoring is subject to the Administrator's approval.


Sec. 63.344  Performance test requirements and test methods.

    (a) Performance test requirements. Performance tests shall be 
conducted using the test methods and procedures in this section and 
Sec. 63.7. Performance test results shall be documented in complete 
test reports that contain the information required by paragraphs (a)(1) 
through (a)(9) of this section. The test plan to be followed shall be 
made available to the Administrator prior to the testing, if requested.
    (1) A brief process description;
    (2) Sampling location description(s);
    (3) A description of sampling and analytical procedures and any 
modifications to standard procedures;
    (4) Test results;
    (5) Quality assurance procedures and results;
    (6) Records of operating conditions during the test, preparation of 
standards, and calibration procedures;
    (7) Raw data sheets for field sampling and field and laboratory 
analyses;
    (8) Documentation of calculations; and
    (9) Any other information required by the test method.
    (b)(1) If the owner or operator of an affected source conducts 
performance testing at startup to obtain an operating permit in the 
State in which the affected source is located, the results of such 
testing may be used to demonstrate compliance with this subpart if:
    (i) The test methods and procedures identified in paragraph (c) of 
this section were used during the performance test;
    (ii) The performance test was conducted under representative 
operating conditions for the source;
    (iii) The performance test report contains the elements required by 
paragraph (a) of this section; and
    (iv) The owner or operator of the affected source for which the 
performance test was conducted has sufficient data to establish the 
operating parameter value(s) that correspond to compliance with the 
standards, as required for continuous compliance monitoring under 
Sec. 63.343(c).
    (2) The results of tests conducted prior to December 1991 in which 
Method 306A, appendix A of this part, was used to demonstrate the 
performance of a control technique are not acceptable.
    (c) Test methods. Each owner or operator subject to the provisions 
of this subpart and required by Sec. 63.343(b) to conduct an initial 
performance test shall use the test methods identified in this section 
to demonstrate compliance with the standards in Sec. 63.342.
    (1) Method 306 or Method 306A, ``Determination of Chromium 
Emissions From Decorative and Hard Chromium Electroplating and 
Anodizing Operations,'' appendix A of this part shall be used to 
determine the chromium concentration from hard or decorative chromium 
electroplating tanks or chromium anodizing tanks. The sampling time and 
sample volume for each run of Methods 306 and 306A, appendix A of this 
part shall be at least 120 minutes and 1.70 dscm (60 dscf), 
respectively. Methods 306 and 306A, appendix A of this part allow the 
measurement of either total chromium or hexavalent chromium emissions. 
For the purposes of this standard, sources using chromic acid baths can 
demonstrate compliance with the emission limits of Sec. 63.342 by 
measuring either total chromium or hexavalent chromium. Hence, the 
hexavalent chromium concentration measured by these methods is equal to 
the total chromium concentration for the affected operations.
    (2) The California Air Resources Board (CARB) Method 425 (which is 
available by contacting the California Air Resources Board, 1102 Q 
Street, Sacramento, California 95814) may be used to determine the 
chromium concentration from hard and decorative chromium electroplating 
tanks and chromium anodizing tanks if the following conditions are met:
    (i) If a colorimetric analysis method is used, the sampling time 
and volume shall be sufficient to result in 33 to 66 micrograms of 
catch in the sampling train.
    (ii) If Atomic Absorption Graphite Furnace (AAGF) or Ion 
Chromatography with a Post-column Reactor (ICPCR) analyses were used, 
the sampling time and volume should be sufficient to result in a sample 
catch that is 5 to 10 times the minimum detection limit of the 
analytical method (i.e., 1.0 microgram per liter of sample for AAGF and 
0.5 microgram per liter of sample for ICPCR).
    (iii) In the case of either paragraph (c)(2) (i) or (ii) of this 
section, a minimum of 3 separate runs must be conducted. The other 
requirements of Sec. 63.7 that apply to affected sources, as indicated 
in Table 1 of this subpart, must also be met.
    (3) Method 306B, ``Surface Tension Measurement and Recordkeeping 
for Tanks Used at Decorative Chromium Electroplating and Anodizing 
Facilities,'' appendix A of this part shall be used to measure the 
surface tension of electroplating and anodizing baths.
    (4) Alternate test methods may also be used if the method has been 
validated using Method 301, appendix A of this part and if approved by 
the Administrator. Procedures for requesting and obtaining approval are 
contained in Sec. 63.7(f).
    (d) Establishing site-specific operating parameter values. (1) Each 
owner or operator required to establish site-specific operating 
parameters shall follow the procedures in this section.
    (2) All monitoring equipment shall be installed such that 
representative measurements of emissions or process parameters from the 
affected source are obtained. For monitoring equipment purchased from a 
vendor, verification of the operational status of the monitoring 
equipment shall include execution of the manufacturer's written 
specifications or recommendations for installation, operation, and 
calibration of the system.
    (i) Specifications for differential pressure measurement devices 
used to measure velocity pressure shall be in accordance with section 
2.2 of Method 2 (40 CFR part 60, appendix A).
    (ii) Specification for differential pressure measurement devices 
used to measure pressure drop across a control system shall be in 
accordance with manufacturer's accuracy specifications.
    (3) The surface tension of electroplating and anodizing baths shall 
[[Page 4971]] be measured using Method 306B, ``Surface Tension 
Measurement and Recordkeeping for Tanks used at Decorative Chromium 
Electroplating and Anodizing Facilities,'' appendix A of this part. 
This method should also be followed when wetting agent type or 
combination wetting agent/foam blanket type fume suppressants are used 
to control chromium emissions from a hard chromium electroplating tank 
and surface tension measurement is conducted to demonstrate continuous 
compliance.
    (4) The owner or operator of a source required to measure the 
velocity pressure at the inlet to an add-on air pollution control 
device in accordance with Sec. 63.343(c)(2), shall establish the site-
specific velocity pressure as follows:
    (i) Locate a velocity traverse port in a section of straight duct 
that connects the hooding on the plating tank or tanks with the control 
device. The port shall be located as close to the control system as 
possible, and shall be placed a minimum of 2 duct diameters downstream 
and 0.5 diameter upstream of any flow disturbance such as a bend, 
expansion, or contraction (see Method 1, 40 CFR part 60, appendix A). 
If 2.5 diameters of straight duct work does not exist, locate the port 
0.8 of the duct diameter downstream and 0.2 of the duct diameter 
upstream from any flow disturbance.
    (ii) A 12-point velocity traverse of the duct to the control device 
shall be conducted along a single axis according to Method 2 (40 CFR 
part 60, appendix A) using an S-type pitot tube; measurement of the 
barometric pressure and duct temperature at each traverse point is not 
required, but is suggested. Mark the S-type pitot tube as specified in 
Method 1 (40 CFR part 60, appendix A) with 12 points. Measure the 
velocity pressure (<greek-D>p) values for the velocity points and 
record. Determine the square root of the individual velocity point 
<greek-D>p values and average. The point with the square root value 
that comes closest to the average square root value is the point of 
average velocity. The <greek-D>p value measured for this point during 
the performance test will be used as the reference for future 
monitoring.
    (5) The owner or operator of a source required to measure the 
pressure drop across the add-on air pollution control device in 
accordance with Sec. 63.343(c) (1) through (4) may establish the 
pressure drop in accordance with the following guidelines:
    (i) Pressure taps shall be installed at any of the following 
locations:
    (A) At the inlet and outlet of the control system. The inlet tap 
should be installed in the ductwork just prior to the control device 
and the corresponding outlet pressure tap should be installed on the 
outlet side of the control device prior to the blower or on the 
downstream side of the blower;
    (B) On each side of the packed bed within the control system or on 
each side of each mesh pad within the control system; or
    (C) On the front side of the first mesh pad and back side of the 
last mesh pad within the control system.
    (ii) Pressure taps shall be sited at locations that are:
    (A) Free from pluggage as possible and away from any flow 
disturbances such as cyclonic demisters.
    (B) Situated such that no air infiltration at measurement site will 
occur that could bias the measurement.
    (iii) Pressure taps shall be constructed of either polyethylene, 
polybutylene, or other nonreactive materials.
    (iv) Nonreactive plastic tubing shall be used to connect the 
pressure taps to the device used to measure pressure drop.
    (v) Any of the following pressure gauges can be used to monitor 
pressure drop: a magnehelic gauge, an inclined manometer, or a ``U'' 
tube manometer.
    (vi) Prior to connecting any pressure lines to the pressure 
gauge(s), each gauge should be zeroed. No calibration of the pressure 
gauges is required.
    (e) Special compliance provisions for multiple sources controlled 
by a common add-on air pollution control device.
    (1) This section identifies procedures for measuring the outlet 
chromium concentration from an add-on air pollution control device that 
is used to control multiple sources that may or may not include sources 
not affected by this subpart.
    (2) When multiple affected sources performing the same type of 
operation (e.g., all are performing hard chromium electroplating), and 
subject to the same emission limitation, are controlled with an add-on 
air pollution control device that is not controlling emissions from any 
other type of affected operation or from any nonaffected sources, the 
applicable emission limitation identified in Sec. 63.342 must be met at 
the outlet of the add-on air pollution control device.
    (3) When multiple affected sources performing the same type of 
operation and subject to the same emission limitation are controlled 
with a common add-on air pollution control device that is also 
controlling emissions from sources not affected by these standards, the 
following procedures should be followed to determine compliance with 
the applicable emission limitation in Sec. 63.342:
    (i) Calculate the cross-sectional area of each inlet duct (i.e., 
uptakes from each hood) including those not affected by the standard.
    (ii) Determine the total sample time per test run by dividing the 
total inlet area from all tanks connected to the control system by the 
total inlet area for all ducts associated with affected sources, and 
then multiply this number by 2 hours. The calculated time is the 
minimum sample time required per test run.
    (iii) Perform Method 306 testing and calculate an outlet mass 
emission rate.
    (iv) Determine the total ventilation rate from the affected sources 
by using equation 1:
[GRAPHIC][TIFF OMITTED]TR25JA95.000


where VR<INF>tot is the average total ventilation rate in dscm/min for 
the three test runs as determined at the outlet by means of the Method 
306 testing; IDA<INF>i is the total inlet area for all ducts associated 
with affected sources; IA<INF>total is the sum of all inlet duct areas 
from both affected and nonaffected sources; and VR<INF>inlet is the 
total ventilation rate from all inlet ducts associated with affected 
sources.
    (v) Establish the allowable mass emission rate of the system 
(AMR<INF>sys) in milligrams of total chromium per hour (mg/hr) using 
equation 2:
[GRAPHIC][TIFF OMITTED]TR25JA95.001


where <greek-S> VR<INF>inlet is the total ventilation rate in dscm/min 
from the affected sources, and EL is the applicable emission limitation 
from Sec. 63.342 in mg/dscm. The allowable mass emission rate 
(AMR<INF>sys) calculated from equation 2 should be equal to or less 
than the outlet three-run average mass emission rate determined from 
Method 306 testing in order for the source to be in compliance with the 
standard. [[Page 4972]] 
    (4) When multiple affected sources performing different types of 
operations (e.g., hard chromium electroplating, decorative chromium 
electroplating, or chromium anodizing) are controlled by a common add-
on air pollution control device that may or may not also be controlling 
emissions from sources not affected by these standards, or if the 
affected sources controlled by the common add-on air pollution control 
device perform the same operation but are subject to different emission 
limitations (e.g., because one is a new hard chromium plating tank and 
one is an existing small, hard chromium plating tank), the following 
procedures should be followed to determine compliance with the 
applicable emission limitation in Sec. 63.342:
    (i) Follow the steps outlined in paragraphs (e)(3)(i) through 
(e)(3)(iii) of this section.
    (ii) Determine the total ventilation rate for each type of affected 
source using equation 3:
[GRAPHIC][TIFF OMITTED]TR25JA95.002


where VR<INF>tot is the average total ventilation rate in dscm/min for 
the three test runs as determined at the outlet by means of the Method 
306 testing; IDA<INF>i,a is 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; IA<INF>total is the sum of all duct areas from 
both affected and nonaffected sources; and VR<INF>inlet,a is 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.
    (iii) Establish the allowable mass emission rate in mg/hr for each 
type of affected source that is controlled by the add-on air pollution 
control device using equation 4, 5, 6, or 7 as appropriate:

VR<INF>hc1  x  EL<INF>hc1  x  60 minutes/hour = AMR<INF>hc1     (4)

VR<INF>hc2  x  EL<INF>hc2  x  60 minutes/hour = AMR<INF>hc2    (5)

 VR<INF>dc  x  EL<INF>dc  x  60 minutes/hour = AMR<INF>dc    (6)

 VR<INF>ca  x  EL<INF>ca  x  60 minutes/hour = AMR<INF>ca    (7)

where ``hc'' applies to the total of ventilation rates for all hard 
chromium electroplating tanks subject to the same emission limitation, 
``dc'' applies to the total of ventilation rates for the decorative 
chromium electroplating tanks, ``ca'' applies to the total of 
ventilation rates for the chromium anodizing tanks, and EL is the 
applicable emission limitation from Sec. 63.342 in mg/dscm. There are 
two equations for hard chromium electroplating tanks because different 
emission limitations may apply (e.g., a new tank versus an existing, 
small tank).
    (iv) Establish the allowable mass emission rate (AMR) in mg/hr for 
the system using equation 8, including each type of affected source as 
appropriate:

 AMR<INF>hc1 + AMR<INF>hc2 + AMR<INF>dc + AMR<INF>ca = AMR<INF>sys    
(8)

The allowable mass emission rate calculated from equation 8 should be 
equal to or less than the outlet three-run average mass emission rate 
determined from Method 306 testing in order for the source to be in 
compliance with the standards.
     (5) Each owner or operator that uses the special compliance 
provisions of this paragraph to demonstrate compliance with the 
emission limitations of Sec. 63.342 shall submit the measurements and 
calculations to support these compliance methods with the notification 
of compliance status required by Sec. 63.347(e).
    (6) Each owner or operator that uses the special compliance 
provisions of this section to demonstrate compliance with the emission 
limitations of Sec. 63.342 shall repeat these procedures if a tank is 
added or removed from the control system regardless of whether that 
tank is a nonaffected source. If the new nonaffected tank replaces an 
existing nonaffected tank of the same size and is connected to the 
control system through the same size inlet duct then this procedure 
does not have to be repeated.


Sec. 63.345  Provisions for new and reconstructed sources.

    (a) This section identifies the preconstruction review requirements 
for new and reconstructed affected sources that are subject to, or 
become subject to, this subpart.
    (b) New or reconstructed affected sources. The owner or operator of 
a new or reconstructed affected source is subject to Sec. 63.5(a), 
(b)(1), (b)(5), (b)(6), and (f)(1), as well as the provisions of this 
paragraph.
    (1) After January 25, 1995, whether or not an approved permit 
program is effective in the State in which an affected source is (or 
would be) located, no person may construct a new affected source or 
reconstruct an affected source subject to this subpart, or reconstruct 
a source such that it becomes an affected source subject to this 
subpart, without submitting a notification of construction or 
reconstruction to the Administrator. The notification shall contain the 
information identified in paragraphs (b) (2) and (3) of this section, 
as appropriate.
    (2) The notification of construction or reconstruction required 
under paragraph (b)(1) of this section shall include:
    (i) The owner or operator's name, title, and address;
    (ii) The address (i.e., physical location) or proposed address of 
the affected source if different from the owner's or operator's;
    (iii) A notification of intention to construct a new affected 
source or make any physical or operational changes to an affected 
source that may meet or has been determined to meet the criteria for a 
reconstruction as defined in Sec. 63.2;
    (iv) An identification of subpart N of this part as the basis for 
the notification;
    (v) The expected commencement and completion dates of the 
construction or reconstruction;
    (vi) The anticipated date of (initial) startup of the affected 
source;
    (vii) The type of process operation to be performed (hard or 
decorative chromium electroplating, or chromium anodizing);
    (viii) A description of the air pollution control technique to be 
used to control emissions from the affected source, such as preliminary 
design drawings and design capacity if an add-on air pollution control 
device is used; and
    (ix) An estimate of emissions from the source based on engineering 
calculations and vendor information on control device efficiency, 
expressed in units consistent with the emission limits of this subpart. 
Calculations of emission estimates should be in sufficient detail to 
permit assessment of the validity of the calculations.
    (3) If a reconstruction is to occur, the notification required 
under paragraph (b)(1) of this section shall include the following in 
addition to the information required in paragraph (b)(2) of this 
section:
    (i) A brief description of the affected source and the components 
to be replaced;
    (ii) A brief description of the present and proposed emission 
control technique, including the information required by paragraphs 
(b)(2) (viii) and (ix) of this section;
    (iii) An estimate of the fixed capital cost of the replacements and 
of constructing a comparable entirely new source;
    (iv) The estimated life of the affected source after the 
replacements; and
    (v) A discussion of any economic or technical limitations the 
source may [[Page 4973]] have in complying with relevant standards or 
other requirements after the proposed replacements. The discussion 
shall be sufficiently detailed to demonstrate to the Administrator's 
satisfaction that the technical or economic limitations affect the 
source's ability to comply with the relevant standard and how they do 
so.
    (vi) If in the notification of reconstruction, the owner or 
operator designates the affected source as a reconstructed source and 
declares that there are no economic or technical limitations to prevent 
the source from complying with all relevant standards or requirements, 
the owner or operator need not submit the information required in 
paragraphs (b)(3) (iii) through (v) of this section.
    (4) The owner or operator of a new or reconstructed affected source 
that submits a notification in accordance with paragraphs (b) (1) 
through (3) of this section is not subject to approval by the 
Administrator. Construction or reconstruction is subject only to 
notification and can begin upon submission of a complete notification.
    (5) Submittal timeframes. After January 25, 1995, whether or not an 
approved permit program is effective in the State in which an affected 
source is (or would be) located, an owner or operator of a new or 
reconstructed affected source shall submit the notification of 
construction or reconstruction required by paragraph (b)(1) of this 
section according to the following schedule:
    (i) If construction or reconstruction commences after January 25, 
1995, the notification shall be submitted as soon as practicable before 
the construction or reconstruction is planned to commence.
    (ii) If the construction or reconstruction had commenced and 
initial startup had not occurred before January 25, 1995, the 
notification shall be submitted as soon as practicable before startup 
but no later than 60 days after January 25, 1995.


Sec. 63.346  Recordkeeping requirements.

    (a) The owner or operator of each affected source subject to these 
standards shall fulfill all recordkeeping requirements outlined in this 
section and in the General Provisions to 40 CFR part 63, according to 
the applicability of subpart A of this part as identified in Table 1 of 
this subpart.
    (b) The owner or operator of an affected source subject to the 
provisions of this subpart shall maintain the following records for 
such source:
    (1) Inspection records for the add-on air pollution control device, 
if such a device is used, and monitoring equipment, to document that 
the inspection and maintenance required by the work practice standards 
of Sec. 63.342(f) and Table 1 of Sec. 63.342 have taken place. The 
record can take the form of a checklist and should identify the device 
inspected, the date of inspection, a brief description of the working 
condition of the device during the inspection, and any actions taken to 
correct deficiencies found during the inspection.
    (2) Records of all maintenance performed on the affected source, 
the add-on air pollution control device, and monitoring equipment;
    (3) Records of the occurrence, duration, and cause (if known) of 
each malfunction of process, add-on air pollution control, and 
monitoring equipment;
    (4) Records of actions taken during periods of malfunction when 
such actions are inconsistent with the operation and maintenance plan;
    (5) Other records, which may take the form of checklists, necessary 
to demonstrate consistency with the provisions of the operation and 
maintenance plan required by Sec. 63.342(f)(3);
    (6) Test reports documenting results of all performance tests;
    (7) All measurements as may be necessary to determine the 
conditions of performance tests, including measurements necessary to 
determine compliance with the special compliance procedures of 
Sec. 63.344(e);
    (8) Records of monitoring data required by Sec. 63.343(c) that are 
used to demonstrate compliance with the standard including the date and 
time the data are collected;
    (9) The specific identification (i.e., the date and time of 
commencement and completion) of each period of excess emissions, as 
indicated by monitoring data, that occurs during malfunction of the 
process, add-on air pollution control, or monitoring equipment;
    (10) The specific identification (i.e., the date and time of 
commencement and completion) of each period of excess emissions, as 
indicated by monitoring data, that occurs during periods other than 
malfunction of the process, add-on air pollution control, or monitoring 
equipment;
    (11) The total process operating time of the affected source during 
the reporting period;
    (12) Records of the actual cumulative rectifier capacity of hard 
chromium electroplating tanks at a facility expended during each month 
of the reporting period, and the total capacity expended to date for a 
reporting period, if the owner or operator is using the actual 
cumulative rectifier capacity to determine facility size in accordance 
with Sec. 63.342(c)(2);
    (13) For sources using fume suppressants to comply with the 
standards, records of the date and time that fume suppressants are 
added to the electroplating or anodizing bath;
    (14) For sources complying with Sec. 63.342(e), records of the bath 
components purchased, with the wetting agent clearly identified as a 
bath constituent contained in one of the components;
    (15) Any information demonstrating whether a source is meeting the 
requirements for a waiver of recordkeeping or reporting requirements, 
if the source has been granted a waiver under Sec. 63.10(f); and
    (16) All documentation supporting the notifications and reports 
required by Sec. 63.9, Sec. 63.10, and Sec. 63.347.
    (c) All records shall be maintained for a period of 5 years in 
accordance with Sec. 63.10(b)(1).


Sec. 63.347  Reporting requirements.

    (a) The owner or operator of each affected source subject to these 
standards shall fulfill all reporting requirements outlined in this 
section and in the General Provisions to 40 CFR part 63, according to 
the applicability of subpart A as identified in Table 1 of this 
subpart. These reports shall be made to the Administrator at the 
appropriate address as identified in Sec. 63.13 or to the delegated 
State authority.
    (1) Reports required by subpart A of this part and this section may 
be sent by U.S. mail, fax, or by another courier.
    (i) Submittals sent by U.S. mail shall be postmarked on or before 
the specified date.
    (ii) Submittals sent by other methods shall be received by the 
Administrator on or before the specified date.
    (2) If acceptable to both the Administrator and the owner or 
operator of an affected source, reports may be submitted on electronic 
media.
    (b) The reporting requirements of this section apply to the owner 
or operator of an affected source when such source becomes subject to 
the provisions of this subpart.
    (c) Initial notifications. (1) The owner or operator of an affected 
source that has an initial startup before January 25, 1995, shall 
notify the Administrator in writing that the source is subject to this 
subpart. The notification shall be submitted no later than 180 calendar 
days after January 25, 1995, and shall contain the following 
information:
    (i) The name, title, and address of the owner or operator;
    (ii) The address (i.e., physical location) of each affected source; 
[[Page 4974]] 
    (iii) A statement that subpart N of this part is the basis for this 
notification;
    (iv) Identification of the applicable emission limitation and 
compliance date for each affected source;
    (v) A brief description of each affected source, including the type 
of process operation performed;
     (vi) For sources performing hard chromium electroplating, the 
maximum potential cumulative potential rectifier capacity;
    (vii) For sources performing hard chromium electroplating, a 
statement of whether the affected source(s) is located at a small or a 
large, hard chromium electroplating facility and whether this will be 
demonstrated through actual or maximum potential cumulative rectifier 
capacity;
    (viii) For sources performing hard chromium electroplating tanks, a 
statement of whether the owner or operator of an affected source(s) 
will limit the maximum potential cumulative rectifier capacity in 
accordance with Sec. 63.342(c)(2) such that the hard chromium 
electroplating facility is considered small; and
    (ix) A statement of whether the affected source is located at a 
major source or an area source as defined in Sec. 63.2.
    (2) The owner or operator of a new or reconstructed affected source 
that has an initial startup after January 25, 1995 shall submit an 
initial notification (in addition to the notification of construction 
or reconstruction required by Sec. 63.345(b) as follows:
    (i) A notification of the date when construction or reconstruction 
was commenced, shall be submitted simultaneously with the notification 
of construction or reconstruction, if construction or reconstruction 
was commenced before January 25, 1995;
    (ii) A notification of the date when construction or reconstruction 
was commenced, shall be submitted no later than 30 calendar days after 
such date, if construction or reconstruction was commenced after 
January 25, 1995; and
    (iii) A notification of the actual date of startup of the source 
shall be submitted within 30 calendar days after such date.
    (d) Notification of performance test. (1) The owner or operator of 
an affected source shall notify the Administrator in writing of his or 
her intention to conduct a performance test at least 60 calendar days 
before the test is scheduled to begin to allow the Administrator to 
have an observer present during the test. Observation of the 
performance test by the Administrator is optional.
    (2) In the event the owner or operator is unable to conduct the 
performance test as scheduled, the provisions of Sec. 63.7(b)(2) apply.
    (e) Notification of compliance status. (1) A notification of 
compliance status is required each time that an affected source becomes 
subject to the requirements of this subpart.
    (2) Before a title V permit has been issued to the owner or 
operator of an affected source, each time a notification of compliance 
status is required under this part, the owner or operator of an 
affected source shall submit to the Administrator a notification of 
compliance status, signed by the responsible official (as defined in 
Sec. 63.2) who shall certify its accuracy, attesting to whether the 
affected source has complied with this subpart. After a title V permit 
has been issued to the owner or operator of an affected source, the 
notification of compliance status shall be submitted to the appropriate 
permitting authority. The notification shall list for each affected 
source:
    (i) The applicable emission limitation and the methods that were 
used to determine compliance with this limitation;
    (ii) If a performance test is required by this subpart, the test 
report documenting the results of the performance test, which contains 
the elements required by Sec. 63.344(a), including measurements and 
calculations to support the special compliance provisions of 
Sec. 63.344(e) if these are being followed;
    (iii) The type and quantity of hazardous air pollutants emitted by 
the source reported in mg/dscm or mg/hr if the source is using the 
special provisions of Sec. 63.344(e) to comply with the standards. (If 
the owner or operator is subject to the construction and reconstruction 
provisions of Sec. 63.345 and had previously submitted emission 
estimates, the owner or operator shall state that this report corrects 
or verifies the previous estimate.) For sources not required to conduct 
a performance test in accordance with Sec. 63.343(b), the surface 
tension measurement may fulfill this requirement;
    (iv) For each monitored parameter for which a compliant value is to 
be established under Sec. 63.343(c), the specific operating parameter 
value, or range of values, that corresponds to compliance with the 
applicable emission limit;
    (v) The methods that will be used to determine continuous 
compliance, including a description of monitoring and reporting 
requirements, if methods differ from those identified in this subpart;
    (vi) A description of the air pollution control technique for each 
emission point;
    (vii) A statement that the owner or operator has completed and has 
on file the operation and maintenance plan as required by the work 
practice standards in Sec. 63.342(f);
    (viii) If the owner or operator is determining facility size based 
on actual cumulative rectifier capacity in accordance with 
Sec. 63.342(c)(2), records to support that the facility is small. For 
existing sources, records from any 12-month period preceding the 
compliance date shall be used or a description of how operations will 
change to meet a small designation shall be provided. For new sources, 
records of projected rectifier capacity for the first 12-month period 
of tank operation shall be used;
    (ix) A statement by the owner or operator of the affected source as 
to whether the source has complied with the provisions of this subpart.
    (3) For sources required to conduct a performance test by 
Sec. 63.343(b), the notification of compliance status shall be 
submitted to the Administrator no later than 90 calendar days following 
completion of the compliance demonstration required by Sec. 63.7 and 
Sec. 63.343(b).
    (4) For sources that are not required to complete a performance 
test in accordance with Sec. 63.343(b), the notification of compliance 
status shall be submitted to the Administrator no later than 30 days 
after the compliance date specified in Sec. 63.343(a).
    (f) Reports of performance test results. (1) Before a title V 
permit has been issued to the owner or operator of an affected source, 
the owner or operator shall report to the Administrator the results of 
any performance test conducted as required by Sec. 63.7 or 
Sec. 63.343(b). After a title V permit has been issued to the owner or 
operator of an affected source, the owner or operator should report 
performance test results to the appropriate permitting authority.
    (2) Reports of performance test results shall be submitted no later 
than 90 days following the completion of the performance test, and 
shall be submitted as part of the notification of compliance status 
required by paragraph (e) of this section.
    (g) Ongoing compliance status reports for major sources. (1) The 
owner or operator of an affected source that is located at a major 
source site shall submit a summary report to the Administrator to 
document the ongoing compliance status of the affected source. The 
report shall contain the information identified in paragraph (g)(3) of 
this [[Page 4975]] section, and shall be submitted semiannually except 
when:
    (i) The Administrator determines on a case-by-case basis that more 
frequent reporting is necessary to accurately assess the compliance 
status of the source; or
    (ii) The monitoring data collected by the owner or operator of the 
affected source in accordance with Sec. 63.343(c) show that the 
emission limit has been exceeded, in which case quarterly reports shall 
be submitted. Once an owner or operator of an affected source reports 
an exceedance, ongoing compliance status reports shall be submitted 
quarterly until a request to reduce reporting frequency under paragraph 
(g)(2) of this section is approved.
    (2) Request to reduce frequency of ongoing compliance status 
reports. (i) An owner or operator who is required to submit ongoing 
compliance status reports on a quarterly (or more frequent basis) may 
reduce the frequency of reporting to semiannual if all of the following 
conditions are met:
    (A) For 1 full year (e.g., 4 quarterly or 12 monthly reporting 
periods), the ongoing compliance status reports demonstrate that the 
affected source is in compliance with the relevant emission limit;
    (B) The owner or operator continues to comply with all applicable 
recordkeeping and monitoring requirements of subpart A of this part and 
this subpart; and
    (C) The Administrator does not object to a reduced reporting 
frequency for the affected source, as provided in paragraphs (g)(2) 
(ii) and (iii) of this section.
    (ii) The frequency of submitting ongoing compliance status reports 
may be reduced only after the owner or operator notifies the 
Administrator in writing of his or her intention to make such a change, 
and the Administrator does not object to the intended change. In 
deciding whether to approve a reduced reporting frequency, the 
Administrator may review information concerning the source's entire 
previous performance history during the 5-year recordkeeping period 
prior to the intended change, or the recordkeeping period since the 
source's compliance date, whichever is shorter. Records subject to 
review may include performance test results, monitoring data, and 
evaluations of an owner or operator's conformance with emission 
limitations and work practice standards. Such information may be used 
by the Administrator to make a judgment about the source's potential 
for noncompliance in the future. If the Administrator disapproves the 
owner or operator's request to reduce reporting frequency, the 
Administrator will notify the owner or operator in writing within 45 
days after receiving notice of the owner or operator's intention. The 
notification from the Administrator to the owner or operator will 
specify the grounds on which the disapproval is based. In the absence 
of a notice of disapproval within 45 days, approval is automatically 
granted.
    (iii) As soon as the monitoring data required by Sec. 63.343(c) 
show that the source is not in compliance with the relevant emission 
limit, the frequency of reporting shall revert to quarterly, and the 
owner shall state this exceedance in the ongoing compliance status 
report for the next reporting period. After demonstrating ongoing 
compliance with the relevant emission limit for another full year, the 
owner or operator may again request approval from the Administrator to 
reduce the reporting frequency as allowed by paragraph (g)(2) of this 
section.
    (3) Contents of ongoing compliance status reports. The owner or 
operator of an affected source for which compliance monitoring is 
required in accordance with Sec. 63.343(c) shall prepare a summary 
report to document the ongoing compliance status of the source. The 
report must contain the following information:
    (i) The company name and address of the affected source;
    (ii) An identification of the operating parameter that is monitored 
for compliance determination, as required by Sec. 63.343(c);
    (iii) The relevant emission limitation for the affected source, and 
the operating parameter value, or range of values, that correspond to 
compliance with this emission limitation as specified in the 
notification of compliance status required by paragraph (e) of this 
section;
    (iv) The beginning and ending dates of the reporting period;
    (v) A description of the type of process performed in the affected 
source;
    (vi) The total operating time of the affected source during the 
reporting period;
    (vii) If the affected source is a hard chromium electroplating tank 
and the owner or operator is limiting the maximum cumulative rectifier 
capacity in accordance with Sec. 63.342(c)(2), the actual cumulative 
rectifier capacity expended during the reporting period, on a month-by-
month basis;
    (viii) A summary of operating parameter values, including the total 
duration of excess emissions during the reporting period as indicated 
by those values, the total duration of excess emissions expressed as a 
percent of the total source operating time during that reporting 
period, and a breakdown of the total duration of excess emissions 
during the reporting period into those that are due to process upsets, 
control equipment malfunctions, other known causes, and unknown causes;
    (ix) A certification by a responsible official, as defined in 
Sec. 63.2, that the work practice standards in Sec. 63.342(f) were 
followed in accordance with the operation and maintenance plan for the 
source;
    (x) If the operation and maintenance plan required by 
Sec. 63.342(f)(3) was not followed, an explanation of the reasons for 
not following the provisions, an assessment of whether any excess 
emission and/or parameter monitoring exceedances are believed to have 
occurred, and a copy of the report(s) required by Sec. 63.342(f)(3)(iv) 
documenting that the operation and maintenance plan was not followed;
    (xi) A description of any changes in monitoring, processes, or 
controls since the last reporting period;
    (xii) The name, title, and signature of the responsible official 
who is certifying the accuracy of the report; and
    (xiii) The date of the report.
    (4) When more than one monitoring device is used to comply with the 
continuous compliance monitoring required by Sec. 63.343(c), the owner 
or operator shall report the results as required for each monitoring 
device. However, when one monitoring device is used as a backup for the 
primary monitoring device, the owner or operator shall only report the 
results from the monitoring device used to meet the monitoring 
requirements of this subpart. If both devices are used to meet these 
requirements, then the owner or operator shall report the results from 
each monitoring device for the relevant compliance period.
    (h) Ongoing compliance status reports for area sources. The 
requirements of this paragraph do not alleviate affected area sources 
from complying with the requirements of State or Federal operating 
permit programs under 40 CFR part 71.
    (1) The owner or operator of an affected source that is located at 
an area source site shall prepare a summary report to document the 
ongoing compliance status of the affected source. The report shall 
contain the information identified in paragraph (g)(3) of this section, 
shall be completed annually and retained on site, and made available to 
the Administrator upon request. The report shall be completed annually 
[[Page 4976]] except as provided in paragraph (h)(2) of this section.
    (2) Reports of exceedances. (i) If both of the following conditions 
are met, semiannual reports shall be prepared and submitted to the 
Administrator:
    (A) The total duration of excess emissions (as indicated by the 
monitoring data collected by the owner or operator of the affected 
source in accordance with Sec. 63.343(c)) is 1 percent or greater of 
the total operating time for the reporting period; and
    (B) The total duration of malfunctions of the add-on air pollution 
control device and monitoring equipment is 5 percent or greater of the 
total operating time.
    (ii) Once an owner or operator of an affected source reports an 
exceedance as defined in paragraph (h)(2)(i) of this section, ongoing 
compliance status reports shall be submitted semiannually until a 
request to reduce reporting frequency under paragraph (h)(3) of this 
section is approved.
    (iii) The Administrator may determine on a case-by-case basis that 
the summary report shall be completed more frequently and submitted, or 
that the annual report shall be submitted instead of being retained on 
site, if these measures are necessary to accurately assess the 
compliance status of the source.
    (3) Request to reduce frequency of ongoing compliance status 
reports. (i) An owner or operator who is required to submit ongoing 
compliance status reports on a semiannual (or more frequent) basis, or 
is required to submit its annual report instead of retaining it on 
site, may reduce the frequency of reporting to annual and/or be allowed 
to maintain the annual report onsite if all of the following conditions 
are met:
    (A) For 1 full year (e.g., 2 semiannual or 4 quarterly reporting 
periods), the ongoing compliance status reports demonstrate that the 
affected source is in compliance with the relevant emission limit;
    (B) The owner or operator continues to comply with all applicable 
recordkeeping and monitoring requirements of subpart A of this part and 
this subpart; and
    (C) The Administrator does not object to a reduced reporting 
frequency for the affected source, as provided in paragraphs (h)(3) 
(ii) and (iii) of this section.
    (ii) The frequency of submitting ongoing compliance status reports 
may be reduced only after the owner or operator notifies the 
Administrator in writing of his or her intention to make such a change, 
and the Administrator does not object to the intended change. In 
deciding whether to approve a reduced reporting frequency, the 
Administrator may review information concerning the source's previous 
performance history during the 5-year recordkeeping period prior to the 
intended change, or the recordkeeping period since the source's 
compliance date, whichever is shorter. Records subject to review may 
include performance test results, monitoring data, and evaluations of 
an owner or operator's conformance with emission limitations and work 
practice standards. Such information may be used by the Administrator 
to make a judgement about the source's potential for noncompliance in 
the future. If the Administrator disapproves the owner or operator's 
request to reduce reporting frequency, the Administrator will notify 
the owner or operator in writing within 45 days after receiving notice 
of the owner or operator's intention. The notification from the 
Administrator to the owner or operator will specify the grounds on 
which the disapproval is based. In the absence of a notice of 
disapproval within 45 days, approval is automatically granted.
    (iii) As soon as the monitoring data required by Sec. 63.343(c) 
show that the source is not in compliance with the relevant emission 
limit, the frequency of reporting shall revert to semiannual, and the 
owner shall state this exceedance in the ongoing compliance status 
report for the next reporting period. After demonstrating ongoing 
compliance with the relevant emission limit for another full year, the 
owner or operator may again request approval from the Administrator to 
reduce the reporting frequency as allowed by paragraph (h)(3) of this 
section.
    (i) Reports associated with trivalent chromium baths. The 
requirements of this paragraph do not alleviate affected sources from 
complying with the requirements of State or Federal operating permit 
programs under title V. Owners or operators complying with the 
provisions of Sec. 63.342(e) are not subject to paragraphs (a) through 
(h) of this section, but must instead submit the following reports:
    (1) Within 180 days after January 25, 1995, submit an initial 
notification that includes:
    (i) The same information as is required by paragraphs (c)(1) (i) 
through (v) of this section; and
    (ii) A statement that a trivalent chromium process that 
incorporates a wetting agent will be used to comply with 
Sec. 63.342(e); and
    (iii) The list of bath components that comprise the trivalent 
chromium bath, with the wetting agent clearly identified; and
    (2) Within 30 days of the compliance date specified in 
Sec. 63.343(a), a notification of compliance status that contains an 
update of the information submitted in accordance with paragraph (i)(1) 
of this section or a statement that the information is still accurate; 
and
    (3) Within 30 days of a change to the trivalent chromium 
electroplating process, a report that includes:
    (i) A description of the manner in which the process has been 
changed and the emission limitation, if any, now applicable to the 
affected source;
    (ii) If a different emission limitation applies, the applicable 
information required by paragraph (c)(1) of this section; and
    (iii) The notification and reporting requirements of paragraphs 
(d), (e), (f), (g), and (h) of this section, which shall be submitted 
in accordance with the schedules identified in those paragraphs.

                 Table 1 to Subpart N of Part 63.--General Provisions Applicability to Subpart N                
----------------------------------------------------------------------------------------------------------------
                                      Applies to                                                                
   General provisions reference        subpart N                               Comment                          
----------------------------------------------------------------------------------------------------------------
63.1(a)(1).......................  Yes.............  Additional terms defined in Sec. 63.341; when overlap      
                                                      between subparts A and N occurs, subpart N takes          
                                                      precedence.                                               
63.1(a)(2).......................  Yes                                                                          
63.1(a)(3).......................  Yes                                                                          
63.1(a)(4).......................  Yes.............  Subpart N clarifies the applicability of each paragraph in 
                                                      subpart A to sources subject to subpart N.                
63.1(a)(6).......................  Yes                                                                          
63.1(a)(7).......................  Yes                                                                          
63.1(a)(8).......................  Yes                                                                          
                                                                                                                
                                                                                                                
[[Page 4977]]63.1(a)(10).........  Yes                                                                          
63.1(a)(11)......................  Yes.............  Sec. 63.347(a) of subpart N also allows report submissions 
                                                      via fax and on electronic media.                          
63.1(a)(12)-(14).................  Yes                                                                          
63.1(b)(1).......................  No..............  Sec. 63.340 of subpart N specifies applicability.          
63.1(b)(2).......................  Yes                                                                          
63.1(b)(3).......................  No..............  This provision in subpart A is being deleted. Also, all    
                                                      affected area and major sources are subject to subpart N; 
                                                      there are no exemptions.                                  
63.1(c)(1).......................  Yes.............  Subpart N clarifies the applicability of each paragraph in 
                                                      subpart A to sources subject to subpart N.                
63.1(c)(2).......................  Yes.............  Subpart N specifies permit requirements for area sources.  
63.1(c)(4).......................  Yes                                                                          
63.1(c)(5).......................  No..............  Subpart N clarifies that an area source that becomes a     
                                                      major source is subject to the requirements for major     
                                                      sources.                                                  
63.1(e)..........................  Yes                                                                          
63.2.............................  Yes.............  Additional terms defined in Sec. 63.341; when overlap      
                                                      between subparts A and N occurs, subpart N takes          
                                                      precedence.                                               
63.3.............................  Yes.............  Other units used in subpart N are defined in that subpart. 
63.4.............................  Yes                                                                          
63.5(a)..........................  Yes.............  Except replace the term ``source'' and ``stationary        
                                                      source'' in Sec. 63.5(a)(1) and (2) of subpart A with     
                                                      ``affected resources.''                                   
63.5(b)(1).......................  Yes                                                                          
63.5(b)(3).......................  Yes.............  Applies only to major affected sources.                    
63.5(b)(4).......................  No..............  Subpart N (Sec. 63.345) specifies requirements for the     
                                                      notification of construction or reconstruction for        
                                                      affected sources that are not major.                      
63.5(b)(5).......................  Yes                                                                          
63.5(b)(6).......................  Yes                                                                          
63.5(d)(1)(i)....................  No..............  Sec. 63.345(c)(5) of subpart N specifies when the          
                                                      application or notification shall be submitted.           
63.5(d)(1)(ii)...................  Yes.............  Applies to major affected sources that are new or          
                                                      reconstructed.                                            
63.5(d)(1)(iii)..................  Yes.............  Except information should be submitted with the            
                                                      Notification of Compliance Status required by Sec.        
                                                      63.347(e) of subpart N.                                   
63.5(d)(2).......................  Yes.............  Applies to major affected sources that are new or          
                                                      reconstructed except: (1) replace ``source'' in Sec.      
                                                      63.5(d)(2) of subpart A with ``affected source''; and (2) 
                                                      actual control efficiencies are submitted with the        
                                                      Notification of Compliance Status required by Sec.        
                                                      63.347(e).                                                
63.5(d)(3)-(4)...................  Yes.............  Applies to major affected sources that are new or          
                                                      reconstructed.                                            
63.5(e)..........................  Yes.............  Applies to major affected sources that are new or          
                                                      reconstructed.                                            
63.5(f)(1).......................  Yes.............  Except replace ``source'' in Sec. 63.5(f)(1) of subpart A  
                                                      with ``affected source.''                                 
63.5(f)(2).......................  No..............  New or reconstructed affected sources shall submit the     
                                                      request for approval of construction or reconstruction    
                                                      under Sec. 63.5(f) of subpart A by the deadline specified 
                                                      in Sec. 63.345(c)(5) of subpart N.                        
63.6(a)..........................  Yes                                                                          
63.6(b)(1)-(2)...................  Yes.............  Except replace ``source'' in Sec. 63.6(b)(1)-(2) of part A 
                                                      with ``affected source.''                                 
63.6(b)(3)-(4)...................  Yes                                                                          
63.6(b)(5).......................  Yes.............  Except replace ``source'' in Sec. 63.6(b)(5) of subpart A  
                                                      with ``affected source.''                                 
63.6(b)(7).......................  No..............  Provisions for new area sources that become major sources  
                                                      are contained in Sec. 63.343(a)(4) of subpart N.          
63.6(c)(1)-(2)...................  Yes.............  Except replace ``source'' in Sec. 63.6(c)(1)-(2) of subpart
                                                      A with ``affected source.''                               
63.6(c)(5).......................  No..............  Compliance provisions for existing area sources that become
                                                      major sources are contained in Sec. 63.343(a)(3) of       
                                                      subpart N.                                                
63.6(e)..........................  No..............  Sec. 63.342(f) of subpart N contains work practice         
                                                      standards (operation and maintenance requirements) that   
                                                      override these provisions.                                
63.6(f)(1).......................  No..............  Sec. 63.342(b) of subpart N specifies when the standards   
                                                      apply.                                                    
63.6(f)(2)(i)-(ii)...............  Yes                                                                          
63.6(f)(2)(iii)..................  No..............  Sec. 63.344(b) of subpart N specifies instances in which   
                                                      previous performance test results for existing sources are
                                                      acceptable.                                               
63.6(f)(2)(iv)...................  Yes                                                                          
63.6(f)(2)(v)....................  Yes                                                                          
63.6(f)(3).......................  Yes                                                                          
63.6(g)..........................  Yes                                                                          
63.6(h)..........................  No..............  Subpart N does not contain any opacity or visible emission 
                                                      standards.                                                
63.6(i)(1).......................  Yes                                                                          
63.6(i)(2).......................  Yes.............  Except replace ``source'' in Sec. 63.6(i)(2)(i) and (ii) of
                                                      subpart A with ``affected source.''                       
63.6(i)(3).......................  Yes                                                                          
63.6(i)(4)(i)....................  No..............  Sec. 63.343(a)(6) of subpart N specifies the procedures for
                                                      obtaining an extension of compliance and the date by which
                                                      such requests must be submitted.                          
63.6(i)(4)(ii)...................  Yes                                                                          
63.6(i)(5).......................  Yes                                                                          
63.6(i)(6)(i)....................  Yes.............  This paragraph only references ``paragraph (i)(4) of this  
                                                      section'' for compliance extension provisions. But, Sec.  
                                                      63.343(a)(6) of subpart N also contains provisions for    
                                                      requesting a compliance extension.                        
63.6(i)(6)(ii)...................  Yes                                                                          
63.6(i)(7).......................  Yes                                                                          
                                                                                                                
                                                                                                                
[[Page 4978]]63.6(i)(8)..........  Yes.............  This paragraph only references ``paragraphs (i)(4) through 
                                                      (i)(6) of this section'' for compliance extension         
                                                      provisions. But, Sec. 63.343(a)(6) of subpart N also      
                                                      contains provisions for requesting a compliance extension.
63.6(i)(9).......................  Yes.............  This paragraph only references ``paragraphs (i)(4) through 
                                                      (i)(6) of this section'' and ``paragraphs (i)(4) and      
                                                      (i)(5) of this section'' for compliance extension         
                                                      provisions. But, Sec. 63.343(a)(6) of subpart N also      
                                                      contains provisions for requesting a compliance extension.
63.6(i)(10)(i)-(iv)..............  Yes                                                                          
63.6(i)(10)(v)(A)................  Yes.............  This paragraph only references `'paragraph (i)(4)'' for    
                                                      compliance extension provisions. But, Sec. 63.343(a)(6) of
                                                      subpart N also contains provisions for requesting a       
                                                      compliance extension.                                     
63.6(i)(10)(v)(B)................  Yes                                                                          
63.6(i)(11)......................  Yes                                                                          
63.6(i)(12)(i)...................  Yes.............  This paragraph only references ``paragraph (i)(4)(i) or    
                                                      (i)(5) of this section'' for compliance extension         
                                                      provisions. But, Sec. 63.343(a)(6) of subpart N also      
                                                      contains provisions for requesting a compliance extension.
63.6(i)(12)(ii)-(iii)............  Yes                                                                          
63.6(i)(13)......................  Yes                                                                          
63.6(i)(14)......................  Yes                                                                          
63.6(i)(16)......................  Yes                                                                          
63.6(j)..........................  Yes                                                                          
63.7(a)(1).......................  Yes                                                                          
63.7(a)(2)(i)-(vi)...............  Yes                                                                          
63.7(a)(2)(ix)...................  Yes                                                                          
63.7(a)(3).......................  Yes                                                                          
63.7(b)(1).......................  No..............  Sec. 63.347(d) of subpart N requires notification prior to 
                                                      the performance test. Sec. 63.344(a) of subpart N requires
                                                      submission of a site-specific test plan upon request.     
63.7(b)(2).......................  Yes                                                                          
63.7(c)..........................  No..............  Sec. 63.344(a) of subpart N specifies what the test plan   
                                                      should contain, but does not require test plan approval or
                                                      performance audit samples.                                
63.7(d)..........................  Yes.............  Except replace ``source'' in the first sentence of Sec.    
                                                      63.7(d) of subpart A with ``affected source.''            
63.7(e)..........................  Yes.............  Subpart N also contains test methods specific to affected  
                                                      sources covered by that subpart.                          
63.7(f)..........................  Yes.............  Sec. 63.344(c)(2) of subpart N identifies CARB Method 425  
                                                      as acceptable under certain conditions.                   
63.7(g)(1).......................  No..............  Subpart N identifies the items to be reported in the       
                                                      compliance test [Sec. 63.344(a)] and the timeframe for    
                                                      submitting the results [Sec. 63.347(f)].                  
63.7(g)(3).......................  Yes                                                                          
63.7(h)(1)-(2)...................  Yes                                                                          
63.7(h)(3)(i)....................  Yes.............  This paragraph only references ``Sec. 63.6(i)'' for        
                                                      compliance extension provisions. But, Sec. 63.343(a)(6) of
                                                      subpart N also contains provisions for requesting a       
                                                      compliance extension.                                     
63.7(h)(3)(ii)-(iii).............  Yes                                                                          
63.7(h)(4)-(5)...................  Yes                                                                          
63.8(a)(1).......................  Yes                                                                          
63.8(a)(2).......................  No..............  Work practice standards are contained in Sec. 63.342(f) of 
                                                      subpart N.                                                
63.8(a)(4).......................  No                                                                           
63.8(b)(1).......................  Yes                                                                          
63.8(b)(2).......................  No..............  Sec. 63.344(d) of subpart N specifies the monitoring       
                                                      location when there are multiple sources.                 
63.8(b)(3).......................  No..............  Sec. 63.347(g)(4) of subpart N identifies reporting        
                                                      requirements when multiple monitors are used.             
63.8(c)(1)(i)....................  No..............  Subpart N requires proper maintenance of monitoring devices
                                                      expected to be used by sources subject to subpart N.      
63.8(c)(1)(ii)...................  No..............  Sec. 63.342(f)(3)(iv) of subpart N specifies reporting when
                                                      the O&M plan is not followed.                             
63.8(c)(1)(iii)..................  No..............  Sec. 63.343(f)(2) identifies the criteria for whether O&M  
                                                      procedures are acceptable.                                
63.8(c)(2)-(3)...................  No..............  Sec. 63.344(d)(2) requires appropriate use of monitoring   
                                                      devices.                                                  
63.8(c)(4)-(7)...................  No                                                                           
63.8(d)..........................  No..............  Maintenance of monitoring devices is required by Secs.     
                                                      63.342(f) and 63.344(d)(2) of subpart N.                  
63.8(e)..........................  No..............  There are no performance evaluation procedures for the     
                                                      monitoring devices expected to be used to comply with     
                                                      subpart N.                                                
63.8(f)(1).......................  Yes                                                                          
63.8(f)(2).......................  No..............  Instances in which the Administrator may approve           
                                                      alternatives to the monitoring methods and procedures of  
                                                      subpart N are contained in Sec. 63.343(c)(8) of subpart N.
63.8(f)(3).......................  Yes                                                                          
63.8(f)(4).......................  Yes                                                                          
63.8(f)(5).......................  Yes                                                                          
63.8(f)(6).......................  No..............  Subpart N does not require the use of CEM's.               
63.8(g)..........................  No..............  Monitoring data does not need to be reduced for reporting  
                                                      purposes because subpart N requires measurement once/day. 
63.9(a)..........................  Yes                                                                          
63.9(b)(1)(i)-(ii)...............  No..............  Sec. 63.343(a)(3) of subpart N requires area sources to    
                                                      comply with major source provisions if an increase in HAP 
                                                      emissions causes them to become major sources.            
63.9(b)(1)(iii)..................  No..............  Sec. 63.347(c)(2) of subpart N specifies initial           
                                                      notification requirements for new or reconstructed        
                                                      affected sources.                                         
63.9(b)(2).......................  No..............  Sec. 63.347(c)(1) of subpart N specifies the information to
                                                      be contained in the initial notification.                 
63.9(b)(3).......................  No..............  Sec. 63.347(c)(2) of subpart N specifies notification      
                                                      requirements for new or reconstructed sources that are not
                                                      major affected sources.                                   
[[Page 4979]]                                                                                                   
                                                                                                                
63.9(b)(4).......................  No                                                                           
63.9(b)(5).......................  No                                                                           
63.9(c)..........................  Yes.............  This paragraph only references ``Sec. 63.6(i)(4) through   
                                                      Sec. 63.6(i)(6)'' for compliance extension provisions.    
                                                      But, Sec. 63.343(a)(6) of subpart N also contains         
                                                      provisions for requesting a compliance extension. Subpart 
                                                      N provides a different timeframe for submitting the       
                                                      request than Sec. 63.6(i)(4).                             
63.9(d)..........................  Yes.............  This paragraph only references ``the notification dates    
                                                      established in paragraph (g) of this section.'' But, Sec. 
                                                      63.347 of subpart N also contains notification dates.     
63.9(e)..........................  No..............  Notification of performance test is required by Sec.       
                                                      63.347(d) of subpart N.                                   
63.9(f)..........................  No                                                                           
63.9(g)..........................  No..............  Subpart N does not require a performance evaluation or     
                                                      relative accuracy test for monitoring devices.            
63.9(h)(1)-(3)...................  No..............  Sec. 63.347(e) of subpart N specifies information to be    
                                                      contained in the notification of compliance status and the
                                                      timeframe for submitting this information.                
63.9(h)(5).......................  No..............  Similar language has been incorporated into Sec.           
                                                      63.347(e)(2)(iii) of subpart N.                           
63.9(h)(6).......................  Yes                                                                          
63.9(i)..........................  Yes                                                                          
63.9(j)..........................  Yes                                                                          
63.10(a).........................  Yes                                                                          
63.10(b)(1)......................  Yes                                                                          
63.10(b)(2)......................  No..............  Sec. 63.346(b) of subpart N specifies the records that must
                                                      be maintained.                                            
63.10(b)(3)......................  No..............  Subpart N applies to major and area sources.               
63.10(c).........................  No..............  Applicable requirements of Sec. 63.10(c) have been         
                                                      incorporated into Sec. 63.346(b) of subpart N.            
63.10(d)(1)......................  Yes                                                                          
63.10(d)(2)......................  No..............  Sec. 63.347(f) of subpart N specifies the timeframe for    
                                                      reporting performance test results.                       
63.10(d)(3)......................  No..............  Subpart N does not contain opacity or visible emissions    
                                                      standards.                                                
63.10(d)(4)......................  Yes                                                                          
63.10(d)(5)......................  No..............  Sec. 63.342(f)(3)(iv) and Sec. 63.347(g)(3) of subpart N   
                                                      specify reporting associated with malfunctions.           
63.10(e).........................  No..............  Sec. 63.347(g) and (h) of subpart N specify the frequency  
                                                      of periodic reports of monitoring data used to establish  
                                                      compliance. Applicable requirements of Sec. 63.10(e) have 
                                                      been incorporated into Sec. 63.347(g) and (h).            
63.10(f).........................  Yes                                                                          
63.11............................  No..............  Flares will not be used to comply with the emmission       
                                                      limits.                                                   
63.12-63.15......................  Yes                                                                          
----------------------------------------------------------------------------------------------------------------

    3. Appendix A to part 63 is amended by adding Methods 306 and 306a 
in numerical order to read as follows:

Appendix A to part 63--Test Methods

* * * * *

Method 306--Determination of Chromium Emissions From Decorative and 
Hard Chromium Electroplating and Anodizing Operations

1. Applicability and Principle

    1.1 Applicability. This method applies to the determination of 
chromium (Cr) in emissions from decorative and hard chrome 
electroplating facilities and anodizing operations.
    1.2 Principle. (a) A sample is extracted isokinetically from the 
source using an unheated Method 5 sampling train (40 CFR part 60, 
appendix A), with a glass nozzle and probe liner, but with the 
filter omitted. The Cr emissions are collected in an alkaline 
solution: 0.1 N sodium hydroxide (NaOH) or 0.1 N sodium bicarbonate 
(NaHCO<INF>3). The collected samples remain in the alkaline solution 
until analysis. Samples with high Cr concentrations may be analyzed 
using inductively coupled plasma emission spectrometry (ICP) at 
267.72 nm. Alternatively, if improved detection limits are required, 
a portion of the alkaline impinger solution is digested with nitric 
acid and analyzed by graphite furnace atomic absorption spectroscopy 
(GFAAS) at 357.9 nm.
    (b) If it is desirable to determine hexavalent chromium 
(Cr<SUP>+6) emissions, the samples may be analyzed using an ion 
chromatograph equipped with a post-column reactor (IC/PCR) and a 
visible wavelength detector. To increase sensitivity for trace 
levels of Cr<SUP>+6, a preconcentration system can be used in 
conjunction with the IC/PCR.

2. Range, Sensitivity, Precision, and Interferences

    2.1  Range. The recommended analytical range for each of the 
three analytical techniques is given below. The upper limit of all 
three techniques can be extended indefinitely by appropriate 
dilution.
    2.1.1  GFAAS Range. As reported in Method 7191 of SW-846 
(Citation 5 in Bibliography), the optimum concentration range for 
GFAAS is 5 to 100 <greek-m>g Cr/l of concentrated analyte.
    2.1.2  ICP Range. A linear response curve for ICP can be 
obtained in the range of 10 to at least 500 <greek-m>g Cr/l of 
absorbing solution.
    2.1.3  IC/PCR Range. In 40 CFR part 266, appendix IX, the lower 
limit of the detection range for IC/PCR when employing a 
preconcentration procedure is reported to be about 0.1 <greek-m>g 
Cr<SUP>+6/l of absorbing solution.
    2.2  Sensitivity.
    2.2.1  Analytical Sensitivity.
    2.2.1.1  ICP Analytical Sensitivity. The minimum detection limit 
for ICP, as reported in Method 6010A of SW-846, is 7 <greek-m>g Cr/
l.
    2.2.1.2  GFAAS Analytical Sensitivity. The minimum detection 
limit for GFAAS, as reported in Method 7191 of SW-846, is 1 
<greek-m>g Cr/l.
    2.2.1.3  IC/PCR Analytical Sensitivity. The minimum detection 
limit for IC/PCR with a preconcentrator, as reported in 40 CFR part 
266, appendix IX is 0.05 <greek-m>g Cr<SUP>+6/l.
    2.2.2  In-stack Sensitivity. The in-stack sensitivity depends 
upon the analytical detection limit, the volume of stack gas 
sampled, and the total volume of the impinger absorbing solution 
plus the rinses. Using the analytical detection limits given in 
sections 2.2.1.1, 2.2.1.2, and 2.2.1.3; a stack gas sample volume of 
1.7 dscm; and a total liquid sample volume of 500 ml; the 
corresponding in-stack detection limits are 0.0021 mg Cr/dscm for 
ICP, 0.00015 mg Cr/dscm for GFAAS, and 0.000015 mg Cr<SUP>+6/dscm 
for IC/PCR with preconcentration. However, it is recommended that 
the concentration of Cr in the analytical solutions be at least five 
times the analytical detection limit to optimize sensitivity in the 
analyses. Using this guideline and the same assumptions for impinger 
sample volume and stack gas sample volume (500 ml and 1.7 dscm, 
respectively), the recommended minimum stack concentrations for 
optimum sensitivity are 0.0103 mg Cr/dscm for ICP, 0.00074 mg Cr/
dscm for GFAAS, and 0.000074 mg Cr<SUP>+6/dscm for IC/PCR with 
preconcentration. If required, the in-stack detection limits can be 
improved by either increasing the stack gas sample volume, 
[[Page 4980]] reducing the volume of the digested sample for GFAAS, 
improving the analytical detection limits, or any combination of the 
three.
    2.3  Precision. The following precision data have been reported 
for the three analytical methods. In the case of the GFAAS there is 
also bias data. In all cases, when sampling precision is combined 
with analytical precision, the resulting overall precision may be 
lower.
    2.3.1  GFAAS Precision. As reported in Method 7191 of SW-846, in 
a single laboratory (EMSL), using Cincinnati, Ohio tap water spiked 
at concentrations of 19, 48, and 77 <greek-m>g Cr/l, the standard 
deviations were <plus-minus>0.1, <plus-minus>0.2, and 
<plus-minus>0.8, respectively. Recoveries at these levels were 97 
percent, 101 percent, and 102 percent, respectively.
    2.3.2  ICP Precision. As reported in Method 6010A of SW-846, in 
an EPA round-robin Phase 1 study, seven laboratories applied the ICP 
technique to acid/distilled water matrices that had been spiked with 
various metal concentrates. For true values of 10, 50, and 150 
<greek-m>g Cr/l; the mean reported values were 10, 50, and 149 
<greek-m>g Cr/l; and the mean percent relative standard deviations 
were 18, 3.3, and 3.8 percent, respectively.
    2.3.3  IC/PCR Precision. As reported in 40 CFR part 266, 
appendix IX, the precision of the IC/PCR with sample 
preconcentration is 5 to 10 percent; the overall precision for 
sewage sludge incinerators emitting 120 ng/dscm of Cr<SUP>+6 and 3.5 
<greek-m>g/dscm of total Cr is 25 percent and 9 percent for 
Cr<SUP>+6 and total Cr, respectively; and for hazardous waste 
incinerators emitting 300 ng/dscm of Cr<SUP>+6 the precision is 20 
percent.
    2.4  Interferences.
    2.4.1  GFAAS Interferences. Low concentrations of calcium and/or 
phosphate may cause interferences; at concentrations above 200 
<greek-m>g/l, calcium's effect is constant and eliminates the effect 
of phosphate. Calcium nitrate is therefore added to the concentrated 
analyte to ensure a known constant effect. Other matrix modifiers 
recommended by the instrument manufacturer may also be suitable. 
Nitrogen should not be used as the purge gas due to cyanide band 
interference. Background correction may be required because of 
possible significant levels of nonspecific absorption and scattering 
at the 357.9 nm analytical wavelength. Zeeman or Smith-Hieftje 
background correction is recommended to correct for interferences 
due to high levels of dissolved solids in the alkaline impinger 
solutions.
    2.4.2  ICP Interferences.
    2.4.2.1  ICP Spectral Interferences. (a) Spectral interferences 
are caused by:
    (1) Overlap of a spectral line from another element;
    (2) Unresolved overlap of molecular band spectra;
    (3) Background contribution from continuous or recombination 
phenomena; and
    (4) Stray light from the line emission of high-concentration 
elements.
    (b) Spectral overlap may be compensated for by computer 
correcting the raw data after monitoring and measuring the 
interfering element. At the 267.72-nm Cr analytical wavelength, 
iron, manganese, and uranium are potential interfering elements. 
Background and stray light interferences can usually be compensated 
for by a background correction adjacent to the analytical line. 
Unresolved overlap requires the selection of an alternative Cr 
wavelength. Consult the instrument manufacturer's operation manual 
for interference correction procedures.
    2.4.2.2  ICP Physical Interferences. High levels of dissolved 
solids in the samples may cause significant inaccuracies due to salt 
buildup at the nebulizer and torch tips. This problem can be 
controlled by diluting the sample or providing for extended rinse 
times between sample analyses. Standards are prepared in the same 
matrix as the samples (i.e., 0.1 N NaOH or 0.1 N NaHCO<INF>3).
    2.4.2.3  ICP Chemical Interferences. These include molecular 
compound formation, ionization effects and solute vaporization 
effects, and are usually not significant in ICP, especially if the 
standards and samples are matrix matched.
    2.4.3  IC/PCR Interferences. Components in the sample matrix may 
cause Cr<SUP>+6 to convert to trivalent chromium (Cr<SUP>+3) or 
cause Cr<SUP>+3 to convert to Cr<SUP>+6. The chromatographic 
separation of Cr<SUP>+6 using ion chromatography reduces the 
potential for other metals to interfere with the post-column 
reaction. For the IC/PCR analysis, only compounds that coelute with 
Cr<SUP>+6 and affect the diphenylcarbazide reaction will cause 
interference. Periodic analyses of reagent water blanks are used to 
demonstrate that the analytical system is essentially free of 
contamination. Sample cross-contamination that can occur when high-
level and low-level samples or standards are analyzed alternately is 
eliminated by thorough purging of the sample loop. Purging can 
easily be achieved by increasing the injection volume of the samples 
to ten times the size of the sample loop.

3. Apparatus

    3.1  Sampling Train. A schematic of the sampling train used in 
this method is shown in Figure 306-1. The train is the same as 
Method 5, section 2.1 (40 CFR part 60, appendix A), except that the 
filter is omitted, and quartz or borosilicate glass must be used for 
the probe nozzle and liner in place of stainless steel. It is not 
necessary to heat the probe liner. Probe fittings of plastic such as 
Teflon, polypropylene, etc. are recommended over metal fittings to 
prevent contamination. If desired, a single combined probe nozzle 
and liner may be used, but such a single glass piece is not a 
requirement of this methodology. Use 0.1 N NaOH or 0.1 N NaHCO<INF>3 
in the impingers in place of water.
    3.2  Sample Recovery. Same as Method 5, section 2.2 (40 CFR part 
60, appendix A), with the following exceptions:
    3.2.1  Probe-Liner and Probe-Nozzle Brushes. Brushes are not 
necessary for sample recovery. If a probe brush is used, it must be 
nonmetallic.
    3.2.2  Sample Recovery Solution. Use 0.1 N NaOH or 0.1 N 
NaHCO<INF>3, whichever was used as the impinger absorbing solution, 
in place of acetone to recover the sample.
    3.2.3  Sample Storage Containers. Polyethylene, with leak-free 
screw cap, 500 ml or 1,000 ml.
    3.2.4  Filtration Apparatus for IC/PCR. Teflon, or equivalent, 
filter holder and 0.45 <greek-m>m acetate, or equivalent, filter.
    3.3  Analysis. For analysis, the following equipment is needed.
    3.3.1  General.
    3.3.1.1  Phillips Beakers. (Phillips beakers are preferred, but 
regular beakers can also be used.)
    3.3.1.2  Hot Plate.
    3.3.1.3   Volumetric Flasks. Class A, various sizes as 
appropriate.
    3.3.1.4  Assorted Pipettes.
    3.3.2  Analysis by GFAAS.
    3.3.2.1  Chromium Hollow Cathode Lamp or Electrodeless Discharge 
Lamp.
    3.3.2.2  Graphite Furnace Atomic Absorption Spectrophotometer.

    3.3.3  Analysis by ICP.

    3.3.3.1  ICP Spectrometer. Computer-controlled emission 
spectrometer with background correction and radio frequency 
generator.
    3.3.3.2  Argon Gas Supply. Welding grade or better.
    3.3.4  Analysis by IC/PCR.

     3.3.4.1  IC/PCR System. High performance liquid chromatograph 
pump, sample injection valve, post-column reagent delivery and 
mixing system, and a visible detector, capable of operating at 520 
nm, all with a nonmetallic (or inert) flow path. An electronic peak 
area mode is recommended, but other recording devices and 
integration techniques are acceptable provided the repeatability 
criteria and the linearity criteria for the calibration curve 
described in section 6.4.1 can be satisfied. A sample loading system 
will be required if preconcentration is employed.
    3.3.4.2  Analytical Column. A high performance ion chromatograph 
(HPIC) nonmetallic column with anion separation characteristics and 
a high loading capacity designed for separation of metal chelating 
compounds to prevent metal interference. Resolution described in 
section 5.5 must be obtained. A nonmetallic guard column with the 
same ion-exchange material is recommended.
    3.3.4.3  Preconcentration Column. An HPIC nonmetallic column 
with acceptable anion retention characteristics and sample loading 
rates as described in section 5.5.

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    3.3.4.4  0.45-<greek-m>m Filter Cartridge. For the removal of 
insoluble material. To be used just prior to sample injection/
analysis.

4. Reagents

    Unless otherwise indicated, all reagents shall conform to the 
specifications established by the Committee on Analytical Reagents 
of the American Chemical Society (ACS reagent grade). Where such 
specifications are not available, use the best available grade.
    4.1  Sampling.
    4.1.1  Water. Reagent water that conforms to ASTM Specification 
D1193-77, Type II (incorporated by reference--see Sec. 63.14). It is 
recommended that water blanks be checked prior to preparing sampling 
reagents to ensure that the Cr content is less than the analytical 
detection limit.
    4.1.2  Sodium Hydroxide (NaOH) Absorbing Solution, 0.1 N or 
Sodium Bicarbonate (NaHCO<INF>3) Absorbing Solution, 0.1 N. Dissolve 
4.0 g of sodium hydroxide in 1 l of water, or dissolve 8.5 g of 
sodium bicarbonate in 1 l of water.
    4.2  Sample Recovery.
    4.2.1  0.1 N NaOH or 0.1 N NaHCO<INF>3. See section 4.1.2. Use 
the same solution for recovery as was used in the impingers.
    4.2.2  pH Indicator Strip, for IC/PCR. pH indicator capable of 
determining the pH of solutions between the pH range of 7 and 12, at 
0.5 pH intervals.
    4.3  Sample Preparation and Analysis.
    4.3.1  Nitric Acid (HNO<INF>3), Concentrated, for GFAAS. Trace 
metals grade or better HNO<INF>3 must be used for reagent 
preparation. The ACS reagent grade HNO<INF>3 is acceptable for 
cleaning glassware.
    4.3.2  HNO<INF>3, 1.0 percent (v/v), for GFAAS. Add, with 
stirring, 10 ml of concentrated HNO<INF>3 to 800 ml of water. Dilute 
to 1,000 ml with water. This reagent shall contain less than 0.001 
mg Cr/l.
    4.3.3  Calcium Nitrate Ca(NO<INF>3)2 Solution (10 <greek-m>g Ca/
ml) for GFAAS. Prepare the solution by weighing 36 mg of 
Ca(NO<INF>3)<INF>2 into a 1 l volumetric flask. Dilute with water to 
1 l.
    4.3.4  Matrix Modifier, for GFAAS. See instrument manufacturer's 
manual for suggested matrix modifier.
    4.3.5  Chromatographic Eluent, for IC/PCR. The eluent used in 
the analytical system is ammonium sulfate based. Prepare by adding 
6.5 ml of 29 percent ammonium hydroxide (NH<INF>4OH) and 33 g of 
ammonium sulfate ((NH<INF>4)<INF>2SO<INF>4) to 500 ml of reagent 
water. Dilute to 1 l with reagent water and mix well. Other 
combinations of eluents and/or columns may be employed provided peak 
resolution, as described in section 5.5, repeatability and 
linearity, as described in section 6.4.1, and analytical sensitivity 
are acceptable.
    4.3.6  Post-Column Reagent, for IC/PCR. An effective post-column 
reagent for use with the chromatographic eluent described in section 
4.3.5 is a diphenylcarbazide (DPC) based system. Dissolve 0.5 g of 
1,5-diphenylcarbazide in 100 ml of ACS grade methanol. Add 500 ml of 
reagent water containing 50 ml of 96 percent spectrophotometric 
grade sulfuric acid. Dilute to 1 l with reagent water.
    4.3.7  Chromium Standard Stock Solution (1,000 mg/l). Procure a 
certified aqueous standard or dissolve 2.829 g of potassium 
dichromate (K<INF>2Cr<INF>2O<INF>7,) in water and dilute to 1 l.
      4.3.8  Calibration Standards for GFAAS. Chromium solutions for 
GFAAS calibration shall be prepared to contain 1.0 percent (v/v) 
HNO<INF>3. The zero standard shall be 1.0 percent (v/v) HNO<INF>3. 
Calibration standards should be prepared daily by diluting the Cr 
standard stock solution (section 4.3.7) with 1.0 percent HNO<INF>3. 
Use at least four standards to make the calibration curve. Suggested 
levels are 0, 5, 50, and 100 <greek-m>g Cr/l.
    4.3.9  Calibration Standards for ICP or IC/PCR. Prepare 
calibration standards for ICP or IC/PCR by diluting the Cr standard 
stock solution (section 4.3.7) with 0.1 N NaOH or 0.1 N NaHCO<INF>3, 
whichever was used as the impinger absorbing solution, to achieve a 
matrix similar to the actual field samples. Suggested levels are 0, 
25, 50, and 100 <greek-m>g Cr/l for ICP, and 0, 0.5, 5, and 10 
<greek-m>g Cr<SUP>+6/l for IC/PCR.
    4.4  Glassware Cleaning Reagents.
    4.4.1  HNO<INF>3, Concentrated. The ACS reagent grade or 
equivalent.
    4.4.2  Water. Reagent water that conforms to ASTM Specification 
D1193-77, Type II, (incorporated by reference--see Sec. 63.14).
     4.4.3 HNO<INF>3, 10 percent (v/v). Add with stirring 500 ml of 
concentrated HNO<INF>3 to a flask containing approximately 4,000 ml 
of water. Dilute to 5,000 ml with water. Mix well. The reagent shall 
contain less than 2 <greek-m>g Cr/l.

5. Procedure

    5.1  Sampling. (a) Same as Method 5, section 4.1 (40 CFR part 
60, appendix A), except omit the filter and filter holder from the 
sampling train, use a glass nozzle and probe liner, do not heat the 
probe, place 100 ml of 0.1 N NaOH or 0.1 N NaHCO<INF>3 in each of 
the first two impingers, and record the data for each run on a data 
sheet such as the one shown in Figure 306-2.
    (b) Clean all glassware prior to sampling in hot soapy water 
designed for laboratory cleaning of glassware. Next, rinse the 
glassware three times with tap water, followed by three additional 
rinses with reagent water. Then soak all glassware in 10 percent (v/
v) HNO<INF>3 solution for a minimum of 4 hours, rinse three times 
with reagent water, and allowed to air dry. Cover all glassware 
openings where contamination can occur with Parafilm, or equivalent, 
until the sampling train is assembled for sampling.
    (c) If the sample is going to be analyzed for Cr<SUP>+6 using 
IC/PCR, determine the pH of the solution in the first impinger at 
the end of the sampling run using a pH indicator strip. The pH of 
the solution should be greater than 8.5. If not, the concentration 
of the NaOH or NaHCO<INF>3 impinger absorbing solution should be 
increased to 0.5 N and the sample should be rerun.
    5.2  Sample Recovery. Follow the basic procedures of Method 5, 
section 4.2, with the exceptions noted below; a filter is not 
recovered from this train.
    5.2.1  Container No. 1. Measure the volume of the liquid in the 
first, second, and third impingers and quantitatively transfer into 
a labelled sample container. Use approximately 200 to 300 ml of 0.1 
N NaOH or 0.1 N NaHCO<INF>3 to rinse the probe nozzle, probe liner, 
three impingers, and connecting glassware; add this rinse to the 
same container.
    5.2.2  Container No. 2 (Reagent Blank). Place approximately 500 
ml of 0.1 N NaOH or 0.1 N NaHCO<INF>3 absorbing solution in a 
labeled sample container.
    5.2.3  Sample Filtration for IC/PCR. If the sample is to be 
analyzed for Cr<SUP>+6 by IC/PCR, it must be filtered immediately 
following recovery to remove any insoluble matter. Nitrogen gas may 
be used as a pressure assist to the filtration process. Filter the 
entire contents of Container No. 1 through a 0.45-<greek-m>m acetate 
filter (or equivalent), and collect the filtrate in a 1,000 ml 
graduated cylinder. Rinse the sample container with reagent water 
three separate times, pass these rinses through the filter, and add 
the rinses to the sample filtrate. Determine the final volume of the 
filtrate and rinses and return them to the rinsed polyethylene 
sample container.
    5.2.4  Sample Preservation. Refrigerate samples upon receipt. 
(Containers Nos. 1 and 2).
    5.3  Sample Preparation and Analysis for GFAAS. For analysis by 
GFAAS, an acid digestion of the alkaline impinger solution is 
required. Two types of blanks are required for the analysis. The 
calibration blank is used in establishing the analytical curve, and 
the reagent blank is used to assess possible contamination resulting 
from the sample processing. The 1.0 percent HNO<INF>3 is the 
calibration blank. The 0.1 N NaOH solution or the 0.1 N NaHCO<INF>3 
from section 5.2.2 is the reagent blank. The reagent blank must be 
carried through the complete analytical procedure, including the 
acid digestion, and must contain the same acid concentration in the 
final solution as the sample solutions.
    5.3.1  Acid Digestion for GFAAS. (a) In a beaker, add 10 ml of 
concentrated HNO<INF>3 to a sample aliquot of 100 ml taken for 
analysis. Cover the beaker with a watch glass. Place the beaker on a 
hot plate and reflux the sample down to near dryness. Add another 5 
ml of concentrated HNO<INF>3 to complete the digestion. Carefully 
reflux the sample volume down to near dryness. Wash down the beaker 
walls and watch glass with reagent water. The final concentration of 
HNO<INF>3 in the solution should be 1 percent (v/v). Transfer the 
digested sample to a 50 ml volumetric flask. Add 0.5 ml of 
concentrated HNO<INF>3, and 1 ml of the 10 <greek-m>g/ml of Ca 
(NO<INF>3)<INF>2.
    (b) Dilute to 50 ml with reagent water. A different final volume 
may be used, based on the expected Cr concentration, but the 
HNO<INF>3 concentration must be maintained at 1 percent (v/v).

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    5.3.2 Sample Analysis by GFAAS. (a) The 357.9-nm wavelength line 
shall be used. Follow the manufacturer's operating instructions for 
all other spectrophotometer parameters.
    (b) Furnace parameters suggested by the manufacturer should be 
employed as guidelines. Since temperature-sensing mechanisms and 
temperature controllers can vary between instruments and/or with 
time, the validity of the furnace parameters must be periodically 
confirmed by systematically altering the furnace parameters while 
analyzing a standard. In this manner, losses of analyte due to 
higher-than-necessary temperature settings or losses in sensitivity 
due to less than optimum settings can be minimized. Similar 
verification of furnace parameters may be required for complex 
sample matrices. Calibrate the GFAAS system following the procedures 
specified in section 6.
    (c) Inject a measured aliquot of digested sample into the 
furnace and atomize. If the concentration found exceeds the 
calibration range, the sample should be diluted with the calibration 
blank solution (1.0 percent HNO<INF>3) and reanalyzed. Consult the 
operator's manual for suggested injection volumes. The use of 
multiple injections can improve accuracy and help detect furnace 
pipetting errors.
    (d) Analyze a minimum of one matrix-matched reagent blank per 
sample batch to determine if contamination or any memory effects are 
occurring. Analyze a calibration blank and a midpoint calibration 
check standard after approximately every 10 sample injections.
    (e) Calculate the Cr concentrations:
    (1) By the method of standard additions (see operator's manual),
    (2) From the calibration curve, or
    (3) Directly from the instrument's concentration readout. All 
dilution or concentration factors must be taken into account. All 
results should be reported in <greek-m>g Cr/ml with up to three 
significant figures.
    5.4  Sample Analysis by ICP. (a) The ICP measurement is 
performed directly on the alkaline impinger solution; acid digestion 
is not necessary provided the samples and standards are matrix 
matched. However, ICP should only be used when the solution analyzed 
has a Cr concentration greater than 35 <greek-m>g/l.
    (b) Two types of blanks are required for the analysis. The 
calibration blank is used in establishing the analytical curve, and 
the reagent blank is used to assess possible contamination resulting 
from sample processing. Use either 0.1 N NaOH or 0.1 N NaHCO<INF>3, 
whichever was used for the impinger absorbing solution, for the 
calibration blank. The calibration blank can be prepared fresh in 
the laboratory; it does not have to be from the same batch of 
solution that was used in the field. Prepare a sufficient quantity 
to flush the system between standards and samples. The reagent blank 
(section 5.2.2) is a sample of the impinger solution used for sample 
collection that is collected in the field during the testing 
program.
    (c) Set up the instrument with proper operating parameters 
including wavelength, background correction settings (if necessary), 
and interfering element correction settings (if necessary). The 
instrument must be allowed to become thermally stable before 
beginning performance of measurements (usually requiring at least 30 
min of operation prior to calibration). During this warmup period, 
the optical calibration and torch position optimization may be 
performed (consult the operator's manual).
    (d) Calibrate the instrument according to the instrument 
manufacturer's recommended procedures, and the procedures specified 
in section 6.3. Before analyzing the samples, reanalyze the highest 
calibration standard as if it were a sample. Concentration values 
obtained should not deviate from the actual values by more than 5 
percent, or the established control limits, whichever is lower (see 
sections 6 and 7). If they do, follow the recommendations of the 
instrument manufacturer to correct for this condition.
    (e) Flush the system with the calibration blank solution for at 
least 1 min before the analysis of each sample or standard. Analyze 
the midpoint calibration standard and the calibration blank after 
each 10 samples. Use the average intensity of multiple exposures for 
both standardization and sample analysis to reduce random error.
    (f) Dilute and reanalyze samples that are more concentrated than 
the linear calibration limit or use an alternate, less sensitive Cr 
wavelength for which quality control data are already established.
    (g) If dilutions are performed, the appropriate factors must be 
applied to sample values. All results should be reported in 
<greek-m>g Cr/ml with up to three significant figures.
    5.5  Sample Analyses by IC/PCR. (a) The Cr<SUP>+6 content of the 
sample filtrate is determined by IC/PCR. To increase sensitivity for 
trace levels of chromium, a preconcentration system is also used in 
conjunction with the IC/PCR.
    (b) Prior to preconcentration and/or analysis, filter all field 
samples through a 0.45-<greek-m>m filter. This filtration should be 
conducted just prior to sample injection/analysis.
    (c) The preconcentration is accomplished by selectively 
retaining the analyte on a solid absorbent (as described in section 
3.4.3.3), followed by removal of the analyte from the absorbent. 
Inject the sample into a sample loop of the desired size (use 
repeated loadings or a larger size loop for greater sensitivity). 
The Cr<SUP>+6 is collected on the resin bed of the column. Switch 
the injection valve so that the eluent displaces the concentrated 
Cr<SUP>+6 sample, moving it off the preconcentration column and onto 
the IC anion separation column. After separation from other sample 
components, the Cr<SUP>+6 forms a specific complex in the post-
column reactor with the DPC reaction solution, and the complex is 
detected by visible absorbance at a wavelength of 520 nm. The amount 
of absorbance measured is proportional to the concentration of the 
Cr<SUP>+6 complex formed. Compare the IC retention time and the 
absorbance of the Cr<SUP>+6 complex with known Cr<SUP>+6 standards 
analyzed under identical conditions to provide both qualitative and 
quantitative analyses.
    (d) Two types of blanks are required for the analysis. The 
calibration blank is used in establishing the analytical curve, and 
the reagent blank is used to assess possible contamination resulting 
from sample processing. Use either 0.1 N NaOH or 0.1 N NaHCO<INF>3, 
whichever was used for the impinger solution, for the calibration 
blank. The calibration blank can be prepared fresh in the 
laboratory; it does not have to be from the same batch of solution 
that was used in the field. The reagent blank (section 5.2.2) is a 
sample of the impinger solution used for sample collection that is 
collected in the field during the testing program.
    (e) Prior to sample analysis, establish a stable baseline with 
the detector set at the required attenuation by setting the eluent 
flow rate at approximately 1 ml/min and the post-column reagent flow 
rate at approximately 0.5 ml/min. Note: As long as the ratio of 
eluent flow rate to PCR flow rate remains constant, the standard 
curve should remain linear. Inject a sample of reagent water to 
ensure that no Cr<SUP>+6 appears in the water blank.
    (f) First, inject the calibration standards prepared, as 
described in section 4.3.9 to cover the appropriate concentration 
range, starting with the lowest standard first. Next, inject, in 
duplicate, the calibration reference standard (as described in 
section 7.3.1), followed by the reagent blank (section 5.2.2), and 
the field samples. Finally, repeat the injection of the calibration 
standards to assess instrument drift. Measure areas or heights of 
the Cr<SUP>+6/DPC complex chromatogram peaks. The response for 
replicate, consecutive injections of samples must be within 5 
percent of the average response, or the injection should be repeated 
until the 5 percent criterion can be met. Use the average response 
(peak areas or heights) from the duplicate injections of calibration 
standards to generate a linear calibration curve. From the 
calibration curve, determine the concentrations of the field samples 
employing the average response from the duplicate injections.

6. Calibration

    6.1  Sampling Train Calibration. Perform all of the calibrations 
described in Method 5, section 5 (40 CFR part 60, appendix A). The 
alternate calibration procedures described in section 7 of Method 5 
(40 CFR part 60, appendix A) may also be used.
    6.2  GFAAS Calibration. Either run a series of chromium 
standards and a calibration blank and construct a calibration curve 
by plotting the concentrations of the standards against the 
absorbencies, or using the method of standard additions, plot added 
concentration versus absorbance. For instruments that read directly 
in concentration, set the curve corrector to read out the proper 
concentration, if applicable. This is customarily performed 
automatically with most instrument computer-based data systems.
    6.2.1  GFAAS Calibration Curve. If a calibration curve is used, 
it should be prepared daily with a minimum of a calibration blank 
and three standards. Calibration standards for total chromium should 
start with 1 percent v/v HNO<INF>3 with [[Page 4985]] no chromium 
for the calibration blank, with appropriate increases in total 
chromium concentration for the other calibration standards (see 
section 4.3.9.). Calibration standards should be prepared fresh 
daily.
    6.3  ICP Calibration. Calibrate the instrument according to the 
instrument manufacturer's recommended procedures, using a 
calibration blank and three standards for the initial calibration. 
Calibration standards should be prepared fresh daily, as described 
in section 4.3.9. Be sure that samples and calibration standards are 
matrix matched. Flush the system with the calibration blank between 
each standard. Use the average intensity of multiple exposures for 
both standardization and sample analysis to reduce random error.
    6.4  IC/PCR Calibration. Prepare a calibration curve using the 
calibration blank and three calibration standards prepared fresh 
daily as described in section 4.3.9. Run the standards with the 
field samples as described in section 5.5.

7. Quality Control

    7.1  GFAAS Quality Control
    7.1.1  GFAAS Calibration Reference Standards. If a calibration 
curve is used, it must be verified by use of at least one 
calibration reference standard (made from a reference material or 
other independent standard material) at or near the mid-range of the 
calibration curve. The calibration reference standard must be 
measured within 10 percent of it's true value for the curve to be 
considered valid. The curve must be validated before sample analyses 
are performed.
    7.1.2  GFAAS Check Standards. (a) Run a check standard and a 
calibration blank after approximately every 10 sample injections, 
and at the end of the analytical run. These standards are run, in 
part, to monitor the life and performance of the graphite tube. Lack 
of reproducibility or a significant change in the signal for the 
check standard indicates that the graphite tube should be replaced. 
Check standards can be the mid-range calibration standard or the 
reference standard. The results of the check standard shall agree 
within 10 percent of the expected value. If not, terminate the 
analyses, correct the problem, recalibrate the instrument, and 
reanalyze all samples analyzed subsequent to the last acceptable 
check standard analysis.
    (b) The results of the calibration blank are to agree within 
three standard deviations of the mean blank value. If not, repeat 
the analysis two more times and average the results. If the average 
is not within three standard deviations of the background mean, 
terminate the analyses, correct the problem, recalibrate, and 
reanalyze all samples analyzed subsequent to the last acceptable 
calibration blank analysis.
    7.1.3  GFAAS Duplicate Samples. Run one duplicate sample for 
every 20 samples, (or one per source test, whichever is more 
frequent). Duplicate samples are brought through the whole sample 
preparation and analytical process separately. Duplicate samples 
shall agree within 10 percent.
    7.1.4  GFAAS Matrix Spiking. Spiked samples shall be prepared 
and analyzed daily to ensure that correct procedures are being 
followed and that all equipment is operating properly. Spiked sample 
recovery analyses should indicate a recovery for the Cr spike of 
between 75 and 125 percent. Spikes are added prior to any sample 
preparation. Cr levels in the spiked sample should provide final 
solution concentrations that fall within the linear portion of the 
calibration curve.
    7.1.5  GFAAS Method of Standard Additions. Whenever sample 
matrix problems are suspected and standard/sample matrix matching is 
not possible or whenever a new sample matrix is being analyzed, the 
method of standard additions shall be used for the analysis of all 
extracts. Section 5.4.2 of Method 12 (40 CFR part 60, appendix A) 
specifies a performance test to determine if the method of standard 
additions is necessary.
    7.1.6  GFAAS Reagent Blank Samples. Analyze a minimum of one 
matrix-matched reagent blank (section 5.2.2) per sample batch to 
determine if contamination or memory effects are occurring. The 
results should agree within three standard deviations of the mean 
blank value.
    7.2  ICP Quality Control.
    7.2.1  ICP Interference Check. Prepare an interference check 
solution to contain known concentrations of interfering elements 
that will provide an adequate test of the correction factors in the 
event of potential spectral interferences. Two potential 
interferences, iron and manganese, may be prepared as 1,000 
<greek-m>g/ml and 200 <greek-m>g/ml solutions, respectively. The 
solutions should be prepared in dilute HNO<INF>3 (1-5 percent). 
Particular care must be taken to ensure that the solutions and/or 
salts used to prepare the solutions are of ICP grade purity (i.e., 
that no measurable Cr contamination exists in the salts/solutions). 
Commercially prepared interfering element check standards are 
available. Verify the interelement correction factors every three 
months by analyzing the interference check solution. The correction 
factors are calculated according to the instrument manufacturer's 
directions. If interelement correction factors are used properly, no 
false Cr should be detected.
    7.2.2  ICP Calibration Reference Standards. Prepare a 
calibration reference standard in the same alkaline matrix as the 
calibration standards; it should be at least 10 times the 
instrumental detection limit. This reference standard should be 
prepared from a different Cr stock solution source than that used 
for preparation of the calibration curve standards and is used to 
verify the accuracy of the calibration curve. Prior to sample 
analysis, analyze at least one reference standard. The calibration 
reference standard must be measured within 10 percent of it's true 
value for the curve to be considered valid. The curve must be 
validated before sample analyses are performed.
    7.2.3  ICP Check Standards. Run a check standard and a 
calibration blank after every 10 samples, and at the end of the 
analytical run. Check standards can be the mid-range calibration 
standard or the reference standard. The results of the check 
standard shall agree within 10 percent of the expected value; if 
not, terminate the analyses, correct the problem, recalibrate the 
instrument, and rerun all samples analyzed subsequent to the last 
acceptable check standard analysis. The results of the calibration 
blank are to agree within three standard deviations of the mean 
blank value. If not, repeat the analysis two more times and average 
the results. If the average is not within three standard deviations 
of the background mean, terminate the analyses, correct the problem, 
recalibrate, and reanalyze all samples analyzed subsequent to the 
last acceptable calibration blank analysis.
    7.2.4  ICP Duplicate Samples. Analyze one duplicate sample for 
every 20 samples, (or one per source test, whichever is more 
frequent). Duplicate samples are brought through the whole sample 
preparation and analytical process. Duplicate samples shall agree 
within 10 percent.
    7.2.5  ICP Reagent Blank Samples. Analyze a minimum of one 
matrix-matched reagent blank (section 5.2.2) per sample batch to 
determine if contamination or memory effects are occurring. The 
results should agree within three standard deviations of the mean 
blank value.
    7.3  IC/PCR Quality Control.
    7.3.1  IC/PCR Calibration Reference Standards. Prepare a 
calibration reference standard in the same alkaline matrix as the 
calibration standards at a concentration that is at or near the mid-
point of the calibration curve. This reference standard should be 
prepared from a different Cr stock solution source than that used 
for preparing the calibration curve standards. The reference 
standard is used to verify the accuracy of the calibration curve. 
Prior to sample analysis, analyze at least one reference standard. 
The results of this analysis of the reference standard must be 
within 10 percent of the true value of the reference standard for 
the calibration curve to be considered valid. The curve must be 
validated before sample analyses are performed.
    7.3.2  IC/PCR Check Standards. (a) Run the calibration blank and 
calibration standards with the field samples as described in section 
5.5. For each standard, determine the peak areas (recommended) or 
the peak heights, calculate the average response from the duplicate 
injections, and plot the average response against the Cr+6 
concentration in <greek-m>g/l. The individual responses for each 
calibration standard determined before and after field sample 
analysis must be within 5 percent of the average response for the 
analysis to be valid. If the 5 percent criteria is exceeded, 
excessive drift and/or instrument degradation may have occurred, and 
must be corrected before further analyses are performed.
    (b) Employing linear regression, calculate a predicted value for 
each calibration standard using the average response for the 
duplicate injections. Each predicted value must be within 7 percent 
of the actual value for the calibration curve to be considered 
acceptable. If not acceptable, remake and/or rerun the calibration 
standards. If the calibration curve is still unacceptable, reduce 
the range of the curve.
    7.3.3  IC/PCR Duplicate Samples. Analyze one duplicate sample 
for every 20 samples, (or one per source test, whichever is more 
frequent). Duplicate samples are brought through the whole sample 
preparation and [[Page 4986]] analytical process. Duplicate samples 
shall agree within 10 percent.
    7.3.4  ICP Reagent Blank Samples. Analyze a minimum of one 
matrix-matched reagent blank (section 5.2.2) per sample batch to 
determine if contamination or memory effects are occurring. The 
results should agree within three standard deviations of the mean 
blank value.

8. Emission Calculations

    Carry out the calculations, retaining one extra decimal figure 
beyond that of the acquired data. Round off figures after final 
calculations.
    8.1 Total Cr in Sample. Calculate M<INF>Cr, the total <greek-m>g 
Cr in each sample, as follows:

M<INF>Cr = (V<INF>ml) (C<INF>S) (F) (D)    Eq.306-1
where:

V<INF>ml = Volume of impinger contents plus rinses, ml.
C<INF>S = Concentration of Cr in sample solution, <greek-m>g Cr/ml.
F = Dilution factor.
= Volume of aliquot after dilution, ml; Volume of aliquot before 
dilution, ml
D = Digestion factor.
= Volume of sample aliquot after digestion, ml; Volume of sample 
aliquot submitted to digestion, ml

    8.2  Average Dry Gas Meter Temperature and Average Orifice 
Pressure Drop. Same as Method 5, section 6.2.
    8.3  Dry Gas Volume, Volume of Water Vapor, Moisture Content. 
Same as Method 5, sections 6.3, 6.4, and 6.5, respectively.
    8.4 Cr  Emission Concentration. Calculate C<INF>Cr, the Cr 
concentration in the stack gas, in mg/dscm on a dry basis, corrected 
to standard conditions, as follows:

C<INF>Cr=(10<SUP>-3 mg/<greek-m>g) (M<INF>Cr/V<INF>m(std))    Eq. 
306-2
where:

 V<INF>m(std)=Gas sample volume measured by the dry gas meter, 
corrected to dry standard conditions, dscm.

    8.5  Isokinetic Variation, Acceptable Results. Same as Method 5, 
sections 6.11 and 6.12, respectively.

9. Bibliography

    1. ``Test Methods for Evaluating Solid Waste, Physical/Chemical 
Methods,'' U. S. Environmental Protection Agency Publication SW-846, 
2nd Edition, July 1982.
    2. Cox, X.B., R.W. Linton, and F.E. Butler. Determination of 
Chromium Speciation in Environmental Particles--A Multitechnique 
Study of Ferrochrome Smelter Dust. Accepted for publication in 
Environmental Science and Technology.
    3. Same as Bibliography of Method 5, Citations 2 to 5 and 7.
    4. California Air Resources Board, ``Determination of Total 
Chromium and Hexavalent Chromium Emissions from Stationary 
Sources.'' Method 425, September 12, 1990.
    5. ``Test Methods for Evaluating Solid Waste, Physical/ Chemical 
Methods'', U. S. Environmental Protection Agency Publication SW-846, 
3rd Edition, November 1986 as amended by Update I , November 1990.

Method 306A--Determination of Chromium Emissions From Decorative and 
Hard Chromium Electroplating and Anodizing Operations

1. Applicability and Principle

    1.1  Applicability. This method applies to the determination of 
chromium (Cr) in emissions from decorative and hard chromium 
electroplating facilities and anodizing operations. The method is 
less expensive and less complex to conduct than Method 306 of this 
appendix. Correctly applied, the precision and bias of the sample 
results will be comparable to those obtained with the isokinetic 
Method 306 of this appendix. This method is applicable under ambient 
moisture, air, and temperature conditions.
    1.2  Principle. A sample is extracted from the source at a 
constant sampling rate determined by a critical orifice and 
collected in a probe and impingers. The sampling time at the 
sampling traverse points is varied according to the stack gas 
velocity at each point to obtain a proportional sample. The 
concentration is determined by the same analytical procedures used 
in Method 306 of this appendix: inductively-coupled plasma emission 
spectrometry (ICP), graphite furnace atomic absorption spectrometry 
(GFAAS), or ion chromatography with a post-column reactor (IC/PCR).

2. Range, Sensitivity, Precision, and Interferences

    Same as Method 306, section 2 of this appendix.

3. Apparatus

    Note: Mention of trade names or specific products does not 
constitute endorsement by the Environmental Protection Agency.
    3.1  Sampling Train. A schematic of the sampling train is shown 
in Figure 306A-1. The components of the train are available 
commercially, but some fabrication and assembly are required. If 
Method 306 equipment is available, the sampling train may be 
assembled as specified in Method 306 of this appendix and the 
sampling rate of the meter box set at the delta H<INF>@ specified 
for the calibrated orifice; this train is then operated as specified 
in this method.
    3.1.1  Probe Nozzle/Tubing and Sheath. Use approximately 1/4 in. 
inner diameter (ID) glass or rigid plastic tubing about 8 in. long 
with a short 90 deg. bend at one end to form the nozzle. Grind a 
slight taper on the nozzle end before making the bend. Attach the 
nozzle to flexible tubing of sufficient length to collect a sample 
from the stack. Use a straight piece of larger diameter rigid tubing 
(such as metal conduit or plastic water pipe) to form a sheath that 
begins about 1 in. from the 90 deg. bend on the nozzle and encases 
the flexible tubing.

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[GRAPHIC][TIFF OMITTED]TR25JA95.010



BILLING CODE 6560-50-C [[Page 4988]] 
    3.1.2  S-Type Pitot. Same as Method 2, section 3 (40 CFR part 
60, appendix A).
    3.1.3  Sample Line. Use thick wall flexible plastic tubing 
(e.g., polyethylene, polypropylene, or polyvinylchloride) about \1/
4\ in. to \3/8\ in. ID to connect the train components. A 
combination of rigid plastic tubing and thin wall flexible tubing 
may be used as long as neither tubing collapses when leak-checking 
the train. Metal tubing cannot be used.
    3.1.4  Impingers. One quart capacity ``Mason'' glass canning 
jars with vacuum seal lids are used. Three impingers are required: 
the first is for collecting the absorbing solution, the second is 
empty and is used to collect any absorbing solution carried over 
from the first impinger, and the third contains the drying agent. 
Install bleak-tight inlet and outlet tubes in the lids of each 
impinger for assembly with the train. The tubes may be made of 
approximately \1/4\ in. ID glass or rigid plastic tubing. For the 
inlet tube of the first impinger, heat the glass or plastic tubing 
and draw until the tubing separates. Cut the tip off until the tip 
orifice is \3/32\ in. in diameter. When fabricating the first 
impinger, place the tip orifice \3/16\ in. above the bottom of the 
jar when assembled. For the second impinger, the inlet tube need not 
be drawn and sized, but the tip should be approximately 2 in. above 
the bottom of the jar. The inlet tube of the third impinger should 
extend to about \1/2\ in. above the bottom of the jar. Locate the 
outlet tube end of all impingers about \1/2\ in. beneath the bottom 
of the lid.
    3.1.5  Manometer. Inclined/vertical type, or equivalent device, 
as described in section 2.2 of Method 2 (40 CFR part 60, appendix 
A).
    3.1.6  Critical Orifice. The critical orifice is a small 
restriction in the sample line (approximately \1/16\ in. in 
diameter) that is located upstream of the vacuum pump and sets the 
sample rate at about 0.75 cfm. An orifice can be made of \3/32\ in. 
brass tubing approximately \9/16\ in. long sealed inside larger 
diameter, approximately \5/16\ in., brass tubing to serve as a 
critical orifice giving a constant sample flow. Materials other than 
brass can be used to construct the critical orifice as long as the 
flow through the sampling train is approximately 0.75 cfm.
    3.1.7  Connecting Hardware. Standard pipe and fittings, \1/4\ 
in. or \1/8\ in., are used to install the vacuum pump and dry gas 
meter in the sampling train.
    3.1.8  Pump Oiler. A glass oil reservoir with a wick mounted at 
the vacuum pump inlet lubricates the pump vanes. The oiler should be 
an inline type and not vented to the atmosphere.
    3.1.9  Vacuum Pump. Gast Model 0522-V103-G18DX, or equivalent, 
capable of delivering at least 1.5 cfm at 15 in. Hg vacuum.
    3.1.10  Oil Trap. An empty glass oil reservoir without wick is 
mounted at pump outlet to prevent oil from reaching the dry gas 
meter.
    3.1.11  Dry Gas Meter. A Rockwell model 175-s test meter, or 
equivalent, with a thermometer installed to monitor meter 
temperature. The dry gas meter must be capable of measuring volume 
to within 2 percent.
    3.2  Sample Recovery.
    3.2.1   Wash Bottles. These are glass or inert plastic, 500 or 
1000 ml, with spray tube.
    3.2.2  Sample Containers. The first mason jar impinger of the 
sampling train serves as the sample container. A new lid and plastic 
wrap are substituted for the impinger inlet/outlet assembly.
    3.3  Analysis. Same as Method 306, section 3.3 of this appendix.

4. Reagents

    4.1  Sampling. Same as Method 306, section 4.1 of this appendix.
    4.2  Sample Recovery. Same as Method 306, section 4.2 of this 
appendix.

5. Procedure

    5.1  Sampling.
    5.1.1  Pretest Preparation.
    5.1.1.1  Port Location. Locate the sampling ports as specified 
in section 2.1 of Method 1 (40 CFR part 60, appendix A). Use a total 
of 24 sampling points for round ducts and 25 points for rectangular 
ducts. Locate the sampling points as specified in section 2.3 of 
Method 1 (40 CFR part 60, Appendix A). Mark the pitot and sampling 
probe with thin strips of tape to permit velocity and sample 
traversing. For ducts less than 12 in. in diameter, use a total of 
16 points.
    5.1.1.2  Velocity Pressure Traverse. (a) Perform a velocity 
pressure traverse before the first sample run. Figure 306A-2 may be 
used to record velocity pressure data. If testing occurs over 
several days, perform the traverse at the beginning of each day. 
Perform velocity pressure traverses as specified in section 3 of 
Method 2 (40 CFR part 60, appendix A), but record only the 
<greek-D>p (velocity head) values for each sampling point.
    (b) Check for cyclonic flow during the first traverse to verify 
that it does not exist; if cyclonic flow does exist, make sure that 
the absolute average angle of misalignment does not exceed 20 deg.. 
If the average angle of misalignment exceeds 20 deg. at an outlet 
location, install straightening vanes to eliminate the cyclonic 
flow. If it is necessary to test an inlet location where cyclonic 
flow exists, it may not be possible to install straightening vanes. 
In this case, a variation of the alignment method must be used. This 
must be approved by the Administrator.

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[GRAPHIC][TIFF OMITTED]TR25JA95.011



BILLING CODE 6560-50-C [[Page 4990]] 
    5.1.1.3  Point Sampling Times. Since the sampling rate of the 
train is held constant by the critical orifice, it is necessary to 
calculate specific sampling times for each point in order to obtain 
a proportional sample. If all sampling can be completed in a single 
day, it is necessary to calculate the point sampling times only 
once. If sampling occurs over several days, recalculate the point 
sample times each day using velocity traverse data obtained earlier 
in the day. Determine the average of the <greek-D>p values obtained 
during the velocity traverse (Figure 306A-2). Calculate the sampling 
times for each point using Equation 306A-1. Convert the decimal 
parts of minutes to seconds. If the stack diameter is less than 12 
in., use 7.5 minutes in place of 5 minutes in the equation and 16 
sampling points.
[GRAPHIC][TIFF OMITTED]TR25JA95.003


Where:

n=Sampling point number.
<greek-D>p=Velocity head measured by Type-S pitot tube, in. H<INF>2O

    5.1.1.4 Preparation of Sampling Train. Assemble the sampling 
train as shown in Figure 306A-1. Secure the nozzle-liner assembly to 
the sheath to prevent slipping when sampling. Before charging, rinse 
the first mason jar impinger with either 0.1 N sodium hydroxide 
(NaOH) or 0.1 N sodium bicarbonate (NaHCO<INF>3); discard the 
solution. Put 250 ml of 0.1 N NaOH or 0.1 N NaHCO<INF>3 absorbing 
solution into the first mason jar impinger. Similarly, rinse the 
second mason jar impinger and leave empty. Put silica gel into the 
third mason jar impinger until the impinger is half full. Place the 
impingers into an ice bath and check to ensure that the lids are 
tight.
    5.1.1.5  Train Leak Check Procedure. Wait until the ice has 
cooled the impingers before sampling. Next, seal the nozzle with a 
finger covered by a piece of clear plastic wrap and turn on the 
pump. The vacuum in the line between the pump and the critical 
orifice must be at least 15 in. Hg. Observe any leak rate on the dry 
gas meter. The leak rate should not exceed 0.02 cfm.
    5.1.2  Sampling Train Operation.
    5.1.2.1  Record all pertinent process and sampling data on the 
data sheet (see Figure 306A-3). Ensure that the process operation is 
suitable for sample collection.

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[GRAPHIC][TIFF OMITTED]TR25JA95.012



BILLING CODE 6560-50-C [[Page 4992]] 
    5.1.2.2  Place the probe/nozzle into the duct at the first 
sampling point and turn on the pump. A minimum vacuum of 15 in. Hg 
or 0.47 atmosphere between the critical orifice and pump is required 
to maintain critical flow. Sample for the time interval previously 
determined for that point. Move to the second point and sample for 
the time interval determined for that point; sample all points on 
the traverse in this manner. Keep ice around the impingers during 
the run. Complete the traverse and turn off the pump. Move to the 
next sampling port and repeat. Record the final dry gas meter 
reading. (NOTE: If an approximate mass emission rate is desired, 
record the stack temperature before and after the run.)
    5.1.2.3  Post Test Leak Check. Remove the probe assembly and 
flexible tubing from the first impinger. Do not cover the nozzle. 
Seal the inlet tube of the first impinger with a finger covered by 
clear plastic wrap and turn on the pump. The vacuum in the line 
between the pump and the critical orifice must be at least 15 in. 
Hg. Observe any leak rate on the dry gas meter. If the leak rate 
exceeds 0.02 cfm, reject the run. If the leak rate is acceptable, 
take the probe assembly and impinger assembly to the sample recovery 
area.
    5.2  Sample Recovery.
    5.2.1   Container No. 1. (a) After the train has been moved to 
the sample recovery area, disconnect the tubing that joins the first 
impinger with the second.
    (b) The first impinger jar is also used as the sample container 
jar. Unscrew the lid from the first impinger jar. Lift the inlet/
outlet tube assembly almost out of the jar, and using the wash 
bottle, rinse the outside of the impinger tip that was immersed in 
the impinger jar with extra absorbing solution; rinse the inside of 
the tip as well.
    (c) Recover the second impinger by removing the lid and pouring 
any contents from the second impinger into the first impinger. Rinse 
the second impinger including the inside and outside of the impinger 
stem as well as any connecting plastic tubing with extra absorbing 
solution and place the rinse into the first impinger.
    (d) Hold the nozzle and connecting plastic tubing in a vertical 
position so that the tubing forms a ``U.'' Using the wash bottle, 
partially fill the tubing with sampling reagent. Raise and lower the 
end of the plastic tubing several times to cause the reagent to 
contact the major portion of the internal parts of the assembly 
thoroughly. Do not raise the solution level too high or part of the 
sample will be lost. Place the nozzle end of the assembly over the 
mouth of the first impinger jar (sample container) and elevate the 
plastic tubing so that the solution flows rapidly out of the nozzle. 
Perform this procedure three times. Next, repeat the recovery 
procedure but allow the solution to flow rapidly out the open end of 
the plastic tubing into the first impinger jar.
    (e) Place a piece of clear plastic wrap over the mouth of the 
first impinger jar. Use a standard lid and band assembly to seal the 
jar. Label the jar with the sample number and mark the liquid level 
to gauge any losses during handling.
    5.2.2  Container No. 2 (Reagent Blank). Place approximately 500 
ml of the 0.1 N NaOH or 0.1 N NaHCO<INF>3 absorbing solution in a 
labeled sample container.
    5.2.3  Sample Filtration for IC/PCR. If the sample is to be 
analyzed for Cr<SUP>+6 by IC/PCR, it must be filtered immediately 
following recovery as described in section 5.2.3 of Method 306 of 
this appendix.
    5.3  Analysis. Sample preparation and analysis procedures are 
identical to Method 306, section 5.3 of this appendix.

6. Calibration

    6.1  Dry Gas Meter. (a) Dry gas meter calibrations may be 
performed by either the manufacturer, a firm who provides 
calibration services, or the tester. The dry gas meter calibration 
coefficient (Y<INF>m) must be determined prior to initial use of the 
meter, and must be checked following each field use.
    (b) If the dry gas meter is new, the manufacturer will have 
specified the Y<INF>m for the meter. The manufacturer may also have 
included a calibration orifice and a data sheet with the meter that 
may be used for calibration purposes. The sheet will specify a 
standard cubic foot volume and a sample time, and these values were 
determined when the orifice was used to set the initial Y<INF>m for 
the meter. The Y<INF>m may be checked by disconnecting the critical 
orifice in the sampling train and replacing it with the calibration 
orifice. The inlet side of the calibration orifice is open to the 
atmosphere and is not reconnected to the sample train. Record the 
initial dry gas meter volume and meter temperature. Turn on the pump 
and operate it for the number of minutes specified by the 
manufacturer's data sheet. Stop the pump and record the final dry 
gas meter volume and temperature. Subtract the start volume from the 
stop volume and average the temperatures. Check the Y<INF>m for the 
dry gas meter after the test by using the following equation:
[GRAPHIC][TIFF OMITTED]TR25JA95.004


Where:

Ft.<SUP>3<INF>m=Cubic feet given by meter manufacturer
T<INF>m=Temperature of meter in degrees Fahrenheit
Ft<SUP>3<INF>pt=Cubic feet from dry gas meter, post test
P<INF>bar=Barometric pressure in inches of mercury

    Compare the Y<INF>m just calculated with the Ym given by the 
manufacturer:
[GRAPHIC][TIFF OMITTED]TR25JA95.005


    If this value is between 0.95 and 1.05, the Y<INF>m of the meter 
is acceptable. If the value lies outside the specified range, the 
test series shall either be voided, or calculations for the test 
series shall be performed using whichever meter coefficient value 
(i.e., before and after) that gives the lower value of total sample 
volume. Return the dry gas meter to the manufacturer for 
recalibration. The calibration may also be conducted as specified in 
section 5.3.1 or section 7 of Method 5 (40 CFR part 60, appendix A), 
except that it is only necessary to check the calibration at an 
approximate flow rate of 0.75 cfm. The calibration of the dry gas 
meter must be checked after each field use in the same manner. If 
the values of Y<INF>m obtained before and after a test series differ 
by more than 5%, the test series shall either be voided, or 
calculations for the test series shall be performed using whichever 
meter coefficient value (i.e., before or after) that gives the lower 
value of total sample volume.
    6.2  GFAA Spectrometer. Same as Method 306, section 6.2 of this 
appendix.
    6.3  ICP Spectrometer. Same as Method 306, section 6.3 of this 
appendix.

7. Quality Control

    Same as Method 306, section 7 of this appendix.

8. Calculations

    8.1  Pollutant Concentration. Calculate C<INF>cr, the Cr 
concentration in the stack gas, in mg/dscm on a dry basis as 
follows:
[GRAPHIC][TIFF OMITTED]TR25JA95.006


where:

M<INF>Cr=Amount of Cr in sample from Method 306 of this appendix, 
Eq. 306-1, <greek-m>g.
T<INF>m=Dry gas meter temperature,  deg.F. [[Page 4993]] 
Y<INF>m=Dry gas meter correction factor, dimensionless.
V<INF>m=Dry gas meter volume, ft<SUP>3.
P<INF>bar=Barometric pressure, in. Hg.

    8.2  Approximate Mass Emission Rate (Optional). Calculate an 
approximate mass emission rate of Cr in kg/hr using the following 
equation:
[GRAPHIC][TIFF OMITTED]TR25JA95.007


where:

r=Radius of stack, in.
(<radical><greek-D>p)<INF>avg=Average of <radical><greek-D>p values.
Ts=Stack temperature,  deg.F.
P<INF>bar=Barometric pressure, in. Hg.
C<INF>Cr=Concentration of Cr, mg/dscm.

    Note: The emission rate calculated using Equation 306A-3 is 
based on an assumed moisture content of 2%.

9. Bibliography

    1. Clay, F.R. Memo, Impinger Collection Efficiency--Mason Jars 
vs. Greenburg-Smith Impingers, Dec. 1989.
    2. Segall, R.R., W.G. DeWees, F.R. Clay, and J.W. Brown. 
Development of Screening Methods for Use in Chromium Emissions 
Measurement and Regulations Enforcement. In: Proceedings of the 1989 
EPA/A&WMA International Symposium--Measurement of Toxic and Related 
Air Pollutants, A&WMA Publication VIP-13, EPA Report No. 600/9-89-
060, p. 785.
    3. Clay, F.R. Chromium Sampling Method. In: Proceedings of the 
1990 EPA/A&WMA International Symposium--Measurement of Toxic and 
Related Air Pollutants, A&WMA Publication VIP-17, EPA Report No. 
600/9-90-026, p. 576.
    4. Clay, F.R. Proposed Sampling Method 306A for the 
Determination of Hexavalent Chromium Emissions from Electroplating 
and Anodizing Facilities. In: Proceedings of the 1992 EPA/A&WMA 
International Symposium--Measurement of Toxic and Related Air 
Pollutants, A&WMA Publication VIP-25, EPA Report No. 600/R-92/131, 
p. 209.

Method 306-B--Surface Tension Measurement and Recordkeeping for 
Chromium Plating Tanks Used at Electroplating and Anodizing Facilities

1. Applicability and Principle

    1.1  Applicability. This method is applicable to all decorative 
plating and anodizing operations where a wetting agent is used in 
the tank as the primary mechanism for reducing emissions from the 
surface of the solution.
    1.2  Principle. During an electroplating or anodizing operation, 
gas bubbles generated during the process rise to the surface of the 
tank liquid and burst. Upon bursting, tiny droplets of chromic acid 
become entrained in ambient air. The addition of a wetting agent to 
the tank bathreduces the surface tension of the liquid and 
diminishes the formation of these droplets.

2. Apparatus

    2.1  Stalagmometer. Any commercially available stalagmometer or 
equivalent surface tension measuring device may be used to measure 
the surface tension of the plating or anodizing tank liquid.
    2.2  Preciser tensiometer. A Preciser tensiometer may be used to 
measure the surface tension of the tank liquid provided the 
procedures specified in ASTM Method D 1331-89, Standard Test Methods 
for Surface and Interfacial Tension of Solutions of Surface Active 
Agents (incorporated by reference--see Sec. 63.14) are followed.

3. Procedure

    3.1  The surface tension of the tank bath may be measured by 
using a Preciser tensiometer, a stalagmometer or any other device 
suitable for measuring surface tension in dynes per centimeter. If 
the Preciser tensiometer is used, the instructions given in ASTM 
Method D 1331-89, Standard Test Methods for Surface and Interfacial 
Tension of Solutions of Surface Active Agents (incorporated by 
reference--see Sec. 63.14) must be followed. If a stalagmometer or 
other device is used to measure surface tension, the instructions 
that came with the measuring device must be followed.
    3.2  (a) Measurements of the bath surface tension are done using 
a progressive system which minimizes the number of surface tension 
measurements required when the proper surface tension is maintained. 
Initially, measurements must be made every 4 hours of tank operation 
for the first 40 hours of tank operation after the compliance date. 
Once there are no exceedances during 40 hours of tank operation, 
measurements may be conducted once every 8 hours of tank operation. 
Once there are no exceedances during 40 hours of tank operation, 
measurements may be conducted once every 40 hours of tank operation 
on an on-going basis, until an exceedance occurs. The maximum time 
interval for measurements is once every 40 hours of tank operation.
    (b) If a measurement of the surface tension of the solution is 
above the 40 dynes per centimeter limit, the time interval reverts 
back to the original monitoring schedule of once every 4 hours. A 
subsequent decrease in frequency would then be allowed according to 
the previous paragraph.

4. Recordkeeping

    4.1  Log book of surface tension measurements and fume 
suppressant additions. The surface tension of the plating or 
anodizing tank bath must be measured as specified in section 3.2. 
The measurements must be recorded in the log book. In addition to 
the record of surface tension measurements, the frequency of fume 
suppressant maintenance additions and the amount of fume suppressant 
added during each maintenance addition will be recorded in the log 
book. The log book will be readily available for inspection by 
regulatory personnel.
    4.2  Instructions for apparatus used in measuring surface 
tension. Also included with the log book must be a copy of the 
instructions for the apparatus used for measuring the surface 
tension of the plating or anodizing bath. If a Preciser tensiometer 
is used, a copy of ASTM Method D 1331-89, Standard Methods for 
Surface and Interfacial Tension of Solutions of Surface Active 
Agents (incorporated by reference--see Sec. 63.14) must be included 
with the log book.

[FR Doc. 95-65 Filed 1-24-95; 8:45 am]
BILLING CODE 6560-50-P