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

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.


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., 1235­136y; 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, 300g­1, 300g­2, 300g­3, 300g­4, 300g­5, 300g­6, 300j­1, 300j­2, 300j­3, 300j­4, 300j­9, 1857 et seq., 6901­6992k, 7401­7671q, 7542, 9601­9657, 11023, 11048.

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

§ 9.1 OMB approvals under the Paperwork Reduction Act.

PART 63-[AMENDED]

1. The authority citation for part 63 continues to read as follows: Authority: 42 U.S.C. 7401 et seq.

2. 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.


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


§ 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 to such sources, as identified in Table 1.

(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.


§ 63.341 Definitions and nomenclature.

(a) Definitions. Terms used in this subpart are defined in the Act, in subpart A of part 63, or in this section. For the purposes of subpart N, if the same term is defined in subpart A and in this section, it shall have the meaning given in this section.

Add-on air pollution control device means equipment installed in the ventilation system of chromium electroplating and anodizing tanks for the purposes of collecting and containing chromium emissions from the tank(s).

Air pollution control technique means any method, such as an add-on air pollution control device or a chemical fume suppressant, that is used to reduce chromium emissions from chromium electroplating and chromium anodizing tanks.

Base metal means the metal or metal alloy that comprises the workpiece.

Bath component means the trade or brand name of each component(s) in trivalent chromium plating baths. For trivalent chromium baths, the bath composition is proprietary in most cases. Therefore, the trade or brand name for each component(s) can be used; however, the chemical name of the wetting agent contained in that component must be identified.

Chemical fume suppressant means any chemical agent that reduces or suppresses fumes or mists at the surface of an electroplating or anodizing bath; another term for fume suppressant is mist suppressant.

Chromic acid means the common name for chromium anhydride (CrO3).

Chromium anodizing means the electrolytic process by which an oxide layer is produced on the surface of a base metal for functional purposes (e.g., corrosion resistance or electrical insulation) using a chromic acid solution. In chromium anodizing, the part to be anodized acts as the anode in the electrical circuit, and the chromic acid solution, with a concentration typically ranging from 50 to 100 grams per liter (g/L), serves as the electrolyte.

Chromium electroplating or chromium anodizing tank means the receptacle or container in which hard or decorative chromium electroplating or chromium anodizing occurs.

Composite mesh­pad system means an add-on air pollution control device typically consisting of several mesh­pad stages. The purpose of the first stage is to remove large particles. Smaller particles are removed in the second stage, which consists of the composite mesh pad. A final stage may remove any reentrained particles not collected by the composite mesh pad.

Decorative chromium electroplating means the process by which a thin layer of chromium (typically 0.003 to 2.5 microns) is electrodeposited on a base metal, plastic, or undercoating to provide a bright surface with wear and tarnish resistance. In this process, the part(s) serves as the cathode in the electrolytic cell and the solution serves as the electrolyte. Typical current density applied during this process ranges from 540 to 2,400 Amperes per square meter (A/m2) for total plating times ranging between 0.5 to 5 minutes.

Electroplating or anodizing bath means the electrolytic solution used as the conducting medium in which the flow of current is accompanied by movement of metal ions for the purposes of electroplating metal out of the solution onto a workpiece or for oxidizing the base material.

Emission limitation means, for the purposes of this subpart, the concentration of total chromium allowed to be emitted expressed in milligrams per dry standard cubic meter (mg/dscm), or the allowable surface tension expressed in dynes per centimeter (dynes/cm).

Facility means the major or area source at which chromium electroplating or chromium anodizing is performed.

Fiber-bed mist eliminator means an add-on air pollution control device that removes contaminants from a gas stream through the mechanisms of inertial impaction and Brownian diffusion. These devices are typically installed downstream of another control device, which serves to prevent plugging, and consist of one or more fiber beds. Each bed consists of a hollow cylinder formed from two concentric screens; the fiber between the screens may be fabricated from glass, ceramic plastic, or metal.

Foam blanket means the type of chemical fume suppressant that generates a layer of foam across the surface of a solution when current is applied to that solution.

Fresh water means water, such as tap water, that has not been previously used in a process operation or, if the water has been recycled from a process operation, it has been treated and meets the effluent guidelines for chromium wastewater.

Hard chromium electroplating or industrial chromium electroplating means a process by which a thick layer of chromium (typically 1.3 to 760 microns) is electrodeposited on a base material to provide a surface with functional properties such as wear resistance, a low coefficient of friction, hardness, and corrosion resistance. In this process, the part serves as the cathode in the electrolytic cell and the solution serves as the electrolyte. Hard chromium electroplating process is performed at current densities typically ranging from 1,600 to 6,500 A/m2 for total plating times ranging from 20 minutes to 36 hours depending upon the desired plate thickness.

Hexavalent chromium means the form of chromium in a valence state of +6.

Large, hard chromium electroplating facility means a facility that performs hard chromium electroplating and has a maximum cumulative potential rectifier capacity greater than or equal to 60 million ampere­hours per year (amp­hr/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 amp­hr/yr.

Stalagmometer means a device used to measure the surface tension of a solution.

Surface tension means the property, due to molecular forces, that exists in the surface film of all liquids and tends to prevent liquid from spreading.

Tank operation means the time in which current and/or voltage is being applied to a chromium electroplating tank or a chromium anodizing tank.

Tensiometer means a device used to measure the surface tension of a solution.

Trivalent chromium means the form of chromium in a valence state of +3.

Trivalent chromium process means the process used for electrodeposition of a thin layer of chromium onto a base material using a trivalent chromium solution instead of a chromic acid solution.

Wetting agent means the type of chemical fume suppressant that reduces the surface tension of a liquid.

(b) Nomenclature. The nomenclature used in this subpart has the following meaning:

(1) AMR = the allowable mass emission rate from each type of affected source subject to the same emission limitation in milligrams per hour (mg/hr).

(2) AMRsys = the allowable mass emission rate from affected sources controlled by an add-on air pollution control device controlling emissions from multiple sources in mg/hr.

(3) EL = the applicable emission limitation from § 63.342 of this subpart in milligrams per dry standard cubic meter (mg/dscm).

(4) IAtotal = the sum of all inlet duct areas from both affected and nonaffected sources in meters squared.

(5) IDAi = the total inlet area for all ducts associated with affected sources in meters squared.

(6) IDAi,a = the total inlet duct area for all ducts conveying chromic acid from each type of affected source performing the same operation, or each type of affected source subject to the same emission limitation in meters squared.

(7) VR = the total of ventilation rates for each type of affected source subject to the same emission limitation in dry standard cubic meters per minute (dscm/min).

(8) VRinlet = the total ventilation rate from all inlet ducts associated with affected sources in dscm/min.

(9) VRinlet,a = the total ventilation rate from all inlet ducts conveying chromic acid from each type of affected source performing the same operation, or each type of affected source subject to the same emission limitation in dscm/min.

(10) VRtot = the average total ventilation rate for the three test runs as determined at the outlet by means of the Method 306 testing in dscm/min.


§ 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 § 63.343(a) of this subpart. 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 add­on 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 add­on air pollution control device also controlling nonaffected sources;

(ii) The emission limitation calculated according to § 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 § 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 10­6 grains per dry standard cubic foot [gr/dscf]); or

(ii) 0.03 mg/dscm (1.3 x 10-5 gr/dscf) if the hard chromium electroplating tank is an existing affected source and is located at a small, hard chromium electroplating facility.

(2)(i) An owner or operator may demonstrate the size of a hard chromium electroplating facility through the definitions in § 63.341(a) of this subpart. Alternatively, an owner or operator of a facility with a maximum cumulative potential rectifier capacity of 60 million amp­hr/yr or more may be considered small if the actual cumulative rectifier capacity is less than 60 million amp­hr/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 amp­hr/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 § 63.346(b)(12). The actual cumulative rectifier capacity for the previous 12­month 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 Federally­enforceable limit on the maximum cumulative potential rectifier capacity of a hard chromium electroplating facility through the title V permit required by § 63.340(e), and by maintaining monthly records in accordance with § 63.346(b)(12) to demonstrate that the limit has not been exceeded. The actual cumulative rectifier capacity for the previous 12­month 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 § 63.346(b)(12) and by this paragraph show that the actual cumulative rectifier capacity over the previous 12­month 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 § 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 10-6 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 10­3 pound­force per foot [lbf/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 §§ 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 § 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 § 63.347(i)(3) and comply with the applicable emission limitation within the timeframe specified in § 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

(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 2, if the specific equipment used is identified in Table 2;


TABLE 2. SUMMARY OF WORK PRACTICE STANDARDS

 

Control technique



Work practice standards



Frequency



Composite mesh-pad (CMP) system



1. Visually inspect device 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.



1. 1/quarter


2. Visually inspect back portion of the mesh pad closest to the fan to ensure there is no breakthrough of chromic acid mist.



2. 1/quarter


3. Visually inspect ductwork from tank or tanks to the control device to ensure there are no leaks.



3. 1/quarter


4. Perform washdown of the composite mesh-pads in accordance with manufacturers recommendations.



4. Per manufacturer



Packed-bed scrubber (PBS)



1. Visually inspect device 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.



1. 1/quarter


2. Visually inspect back portion of the chevron blade mist eliminator to ensure that it is dry and there is no breakthrough of chromic acid mist.



2. 1/quarter


3. Same as number 3 above.



3. 1/quarter


4. Add fresh makeup water to the top of the packed bed.a,b



4. Whenever makeup is added



PBS/CMP system


1. Same as for CMP system
2. Same as for CMP system
3. Same as for CMP system
4. Same as for CMP system



1. 1/quarter
2. 1/quarter
3. 1/quarter
4. Per manufacturer



Fiber-bed mist eliminatorc



1. Visually inspect fiber-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 ductwork from tank or tanks to the control device to ensure there are no leaks.

3. Perform washdown of fiber elements in accordance with manufacturers recommendations.



1. 1/quarter




2. 1/quarter


3. Per manufacturer



Air pollution control device (APCD) not listed in rule



To be proposed by the source for approval by the Administrator



To be proposed by the source for approval by the Administrator



Monitoring Equipment



Pitot tube


Backflush with water, or 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.



1/quarter


Stalagmometer


Follow manufacturers recommendations.



aIf greater than 50 percent of the scrubber water is drained (e.g., for maintenance purposes), makeup water may be added to the scrubber basin.

bFor horizontal-flow scrubbers, top is defined as the section of the unit directly above the packing media such that the makeup water would flow perpendicular to the air flow through the packing. For vertical-flow units, the top is defined as the area downstream of the packing material such that the makeup water would flow countercurrent to the air flow through the unit.

cWork practice standards for the control device installed upstream of the fiber-bed mist eliminator to prevent plugging do not apply as long as the work practice standards for the fiber-bed unit are followed.


(C) If the specific equipment used is not identified in Table 2, 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 § 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 § 63.346(b). Reporting associated with the operation and maintenance plan is identified in § 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.


§ 63.343 Compliance provisions.

(a) Compliance dates.

(1) The owner or operator of an existing affected source shall comply with the emission limitations in § 63.342 of this subpart as follows:

(i) No later than 1 year after the effective date of this subpart if the affected source is a decorative chromium electroplating tank; and

(ii) No later than 2 years after the effective date of this subpart 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 the effective date of these standards 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 the proposal date of these standards but before the effective date shall follow the compliance schedule of § 63.6(b)(3) and (4) of subpart A.

(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 § 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 § 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 §§ 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 § 63.6(i) of subpart A. 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 part 70 or Federal title V regulations in this chapter (42 U.S.C. 7661), whichever are 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 § 63.7, using the procedures and test methods listed in § 63.7 and § 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 § 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 § 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 § 63.342 through the use of a composite mesh-pad system shall determine the outlet chromium concentration using the test methods and procedures in § 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 § 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 ± 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 § 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 mesh­pad system shall be operated within ± 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 § 63.342 through the use of a packed-bed scrubber system shall determine the outlet chromium concentration using the procedures in § 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 § 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 ± 1 inch of water column from the pressure drop value and ± 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 § 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 ± 10 percent of the velocity pressure value established during the initial performance test, and within ± 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 § 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 § 63.342 through the use of a fiber-bed mist eliminator shall determine the outlet chromium concentration using the procedures in § 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 § 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 ± 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 § 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 ± 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 agent­type/foam blanket fume suppressants.

(i) During the initial performance test, the owner or operator of an affected source complying with the emission limitations in § 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 § 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 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 § 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 § 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 § 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 § 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 2, 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 2, 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 § 63.8(f)(1), (f)(3), (f)(4), and (f)(5) of subpart A.

(ii) After receipt and consideration of an application for an alternative monitoring method, the Administrator may approve alternatives to any 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 § 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 § 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.


§ 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 § 63.7 of subpart A. 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 § 63.343(c) of this subpart.

(2) The results of tests conducted prior to December 1991 in which Method 306A 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 § 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 § 63.342.

(1) Method 306 or Method 306A, "Determination of Chromium Emissions from Decorative and Hard Chromium Electroplating and Anodizing Operations" 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 shall be at least 120 minutes and 1.70 dscm (60 dscf), respectively. Methods 306 and 306A 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 § 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 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 § 63.7 of subpart A that apply to affected sources, as indicated in Table 1, must also be met.

(3) Method 306B, "Surface Tension Measurement and Recordkeeping for Tanks used at Decorative Chromium Electroplating and Anodizing Facilities," 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 and if approved by the Administrator. Procedures for requesting and obtaining approval are contained in § 63.7(f) of subpart A.

(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 be measured using Method 306B, "Surface Tension Measurement and Recordkeeping for Tanks used at Decorative Chromium Electroplating and Anodizing Facilities." 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 § 63.343(c)(2), shall establish the site­specific 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 (Dp) values for the velocity points and record. Determine the square root of the individual velocity point Dp 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 Dp 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 § 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 § 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 § 63.342:

(i) Calculate the cross­sectional 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:

Vrtot x (IDAi)/((sum)IAtotal) = Vrinlet (1)

were VRtot 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; IDAi is the total inlet area for all ducts associated with affected sources; IAtotal is the sum of all inlet duct areas from both affected and nonaffected sources; and VRinlet is the total ventilation rate from all inlet ducts associated with affected sources.

(v) Establish the allowable mass emission rate of the system (AMRsys) in milligrams of total chromium per hour (mg/hr) using equation 2:

(sum)VRinlet x EL x 60 minutes/hour = AMRsys (2)

where (Sum)VRinlet is the total ventilation rate in dscm/min from the affected sources, and EL is the applicable emission limitation from § 63.342 in mg/dscm. The allowable mass emission rate (AMRsys) 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.

(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 § 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:


VRtot x (IDAi,a)/((sum)IAtotal) = Vrinlet,a (3)






where VRtot 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; IDAi,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; IAtotal is the sum of all duct areas from both affected and nonaffected sources; and VRinlet,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:

VRhc1 x ELhc1 x 60 minutes/hour = AMRhc1 (4)
VRhc2 x ELhc2 x 60 minutes/hour = AMRhc2 (5)
VRdc x ELdc x 60 minutes/hour = AMRdc (6)
VRca x ELca x 60 minutes/hour = AMRca (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 § 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:

AMRhc1 + AMRhc2 + AMRdc + AMRca = AMRsys (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 § 63.342 shall submit the measurements and calculations to support these compliance methods with the notification of compliance status required by § 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 § 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.


§ 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 § 63.5(a), (b)(1), (b)(5), (b)(6), and (f)(1) of subpart A, as well as the provisions of this paragraph.

(1) After the effective date of these standards, whether or not an approved permit program is effective in the State in which an affected sources 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 § 63.2 of subpart A;

(iv) An identification of subpart N 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 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 the effective date of this subpart, 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 the effective date of this subpart, 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 the effective date of this subpart, the notification shall be submitted as soon as practicable before startup but no later than 60 days after the effective date of this subpart.


§ 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 as identified in Table 1.

(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 § 63.342(f) and Table 2 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 § 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 § 63.344(e);

(8) Records of monitoring data required by § 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 § 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 § 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 § 63.10(f) of subpart A; and

(16) All documentation supporting the notifications and reports required by § 63.9 and § 63.10 of subpart A and § 63.347 of this subpart.

(c) All records shall be maintained for a period of 5 years in accordance with § 63.10(b)(1) of subpart A.


§ 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. These reports shall be made to the Administrator at the appropriate address as identified in § 63.13 of subpart A, or to the delegated State authority.

(1) Reports required by subpart A 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 the effective date of this subpart 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 the effective date of this subpart 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;

(iii) A statement that subpart N 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 § 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 § 63.2 of subpart A.

(2) The owner or operator of a new or reconstructed affected source that has an initial startup after the effective date of this standard shall submit an initial notification (in addition to the notification of construction or reconstruction required by § 63.345(b) of this subpart) 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 the effective date of this subpart;

(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 the effective date of this subpart; 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 § 63.7(b)(2) of subpart A 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 § 63.2 of subpart A) 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 § 63.344(a), including measurements and calculations to support the special compliance provisions of § 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 § 63.344(e) to comply with the standards. (If the owner or operator is subject to the construction and reconstruction provisions of § 63.345 of this subpart 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 § 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 § 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 § 63.342(f);

(viii) If the owner or operator is determining facility size based on actual cumulative rectifier capacity in accordance with § 63.342(c)(2), records to support that the facility is small. For existing sources, records from any 12­month 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 12­month 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 § 63.343(b) of this subpart, 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 § 63.7 of subpart A and § 63.343(b) of this subpart.

(4) For sources that are not required to complete a performance test in accordance with § 63.343(b) of this subpart, the notification of compliance status shall be submitted to the Administrator no later than 30 days after the compliance date specified in § 63.343(a) of this subpart.

(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 § 63.7 of subpart A or § 63.343(b) of this subpart. 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 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 § 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 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 5­year 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 § 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 § 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 § 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 § 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 § 63.2 of subpart A, that the work practice standards in § 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 § 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 § 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 § 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 title V.

(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 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 § 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 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 5­year 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 § 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 § 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 of the effective date of this subpart, 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 § 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 § 63.343(a) of this subpart, 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.


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 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 (NaHCO3). 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.
If it is desirable to determine hexavalent chromium (Cr+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+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 SW­846 (Citation 5 in Bibliography), the optimum concentration range for GFAAS is 5 to 100 mg 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 mg Cr/l of absorbing solution.

2.1.3 IC/PCR Range. In EPA Method Cr+6 (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 mg Cr+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 SW­846, is 7 mg Cr/l.

2.2.1.2 GFAAS Analytical Sensitivity. The minimum detection limit for GFAAS, as reported in Method 7191 of SW­846, is 1 mg Cr/l.

2.2.1.3 IC/PCR Analytical Sensitivity. The minimum detection limit for IC/PCR with a preconcentrator, as reported in Method Cr+6, is 0.05 mg Cr+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+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+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, 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 mg Cr/l, the standard deviations were ±0.1, ±0.2, and ±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 mg Cr/l; the mean reported values were 10, 50, and 149 mg 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 Method Cr+6, 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+6 and 3.5 mg/dscm of total Cr is 25 percent and 9 percent for Cr+6 and total Cr, respectively; and for hazardous waste incinerators emitting 300 ng/dscm of Cr+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 mg/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. 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. 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 NaHCO3).

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+6 to convert to trivalent chromium (Cr+3) or cause Cr+3 to convert to Cr+6. The chromatographic separation of Cr+6 using ion chromatography reduces the potential for other metals to interfere with the post­column reaction. For the IC/PCR analysis, only compounds that coelute with Cr+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, 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 NaHCO3 in the impingers in place of water.

3.2 Sample Recovery. Same as Method 5, section 2.2, 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 NaHCO3, 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 mm 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.

3.3.4.4 0.45-mm 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). 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 (NaHCO3) 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 NaHCO3. 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 (HNO3), Concentrated, for GFAAS. Trace metals grade or better HNO3 must be used for reagent preparation. The ACS reagent grade HNO3 is acceptable for cleaning glassware.

4.3.2 HNO3, 1.0 percent (v/v), for GFAAS. Add, with stirring, 10 ml of concentrated HNO3 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(NO3)2 Solution (10 µg Ca/ml) for GFAAS. Prepare the solution by weighing 36 mg of Ca(NO3)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 (NH4OH) and 33 g of ammonium sulfate ((NH4)2SO4) 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 (K2Cr2O7,) 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) HNO3. The zero standard shall be 1.0 percent (v/v) HNO3. Calibration standards should be prepared daily by diluting the Cr standard stock solution (section 4.3.7) with 1.0 percent HNO3. Use at least four standards to make the calibration curve. Suggested levels are 0, 5, 50, and 100 mg 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 NaHCO3, 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 mg Cr/l for ICP, and 0, 0.5, 5, and 10 mg Cr+6/l for IC/PCR.

4.4 Glassware Cleaning Reagents.

4.4.1 HNO3, 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).

4.4.3 HNO3, 10 percent (v/v). Add with stirring 500 ml of concentrated HNO3 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 mg Cr/l.

5. Procedure

5.1 Sampling. Same as Method 5, section 4.1, 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 NaHCO3 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.

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) HNO3 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.

If the sample is going to be analyzed for Cr+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 NaHCO3 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 NaHCO3 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 NaHCO3 absorbing solution in a labeled sample container.

5.2.3 Sample Filtration for IC/PCR. If the sample is to be analyzed for Cr+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-mm 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 HNO3 is the calibration blank. The 0.1 N NaOH solution or the 0.1 N NaHCO3 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. In a beaker, add 10 ml of concentrated HNO3 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 HNO3 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 HNO3 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 HNO3, and 1 ml of the 10 µg/ml of Ca(NO3)2. Dilute to 50 ml with reagent water. A different final volume may be used, based on the expected Cr concentration, but the HNO3 concentration must be maintained at 1 percent (v/v).

5.3.2 Sample Analysis by GFAAS. The 357.9-nm wavelength line shall be used. Follow the manufacturer's operating instructions for all other spectrophotometer parameters.

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.

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 HNO3) 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.

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.

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 mg Cr/ml with up to three significant figures.

5.4 Sample Analysis by ICP. 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 mg/l.

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 NaHCO3, 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.

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).

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.

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.

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.

If dilutions are performed, the appropriate factors must be applied to sample values. All results should be reported in mg Cr/ml with up to three significant figures.

5.5 Sample Analyses by IC/PCR. The Cr+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.

Prior to preconcentration and/or analysis, filter all field samples through a 0.45-mm filter. This filtration should be conducted just prior to sample injection/analysis.

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+6 is collected on the resin bed of the column. Switch the injection valve so that the eluent displaces the concentrated Cr+6 sample, moving it off the preconcentration column and onto the IC anion separation column. After separation from other sample components, the Cr+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+6 complex formed. Compare the IC retention time and the absorbance of the Cr+6 complex with known Cr+6 standards analyzed under identical conditions to provide both qualitative and quantitative analyses.

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 NaHCO3, 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.

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+6 appears in the water blank.

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+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. The alternate calibration procedures described in section 7 of Method 5 may also be used.

6.2 GFAAS Calibration. Either (1) 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 (2) 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 HNO3 with 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. 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.

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 mg/ml and 200 mg/ml solutions, respectively. The solutions should be prepared in dilute HNO3 (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. 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 mg/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.

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 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 MCr, the total mg Cr in each sample, as follows:

MCr = (Vml) (CS) (F) (D) Eq. 306-1

where:
Vml = Volume of impinger contents plus rinses, ml.
CS = Concentration of Cr in sample solution, mg 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 CCr, the Cr concentration in the stack gas, in mg/dscm on a dry basis, corrected to standard conditions, as follows:

CCr = (10-3 mg/mg) (MCr/Vm(std)) Eq. 306-2

where:
Vm(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. Correctly applied, the precision and bias of the sample results will be comparable to those obtained with the isokinetic Method 306. 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: 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.

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 and the sampling rate of the meter box set at the delta H@ 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° 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° bend on the nozzle and encases the flexible tubing.

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 leak­checking 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 bleak­tight 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.

4. Reagents

4.1 Sampling. Same as Method 306, Section 4.1.

4.2 Sample Recovery. Same as Method 306, Section 4.2.

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. 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. 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, but record only the Dp (velocity head) values for each sampling point. 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°. If the average angle of misalignment exceeds 20° 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.

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 Dp 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.


Eq. 301A-1

Where:
n = Sampling point number.
p = Velocity head measured by Type-S pitot tube, in. H2O

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 (NaHCO3); discard the solution. Put 250 ml of 0.1 N NaOH or 0.1 N NaHCO3 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.

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. After the train has been moved to the sample recovery area, disconnect the tubing that joins the first impinger with the second.

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.

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.

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.

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 NaHCO3 absorbing solution in a labeled sample container.

5.2.3 Sample Filtration for IC/PCR If the sample is to be analyzed for Cr+6 by IC/PCR, it must be filtered immediately following recovery as described in Section 5.2.3 of Method 306.

5.3 Analysis. Sample preparation and analysis procedures are identical to Method 306, Section 5.3.

6. Calibration

6.1 Dry Gas Meter. 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 (Ym) must be determined prior to initial use of the meter, and must be checked following each field use.
If the dry gas meter is new, the manufacturer will have specified the Ym 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 Ym for the meter. The Ym 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 Ym for the dry gas meter after the test by using the following equation:

Ft.3m (Tm + 460)
Y = ______________________
17.647 (Ft3pt) (Pbar)

Where:
Ft.3m = Cubic feet given by meter manufacturer
Tm = Temperature of meter in degrees Fahrenheit
Ft3pt = Cubic feet from dry gas meter, post test
P bar = Barometric pressure in inches of mercury
Compare the Ym just calculated with the Ym given by the manufacturer:

Ym (manufacturer)
__________
Ym (calculated after test)

If this value is between 0.95 and 1.05, the Ym 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, 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 Ym 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.

6.3 ICP Spectrometer. Same as Method 306, Section 6.3.

7. Quality Control

Same as Method 306, Section 7.

8. Calculations

8.1 Pollutant Concentration. Calculate CCr, the Cr concentration in the stack gas, in mg/dscm on a dry basis as follows:


Eq. 306A-2

Eq. 306-1, mg.

where:

MCr = Amount of Cr in sample from Method 306,
Tm = Dry gas meter temperature, °F.
Ym = Dry gas meter correction factor, dimensionless.
Vm = Dry gas meter volume, ft3.
Pbar = 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:



Eq. 306A-3


where:

r = Radius of stack, in.

(ÖDp)avg = Average of ÖDp values.

Ts = Stack temperature, °F.

Pbar = Barometric pressure, in. Hg.

CCr = Concentration of Cr, mg/dscm.
NOTE: The emission rate calculated using Equation 306!-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 bath reduces 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 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 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 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.
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 must be included with the log book. If a stalagmometer or other surface tension measuring device is used, the instructions that came with the apparatus must be included with the log book.

TABLE 1. GENERAL PROVISIONS APPLICABILITY TO SUBPART N

 

General Provisions Reference



Applies to Subpart N



Comment


63.1(a)(1)


Yes



Additional terms defined in 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



63.1(a)(10)


Yes



63.1(a)(11)


Yes



§ 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



§ 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 § 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 § 63.5(a)(1) and (2) of subpart A with "affected sources."



63.5(b)(1)


Yes



63.5(b)(3)


Yes



Applies only to major affected sources.



63.5(b)(4)


No



Subpart N (§ 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



§ 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 § 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 § 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 § 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 § 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 § 63.5(f) of subpart A by the deadline specified in § 63.345(c)(5) of subpart N.



63.6(a)


Yes



63.6(b)(1)-(2)


Yes



Except replace "source" in § 63.6(b)(1)-(2) of subpart A with "affected source."



63.6(b)(3)-(4)


Yes



63.6(b)(5)


Yes



Except replace "source" in § 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 § 63.343(a)(4) of subpart N.



63.6(c)(1)-(2)


Yes



Except replace "source" in § 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 § 63.343(a)(3) of subpart N.



63.6(e)


No



§ 63.342(f) of subpart N contains work practice standards (operation and maintenance requirements) that override these provisions.



63.6(f)(1)


No



§ 63.342(b) of subpart N specifies when the standards apply.



63.6(f)(2)(i)-(ii)


Yes


63.6(f)(2)(iii)


No


§ 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 §§ 63.6(i)(2)(i) and (ii) of subpart A with "affected source."



63.6(i)(3)


Yes



63.6(i)(4)(i)


No



§ 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, § 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



63.6(i)(8)


Yes



This paragraph only references "paragraphs (i)(4) through (i)(6) of this section" for compliance extension provisions. But, § 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, § 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, § 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, § 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



§ 63.347(d) of subpart N requires notification prior to the performance test. § 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



§ 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 § 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



§ 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 [§ 63.344(a)] and the timeframe for submitting the results [§ 63.347(f)].



63.7(g)(3)


Yes



63.7(h)(1)-(2)


Yes



63.7(h)(3)(i)


Yes



This paragraph only references "§ 63.6(i)" for compliance extension provisions. But, § 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 § 63.342(f) of subpart N.



63.8(a)(4)


No



63.8(b)(1)


Yes



63.8(b)(2)


No



§ 63.344(d) of subpart N specifies the monitoring location when there are multiple sources.



63.8(b)(3)


No



§ 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



§ 63.342(f)(3)(iv) of subpart N specifies reporting when the O&M plan is not followed.



63.8(c)(1)(iii)


No


§ 63.343(f)(2) identifies the criteria for whether O&M procedures are acceptable.



63.8(c)(2)-(3)


No



§ 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 §§ 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 § 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


§ 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


§ 63.347(c)(2) of subpart N specifies initial notification requirements for new or reconstructed affected sources.



63.9(b)(2)


No



§ 63.347(c)(1) of subpart N specifies the information to be contained in the initial notification.



63.9(b)(3)


No



§ 63.347(c)(2) of subpart N specifies notification requirements for new or reconstructed sources that are not major affected sources.



63.9(b)(4)


No



63.9(b)(5)


No



63.9(c)


Yes



This paragraph only references "§ 63.6(i)(4) through § 63.6(i)(6)" for compliance extension provisions. But, § 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 § 63.6(i)(4).



63.9(d)


Yes



This paragraph only references "the notification dates established in paragraph (g) of this section." But, § 63.347 of subpart N also contains notification dates.



63.9(e)


No



Notification of performance test is required by § 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



§ 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 § 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



§ 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 § 63.10(c) have been incorporated into § 63.346(b) of subpart N.



63.10(d)(1)


Yes



63.10(d)(2)


No



§ 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



§ 63.342(f)(3)(iv) and § 63.347(g)(3) of subpart N specify reporting associated with malfunctions.



63.(10)(e)


No



§§ 63.347(g) and (h) of subpart N specify the frequency of periodic reports of monitoring data used to establish compliance. Applicable requirements of § 63.10(e) have been incorporated into §§ 63.347(g) and (h).



63.10(f)


Yes



63.11


No



Flares will not be used to comply with the emission limits



63.12-63.15


Yes



 

 

 


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You should consult with legal counsel and appropriate authorities before interpreting any regulations or undertaking any specific course of action.

Please note that many of the regulatory discussions on STERC refer to federal regulations. In many cases, states or local governments have promulgated relevant rules and standards
that are different and/or more stringent than the federal regulations. Therefore, to assure full compliance, you should investigate and comply with all applicable federal, state and local regulations.