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Compliance Requirements of New EPA Regulations on Area Sources in the Plating and Polishing Industry


Shaikh A. Tayeb and Tapan K. Das

The U.S. EPA has developed new requirements to reduce air pollution from plating and polishing facilities. Shaikh Tayeb and Tapan Das, from the Delaware Dept. of Natural Resources & Environmental Control, discuss the new compliance and reporting requirements, in addition to providing suggestions on how to cost-effectively minimize your facility's emissions. Links and downloads to helpful compliance documents are also provided.

On July 1, 2008, the EPA published its National Emissions Standards for Hazardous Air Pollutants (HAPs) for smaller-emitting sources, known as area sources, in the plating and polishing industry.1 The owner or op

Editor's Note
For a review of relevant terminology, please see the “Definitions” section near the end of this article.)
erator of plating and polishing facilities must take actions to comply with the new regulations, as outlined by Subpart WWWWWW of 40 CFR Part 63.

The vapor from area source plating and polishing facilities contains cadmium, chromium, manganese, nickel, lead, and other harmful chemicals that pose health risks. It should be noted that plating tanks at area sources that are subject to the EPA “Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks” are not subject to this rule. These area sources are subject to 40 CFR Part 63, Subpart N.2

Plating & Polishing Facilities Subject to New Regulations

When a plating and polishing facility is an area source of HAP emissions and meets the criteria specified in paragraphs (1) through (3) of this section, it is subject to Subpart WWWWWW.3

  1. A plating and polishing facility is a plant site that is engaged in one or more of the processes listed in paragraphs (i) through (vi): (i) Electroplating other than chromium electroplating (i.e., non-chromium electroplating); (ii) Electroless or non-electrolytic plating; (iii) Other non-electrolytic metal coating processes, such as chromate conversion coating, nickel acetate sealing, sodium dichromate sealing, and manganese phosphate coating; and thermal spraying; (iv) Dry mechanical polishing of finished metals and formed products after plating; (v) Electroforming; (vi) Electropolishing
  2. An area source of HAP emissions is any stationary source or group of stationary sources within a contiguous area under common control that does not have the potential to emit any single HAP at a rate of 9.07 megagrams per year (10 tons per year) or more and any combination of HAPs at a rate of 22.68 megagrams per year (25 tons per year) or more. In short, this is called the “10/25 rule.”
  3. Plating and polishing facility uses or has emissions of compounds of one or more plating and polishing metal HAP, which means any compound of any of the following metals: cadmium, chromium, lead, manganese, and nickel. With the exception of lead, plating and polishing metal HAPs also include any of these metals in their elemental form.

Compliance Criteria

Table 1 lists various plating and polishing operations and their compliance requirements.1,3

Table 1: Plating & Polishing Operations and Compliance Requirements1,2
Plating/PolishingCompliance Requirements
Non-cyanide electroplating, electroforming, or electropolishing with pH <12
  • Use wetting agent/fume suppressant (WAFS), control device, or tank cover
  • Management practices to minimize or eliminate potential emissions
Flash or short-term electroplating
  • Use tank covers or limit plating time to 3 min/hr or 1 hr/day
  • Management practices to minimize or eliminate potential emissions
Dry mechanical polishing and thermal spraying (permanent operations)
  • Exhaust emissions to a control device
Cyanide electroplating (pH greater than or equal to 12), non-electrolytic plating and coating operations (such as electroless nickel plating and chromate conversion coating), and temporary thermal spraying
  • Management practices to minimize or eliminate potential emissions

 

Practicable & Cost-Effective Steps to Minimize or Eliminate Emissions

Table 2 summarizes the management practices to minimize or eliminate potential emissions from plating and polishing operations.3

Table 2: Management Practices to Minimize or Eliminate Potential Emissions from Plating and Polishing Operations
StepsActions to Be Taken
Tank liquidWhen removing parts processed in the tank, try to keep tank liquid in the tank as practicable.
Drip timeMake the drip time as long as you can when removing parts from the tank. Remove parts slowly from the tank or use drain boards (“drip shields”).
Design criteriaDesign barrels, racks, and parts to minimize dragout of bath solution.
Tank coversUse tank covers.
Heating of process tankMinimize or reduce heating of process tanks as practicable.
MaintenancePerform regular repair, maintenance, and preventive maintenance of racks, barrels, and other equipment.
Bath contaminationMinimize bath contamination as practicable by not dropping parts or quickly recovering dropped parts, using distilled/de-ionized water, filtering the water, pre-cleaning the parts before plating, and rinsing pretreated parts before plating.
Bath levelChemicals and other bath ingredients should be at the correct levels in the tank.
HousekeepingOn an as-needed basis, perform general good housekeeping, such as regular sweeping, vacuuming, and washdowns.
Spills and tank overflowMinimize spills and overflow of tanks as much as possible.
InspectionConduct routine inspections to identify leaks from the bath tanks.

 

Recordkeeping & Reporting Requirements

The owner or operator of the plating and polishing facilities shall follow the recordkeeping and reporting requirements outlined in Table 3, in order to comply with Subpart WWWWWW.3

Table 3: Recordkeeping and Reporting Requirements
RecordkeepingReporting
  • Records that demonstrate compliance with management practices.
  • For cyanide tanks, the one-time pH measurement value.
  • For non-cyanide tanks, amount and frequency of WAFS additions, if applicable.
  • For short-term or flash electroplating tanks, the daily plating time.
  • For batch electroplating tanks using covers as a control option, the time the tank is operated with cover in place.
  • For continuous electroplating tanks, amount of tank surface covered and time tank is operated with cover in place.
  • Operating manuals for all required control systems.
  • All required notifications and reports, with supporting documentation.
  • Records should be kept in a form suitable and readily available for review.
Notification of Compliance Status
  • Existing Sources: 07/01/2010.
  • New Sources: Upon start-up.

First Certification of Compliance Report

  • Existing Sources: Jan. 31, 2011.
  • New Sources: Jan. 31 of year following start-up.
  • Prepare but do not submit.

Annual Certification of Compliance Report

  • Prepare by Jan. 31 of each year following first report.
  • Do not submit unless deviations occur.

 

Conclusions

The final rule will affect each facility in a different way. The facility’s management has to decide the optimum operational criterion with respect to cost and specific applicable requirements of the rule. This article clarifies the rule in a manner that is easy to understand and easy to implement as standard operational procedures. This will ultimately help to eliminate the costly future expenses due to non-compliance status of the facility. The plating and polishing facilities subject to this new rule should contact the local permitting authorities to determine if they have any additional regulatory requirements with respect to air, solid waste, and water quality.

Definitions1

Cyanide plating means plating processes performed in tanks that use cyanide as a major bath ingredient and that operate at a pH of 12 or higher, and use or emit any of the plating and polishing metal HAPs, as defined in this section. Electroplating and electroforming are performed with or without cyanide. The cyanide in the bath works to dissolve the HAP metal added as a cyanide compound (e.g., cadmium cyanide) and creates free cyanide in solution, which helps to corrode the anode.

These tanks are self-regulating to a pH of 12 due to the caustic nature of the cyanide bath chemistry. The cyanide in the bath is a major bath constituent and not an additive; however, the self-regulating chemistry of the bath causes the bath to act as if wetting agents/fume suppressants are being used and to ensure an optimum plating process. All cyanide plating baths at pH greater than or equal to 12 have cyanide-metal complexes in solution. The metal HAP to be plated is not emitted because it is either bound in the metal-cyanide complex or reduced at the cathode to elemental metal, and plated onto the immersed parts.

Cyanide baths are not intentionally operated at a pH less than 12 because unfavorable plating conditions would occur in the tank, among other negative effects.

Dry mechanical polishing means a process used for removing defects from and smoothing the surface of finished metals and formed products after plating with any of the plating and polishing metal HAPs, as defined in this section, using hard-faced abrasive wheels or belts and where no liquids or fluids are used to trap the removed metal particles.

Electroforming indicates an electrolytic process using or emitting any of the plating and polishing metal HAPs, as defined in this section, that are used for fabricating metal parts. This process is essentially the same as electroplating except that the plated substrate (mandrel) is removed, leaving only the metal plate. In electroforming, the metal plate is self-supporting and generally thicker than in electroplating.

Electroless plating signifies a non-electrolytic process that uses or emits any of the plating and polishing metal HAPs, as defined in this section, in which metallic ions in a plating bath or solution are reduced to form a metal coating at the surface of a catalytic substrate without the use of external electrical energy. Electroless plating is also called non-electrolytic plating. Examples include, but are not limited to, chromate conversion coating, nickel acetate sealing, sodium dichromate sealing, and manganese phosphate coating.

HAP stands for “hazardous air pollutant” as defined from the list of 188 chemicals and compounds specified in the Clean Air Act Amendments of 1990; HAPs are also called “air toxics.” The five plating and polishing metal HAPs, as defined in this section, are on this list of 188 chemicals.

Thermal spraying (also referred to as metal spraying or flame spraying) is a process that uses or emits any of the plating and polishing metal HAPs, as defined in this section, in which a metallic coating is applied by projecting molten or semi-molten metal particles onto a substrate. Commonly used thermal spraying methods include high-velocity oxy-fuel spraying, flame spraying, electric arc spraying, plasma arc spraying, and detonation gun spraying.

Wetting agent/fume suppressant (WAFS) indicates any chemical agent that reduces or suppresses fumes or mists from a plating and polishing tank by reducing the surface tension of the tank bath.

Notes

  1. Subpart WWWWWW, National Emissions Standards for Hazardous Air Pollutants: Area Source Standards for Plating and Polishing Operations. Federal Register 37747, Vol. 73, No. 127, July 1, 2008.
  2. Tayeb, S.A., French, J.L. Air permitting for hard chromium electroplating facilitates based on maximum achievable control technology (MACT) standards. Metal Finishing 2008;106(11): 33–9.
  3. U.S. EPA. Summary of Regulations Controlling Air Emissions from Plating and Polishing Operations. Available at: http://www.epa.gov/ttn/atw/area/platpolb.pdf.

About the Authors

Shaikh A. Tayeb, PhD, PE, BCEE, is employed by the State of Delaware as an engineer in the Air Quality Management Section for the Department of Natural Resources and Environmental Control. He reviews and recommends various source category air permits, including metal finishing. Tayeb holds a PhD in chemical engineering and an MS in environmental technology. He is a registered professional engineer in multiple states, including Delaware. Tayeb is a member of the American Academy of Environmental Engineers, Annapolis, Md.

Tapan K. Das is employed by the State of Delaware in the Air Quality Management Section for the Department of Natural Resources and Environmental Control. He has worked as an environmental engineer for 19 years in the Engineering and Compliance Division. Das holds numerous patents on surface finishing and was a project engineer in Plating and Organic Finishing at Textron, Inc., during the 1970s. He holds a BS in chemical engineering and an MBA in finance.

*The views and opinions expressed in this article are those of the authors and do not necessarily represent those of the State of Delaware or Department of Natural Resources and Environmental Control.

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