New EPA Air Emissions Standards for Iron and Steel Foundries

Jeff Hannapel and Craig Schmeisser

Pursuant to a court ordered deadline, the U.S. Environmental Protection Agency (EPA) issued the final rule of the National Emissions Standard for Hazardous Air Pollutants (NESHAP):  Iron and Steel Foundries Major Source Residual Risk and Technology Review and Area Source Technology Review on September 10, 2020 (85 Fed. Reg. 56080). This rule finalized changes to two existing regulations that impacted the industry since 2004 for larger iron and steel foundries (Foundry Major Source Maximum Achievable Control Technology [MACT] Rule or Foundry MACT), and since 2008 for other iron and steel foundries (Foundry Area Source Generally Available Control Technology [GACT] Rule or Foundry GACT).

The final rule: (1.) does not impose any new emissions limits on iron or steel foundries; (2.) removes the exemption for exceedances of emission limits during periods of startup, shutdown and malfunction from the Foundry MACT (this exemption did not exist in the Foundry GACT); (3.) for foundries subject to the Foundry MACT, the rules have been changed to specify work practices to demonstrate compliance during periods of cupola startup and shutdown, possibly requiring changes to the foundry’s existing Operation and Maintenance Plan; (4.) requires electronic reporting of performance test results and compliance reports for all iron and steel foundries; and (5.) makes minor corrections and revisions to some select rule provisions for major and area sources. The fact that the final rule does not impose more stringent emissions limits or additional control technologies is testament that iron and steel foundries have implemented effective control measures to reduce hazardous air pollutant (HAP) emissions and minimize risks to human health and the environment.

Rulemaking Process

Starting in 2016, the AFS Air Quality Committee worked closely with EPA officials on the development of this rulemaking. These efforts included: helping identify the facilities subject to the rule, reviewing emissions data, identifying pollution control technology developments and work practices, and noting clarifications on foundry operations. 

Throughout this process, the AFS Air Quality Committee responded to EPA’s information requests, prepared comments on the proposed rule, performed quality reviews of facility emissions data, clarified how foundry production processes and emissions control devices operated, and offered suggestions for work practices to ensure compliance with the applicable NESHAP requirements. These cooperative efforts produced final rules that are protective of human health and the environment and consistent with safe operating practices for foundries.

Residual Risk and Technology Review

Residual Risk—The residual risk review only applies to major sources and need only be conducted one time, eight years after the promulgation of the original Foundry MACT rule. EPA must evaluate the risk to public health remaining after the application of MACT-based standards and revise them to provide an ample margin of safety to protect public health or to prevent an adverse environmental effect, taking into account costs, energy, safety and other relevant factors. 
EPA found the residual risk from the iron and steel foundries source category was acceptable and the existing Foundry MACT provided an ample margin of safety to protect public health. Furthermore, EPA concluded more stringent standards were not necessary to prevent any adverse environmental effect.

Technology Review—Every eight years, EPA must review the MACT standards for major sources and the GACT standards for area sources to determine whether any new control technologies for the source category are available. EPA must also consider developments in practices, processes and control technologies to determine if the standards should be revised.

EPA determined there were no new developments in practices, processes and control technologies that would necessitate revising the MACT or GACT Rules for iron and steel foundries. EPA also concluded the significant costs of any additional controls to reduce HAP emissions further would provide little or no residual risk reduction and was unnecessary to ensure an ample margin of safety.

Foundry MACT

Summary of Provisions for Major Sources—With the elimination of the exemption for periods of startup, shutdown and malfunction, foundries must always comply with emissions limits or work practices. The final rule sets forth these requirements and how to demonstrate compliance through changes to the Foundry MACT.
Emissions Limits—The applicable emissions limits, including for particulate matter (PM) and metal HAPs, would apply at all times. [40 CFR 63.7690(a)] In the final rule, EPA clarified that the 20 ppmv volatile organic HAP emission limit applies while the cupola is “on blast” (i.e., normal operations). [40 CFR 63.7690(a)(8)]
Work Practices—The Foundry MACT now requires that during periods of “off blast,” cupola melting furnaces must reduce emissions to the extent practicable [40 CFR 63.7700(g)].

Specifically, foundries subject to the major source rule must operate afterburner and other thermal combustion controls with a flame present at all times while the cupola is “off blast.”  This would include: 

  • The latter portion of coke bed preparation step.
  • Initial metallic charging step during cupola startup. 
  • The slag and residual metal removal step during cupola 
  • shutdown. 
  • Idling conditions when blast air is turned off or down to the point that the cupola does not produce additional molten metal.
  • The afterburner and other thermal combustion controls are not required during the following: 
  • Cupola startup steps of refractory curing and cupola bed 
  • preparation. 
  • Cupola shutdown steps of cooling and banking or bottom drop.

The facility must, however, comply with the operations and maintenance requirements of 40 CFR 63.7710 and the opacity limits in 40 CFR 63.7690(a)(7) during these periods. In addition, foundries must light the cupola afterburner or other thermal combustion control as soon as practicable during the cupola startup step of the coke bed preparation, following procedures included in the Operation and Maintenance Plan required by 40 CFR 63.7710(b), but no later than 30 minutes after blast air is started to begin coke bed burn-in.

Transition Period—Until March 9, 2021, a foundry subject to the Foundry MACT may continue to operate under its current Operations and Maintenance Plan and Startup, Shutdown and Malfunction Plan. After March 9, 2021, the Startup, Shutdown and Maintenance Plan is no longer allowed or required and a subject foundry must comply with the above work practice standards and address any required changes in their Operations and Maintenance Plan. 

Operations & Maintenance Plan—To address the new cupola work practice standards for the Foundry Major Source MACT, iron and steel foundries must ensure their plan specifically includes the work practices discussed above.

To demonstrate continuous compliance with the applicable work practices in the final rule, foundries must keep daily records to document the relevant times of “off blast,” including:

  • The time blast air is started to begin the coke bed burn-in.
  • The time the cupola afterburner or other thermal combustion device is lit.
  • The time metal production starts during cupola startup. 
  • The time when metal production ends.
  • The time slag removal is completed during cupola shutdown. 
  • The time the afterburner or other thermal combustion device is turned off during cupola shutdown. 
  • The times idling starts and stops [40 CFR 63.7744(c)].

Electronic Reporting—Foundries must submit semiannual reports, performance test results, CMS performance evaluation results and other documents to EPA electronically via the Compliance and Emissions Data Reporting Interface (CEDRI) [40 CFR 63.7744(e)-(i)]. CEDRI is accessed via the EPA Control Data Exchange website that many foundries use for annual Toxics Release Inventory reporting purposes at 

Foundry GACT

Summary of Provisions for Area Sources—The final rule did not make any significant revisions to the requirements for area sources, but did include minor corrections and clarifications for the following:

  • Management practices for metallic scrap and mercury switches.
  • Management practices and compliance requirements.
  • Operations and maintenance requirements.
  • Monitoring requirements.
  • Performance test requirements. 
  • Recordkeeping and reporting requirements. 
  • Definitions.

Notification Prior to Opacity Observations—The final rule clarified that foundries subject to the Foundry GACT do not need to provide notification to EPA prior to semiannual opacity (visible emissions) observations. Foundries must, however, report the results of the visible emissions observation and must also provide notification to EPA prior to conducting stack performance testing consistent with applicable regulations.

Electronic Reporting—The requirements for area sources are the same as those for major sources discussed previously [40 CFR 63.10899(c)-(g)]. 
Estimated Regulatory Costs

EPA estimated that the first-year incremental compliance cost was $2,380 per major source facility and $720 annually for subsequent years. The first-year incremental compliance cost was $900 per area source facility and $170 for subsequent years.


Stakeholders will have until November 9 to file a petition for judicial review of the regulation. It is not clear if any party will challenge the rule, but if so, AFS would be in the position of defending the final rule as consistent with the requirements of the Clean Air Act.

Federal law mandates that EPA assess whether existing HAP emissions standards are effective. To their credit, iron and steel foundries have effectively implemented control measures that reduce HAP emissions and minimize risks to human health and the environment. Furthermore, in this rulemaking, AFS identified substantial work practices for EPA that will continue this environmental success story.   

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