Case Study: Nonferrous Foundry Air Permitting In 2016

Presented By

S. Lee Johnson and John A. McGreevy9/23/2016

Prepared For

Michigan DEQ after Flint – An Overview

► Biggest environmental story in decades► Ripple effects throughout MDEQ► Changing public perception

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Background

► Nonferrous foundry located in Detroit, MI▪ Four furnaces, all electric aluminum melters▪ Alloys used in castings had trace metal content changes from

different suppliers▪ Operated under Rule 290 exemption (“low emissions”)

► October 2015 notice of violation alleged the following:▪ Increased content of carcinogenic toxic air contaminants

(TACs)▪ Rule 290 exemption does not apply with emissions of

carcinogens with low Initial Risk Screening Level (IRSL) values

▪ Facility should submit a permit application

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Tramp / trace metal content

► Some tramp metals are considered carcinogenic toxic air contaminants by DEQ, with very low IRSLs▪ Beryllium 0.004 µg/m3 (annual)▪ Nickel 0.0042 µg/m3 (annual)

► Low screening levels make equipment emitting these TACs ineligible for the Rule 290 exemption▪ IRSL less than 0.04 µg/m3

► Affects small furnaces and other units that do not qualify for other permit exemptions

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Tramp / trace metal emissions

► In this case, the melting point of both Be and Ni are more than 1000 0F higher than the furnace operating temperatures

► Content is not the same as emissions▪ MDEQ AQD Field Operations was unwilling to assume no

tramp metal emissions occurred or emissions were metal oxides

► MDEQ AQD Permitting Section allowed emissions to be treated as particulates without speciating metal content▪ Justifications include melting/boiling points (temperature),

air/metal interface oxidation, complex chemistry

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Tramp / trace metal emissionsNickel is not a carcinogen

► U.S. EPA has designated specific compounds containing nickel as carcinogenic

▪ Nickel (metal) and nickel oxide are not designated as carcinogenic at this time

▪ Established a screening level these specific compounds

► The DEQ’s own analysis identifies only two nickel compounds as carcinogenic

▪ The same as U.S. EPA▪ Fossil fuel (coal) combustion emissions and nickel refinery dust

► DEQ AQD Permit Section applies the IRSL to nickel emissions▪ May be highly restrictive▪ No clear basis for this determination▪ How many other TAC screening thresholds?

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Fluxing types

► MDEQ Field Operations does not distinguish between cover fluxing and other fluxing operations

► Furnaces using only cover fluxes which contain hazardous air pollutants (chlorine, fluorine) are ineligible for the Rule 282 exemptions▪ 282(a)(iv) Crucible, pot, or induction ≤ 1,000 pounds▪ 282(a)(vi) Electric res. melters/holders ≤ 6,000 per batch

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Emissions factors

► MDEQ AQD Permit Section rejected a flux emissions factor from a prior permit for the same facility/operation

► The Permit Section uses a spreadsheet to calculate flux emissions from aluminum melting▪ Calculations based on a 1992 memo▪ Could not verify basis of these factors

► The Permit Section accepted particulate emissions factors derived from a 2005 CERP, instead of AP-42 or WebFIRE▪ The derived emissions factors were one to two orders of

magnitude lower

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Special Conditions

► Draft permit contained a condition requiring the use of “clean charge”▪ State reason was to avoid being subject to federal hazardous air

pollution rules for secondary aluminum production

► Requested that this be removed as unnecessary▪ Another secondary aluminum operation like a sweat furnace or

thermal chip dryer is required for this rule to be applicable

► AQD Permit Section did not remove this condition▪ Could lead to an inspector concluding that a sources is subject to

the rule, when it is not▪ Any melting of material not meeting the definition of “clean

charge” may be considered a permit violation

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Permitting timeline

► DEQ AQD Permit Section has a 180 day clock for permit issuance or denial

► This clock continues to run, regardless of circumstances▪ Permit writer on vacation or different project▪ Waiting on additional information from the facility

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Questions / Discussion

► Thank you for your attention

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