Emission Summary and Dispersion Modeling Report – Executive Summary Arcelormittal Dofasco Facility, Hamilton, Ontario

ArcelorMittal Dofasco G.P. Box 2460, Hamilton Ontario, Canada L8N 3J5 Phone: (905) 548-7200 http://dofasco.arcelormittal.com

Sept. 2017

Emission Summary and Dispersion Modeling Report – Executive Summary ArcelorMittal Dofasco Facility, Hamilton, Ontario

ArcelorMittal Dofasco G.P. (Dofasco) operates an integrated steel mill located at 1330 Burlington Street East in Hamilton, Ontario (the Facility). The Facility takes coal, iron ore, scrap steel, and fluxes to produce more than 4 million tons of flat rolled and tubular steel products per year. Major customers include the automotive, construction, energy, manufacturing, pipe and tube, appliance, container and steel distribution industries. In 2016, the Facility included two coke plants, three blast furnaces, a KOBM basic oxygen furnace and an electric arc furnace in the steelmaking plant, two slab casters, a hot strip rolling mill, cold mills, annealing furnaces, galvanizing lines, an electrolytic coating line and two tube mills. Approximately 5,000 people work at the Facility.

The Facility was constructed prior to November 30, 2005 and the North American Industrial Classification System (NAICS) code that best describes its primary operations is 331110 – Iron and Steel Mills and Ferro-Alloy Manufacturing. The Facility was phased-in under Schedule 4 of Ontario Regulation (O.Reg.) 419/05 and must have an Emission Summary and Dispersion Modelling (ESDM) Report in place in accordance with s.26 of the regulation.

This ESDM Report meets the requirement of O.Reg. 419/05 and has been prepared using the Ontario Ministry of Environment and Climate Change (MOECC) publication: “Procedure for Preparing an Emission Summary and Dispersion Modelling Report”, dated February 2017 (ESDM Procedure Document).

The maximum point of impingement (POI) concentrations were calculated based on the operating conditions where significant sources were operating simultaneously at their maximum rate of production for the averaging time. The exception to this is where physical or operational limitations exist, which would exclude two pieces of equipment from operating simultaneously. The maximum emission rates for each significant compound emitted from the significant sources were calculated in accordance with s.11 of O.Reg. 419/05 and the data quality assessment follows the process outlined in the ESDM Procedure Document.

A maximum POI concentration for each significant contaminant emitted from the Facility was determined based on these conservative emission rates and the US EPA AERMOD dispersion model; the results are presented in the following Emission Summary Table. The POI concentrations listed in the Emission Summary Table were compared against limits that apply to the Facility, as listed in the MOECC’s publication “Air Contaminants Benchmark List: Standards, guidelines and screening levels for assessing point of impingement concentrations of air contaminants”, dated December 13, 2016 [List of Ministry POI Limits and Screening Levels].

The assessment of the site’s compliance with the MOECC’s air quality criteria yields the following:

 The majority of compounds are predicted to be below their MOECC POI limits (including Schedule 3 standards and MOECC guideline criteria).  Five (5) compounds (i.e., benzene, benzo(a)pyrene, total reduced sulphur, total suspended particulate, manganese) are predicted to be below the Site Specific Standards approved by the MOECC for the site.  Multiple compounds have been considered negligible through dispersion modelling because they are below 1% of their MOECC POI Limits, JSL values or the MOECC’s de minimus limit.  Four (4) compounds (e.g. sodium) do not have MOECC POI limits and are predicted to be below MOECC approved maximum ground level concentrations documented in the Emission Summary and Dispersion Modelling Report ArcelorMittal Dofasco Facility, Hamilton, Ontario (July, 2009).  One (1) compound (Chromium VI) was predicted to have exceeded the MOECC’s annual standard. The MOECC was notified of the modeled exceedance. In December 2016, production at the largest Chromium VI emission source (#2 Galv) was permanently stopped. Predictive modelling for the 2017 operating year shows that the facility is expected to meet the annual standard.

Details on the significant compounds are presented in the following Emission Summary Table.

In accordance with the requirements of the Environmental Compliance Approval with Limited Operational Flexibility (ECA with LOF) issued to the site, Dofasco maintains a log that describes modifications to the Facility.

ARCELORMITTAL DOFASCO EMISSION SUMMARY TABLE – 2016 OPERATING YEAR Total Facility Maximum POI Air Averaging MOECC POI Emission Rate Concentration Regulation Percentage of Contaminant CAS No. Dispersion Period Limit [g/s] [µg/m³] Schedule No. MOECC Limit [%] Model Used [hours] [µg/m³] 2016 Actual 2016 Actual Arsenic 7440-38-2 8.51E-04 AERMOD 3.27E-03 24 0.3 Guideline 1.09% Mineral Spirits N/A 1.76E+00 AERMOD 3.33E+01 24 2600 Reg 419 Standard 1.28% Cobalt 7440-48-4 4.54E-04 AERMOD 1.30E-03 24 0.1 Guideline 1.30% Vanadium 7440-62-2 5.86E-03 AERMOD 3.05E-02 24 2 Reg 419 Standard 1.53% Tin 7440-31-5 8.05E-03 AERMOD 1.57E-01 24 10 Reg 419 Standard 1.57% Butyl Cellosolve 111-76-2 1.53E-02 AERMOD 1.11E+01 10 min** 500 Guideline 2.22% Titanium dioxide 13463-67-7 1.17E-01 AERMOD 7.79E-01 24 34 Guideline 2.29% Sulfuric acid 7664-93-9 2.88E-03 AERMOD 1.15E-01 24 5 Reg 419 Standard 2.31% Boric acid 10043-35-3 1.86E-02 AERMOD 9.78E-01 24 33 Guideline 2.96% Nickel 7440-02-0 4.05E-03 AERMOD 1.79E-03 Annual 0.04 Reg 419 Standard 4.48% Beryllium 7440-41-7 1.08E-04 AERMOD 4.94E-04 24 0.01 Reg 419 Standard 4.94% Aluminum oxide 1344-28-1 1.15E+00 AERMOD 6.43E+00 24 120 Guideline 5.36% Hydrogen cyanide 74-90-8 2.21E-02 AERMOD 4.31E-01 24 8 Reg 419 Standard 5.39% Dioxin Furan N/A 4.75E-08 AERMOD 5.45E-08 24 0.000001 URT 5.45% Zinc 7440-66-6 1.54E+00 AERMOD 7.15E+00 24 120 Reg 419 Standard 5.96% Naphthalene 91-20-3 1.58E-01 AERMOD 4.62E+00 10 min** 50 Guideline 9.25% Sodium hydroxide 1310-73-2 3.72E-02 AERMOD 9.25E-01 24 10 Guideline 9.25% Cadmium 7440-43-9 1.98E-03 AERMOD 2.32E-03 24 0.025 Reg 419 Standard 9.28% Lead 7439-92-1 4.49E-02 AERMOD 2.15E-02 30 day 0.2 Reg 419 Standard 10.74% Lead 7439-92-1 4.49E-02 AERMOD 5.57E-02 24 0.5 Reg 419 Standard 11.13% Ethylene 74-85-1 6.69E-01 AERMOD 4.66E+00 24 40 Guideline 11.66% Magnesium oxide 1309-48-4 1.92E+00 AERMOD 1.43E+01 24 120 Reg 419 Standard 11.92% Phenol 108-95-2 1.73E-01 AERMOD 4.49E+00 24 30 Reg 419 Standard 14.96% Calcium oxide 1305-78-8 2.18E-01 AERMOD 1.56E+00 24 10 Reg 419 Standard 15.63% Naphthalene 91-20-3 1.58E-01 AERMOD 4.30E+00 24 22.5 Guideline 19.10% Chromium (VI) 7440-47-3 5.64E-04 AERMOD 1.40E-02 24 0.07 URT 19.96% Hydrochloric Acid 7647-01-0 9.54E-01 AERMOD 4.49E+00 24 20 Reg 419 Standard 22.46% Calcium hydroxide 1305-62-0 4.49E-01 AERMOD 4.06E+00 24 13.5 Reg 419 Standard 30.09% Chromium (Total) N/A 1.70E-02 AERMOD 1.88E-01 24 0.5 Reg 419 Standard 37.67% Ammonia 7664-41-7 2.02E+00 AERMOD 4.10E+01 24 100 Reg 419 Standard 41.01% Silicon Dioxide 14808-60-7 4.44E-01 AERMOD 2.20E+00 24 5 Guideline 44.03% Dioxin Furan N/A 4.75E-08 AERMOD 5.45E-08 24 0.0000001 Reg 419 Standard 54.47% Ferric oxide 1309-37-1 7.48E+00 AERMOD 1.62E+01 24 25 Reg 419 Standard 64.80%

Notes: * Site specific level reviewed and approved by the MOECC in the ESDM submitted in support of the ECA with LOF for the site. ** In accordance with MOECC guidelines, 10-minute POI concentrations modelled at nearest sensitive receptor.