Public Notification to Solicit Comments and Notice of Public Hearing on the
Proposed New Source Review/Prevention of Significant Deterioration Permit
for United States Steel Corporation – Edgar Thomson
Notice is hereby given under Article XXI, §2102.05(c), that the Allegheny County
Health Department (ACHD) is soliciting comments on the Proposed New Source
Review/Prevention of Significant Deterioration Permit for United States Steel
Corporation – Edgar Thomson Plant, 13th Street and Braddock Avenue, Braddock,
PA 15104 as described in the Company’s December 29, 2025, Permit Application
and subsequent supplemental submissions. Specifically, the installation consists of
a new hot strip mill (HSM) with two 476 MMBtu/hr, each walking beam furnaces,
a new ladle metallurgy facility (LMF), a new slab grinder, one (1) 2,500 hp
emergency diesel engine, three (3) fire pump engines (two engines rated @ 366
KW and one @ 135 Kw), and three (3) new cooling towers. The proposed HSM will
have a capacity of 3,500,000 tons/year of sheet metal production. The furnaces
will combust natural gas and coke oven gas and will be equipped with low-NOX
burners. The proposed LMF and slab grinding operation will each be equipped with
a baghouse. The proposed engines will fire ultra-low sulfur diesel.
The ACHD is seeking comments on the following draft permits. Members of the
public may request copies of the documents through the Department’s Regulated
Entities Portal (REP), by emailing aqpermits@Allegheny County.US, or calling (412)
578-8103. Written comments may be submitted to the Department at 836 Fulton
Street, Pittsburgh, PA 15233 or by e-mail at aqpermits@Allegheny County.US
by 11:59 pm on Tuesday, November 17, 2026. Comments will not be accepted
after this time. REP may be accessed on the ACHD website at https://www.
alleghenycounty.us/Services/Health-Department/Air-Quality/Regulated-Entities-
Portal.
A public hearing will be held regarding the proposed issuance of these permits
on Tuesday, November 10, 2026 at Carnegie One Library in Braddock, 419 Library
St, Braddock, PA 15104. Anyone who would like to speak at the hearing should
register online at least 24 hours in advance of the hearing on the Department’s
permits webpage at https://alleghenycounty.us/AQnotices.
Based on the information provided by the applicant and ACHD’s own analysis, the
project will result in the following combined potential emissions increases for all
proposed equipment: Nitrogen Oxides: 146.58 tons/yr; Carbon Monoxide: 61.96
tons/yr; Volatile Organic Compounds: 15.11 tons/yr; Sulfur Oxides: 247.76 tons/
yr; Particulate Matter: 43.28 tons/yr; PM10: 30.54; PM2.5: 25.96; Total HAP: 17.56
ton/yr. Based on the information above, the installation of the new units will result
in a significant net increase in NOX, SOX, CO, PM10, and PM2.5 emissions under
the Prevention of Significant Deterioration (PSD) regulations and Nonattainment
New Source Review (NNSR) regulations. The facility intends to partially offset the
increase in emissions by discontinuing operation of the hot strip mill at the US
Steel Irvin plant.
Based on the information provided by the applicant and ACHD’s own analysis, the
potential emissions from the proposed new equipment at US Steel Edgar Thomson
will not significantly impact air quality. To ensure compliance with the applicable
standards, ACHD has placed the following conditions in the proposed Permit:
1. Operational limitations limiting throughput in the HSM, LMF, and slab grinder;
use of low NOX burners on the HSM furnaces; use of a baghouse on the LMF and
slab grinder; limiting emergency generator and fire pumps use to ultra-low sulfur
diesel and limited hours per year; use of drift eliminators on the cooling towers;
and limiting total dissolved solids in the cooling towers. The permit includes the
applicable requirements of 40 CFR Part 63, Subpart FFFFF: National Emission
Standards for Hazardous Air Pollutants for Integrated Iron and Steel and 40 CFR
Part 60, Subpart IIII: Standards of Performance for Stationary Compression Ignition
Internal Combustion Engines
2. NOX, SO2, and PM2.5 Emission Offsets – requiring the permittee to demonstrate
that emission reduction credits from the PADEP registry system or emissions
reductions from existing sources in Allegheny County are secured to offset the net
increase in NOX and SO2 emissions from the project by at least the ratios set forth
in Article XXI §2102.06.b.4. The permittee also maintains the capability to offset
increases in PM2.5.
3. Testing Requirements including emissions testing per Article XXI 2108.02(a) for
NOX, SO2, CO, VOC, PM, PM10, PM2.5 on the HSM and testing for PM on the LMF.
4. Monitoring Requirements including fuel monitoring on the HSM furnaces;
baghouse monitoring and a bag leak detection system on the LMF; baghouse
monitoring on the slab grinder; non-resettable hour meters on the emergency
generator and fire pumps; and monitoring of total dissolved solids in the cooling
towers.
5. Recordkeeping including recording of sufficient data to demonstrate compliance
with the permit conditions. The records shall include at a minimum records of all
required monitoring data; records of the results of required inspections, episodes
of non-compliance with any permit condition, and corrective actions taken;
records of all the stack tests performed; records of the date, time and duration of
any malfunction, the cause of the malfunction and the action taken to correct the
malfunction; records of fuel consumption; records of each adjustment conducted
on the combustion units; records of cold starts and operating hours for the
emergency generator and fire pumps; records of diesel fuel certifications from fuel
suppliers; records of tune-ups on the furnaces and records of total dissolved solids
in the cooling towers.
6. Reporting Requirements including semi-annual reports of all information
required under recordkeeping.
adno=422971 Public Notification to Solicit Comments and Notice of Public Hearing on the Proposed New Source Review / Prevention of Significant Deterioration Permit for United States Steel Corporation – Edgar Thomson Notice is hereby given under Article XXI , §2102.05 ( c ) , that the Allegheny County Health Department ( ACHD ) is soliciting comments on the Proposed New Source Review / Prevention of Significant Deterioration Permit for United States Steel Corporation – Edgar Thomson Plant , 13th Street and Braddock Avenue , Braddock , PA 15104 as described in the Company’s December 29 , 2025 , Permit Application and subsequent supplemental submissions . Specifically , the installation consists of a new hot strip mill ( HSM ) with two 476 MMBtu / hr , each walking beam furnaces , a new ladle metallurgy facility ( LMF ) , a new slab grinder , one ( 1 ) 2,500 hp emergency diesel engine , three ( 3 ) fire pump engines ( two engines rated @ 366 KW and one @ 135 Kw ) , and three ( 3 ) new cooling towers . The proposed HSM will have a capacity of 3,500,000 tons / year of sheet metal production . The furnaces will combust natural gas and coke oven gas and will be equipped with low – NOX burners . The proposed LMF and slab grinding operation will each be equipped with a baghouse . The proposed engines will fire ultra – low sulfur diesel . The ACHD is seeking comments on the following draft permits . Members of the public may request copies of the documents through the Department’s Regulated Entities Portal ( REP ) , by emailing aqpermits @ Allegheny County.US , or calling ( 412 ) 578-8103 . Written comments may be submitted to the Department at 836 Fulton Street , Pittsburgh , PA 15233 or by e – mail at aqpermits @ Allegheny County.US by 11:59 pm on Tuesday , November 17 , 2026. Comments will not be accepted after this time . REP may be accessed on the ACHD website at https : // www . alleghenycounty.us/Services/Health-Department/Air-Quality/Regulated-Entities- Portal . A public hearing will be held regarding the proposed issuance of these permits on Tuesday , November 10 , 2026 at Carnegie One Library in Braddock , 419 Library St , Braddock , PA 15104. Anyone who would like to speak at the hearing should register online at least 24 hours in advance of the hearing on the Department’s permits webpage at https://alleghenycounty.us/AQnotices . Based on the information provided by the applicant and ACHD’s own analysis , the project will result in the following combined potential emissions increases for all proposed equipment : Nitrogen Oxides : 146.58 tons / yr ; Carbon Monoxide : 61.96 tons / yr ; Volatile Organic Compounds : 15.11 tons / yr ; Sulfur Oxides : 247.76 tons / yr ; Particulate Matter : 43.28 tons / yr ; PM10 : 30.54 ; PM2.5 : 25.96 ; Total HAP : 17.56 ton / yr . Based on the information above , the installation of the new units will result in a significant net increase in NOX , SOX , CO , PM10 , and PM2.5 emissions under the Prevention of Significant Deterioration ( PSD ) regulations and Nonattainment New Source Review ( NNSR ) regulations . The facility intends to partially offset the increase in emissions by discontinuing operation of the hot strip mill at the US Steel Irvin plant . Based on the information provided by the applicant and ACHD’s own analysis , the potential emissions from the proposed new equipment at US Steel Edgar Thomson will not significantly impact air quality . To ensure compliance with the applicable standards , ACHD has placed the following conditions in the proposed Permit : 1. Operational limitations limiting throughput in the HSM , LMF , and slab grinder ; use of low NOX burners on the HSM furnaces ; use of a baghouse on the LMF and slab grinder ; limiting emergency generator and fire pumps use to ultra – low sulfur diesel and limited hours per year ; use of drift eliminators on the cooling towers ; and limiting total dissolved solids in the cooling towers . The permit includes the applicable requirements of 40 CFR Part 63 , Subpart FFFFF : National Emission Standards for Hazardous Air Pollutants for Integrated Iron and Steel and 40 CFR Part 60 , Subpart IIII : Standards of Performance for Stationary Compression Ignition Internal Combustion Engines 2. NOX , SO2 , and PM2.5 Emission Offsets – requiring the permittee to demonstrate that emission reduction credits from the PADEP registry system or emissions reductions from existing sources in Allegheny County are secured to offset the net increase in NOX and SO2 emissions from the project by at least the ratios set forth in Article XXI §2102.06.b.4 . The permittee also maintains the capability to offset increases in PM2.5 . 3. Testing Requirements including emissions testing per Article XXI 2108.02 ( a ) for NOX , SO2 , CO , VOC , PM , PM10 , PM2.5 on the HSM and testing for PM on the LMF . 4. Monitoring Requirements including fuel monitoring on the HSM furnaces ; baghouse monitoring and a bag leak detection system on the LMF ; baghouse monitoring on the slab grinder ; non – resettable hour meters on the emergency generator and fire pumps ; and monitoring of total dissolved solids in the cooling towers . 5. Recordkeeping including recording of sufficient data to demonstrate compliance with the permit conditions . The records shall include at a minimum records of all required monitoring data ; records of the results of required inspections , episodes of non – compliance with any permit condition , and corrective actions taken ; records of all the stack tests performed ; records of the date , time and duration of any malfunction , the cause of the malfunction and the action taken to correct the malfunction ; records of fuel consumption ; records of each adjustment conducted on the combustion units ; records of cold starts and operating hours for the emergency generator and fire pumps ; records of diesel fuel certifications from fuel suppliers ; records of tune – ups on the furnaces and records of total dissolved solids in the cooling towers . 6. Reporting Requirements including semi – annual reports of all information required under recordkeeping . adno = 422971