19 Major Metropolitan Areas at Risk

ABC News 

At Risk Metro Areas in the United States.

Number of Refineries using Hydrofluoric Acid 
        Areas with populations between 1,000,000 and 8,000,000

3   in metro Philadelphia PA and downwind Wilmington DE, and Camden NJ in kill/maim-zone 20-mile radii 
3   New Orleans LA 
1   Baton Rouge LA  
3   Salt Lake City UT   
2   Chicago IL    
2   Los Angeles CA
1    Twin Cities Minneapolis/St. Paul MN

Areas with populations between 300,000 to 1,000,000

Texas has 7 HFA refineries: 
2   Corpus Christi
2   Port Arthur/Galveston
2    Texas City
1    Pasadena (Houston metro) 
1    Canton OH
2    Memphis TN 

Major towns with populations below 300,000
1     Billings MT
1     Duluth/Superior MN
1     Ferndale/Bellingham WA
1     Ashland KY
1     Ponca City OK 
1     Crawford County IL   

Plus 18 refineries in rural towns facing doom or new prosperity, see column G on ARDMAC Excel spreadsheets.