NR 463.22(28)(28) “Scrap preheater” means a vessel or other piece of equipment in which metal scrap that is to be used as melting furnace feed is heated to a temperature high enough to eliminate moisture and other volatile impurities or tramp materials by direct flame heating or similar means of heating. NR 463.22(29)(29) “Scrubber blowdown” means liquor or slurry discharged from a wet scrubber that is either removed as a waste stream or processed to remove impurities or adjust its composition or pH before being returned to the scrubber. NR 463.22(30)(30) “Work practice standard” means any design, equipment, work practice, operational standard or combination thereof, that is promulgated pursuant to section 112 (h) of the Clean Air Act (42 USC 7412 (h)). NR 463.22(31)(31) “You” or “your” means the owner or operator of an iron and steel foundry. NR 463.22 HistoryHistory: CR 06-110: cr. Register July 2007 No. 619, eff. 8-1-07. NR 463.23NR 463.23 Emissions limitations, work practice standards and operation and maintenance requirements. NR 463.23(1)(a)(a) You shall meet each of the following emission limits or standards that applies to you: NR 463.23(1)(a)1.1. For each electric arc metal melting furnace, electric induction metal melting furnace or scrap preheater at an existing iron and steel foundry, as described in s. NR 463.21 (3) (c), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for particulate matter (PM) in subd. 1. a. or the limit for total metal HAP in subd. 1. b.: NR 463.23(1)(a)2.2. For each cupola metal melting furnace at an existing iron and steel foundry, as described in s. NR 463.21 (3) (c), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for PM in subd. 2. a. or the limit for total metal HAP in subd. 2. b.: NR 463.23(1)(a)3.3. For each cupola metal melting furnace or electric arc metal melting furnace at a new iron and steel foundry, as described in s. NR 463.21 (3) (d), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for PM in subd. 3. a. or, alternatively, the limit for total metal HAP in subd. 3. b.: NR 463.23(1)(a)4.4. For each electric induction metal melting furnace or scrap preheater at a new iron and steel foundry, as described in s. NR 463.21 (3) (d), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for PM in subd. 4. a. or, alternatively, the limit for total metal HAP in subd. 4. b.: NR 463.23(1)(a)5.5. For each pouring station at an existing iron and steel foundry, as described in s. NR 463.21 (3) (c), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for PM in subd. 5. a. or, alternatively, the limit for total metal HAP in subd. 5. b.: NR 463.23(1)(a)6.6. For each pouring area or pouring station at a new iron and steel foundry, as described in s. NR 463.21 (3) (d), you may not discharge emissions through a conveyance to the atmosphere that exceed either the limit for PM in subd. 6. a. or, alternatively, the limit for total metal HAP in subd. 6. b.: NR 463.23(1)(a)7.7. For each building or structure housing any emissions source at the iron and steel foundry, you may not discharge any fugitive emissions to the atmosphere that exhibit opacity greater than 20% averaged over 6 minutes except for one 6-minute average per hour that does not exceed 27% opacity. NR 463.23(1)(a)8.8. For each cupola metal melting furnace at a new or existing iron and steel foundry, you may not discharge emissions of volatile organic hazardous air pollutants (VOHAP) through a conveyance to the atmosphere that exceed 20 parts per million by volume (ppmv) corrected to 10% oxygen.