Wisconsin Administrative Code
Department of Natural Resources
NR 400-499 - Environmental Protection - Air Pollution Control
Chapter NR 463 - National Emission Standards For Hazardous Air Pollutants For Metals Treating And Processing
Subchapter III - Iron and Steel Foundries
Section NR 463.23 - Emissions limitations, work practice standards and operation and maintenance requirements

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.:

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.:

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.:

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.:

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.:

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.:

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.

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.

9. As an alternative to the work practice standard in sub. (2) (e) for a scrap preheater at an existing iron and steel foundry or in sub. (2) (f) for a scrap preheater at a new iron and steel foundry, as described in s. NR 463.21(3) (d), you may not discharge emissions of VOHAP through a conveyance to the atmosphere that exceed 20 ppmv.

10. For one or more automated conveyor and pallet cooling lines that use a sand mold system, or one or more automated shakeout lines that use a sand mold system, at a new iron and steel foundry, as described in s. NR 463.21(3) (d), you may not discharge emissions of VOHAP through a conveyance to the atmosphere that exceed a flow-weighted average of 20 ppmv.

11. For each triethylamine (TEA) cold box mold or core making line at a new or existing iron and steel foundry, you shall meet either the emission limit in subd. 11. a. or the emission standard in subd. 11. b.:

1. You shall install, operate and maintain a capture and collection system for all emission sources subject to an emission limit or standard for VOHAP or TEA in par. (a) 8. to 11. in accordance with both of the following:

2. You shall operate each wet scrubber applied to emissions from a metal melting furnace, scrap preheater, pouring area or pouring station subject to an emission limit for PM or total metal HAP in par. (a) 1. to 6. to insure that the 3-hour average pressure drop and scrubber water flow rate does not fall below the minimum levels established during the initial or subsequent performance test.

3. You shall operate each combustion device applied to emissions from a cupola metal melting furnace subject to the emission limit for VOHAP in par. (a) 8. to insure that the 15-minute average combustion zone temperature does not fall below 1,300ºF. Periods when the cupola is off blast and for 15 minutes after going on blast from an off blast condition are not included in the 15-minute average.

4. You shall operate each combustion device applied to emissions from a scrap preheater subject to the emission limit for VOHAP in par. (a) 9. or from a TEA cold box mold or core making line subject to the emission limit for TEA in par. (a) 11. to insure that the 3-hour average combustion zone temperature does not fall below the minimum level established during the initial or subsequent performance test.

5. You shall operate each wet acid scrubber applied to emissions from a TEA cold box mold or core making line subject to the emission limit for TEA in par. (a) 11. to insure both of the following:

1. A description of the device.

2. Test results collected in accordance with s. NR 463.25(3) verifying the performance of the device for reducing emissions of PM, total metal HAP, VOHAP or TEA to the levels required by this subchapter.

3. A copy of the operation and maintenance plan required by sub. (3) (b).

4. A list of appropriate operating parameters that will be monitored to maintain continuous compliance with the applicable emissions limitations.

5. Operating parameter limits based on monitoring data collected during the performance test.

1. A materials acquisition program to limit organic contaminants according to the following requirements as applicable:

2. A materials acquisition program specifying that the scrap supplier remove accessible mercury switches from the trunks and hoods of any automotive bodies contained in the scrap and remove accessible lead components such as batteries and wheel weights. You shall obtain and maintain onsite a copy of the procedures used by the scrap supplier for either removing accessible mercury switches or for purchasing automobile bodies that have had mercury switches removed, as applicable.

3. Procedures for visual inspection of a representative portion, but not less than 10%, of all incoming scrap shipments to ensure the materials meet the specifications. The inspection procedures shall do all of the following:

1. You shall install, operate and maintain a gas-fired preheater where the flame directly contacts the scrap charged.

2. You shall charge only material that is subject to and in compliance with the scrap certification requirement in par. (b).

1. Monthly inspections of the equipment that is important to the performance of the total capture system, such as pressure sensors, dampers and damper switches. The inspections shall include observations of the physical appearance of the equipment, such as the presence of holes in the ductwork or hoods, flow constrictions caused by dents or accumulated dust in the ductwork and fan erosion. The operation and maintenance plan shall also include requirements to repair the defect or deficiency as soon as practicable.

2. Operating limits for each capture system for an emissions source subject to an emissions limit or standard for VOHAP or TEA in sub. (1) (a) 8. to 11. You shall establish the operating limits according to all of the following requirements:

3. A preventive maintenance plan for each control device, including a preventive maintenance schedule that is consistent with the manufacturer's instructions for routine and long-term maintenance.

4. A site-specific monitoring plan for each bag leak detection system. For each bag leak detection system that operates on the triboelectric effect, the monitoring plan shall be consistent with the recommendations contained in the U.S. Environmental Protection Agency guidance document "Fabric Filter Bag Leak Detection Guidance'', EPA-454/R-98-015, incorporated by reference in s. NR 484.06(4) (c). The owner or operator shall operate and maintain the bag leak detection system according to the site-specific monitoring plan at all times. The baghouse monitoring plan is subject to approval by the department and shall address all of the following items:

5. A corrective action plan for each baghouse. The plan shall include the requirement that, in the event a bag leak detection system alarm is triggered, you shall initiate corrective action to determine the cause of the alarm within one hour of the alarm, initiate corrective action to correct the cause of the problem within 24 hours of the alarm and complete the corrective action as soon as practicable. Corrective actions taken may include any of the following:

6. Procedures for providing an ignition source to mold vents of sand mold systems in each pouring area and pouring station unless you determine the mold vent gases either are not ignitable, ignite automatically or cannot be ignited due to accessibility or safety issues. You shall document and maintain records of the determination of ignitability, accessibility and safety. The determination may encompass multiple casting patterns provided the castings utilize similar sand-to-metal ratios, binder formulations and coating materials. The determination of ignitability shall be based on observations of the mold vents within 5 minutes of pouring, and the flame shall be present for at least 15 seconds for the mold vent to be considered ignited. For the purpose of the determination made under this subdivision, both of the following apply: