Industrial Wastewater Discharge Permit Renewal - Suzuki

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5 PERMIT BRIEFING MEMO 1. Facility Description Suzuki Garphyttan Corporation engages in the manufacturing of steel wire for automotive springs. The incoming steel rod undergoes several processes. First, 10% of the rod is shaved off the surface of the rod. It is then heat treated which leaves the rod with an oxide layer. The oxide is removed using HCl and a bipolar caustic. Bipolar caustic means that an electric current is applied to the wire to facilitate cleaning when in the caustic NaOH. The rod is then coated prior to the drawing operation. A surface activation solution is applied to facilitate coating then the rod is submerged in the zinc phosphate coating bath. Since the bath is phosphoric acid based, the wire is submerged in a lime solution as a precautionary step to neutralize any phosphoric acid in the event that the rod was not rinsed adequately after the zinc phosphate bath. The wire is then drawn to size, and heat treated to harden and temper the wire. The wire receives an Eddy Current (EC) Test surface inspection to check for defects in the surface of the wire. 2. Discharge description: Discharge is process flow only. Twelve-month average flow is 10,164 gpd. The maximum flow over the past twelve months was 19,992 gpd. 3. Sample Site Description Sample Site Outfall #231 is located outside the main facility in a locked shed, which is attached to the north wall of the building. The wastewater discharge flows through a weir box for flow measurement in the shed prior to discharge. The composite sample is collected in the discharge pipe after the final chamber of the weir box. Grab samples are collected after the final discharge tank in the weir box. Samples are of process water only, sanitary is excluded. 4. Wastewater Treatment Wastewater treatment consists of Chemical Precipitation, Flocculation, Neutralization, Sedimentation, and Filtration with a filter press. The filter press effluent discharges to the beginning of the wastewater pretreatment process. 5. Classification Suzuki Garphyttan Corporation is classified as a Categorical Industrial User (CIU) as defined in the South Bend Municipal Code. Specifically, Suzuki Garphyttan Corporation is classified as a metal finisher covered by 40 CFR 433.17 (PSNS) due to the zinc phosphate coating. A review of Suzuki’s process was performed in 2007 to determine if, based on the process of acid pickling steel, Suzuki had been correctly classified as a metal