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1.3 Rinse Water from Copper Cvanide Platine - Metal Finishine Operations Site 2010 quantity (lb) rSLAC 16,689 Raw Materiels: Metal finishing Copper Cyanide operations,Wa m Baths including pailse Carbon Steel, cleaning and32) Stainless steel, metal plating Copper, and Aluminum parts _. _. _ _ �lDischarge Product INto PO"FXV Filter Cake I J Off-site (CWC 181) Disposal FIGURE ILIA: METAL FINISHING PROCESS WASTE GENERATION PROCESS Hazardous Waste and Process Description The hazardous waste is rinse water containing drag -out of the copper cyanide plating bath. The process is the plating of parts dipped in the copper cyanide plating bath. An overview of metal finishing operations is provided below to give some background information on the generation of this hazardous waste and on the supporting processes and operation that are associated with this waste. The Metal Finishing Operations Group (MFO) in the SLAC Mechanical Fabrication Department (MFD) performs plating of carbon steel, stainless steel, copper, and aluminum parts and uses several processes for cleaning and plating of metal parts. The process operations are rarely mass production -oriented. Instead, MFO operates on ajob- shop or small -batch basis. Parts are subjected to several process steps, depending on the substrate metal and the plating that is added to the substrate surface. Typical process steps include bead or sand blasting to remove scale, vapor degreasing to remove machining oils and other organics, alkaline cleaning to remove organics and for surface preparation, acid cleaning to remove oxidation and for surface preparation for plating, electroplating or electroless plating, and drying. Metals that are plated by MFO include mainly copper, nickel, tin, rhodium, indium, silver, and gold. The process steps employed depend on the surface finishing specifications required of the research being performed and the application of the equipment being fabricated. MFO has traditionally used copper cyanide to plate parts, for example, in the high- voltage klystrons used in the two-mile linear accelerator at SLAC. Copper cyanide plating provides unique coating properties that are not readily replicated with non - cyanide copper plating baths. MFO also uses its cyanide plating capabilities to support other national laboratory research throughout the country. Other laboratory researchers have also requested copper cyanide in their surface finishing specifications. After the parts are immersed in the cyanide bath, they are handled carefully to reduce drag -out before the parts are immersed in a single -stage rinse water bath. The rinse water is treated on-site in batch mode in treatment tanks, using a conventional, two-step alkaline and sodium hypochlorite oxidation process to destroy the cyanide. After the cyanide destruction processing, the treated rinse water is forwarded to the Metal Finishing Pretreatment Facility (MFPF), a conventional pH adjustment -flocculation - sedimentation pretreatment system of tanks, to precipitate and remove the copper and other heavy metal before discharging the treated water to the sanitary sewer. This cyanide rinse water is considered Category A because it is treated on-site and treated water is discharged to the POTW. The water is treated to meet discharge requirements of the POTW under the Clean Water Act. The copper is precipitated and collected in a settling tank in the form of metal hydroxide sludge in the MFPF. The sludge is concentrated in a filter press to form a fllter cake. The filter cake is dried and packaged for shipment to an off-site, permitted treatment, storage and disposal facility. The copper cyanide treatment process, the MFPF, and the sludge drying processes are authorized to operate under the California Tiered Permitting program. MFO also works with gold and silver cyanide baths. Drag -out and rinse waters are typically minimal, as the parts being plated tend to be small. As a result, drag -out and rinse waters are returned to the bath to conserve gold and silver use, eliminating the need for treatment of a rinse water waste stream. This approach is not as easily done with copper cyanide, since the parts can be larger in size and bath integrity can be more difficult to control. Hazardous Waste Management Approaches Source reduction measures implemented to date include careful monitoring of all the baths, including cyanide baths, to prolong their useful life. Alternative measures in the form of operation changes, such as using a countercurrent rinse bath, are not technically feasible due to space limitations. Some efforts have been made in the last four years to consolidate larger jobs requiring copper cyanide plating so that the baths are further used to their full extent before requiring replacement. SOURCE REDUCTION/POLLUTION PREVENTION EVALUATION Description of Measure: A major source reduction measure that has been considered is the replacement of cyanide copper plating with a non -cyanide copper altcmative. In 2010, SLAC has had a third -party consultant review the options for replacement of cyanide baths in SLAC metal finishing operations. The resulting review did not identify and clear alternatives September 1, 2011 SB 14 Plan 10 September 1, 2011 SB 14 Plan