Several months ago, we changed our metal finishing operations so that we are only performing non-cyanide zinc plating on carbon steel followed by chromating. Our wastewater treatment filter press cake has been classified as a listed RCRA hazardous waste under F006. We have been attempting to get our filter press cake approved into a licensed sanitary landfill as a non-hazardous waste, but the state EPA still considers the waste as F006 because of the chromating after plating. Do you have any guidance on the issue that could help our case? We have done extensive testing of the filter press cake, and it does not meet the RCRA hazardous waste characteristics. S.J.
The problem is that your state EPA is referring to the original background documents for the listing of F006 sludges from electroplating operations where chromat-ing is described as a chemical conversion process. We strongly recommend that you direct your state EPA to the 12/2/86 Federal Register, page 43,351. In this interpretative rule, U.S.EPA clarified the F006 listing by stating “. . . the F006 listing included only common and precious metals electroplating, anodizing, chemical etching and milling, and cleaning and stripping when associated with these processes. Although the listing background document noted other processes, these were not part of the promulgated listing. Accordingly, the following processes are not included under the F006 listing: chemical conversion coating, electroless plating and printed circuit board manufacturing.” Armed with this information, we believe you will be successful in obtaining approval, for we have done so twice within the last year.
One of the interesting results of this rule is that treatment of wastewater from steel phosphating does not produce a listed RCRA hazardous waste while aluminum phosphating does produce a listed RCRA hazardous waste under F019 wastewater treatment sludges from chemical conversion coating of aluminum.