Laserfiche WebLink
5 <br />compliance with applicable industrial wastewater <br />effluent requirements, including the federal categorical <br />standards and local pretreatment limitations for the <br />metropolitan disposal system for metals and cyanide <br />concentrations, wastewater pH, and any applicable federal <br />regulations for wastewater discharges. <br />Environmental Protection Agency (EPA) categorical <br />wastewater pretreatment regulations 40 CFR Part 433 for <br />electroplating facilities and 40 CFR Part 433 for metal <br />finishing facilities apply to the proposed facility. <br />Local pretreatment limitations for the metropolitan, <br />disposal system (MDS) as set by the MWCC also apply to <br />the facility. <br />Metals which will be limited by concentration in the <br />wastewater discharge include cadmium, total chromium, <br />copper, lead, nickel, and zinc. There is also a <br />limitation for mercury, but it is expected that mercury <br />concentrations will be below minimal detectable limits in <br />the wastewater discharge from the project to the sanitary <br />sewer. The total cyanide concentration and pH will also <br />be limited. In addition, the facility must pay for <br />discharging total suspended solids concentrations or <br />chemical oxygen demand levels over set base levels. <br />Plastic polymers used for metal precipitation will <br />contribute to the total suspended solids component. <br />The Agency staff expects that there will be a greater <br />reduction in the amount of metals to be discharged to the <br />sanitary sewer with the project than if each individual <br />metal waste generator pretreated its own wastes. <br />Processes to be used at the facility to remove metals <br />from the incoming waste stream will include ion exchange, <br />activated carbon absorption, chromium reduction, <br />electrochemical recovery, metal precipitation, filter <br />press, and sludge thickening processes. Cyanide removal <br />will be accomplished with a cyanide oxidation procebs. <br />After metals removal, wastewater from these processes <br />will be treated further by clarification and <br />neutralization, and multimedia or sand filtration. <br />Ill 2, 9) <br />G. Air Quality and Noise <br />Process air emissions will not be significant since <br />water -based, not organic solvent -based, processing will <br />occur at the facility. Hcwever, an air emission facility <br />permit may be required for the facility if hooding or <br />venting to the outside air is to occur or if a boiler is <br />installed which would trip permitting requirements in <br />Minnesota Rules Part 7005.0200-7005.0280. Determination <br />of the need for an air quality permit will be made after <br />