A Demonstration Project of Pollution Prevention in the Metal Finishing Industry

This paper describes the results of an industrial pollution prevention pilot project in Nebraska. The goal of the project is to demonstrate that through proper management and operating practices, that industrial pollution can effectively be reduced significantly. The net effect of this pollution prevention program is to improve the economic worth of the industry by lowering expenditures on pollution control measures as well as minimizing regulatory burdens. The industrial pollution prevention pilot program is taking place at an aging manufacturing facility that produces fabricated metal products for farm and industrial use including structural steel members and plates, farm gates, fencing, and livestock watering tanks, in addition to a wide variety of structural bolts, fasteners, and so on. During manufacturing, the facility performs many operations including electroplating, conversion coating, cleaning, machining, grinding, impact deformation, shearing, welding, sand blasting, hot-dip galvanizing, painting, assembly and testing. Many of these processes result in the production of hazardous pollutants that must be disposed of in some fashion. For example, the electroplating line results in the production of acids and rinse water containing zinc and chromium and the hot-dip galvanizing line results in the production of acids and rinse water containing zinc, lead and iron. The painting processes result in the production of used industrial acids, solvents, and chemicals used for cleaning and degreasing metal components. By design, the initial recommended operational changes and process modifications to the plant to prevent or reduce waste were simple to implement, and their pay-back periods were fairly short. For example, modifications requiring minor structural changes in galvanizing resulted in reducing rinse water use by about 60 % thus leading to savings of about $250 per day in water consumption and waste treatment. Additional modifications requiring larger investments also were presented for implementation by the facility after initial modifications were completed.