Technical Plating Reduces Wastewater Volumes and Avoids Paying SAC
Technical Plating Incorporated is a small metal finishing company located in Brooklyn Park. Their Industrial Discharge Permit was up for renewal in October 2002. We notified them that our review of their wastewater discharge volume showed they were exceeding their SAC baseline of 40,500 gallons per day (gpd) and may need to pay $56,000 in additional SAC units. The company was given two options: first, to pay for additional SAC units equivalent to the increased discharge based on the review, or second, to conduct a 30-day wastewater volume study if they plan to initiate wastewater reduction measures.
Technical Plating chose the second option, but not solely for the purpose of avoiding additional SAC payment. Lowering their discharge volumes would also alleviate some of the stress put on their pretreatment system with the increased flows.
After working with a summer intern from MnTAP, Technical Plating instituted two process modifications to reduce wastewater volumes. They installed a rinse water reuse system that consists of a collection tank, a sand filter, and a supply tank where clean water is stored and then fed back into the plating line. Next, they installed flowmeters on one plating line and implemented specific operating instructions for employees to follow to improve flow controls on the line. The 30-day volume study, conducted after these changes were made, showed wastewater volumes well below their SAC baseline. From these simple changes the company managed to avoid the additional SAC payment, and benefits from a more efficiently operated pretreatment system.
The MnTAP intern came up with some other very innovative ways for Technical Plating to reduce their wastewater volumes, particularly with their barrel rinsing, which may be instituted in the future. View the full project summary at http://mntap.umn.edu/