A manufacturer of railcar bearings, wheels, and axles needed a wastewater system upgrade to treat for oil, grease, suspended solids, and dissolved metals in a mix of process water and storm water runoff. The existing wastewater treatment system in place at the facility consisted of a small equalization tank, traditional clarifier and sand filter. Oils and greases want to float in the wastewater stream unless additional chemicals are added to cause them to sink; thus, the clarifier had a difficult time removing them from the water. Heavy rainfall would also overwhelm the clarifier, rendering it even less effective in removing the oil, grease and fine solids from the wastewater stream.
As a result, the sand filter that followed would commonly blind over, requiring a large amount of operator interface, a high frequency of backwashes and a complete replacement of the sand media twice annually, costing the company over $50,000 annually. Additionally, the poor removal of the clarifier and blinding filter media put the facility’s final discharge at risk of being out of compliance and contributed to an overall inability to handle peak flows.