Three fabricators that are not connected to sewer lines have to meet discharge limits doe oil and grease of 5 PPM before discharging to surface water. All three pressure wash tubing to remove light oil. Once the facility cleans the finished product (storage cabinets), the water passes through a 10-micron filter bag, followed by a drum of HS-200 at 1/4 gpm. The concentration of the inflow is 30-50 PPM oil and rease. The outflow meets discharge standards and the filtration vessels last about a year.