Oil in the wastewater from vehicle and equipment wash-down contains hydrocarbons, grease, and suspended solids that can severely impact wastewater treatment performance. If not properly managed, these contaminants can bypass treatment systems, cause blockages, and discharge pollutants directly into the environment.

In Australia, the EPA typically requires treated discharge to contain less than 10 mg/L of total petroleum hydrocarbons (TPH) and to be free of visible oil sheens before release to sewer or stormwater. Non-compliance can result in environmental harm, regulatory penalties, and operational downtime.

To meet these standards, compliant wastewater treatment systems must integrate Oil Water Separators (e.g., coalescing plate or vertical tube technology) designed to efficiently remove free oils, grease, and suspended solids prior to reuse or lawful discharge.