Unroofed wash bays may be permitted; however, they are subject to strict EPA and council requirements because of the risk of stormwater ingress and contaminated runoff. In most jurisdictions, unroofed systems must incorporate rainwater diversion, first-flush diversion, and oil–water separation to prevent hydrocarbons, sediment, and heavy metals from entering stormwater drains.

Under EPA stormwater management guidelines, uncontrolled discharge from an unroofed wash bay can result in non-compliance penalties and significant environmental harm.

Washbay HQ provides engineered above-ground wash bay systems specifically designed for unroofed applications, featuring:

  • Automated stormwater diversion valves to isolate wash water from rainwater.

  • First-flush capture tanks to contain the most contaminated runoff.

  • Integrated oil–water separators ensuring discharge remains below 10 mg/L TPH and free of visible oil sheens.

  • Modular construction that allows for rapid setup and relocation, avoiding costly civil works and long approval delays.

This ensures our clients can operate unroofed wash bays legally, safely, and in full compliance with EPA, WHS, and council regulations.