AQIS-Compliant Airport Wash Bay Installed at Hong Kong International Airport

The Challenge

As part of the ambitious design for Hong Kong’s new 12.48 km² international airport, one of the largest passenger terminals in the world, planners needed to incorporate cutting-edge water treatment systems across the site. With over 50 million passengers expected annually, every component of the facility had to meet strict environmental and engineering standards.

One of the most complex challenges: designing a massive, unroofed aircraft wash bay capable of:

• Remaining fully compliant with local and international environmental standards
• Washing two Boeing 747s simultaneously
• Handling over 50,000 m² of wash area
• Operating under frequent peak use
• Diverting and treating first flush rainwater
• Integrating harvested water reuse

The Plan

Fox Environmental Systems was engaged to engineer a custom First Flush Diversion System capable of supporting the scale and technical demands of the site. The system needed to manage both washwater and stormwater automatically, even in Hong Kong’s high rainfall climate.

The Solution

Fox supplied a fully automated, custom-engineered First Flush plate-mounted diversion system, purpose-built for the site’s unique requirements. Key features included:

• Custom-sized diversion valves, designed for large-scale flow rates
• Plate-mounted components for ease of installation and durability
• Dual-mode diversion, handling both aircraft washdown water and the first 10 mm of rainfall
• Integration with a broader water treatment system for compliance and reuse

The Outcome

At the time of design, this was believed to be one of the largest wash bays in the world. Our engineering team, together with Fox Environmental Systems, broke new ground with this system. We’re very pleased with the result.”
— Anthony Cheung Man Yuen, CEO

The result is a compliant, high-performance wash bay supporting heavy airport operations while protecting nearby waterways and infrastructure.