During the upgrade of Sydney Airport in preparation for the Airbus A380 super jumbo, a stormwater trunk drainage line was installed to carry runoff from new runway aprons and carpark areas.
Rocla Pipeline Products supplied steelreinforced concrete drainage pipes in 1200mm and 1050mm diameters for the drainage line, as well as a large in-line pollutant interceptor to trap oil and sediment washed off the hard surfaces.
The outlet pipes discharge into the mouth of the Cooks River at the edge of Botany Bay.
Constraints imposed by existing structures meant the pollutant trap had to be designed as two parallel tanks to achieve the required capacity. The tanks were constructed from Rocla® 2100mm diameter steel-reinforced concrete pipes with cast-in ends.
The tanks included a series of cast-in weirs at the top and bottom, to capture floating debris, fuels, oil and sediments, and four Rocla CPO® entry pits for maintenance.
A 7-metre pit was excavated for the tanks, below groundwater level, which required dewatering during construction.
To simplify installation, the tanks were set into a large in situ concrete base at ground level then lowered into the pit using an 80-tonne crane.
The pollution control system was designed by Hyder Consulting and installed by Antoun Civil Engineering.
Antoun’s project manager, Robert Burroughs, described the precast tanks and in situ base as “A good, simple idea and a quick way of completing what could have been a very difficult job.”