CDS® Unit – the right choice for big pollution trap

Blacktown City Council in western Sydney recently installed the largest CDS® gross pollutant trap yet manufactured by Rocla, as part of its comprehensive stormwater management program.

The CDS® P3024 Unit is the largest of six new stormwater quality improvement devices being installed in key locations around the Blacktown local government area. The new devices will complement the existing 130 traps in use around the city.

The 3-metre diameter CDS® Unit is one of two being installed in the most significant part of the project, at Goroka Street, Whalan. The installation includes extensive rehabilitation works of the drainage channel at the site, where currently untreated flow from three 1350mm diameter pipes drains into an urban waterway.

Designing twin CDS® Units into the project provided the consultants and project managers, Water Conservation Group, with the flexibility to implement the project in stages, with later construction of a diversion weir after downstream rehabilitation works, and installation of the mirror-image CDS® Unit during a future stage. A purpose-designed diversion weir structure, one of the unique features of the CDS® range, allowed an uncompromised fit in the difficult location. An off-take connection was also included, providing for future connection to a proposed stormwater harvesting tank.

The CDS® Unit was specified for its flexibility and performance, as well as its cost-effectiveness in construction and maintenance. When completed, it is expected that the twin CDS® Units will capture a potential 120 tonnes of litter, sediment and natural pollution a year.

Blacktown Mayor, Cr Charlie Lowles, who visited the site to inspect construction activities, said gross pollutant traps were a cost-effective way to maintain stormwater systems.

“Stopping problems and pollution at the source helps protect the environment and lessens Council’s maintenance costs,” Cr Lowles said.