Severn Trent supplies filter underdrain system

The Severn Trent project is the first public-private partnership water project of its kind in Western Australia. The plant will have an initial capacity of 165 million l/day (43.5 million gal/day) and a maximum capacity of 240 million l/day (63.4 million gal/day). Construction on the project began in the second half of 2011, and the plant is scheduled to commence operations in July 2013.

The contract for the filter underdrain system was awarded by the Helena Water consortium, which comprises ACCIONA Agua, United Utilities Australia, Brookfield Multiplex and Royal Bank of Scotland. Helena Water is designing and building the facility.

The TETRA LP Block is a dual parallel lateral underdrain system constructed from high density polyethylene (HDPE)-moulded plastic blocks that distribute air and water for either concurrent or sequential backwashing. The system has a lightweight construction and nozzle-less design. The TETRA underdrain filters feature the patented Grout Grip design, which increases resistance to uplift from the filter floor and offers improved pullout strength. The system also features the TETRA FlumeFlow, a backwash air and water distribution system that works in tandem with the TETRA LP Block design.