Te Atatu Road, Auckland, New Zealand
United Civil Construction Limited
Auckland Transport (AT) is carrying out the Te Atatu corridor improvement project to boost the efficiency and safety of one of West Auckland's busiest roads.
The StormFilters for this project have been designed using mass load method to treat higher sediment loading (600kg/ha/yr) on high-trafficked roads (>20,000 v/d) compared to typical residential and low trafficked roads (300kg/ha/yr).
The flow rate through each cartridge is reduced to 1/2 flow to increase the contact time of contaminants and hence removal efficiencies.
Both vaults are peak diversion models where it is installed with an internal bypass structure to divert peak flows higher than water quality flow from the treatment chamber to prevent re-suspension of captured contaminants.
This mass load sizing is a requirement by the Auckland Motorway Alliance (AMA) to ensure optimum frequencies between maintenance activities.
A blend of Perlite, Zeolite and Carbon have been used as the media of choice to specifically target TSS (Perlite), Dissolved Metal (Zeolite) and TPH (Carbon).
The 25x69cm Cartridge StormFilter is designed to treat 27.2 L/s, retain 5000L of live storage during rainfall event and allow 230 L/s to bypass through the system during 100 year storm.
The 53x69cm Cartridge StormFilter is designed to treat 57.67 L/s, retain 6700L of live storage during rainfall event and allow 469.33 L/s to bypass through the system during 100 year storm.