$7.5million wastewater treatment plant upgrade first to use new technology

Rotorua District Council (RDC) is to carry out New Zealand’s first application of MBR (Membrane Bio Reactor) technology to treat large scale community wastewater.

RDC has commissioned AWT NZ Ltd to commence the engineering design work for the $7.5million upgrade of the city’s wastewater treatment plant.

The upgrade will allow for the connection of infill development within the existing catchment and new catchment, arising from the completion of a number of new sewerage schemes within the Rotorua basin.

RDC’s HYDRUS business manager Greg Manzano says the main aspect of the upgrade is construction of a state-of-the-art MBR plant with the capability of treating large quantities of wastewater over a small footprint.

“In the long term the upgrade will enable the council to fully comply with strict environmental requirements at the discharge end of the treatment plant. Currently compliance is measured at the end of the land treatment system at the Whakarewarewa Forest.

“The MBR plant will be retrofitted on to an unused existing tank, reducing the expense of structural costs and making good use of otherwise redundant infrastructure.”

A contract has been let to GE Power and Water to supply the membrane filters and additional equipment.

The operation of the existing plant will not be affected during the upgrade, which is expected to be completed and functioning by June 2011.