Restoring water quality
The largest environmental restoration programme ever undertaken in New Zealand, the upgrade of Watercare Services’ wastewater treatment in Mangere reduced pathogens in the treated wastewater by 10,000 times, raising water quality in the Manukau Harbour to its highest level since the 1930s. The removal of the oxidation ponds not only enabled the restoration of coastal tidal flats and the rehabilitation of 13 kilometres of coastline, it also means the harbour is no longer used as part of the treatment process.
Fletcher, in joint venture with Civil & Civic, was engaged to upgrade the existing wastewater treatment plant to meet improved discharge standards, including construction of a new advanced treatment facility, ultra-violet disinfection facilities, new biosolids facilities, upgrade of existing power supply, demolition of redundant plant, decommissioning 500Ha of oxidation ponds and foreshore restoration. The new treatment plant uses world-leading technology and has the capacity to cater for Auckland’s growing population for approximately 30 years.
The new treatment plant uses world-leading technology and has the capacity to cater for Auckland’s growing population for approximately 30 years.
Handling over 319 million litres of wastewater every day, Mangere is New Zealand’s largest wastewater treatment plant, and any disruption to normal operations was simply not an option. The plant remained fully operational as the new facility was built, required a carefully staged construction and commissioning approach and astute stakeholder management.