Mayor Phil Goff opens Watercare’s new Biological Nutrient Removal (BNR) facility


Mayor Phil Goff opens the BNR facility.
Mayor Phil Goff radios the control room to start the BNR blowers.

The official opening of the new Biological Nutrient Removal facility at our Māngere Wastewater Treatment Plant  takes the plant into a new era, adding treatment capacity for a further 250,000 residents, as Auckland’s population grows.
On 1 June, Auckland Mayor Phil Goff and 40 assembled guests braved the early morning winter chill and climbed to the top of a stairwell overlooking a grid of new reactors. They included Auckland councillor Alf Filipaina and Māngere-Ōtāhuhu Local Board chair Lemauga Lydia Sosene, representing local government. Iwi representatives included Te Warena Taua of Te Kawerau iwi and Kowhai Olsen.
The Mayor sent a radio message to the control room to ‘start up the blowers’, sending draughts of compressed air into the reactors and activating the treatment process.
He said that the investment by Auckland council through Watercare of $141 million in the upgraded wastewater facility was critically important.
“It helps us increase the capacity of the plant to cater for a further quarter of a million people to match Auckland’s extraordinary growth.
“Just as importantly, it improves the quality of the water treated by removing nitrogen, phosphorous and carbon.
“This is the largest wastewater infrastructure project in Australasia at the present time and part of our commitment to creating a pristine environment for a world class city.
“Improving water quality in Auckland is a priority for this council. We are spending more than $26 billion over the next 10 years investing in infrastructure including upgrading our waste and storm water infrastructure which will clean up our beaches and harbours by reducing wastewater overflows into our harbour by up to 90 per cent,” said Mayor Goff.
The project was delivered by a joint venture between McConnell Dowell and HEB Construction. Earthworks began in late 2013 and at its height, up to 250 contractors a day were on site.  The new facility includes two new four-stage treatment reactors, two new 52-metre diameter clarifiers and associated pump stations, pipes and blower facilities.
Watercare chief executive Raveen Jaduram paid tribute to the many Watercare staff and contractors who worked on the new facility: “The project has gone extremely well despite some torrential rain we experienced last year, providing some testing conditions for everyone involved.

“Watercare’s has a $5.5 billion capital infrastructure investment forecast during the next 10 years, showing our commitment to improving water and wastewater services for the people of Auckland for many years to come.”
The new BNR facility was built on land adjacent to the existing plant. In order for work to take place, a new road linking Ascot Road and Puketutu Island had to be constructed. The public has benefitted too, with the creation of a new pathway between the hugely popular Watercare Coastal Walkway and Greenwood Road Park.
We have carried out extensive planting in the area as part of the Māngere Coastal Restoration project in early 2000s. With BNR construction more landscaping and planting of 100,000 native plants was done to complement the facility, which lies to the south of the existing Māngere treatment plant. 
Both Māngere and Rosedale wastewater treatment plants use primary (mechanical), secondary (biological) and tertiary (filtration and ultraviolet radiation) methods to treat wastewater before it’s discharged into the Manukau and Waitematā Harbours.
The wastewater discharge point always attracts large amounts of wildlife. This week, seals have been seen swimming, diving for fish and sunbathing on rocks.