Wastewater plant expansion on track

Publish Date : 02 Aug 2017
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Māngere-Ōtāhuhu Local Board members took a tour of Watercare's Mangere Wastewater Treatment Plant to view progress on the new Biological Nutrient Removal (BNR) facility at the plant.

Work on expanding the new Biological Nutrient Removal (BNR) facility at Watercare’s Māngere Wastewater Treatment Plant is progressing well and is on track to be completed by the end of the year.

This week Māngere-Ōtāhuhu Local Board members got the chance to check out progress.

"We have not visited the site for some time and it was helpful to see the impressive large construction project in progress," says local board chair Lemauga Lydia Sosene. 

"It was also pleasing to see the extensive planting project in the surrounding areas and continued focus on walking and cycling initiatives close to the site." 

Wastewater treatment plant progressing2

What is Biological Nutrient Removal and why is it needed? 

Biological Nutrient Removal (BNR) is a process that removes nitrogen and phosphorus from wastewater before it is discharged into surface or ground water.

Nitrogen and phosphorous, in large amounts, can cause problems such as algal blooms, murky water, and the death of plants, fish and other species. So it's important we have a facility that can keep up with demand, and keep removing these from our wastewater. 

The new facility will increase Mangere’s BNR capacity as Auckland’s population grows by an estimated one million people over the next 30 years.

Project progressing well

Watercare’s BNR project manager, Sven Harlos has overseen the design and construction.

“The project has gone extremely well despite some torrential rain we’ve experienced earlier this year," he says.

"Construction activity will taper off in September and then commissioning will begin, followed by performance testing next year.” 

The plant’s increased capacity will mean less treated wastewater will flow into the Manukau Harbour during heavy rainfall, which is good news for the environment. 

Benefits for the community

In order for work to take place, a new road linking Ascot Road and Puketutu Island had to be constructed.

The public has benefited too, with the creation of a new pathway between the hugely popular Watercare Coastal Walkway and Greenwood Road Park. 

Watercare carried out extensive planting in the area as part of the Māngere Coastal Restoration project in the early 2000s. With BNR construction, more landscaping and planting of 100,000 native plants was done to shield the facility, which is south of the existing Māngere treatment plant. 

The BNR project forms part of Watercare's $4.9 billion capital infrastructure investment forecast during the next 10 years.

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