Video | Agriculture | Confidence | Economy | Energy | Employment | Finance | Media | Property | RBNZ | Science | SOEs | Tax | Technology | Telecoms | Tourism | Transport | Search

 


Top environmental award for Kawakawa Bay wastewater system

Top environmental award for Kawakawa Bay wastewater system

Watercare’s Kawakawa Bay wastewater system has received one of three Environment and Sustainability Awards for large projects presented by IPENZ, Auckland Branch at the prestigious Arthur Mead Awards Function.

Named after long-serving Auckland City Waterworks Engineer, botanist, and outdoorsman Arthur Mead, who was responsible for the initial survey and design work on the Upper Nihotupu and Huia Dams, the awards are presented annually to the projects that best address sustainability, potential adverse environmental effects, waste management and community involvement.

Watercare Acting Chief Executive Raveen Jaduram said continuing to improve the company’s wastewater treatment services in order to enhance the health of Auckland’s harbours, estuaries and waterways remained one of Watercare’s main objectives and a key focus of the company’s capital investment plans. The Kawakawa Bay project also illustrated the close working relationships Watercare maintained with iwi, residents, and community groups across Auckland.

Designed by Australasian engineering consultancy Harrison Grierson, and constructed by Fulton Hogan, who also managed the network during its first year of operation, the Kawakawa Bay system was handed over to Watercare last year. The system enabled the removal of aging septic tanks that had over time polluted groundwater and local streams, leading to the Bay being declared unsafe for swimming in 2002. Its safe-for-swimming status was restored in November 2012.

Harrison Grierson Technical Director Colin Cranfield said the use of a vacuum system, which was a first for New Zealand, allowed shallow pipelines to be constructed quickly, minimising disturbance to the residents.

“The spread out nature of the development over four kilometres of coastline, the sandy soils, and the high water table, made a vacuum system the best option for the Bay,” he said.

In a vacuum collection system, wastewater from individual properties drains to a pit and is then drawn into the vacuum pipe network through the operation of a pneumatically controlled vacuum interface valve in the pit. Once in the network, wastewater moves along the pipeline to the vacuum pump station by the differential pressure that is created by the opening and closing of the vacuum valves throughout the pipe network. Wastewater is subsequently conveyed from the collection tank at the vacuum pump station to the treatment plant via positive displacement pumps and a pressure rising main.

The Kawakawa Bay treatment plant employs an advanced, four-stage treatment process similar to that used at Watercare’s larger Mangere and Rosedale facilities. Wastewater passes through alternating oxygen-rich and oxygen-depleted environments, enabling a range of different bacteria to break down organic contaminants.

Residual organic contaminants and nitrogen are removed in a biological membrane reactor; bacteria and viruses by ultrafiltration. The treated effluent then flows to storage lagoons from where it is used to spray irrigate forest behind the treatment plant, more than two kilometres from the foreshore.

ends

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Half Empty: Fonterra's 2017 Opening Forecast Below Expectations

Fonterra Cooperative Group raised its forecast farmgate milk payout for next season by less than expected as the world's largest dairy exporter predicts lower prices will crimp production and supply will pick up. The New Zealand dollar fell. More>>

ALSO:

Pest Control: Mouse Blitz Team Leaves For Antipodes

The Million Dollar Mouse project to rid Antipodes Island of mice is underway with the departure of a rodent eradication team to the remote nature reserve and World Heritage Area. More>>

Gongs Got: Canon Media Awards & NZ Radio Awards Happen

Radio NZ: RNZ website The Wireless, which is co-funded by NZ On Air, was named best website, while Toby Manhire and Toby Morris won the best opinion general writing section for their weekly column on rnz.co.nz and Tess McClure won the best junior feature writer section. More>>

ALSO:

Pre-Budget: Debt Focus Risks Losing Opportunity To Stoke Economy

The Treasury is likely to upgrade its forecasts for economic growth in Budget 2016 next week but Finance Minister Bill English has already signalled that more of his focus is on debt repayment than on fiscal stimulus or tax cuts... More>>

ALSO:

Fulton Hogan's Heroes: Managing Director Nick Miller Resigns

Fulton Hogan managing director Nick Miller will leave the privately owned construction company after seven years in charge. The Dunedin-based company has kicked off a search for a replacement, and Miller will stay on at the helm until March next year, or until a successor has been appointed and a transition period completed. More>>

ALSO:

Gordon Campbell: On Electricity, Executions, And Bob Dylan

The Electricity Authority has unveiled the final version of its pricing plan for electricity transmission. This will change the way transmission prices (which comprise about 10% of the average power bill) are computed, and will add hundreds of dollars a year to power bills for many ordinary consumers. More>>

ALSO:

Half Empty: Fonterra NZ, Australia Milk Collection Drops In Season

Fonterra Cooperative Group says milk collection is down in New Zealand and Australia, its two largest markets, in the first 11 months of the season during a period of weak dairy prices. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Business
Search Scoop  
 
 
Powered by Vodafone
NZ independent news