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

 

Post-Post: Brian Roche To Step Down As NZ Post CEO

Brian Roche will step down as chief executive of New Zealand Post in April 2017, having led the state-owned postal service's drive to adjust to shrinking mail volumes with a combination of cost cuts, asset sales, modernisation and expansion of new businesses. More>>

ALSO:

Company Results: Air NZ Rides The Tourism Boom With Record Full-Year Earnings

Air New Zealand has ridden the tourism boom and staved off increased competition to deliver the best full-year earnings in its 76-year history. More>>

ALSO:

New PGP: Sheep Milk Industry Gets $12.6M Crown Funding

The Sheep - Horizon Three programme aims to develop "a market driven, end-to-end value chain generating annual revenues of between $200 million and $700 million by 2030," according to a joint statement. More>>

ALSO:

Half Full: Fonterra Raises Forecast Milk Price

Fonterra Co-operative Group Limited today increased its 2016/17 forecast Farmgate Milk Price by 50 cents to $4.75 per kgMS. When combined with the forecast earnings per share range for the 2017 financial year of 50 to 60 cents, the total payout available to farmers in the current season is forecast to be $5.25 to $5.35 before retentions. More>>

ALSO:

Keep Digging: Seabed Ironsands Miner TransTasman Tries Again

The first company to attempt to gain a resource consent to mine ironsands from the ocean floor in New Zealand's Exclusive Economic Zone has lodged a new application containing fresh scientific and other evidence it hopes will persuade regulators after their initial application was turned down in 2014. More>>

Wool Pulled: Duvets Sold As ‘Premium Alpaca’ Mostly Sheep’s Wool

Rotorua business Budge Collection Limited (Budge) and sole director, Sun Dong Kim, were convicted and fined a total of $71,250 in Auckland District Court after each pleading guilty to four charges of misrepresenting how much alpaca fibre was in their duvets. More>>

Get More From Scoop

 
 
 
 
 
 
 
 
 
Business
Search Scoop  
 
 
Powered by Vodafone
NZ independent news