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

 

What Winter? Temperature Records Set For June 20-22

The days around the winter soltice produced a number of notably warm tempertaures. More>>

Conservation Deal: New Kākāpō Recovery Partnership Welcomed

Conservation Minister Maggie Barry says the new kakapo recovery partnership between DOC and Meridian Energy is great news for efforts to save one of New Zealand’s most beloved birds. More>>

ALSO:

Tech Sector Report: Joyce Warns Asian Tech Investors View NZ As Hobbits And Food

Speaking in Wellington at the launch of a report showcasing the value of the technology sector to the New Zealand economy, Joyce said more had to be done to tell the country's technology stories overseas. More>>

ALSO:

Mediaglommeration: APN Gets OIO Approval For Demerger Plan

APN News & Media has received Overseas Investment Office approval for its plan to split out its NZME unit ahead of a potential merger with rival Fairfax Media's New Zealand operations. More>>

New Paper: Ninety-Day Trial Period Has No Impact On Firms' Hiring

The introduction of a 90-day trial period has had no impact on hiring by New Zealand companies although they are now in widespread use, according to researchers at Motu Economic and Public Policy Research. More>>

ALSO:

Corrections: Serco Exits Equity Stake, Remains As Operator

Serco has sold its equity stake in the company that holds the contract to design, build and run Wiri Prison in South Auckland but continues as sub-contractor to operate the facility. More>>

GDP: NZ Economy Grows Faster-Than-Forecast 0.7%

New Zealand's economy grew at a faster pace than expected in the first quarter of 2016 as construction expanded at the quickest rate in two years. The kiwi dollar jumped after the data was released. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Business
Search Scoop  
 
 
Powered by Vodafone
NZ independent news