New treatment plant outfall
October 26, 2005
Open Days to tell public about new treatment plant outfall
North Shore City Council is inviting the public to find out more about its proposed new outfall for the Rosedale Wastewater Treatment Plant this weekend.
It's a great chance for ratepayers to see where $75 million of their money is being invested to improve beach water quality.
Information about the environmental improvement project will be on display on Saturday and Sunday at the former Mairangi Bay Women's Bowling clubrooms in Maxwelton Dr, Mairangi Bay, and council staff will be on hand to answer any questions.
The open days will run from 10am to 4pm on Saturday October 29, and 11am to 3pm on Sunday, October 30.
General manager of North Shore City's water services division, Geoff Mason, says the new outfall is a key project that will further improve the efficiency and capacity of the city's 43-year-old treatment plant.
"It will be one of the largest projects our council has undertaken, and is needed to ensure our wastewater system continues to meet the needs of our growing city."
And, he says, because of the magnitude of the project, it is inevitable there will be some inconvenience to the community.
"Although construction is not likely to start until 2008, we're holding these open days to ensure the public are well aware of the project and its implications on the community. "The new outfall is required to cope with the needs of our growing city, and will discharge the effluent further out to sea than the existing outfall," he says.
The North Shore City Council already has permission from the Auckland Regional Council to build the tunnel with a completion date of 2010. The outfall route stretches 2.6km from the treatment plant to Mairangi Bay, running beneath streets, parks and reserves and council-owned land.
It will then run under the seabed 2.8 km out into the channel. "The existing outfall is nearing the end of its lifespan, is too small to cope with further demand and has had major repairs in recent times," says Geoff Mason. The current outfall also discharges treated effluent just 600 metres from shore, and a new outfall further offshore is necessary to keep the effluent plume further away from the coast.
"Improved beach water quality is the goal but it comes at a price. We urge residents to come and find out more about this project,' Mr Mason says.
The new tunnel will have a design life of at least 100 years, and will have up to six times more capacity than the existing outfall.
Additionally, at its discharge point diffusers will ensure the treated effluent is dispersed widely into the sea, unlike the present outfall which discharges the treated effluent directly from the end of the outfall pipe.