Petition to end wastewater pollution in Manukau Harbour2 min read
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A community petition is calling for legislation to prevent Watercare from discharging wastewater into the Manukau Harbour from the Māngere Wastewater Treatment Plant.
The petition was launched by the Manukau Harbour Restoration Society, with full support from The Onehunga Enhancement Society and Aotea Sea Scouts. A member of all three groups, Stephen Lasham, says, “there are better ways to do it, and there needs to be more incentive to actually look at alternatives.”
He says the closed nature of the harbour inhibits the natural flushing of contaminants, and even when treated, wastewater pollution disrupts the marine environment, changing the ecosystem and encouraging weed growth.
The petition calls for updated legislation enabling the government to direct and support Auckland Council and Watercare to “plan for future methods of discharge management so that discharge consents into the Manukau Harbour and its tributaries cease to be needed once current consents lapse.”
Alternative options proposed include a direct pipeline into the Tasman Sea, that wastewater be piped to reservoirs for reprocessing into Auckland’s water supply, or purify wastewater into a standard acceptable for drinking water.
Watercare’s current consent expires in 2032, though they plan to renew it before then, and are already working on ways to reduce wastewater discharge. “We are actively investigating purified recycled water as a potential future water source for Auckland,” says Watercare’s wastewater production manager, Jon Piggot.
“Purified recycled water involves taking treated wastewater and further purifying it to make it safe to drink. At the Māngere Wastewater Treatment Plant, we’ve set up a pilot recycled water facility that can produce recycled non-potable water and purified recycled water,” he says.
“The pilot plant enables us to explore the benefits and trade-offs of different technologies, and gives us a better understanding of water quality, plant requirements and operational costs in removing pathogens and chemicals that may be found in Auckland’s wastewater.
“We are very proud of the performance of our Māngere Wastewater Treatment Plant, which consistently meets its stringent resource consent conditions.”
Watercare conducts daily, twice daily and weekly basis tests for pH, Enterococci bacteria, petroleum hydrocarbons and nitrogen, and they carry out monthly testing of marine water quality at 11 sites within the harbour.
The petition can be found at community.greenpeace.org.nz/petitions/stop-polluting-the-manukau-harbour-2
