The Southland Times
Plea to spread city’s sewage bio-solids on reserve land
Bio-solids from the city’s sewage treatment plant could be spread over reserve land at Sandy Point, the Invercargill City Council says.
The bio-solids that will be used are a waste product of the Clifton treatment plant, consisting of sewage that has had all its water content removed and has been heat treated.
The city council is proposing to apply the bio-solids over a 42-hectare area between Christies Track and the Southland Golf Club course – about 200m from Oreti Beach.
The area was previously leased by the council for grazing but plans were in place to develop it into a recreational area with native plantings.
The bio-solids provide an improved growing environment for the planting.
Invercargill City Council parks manager Robin Pagan said there was no guarantee there would not be an odour after the bio-solids had been spread. “You tend to get a wee bit of an odour when you spread any kind of dry soil.’’
The materials would most likely be spread some time during summer, Mr Pagan said.
The initiative was an experiment and was looking at ways to dispose of the waste while fertilising the soil, he said.
There would be a high level of monitoring with water bores and other measures to make sure there was no seepage from the waste, Mr Pagan said.
The council report on the proposal says there would be up to three bio-solids applications over the area during a 10-year period.
Each application will take two to three weeks, involving the transport of bio-solids by truck from the Clifton Wastewater Treatment Plant, and spreading using agricultural machinery. Biosolids applications would be at intervals of one to three years.
Bio-solid application has been used in other parts of New Zealand including the Coromandel and Nelson.
In Auckland the issue has been contentious with the Auckland Regional Council rejecting Watercare Service’s bid to put bio-solids on an island called Puketutu in the Manukau Harbour. The island is marked as a waahi tapu in the Manukau district plan, and many Maori groups oppose putting sewage there.
The Ministry for the Environment sets targets for councils to try and reduce the amount of waste dumped in landfills, with bio-solid application to land one of the methods recommended.