Two Central Otago landowners are starting to apply for
resource consent to use sewage sludge on their farms in
response to the Queenstown Lakes District Council seeking
expressions of interest from those keen to use sludge from
Wanaka's Project Pure waste water treatment plant.
In a report to last week's utilities committee meeting,
strategic project manager Martin O'Malley said there were
eight responses, including from two landowners based in
Tarras and Hawea.
He said the landowner option was prioritised because it
required no extra treatment.
"I am particularly excited that there are landowners
interested in looking further at how this material could
potentially be used," he said.
Both landowners had suitable locations and farming practices
to use the material.
A representative from the Otago Regional Council (ORC) and a
land treatment expert from CPG NZ Ltd attended meetings to
give advice on consenting issues and how applying sludge
could work.
"Further work is required over the next few months to
negotiate a formal agreement with the landowners and to
prepare the application for a consent with the ORC," Mr
O'Malley said.
QLDC solid waste manager Stefan Borowy told the utilities
committee the land owner in Tarras was applying for consent.
Sludge would continue to be disposed to landfill until a
formal agreement was reached and a consent granted.
Sludge waste would make up about 10% of the district's waste
by 2014, a percentage similar to the proportional amount of
construction and demolition waste.
It costs $229 per tonne to dispose of sludge to landfill, or
about $16,000 a month for 70 tonnes.
"By dumping sludge in the landfill there is the potential
that the moisture within the sludge and the nature of the
material will give rise to methane gas production in the
future.
This may result in additional future costs associated with
the collection and treatment of this methane gas," he said.
Cr Gillian Macleod questioned whether there could be mercury
in the sludge used on the land, but Mr Borowy said the risk
of mercury contamination would be minimal.
Sludge from Queenstown's proposed waste water treatment plant
Project Shotover would eventually also be used by the
landowners.
Consents for Project Shotover are subject to Environment
Court appeals.
"When we get Project Shotover included it is unlikely, but
not impossible, that the same sites will be used.
We will most likely be asking for expressions of interest
again from landowners in the area, including the Wakatipu,"
QLDC general manager infrastructure services Mark Kunath told
the committee.
Farms keen to use sludge
These farmers understand that the sludge is, in fact, a resource which can help them build good soil. This contrasts with the attitude of QLDC and most other councils that see the by-products of our activities only as waste.
The recent fuss over farming proposals for the Mackenzie Country has highlighted this silly thinking. The so-called "waste equivalent of a town of 250,000 people" would actually go a limited way towards rebuilding the depleted soil there.