Land near Luggate could soon be the site of New Zealand's
first solar drying facility for turning sludge into
''Project Groundswell'' is a proposed partnership between the
Queenstown Lakes District Council and Fulton Hogan that would
establish a natural system for producing fertiliser out of
sludge from Wanaka's Project Pure wastewater plant.
At present, the nutrient-rich sludge is trucked more than
70km and buried in the Victoria Flats landfill, where it is
producing methane and has no environmental benefit.
The council held an open tender process to find a better
alternative to landfill disposal and the drying system
proposed by Fulton Hogan was best suited to local conditions
''We're looking for new ways that we can be more
environmentally-friendly and cost effective and this [solar
drying] is something that's great to trial here in a
beautiful environment and potentially be able to use in other
areas,'' QLDC infrastructure and assets general manager Erik
''This is a great opportunity for the district to make some
positive changes in how we manage and reuse our waste.''
The new system would also provide annual savings of $113,000,
or $23.54 a year for every household in Wanaka and Albert
Town connected to Project Pure.
''We've had great feedback on the proposal so far, because of
the environmental and financial advantages.''
If approved, the $1.3 million greenhouse-style solar drying
facility would be built and operated by Fulton Hogan on land
it owns on the corner of McKay Rd and State Highway 8A.
It would use German WendeWolf technology - widely used in
Europe and North America, and also installed in Toowoomba,
Australia - involving a combination of vents, flaps and fans
to keep air flowing inside the building and dry the sludge
As the moisture evaporates the volume of material reduces so
that for every 1000 tonnes of sludge brought to the facility,
between 100 and 200 tonnes of dry matter is left.
Luggate would be the first community in New Zealand to adopt
Neighbouring landowners have already given approval for the
dried material to be ploughed into the ground at their
properties, improving the soil fertility for growing silage
or hay. Animals would not graze the land for a minimum of
three years after the sludge was applied.
During the drying process the aerobic bacteria active in the
sludge changed the odour to a smell similar to compost, Mr
There would be no smell noticeable outside the boundary of
the facility, and the nearest dwelling was 850m away, across
the Clutha River.
Following a consent process, it would take up to six months
to build the drying facility and it was hoped to start
delivering sludge there by the end of June 2014. The council
would pay a set rate for every tonne of sludge dried.
The proposal will be discussed with the Luggate community at
a drop-in information session tonight, and iwi, environmental
groups and other local interest groups are also being