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Waste not want not - some short answers
Q What happens next? A The City Council will debate the issue this
month or in November and decide which
of the ECan commissioners’ decisions it wants
to challenge. In the meantime, Council staff will
be talking to interested parties to see which
disagreements can be resolved without having
to go to court. Q How much extra will an ocean pipeline
cost? A A report last month says there is a
difference of about $39 million between
what the Council already has said it will pay
($33.5m) for treatment works and other
environmental improvements and what they
think it will cost ($72.4m) if a pipeline is added.
However, if they take out the UV plant ($6.4m)
and the landscape and recreational amenity
($14.4m), the difference is about $18.1m. Q Does an ocean outfall mean sewage in the
surf? A No. There is no chance any council in New
Zealand will ever again get permission to
put untreated or poorly treated wastewater
into the environment. CCC will keep upgrading
the quality of its treatment at the Christchurch
plant and there is no suggestion this upgrading
work should stop or be scaled back. As well, the ocean outfall being talked about
would be at least 2km off the beach – about
seven times the length of the New Brighton Pier.
And the pipe would have a series of emitters over
the last 400 metres which would mix the outflow
as much as possible with the seawater. Scientists
who reviewed the public health work done on the
project say that, even without UV treatment, there
is “minimal predicted impact on beach swimmers”. Q So will the Estuary be safe for swimming?
A According to a group of scientists who
went over all the public-health work done
so far on the wastewater question and looked
at new national water-quality guidelines,
removing the outfall from the Estuary would
improve the quality of its waters. But they
thought that unless more work was done to
keep other contamination out of the Heathcote
and Avon rivers, the Estuary’s beaches could still
be poor places for people to play in the water. Another group of scientists looked at
environmental factors and said it would mean a
“pretty significant” cut in the amount and
degree of sea lettuce growing in the Estuary.
The water’s colour and clarity would also
improve, they said. Q Why can’t we recover the nutrients and
the water and re-use them? A The short answer is the cost. Most places
that use systems to extract water from
wastewater do it because they have a dire
shortage of water. Staff told a meeting last
month that these systems could cost up to
$180m to install and up to seven times as much
as the current plant to operate each year. |