Source: Radio New Zealand, 8 Februay 2017
Extreme weather due to climate change is going to put more
pressure on drinking water infrastructure, leading to more boil
notices and e-coli scares, says a public health
Napier, Levin and Lower Hutt
have all had recent threats to the quality of drinking water,
while a government inquiry into the Havelock North water crisis
last year continues.
The Horowhenua District Council has again had to issue a
precautionary boil notice to residents of Levin after overnight
rain brought mud and debris from slips into the Ohau River.
A boil notice was issued on 3 February, but was revoked during
The Ohau River supplied the council's treatment plant, which
treated it before it was made available to Levin residents to
services manager Paul Gaydon said the murkiness of the water was
too high and Levin has had to resort to its backup water
"We've monitored the turbidity of the Ohau through the morning
and it's gone up steeply.
"We're hoping it will come down just as quickly but we've had to
stop production and it's still stopped.
He said people needed to be careful with their water use.
"It's serious, you know. We have some water on hand in the
reservoirs but we need people to be very careful and very aware
that we're in quite a difficult situation."
In Napier the reservoir tank that tested positive for e-coli
last week has been given the all-clear after three consecutive
The Napier City Council started to treat the Enfield Road
reservoir with chlorine last Thursday after two positive e-coli
Council spokesperson Chris Dolley said that reservoir was still
only partly back in operation and residents should still be careful
about water use.
decided the safest course of action is to continue chlorinating for
the next three to four days while we have the reservoir cleaned by
a team of divers.
"This will remove any doubt about what was the potential
contaminant for this reservoir," Mr Dolley said.
Wellington Water said it expected a third consecutive negative
test for e-coli to come in this evening after testing 21 water
sites in Lower Hutt.
More issues around drinking water supply were likely to surface,
according to Michael Baker.
A public health professor at the University of Otago in
Wellington, Dr Baker said climate change would mean extreme
weather, such as floods and heavy rain, would continue to test
infrastructure protecting drinking water.
"Extreme weather events put
huge stress on a number of systems, particularly drinking water
"That's because of flooding events, which can overwhelm normal
treatment facilities, but also they can knock out power supplies
and back up systems.
But Dr Baker said the jury was still out as to whether there was
an increase of cases where drinking water had been jeopardised.
"There's obviously heightened awareness about water
contamination at the moment.
"You really have to take a long term perspective and look at
data on waterborne disease outbreaks and levels of
Hastings District Council mayor Lawrence Yule agreed with Dr
Baker that more adverse weather events were going to challenge
drinking water infrastructure.
He said an inquiry looking into the Havelock North water crisis
may raise questions about the government's specified drinking water
standards, which were last revised in 2008.
"Even in the Havelock North case the testing was being done more
than was required by the New Zealand drinking water standards, yet
a whole lot people still got sick.
"So I think that the inquiry will look at that and I expect
there will be some changes recommended as part of that."
Mr Yule, who was also the president of Local Government New
Zealand expected there would also be stronger rules on land use
near drinking supplies to minimise the level of contamination from