Maraka! Maraka! Otautahi rises from the ruins - te karaka

38 te KaraKa MaKarIrI 2011
wasteful
Parts of the Christchurch sewerage system twisted and ruptured
during the recent earthquakes, forcing many residents to use portable
or chemical toilets. Now, more than ever, seems like the right time
to rethink a stressed and outdated system that is failing Ōtautahi
ratepayers. Kaituhituhi Kim triegaardt reports on some solutions
that are better for the environment and respect Māori values.
LITTLe eSCAPeD THe TRAIL OF DeSTRUCTION LeFT BY THe
September and February earthquakes and ongoing aftershocks,
including Christchurch’s vast sewage system. The shattered
network left raw sewage flowing onto our beaches and into our
rivers raising the question of whether it’s time for a rethink on
how the city deals with its waste.
Some of the answers may lie within a study that looked at alternative
ways to manage waste that is less stressful on the environment
and in line with Māori values.
Tiaki Para is the result of a five-year research project looking at
Māori and Ngāi Tahu perspectives on waste management and the
critical role for Māori in setting the future direction of how human
waste is managed.
Te Rūnanga o Ngāi Tahu environmental advisor and co-author
of Tiaki Para, Craig Pauling (Ngāi Tahu – Ngāi Te Ruahikihiki),
says that people generally don’t spend much time thinking about
waste management practices, because, “poos just aren’t cool”.
However, in Christchurch’s post earthquake environment
people have been forced to think about it, as portable and chemical
toilets replace flushing toilets and while the sewer pipes and
Bromley Treatment plant are trying to be repaired.
Christchurch has one of the flattest sewerage systems in the
world and the volume of wastewater is not sufficient to cause a
rapid flow making it necessary to flush extra water through the
pipes to move waste along. It is this use, of what is often referred
to as “the best water in the world”, which the Tiaki Para report is
questioning and shedding new light on.
Christchurch City Council water and waste manager Mark
Christison says the city had just started looking at its wastewater
strategy when the September earthquake hit.
“This work is continuing but is slowed down by higher priority
work at present. We are working with researchers at Canterbury
University and expertise from overseas looking at improving resilience
of the wastewater network through the rebuild.”
Christison believes that gravity sewers to a centralised treatment
plant will continue to be the main stay of the wastewater
system, but that rebuilt sections will use modern materials and
construction techniques, and are therefore likely to have added
resilience in combating the effects of liquefaction and lateral
spreading.
Dr Jamie Ataria (Ngāti Kahungunu, Rongomai Wahine,
Ngāti Tūwharetoa) is co-author of the Tiaki Para report. He is
an ecotoxicologist at Lincoln University who studies the effects
of contaminants such as human waste on the environment.
He believes February’s earthquake has given the city the opportunity
to explore new and better alternatives for a modern waste
treatment system.
“In Christchurch we use beautiful, clean aquifer water to flush
away our waste. It’s just used as a transport medium and the infrastructure
to do that is what has broken and caused the problems
after the quake.
“Maybe it’s time to look at taking waste out of the water, using
composting toilets for instance, or even stop the use of water at all.
“We’ve got a blank slate, so this could be the opportunity to
create a demonstration suburb where you have different systems
for dealing with human waste.”
Dr Kepa Morgan, senior lecturer in civil and environmental
engineering at the University of Auckland, endorses the Tiaki Para
report and says the current centralised wastewater system goes
against Māori protocol of respecting the mauri (spirit) of water,
especially when the wastewater is then mixed into our rivers,
lakes, harbours and seas, from where we collect our food.
Morgan (Ngāti Pikiao, Te Arawa, Ngāti Kahungunu, Kāi Tahu
– Kāti Kuri, Kāti Huirapa) agrees that now is the right time for
Christchurch to be considering alternatives to a centralised
sewerage system. He says it’s all part of a “build back better”
philosophy where after a disaster occurs a better system replaces a
system that is shown to be fallible.
This approach can be difficult to implement because following
a natural disaster many people want things to return to normal as
soon as possible and so can be resistant to new technologies that
are unfamiliar, says Morgan.
Morgan suggested after the September quake that when the
council fixed the broken sewers they considered installing a dry
composting system in one in ten houses.
“The advantage with dry composting toilets is that they do
not require a water source to operate and will not fail if there is
no electricity supply. Therefore unless the dwelling is unsafe to
occupy, the dry composting toilet should continue to be available
for use immediately after an earthquake.”
Dry composting toilets are waterless toilets where waste is
collected in a chamber below the toilet pedestal. A low-powered
electric or solar fan sucks air from a vent pipe, creating a vacuum,
eliminating odours inside the toilet cubicle and speeding the
composting process. A solar-powered heater can also be used to
enhance the decomposition process. Although the toilets aren’t
widely used in Aotearoa, there is a joint Australian-New Zealand
standard for their installation and operation.
Morgan says for a typical 5-person family a dry composting
unit may only require emptying every two years. He adds that the
resulting compost is not toxic and can be added like fertiliser to
the ground. Although, he says, as the Tiaki Para report suggests,
it’s preferable not to put it straight onto the vegetable garden.
The challenge ahead highlighted in the Tiaki Para study is the
lack of understanding of Māori cultural beliefs and practices,
in particular mahinga kai (food gathering) and the tapu ascribed
to human bodily wastes, including things such as fingernails
and hair.
“The biggest thing we found was the depth and range of
traditional beliefs that exist around dealing with waste and how,
post-colonisation, these traditional practices were supplanted by
modern technology and uninformed decision making that often
inadvertently offended cultural values,” says Pauling.
The study was designed to gain greater understanding of the
issues, and to document Māori and Ngāi Tahu perspectives on
waste and preferences for waste management. It’s one of only a
few reports that exist on the subject and highlights the critical role
Māori should take to ensure waste management practices reflect
their cultural values.
For instance, the practice of discharging waste into a waterways
or out to sea is problematic for Māori when it comes into
contact with food gathering areas, because the polluted water is
seen to degrade the health of the area, even if the waste is treated.
“Having a sewage outfall pipe over food beds hinders our
ability to gather food safely, and in turn it impacts on our duties
of manaakitanga and as kaitiaki,” says Pauling. “There are also
te KaraKa MaKarIrI 2011 39