A drill rig in use in 1995 by Southgas Resources which
unsuccessfully fracked to release coal seam gas near Ohai.
Photo by Dr Murry Cave.
The use of hydraulic fracturing of rock, or ''fracking'',
appears more widespread than originally thought, with some
instances of fracking in Otago and earlier in Southland coming
All four attempts were unsuccessful in their quests to
release coal seam gas, test rock pressure or try to improve
In December Dr Jan Wright, the Parliamentary Commissioner for
the Environment, released an interim report evaluating the
environmental impacts of fracking around the country.
While concentrating research on Taranaki, Dr Wright also
found recent fracking for groundwater by the Otago Regional
Council (ORC) in 2011, rock pressure testing during
construction of the Clyde dam in 1983 and two fracking
attempts for coal seam gas in Ohai, Southland, in 1995.
The public and environmental outcry over fracking, in which
water and chemicals are mixed and injected at high pressure
into rock to fracture it and release otherwise trapped oil or
gas deposits, is mostly about chemicals entering water
tables, or disposal of chemicals at ground level.
While Dr Wright's 120-page interim report found no reason for
a moratorium on fracking around New Zealand, and emphasised
risk management, she raised enough concerns to warrant
further investigation by her.
Dr Wright's interim report said fracking could be used for
purposes other than oil and gas extraction, and said the ORC
fracked a water bore in Central Otago in 2011, to try to
improve its yield, but was unsuccessful.
''This is unlikely to have been the only use of fracking to
improve groundwater flow in New Zealand,'' Dr Wright said,
noting the fracking of water bores was ''common'' in some
drier parts of the world.
The ORC said in a 60-page March 2012 publication
''Groundwater exploration in the Ida Valley'' that at one of
two bore holes it tried fracking ''to try to improve its
Otago Regional Council director resource management Selva
Selvarajah was contacted and said the hydrofracking at the
Cresslea bore, in 2011, was done without chemicals, which
environmentalists believe could contaminate groundwater.
The Ida test bore hole was cement-lined and left for a month
before workers ''applied high pressure water'' until the rock
Water yields did not subsequently increase.
Dr Selvarajah said while the process was relatively common in
Australia, he understood the Ida Valley hydrofracking was the
first time it had been undertaken in New Zealand.
It did not require resource consent, as it came under
specific rules for bore drilling in the ORC's water plan.
''[But] when it comes to fracking for oil and gas, resource
consents will be very stringent on dealing with any adverse
effects on the environmental systems,'' Dr Selvarajah said.
He described hydrofracking as a ''minor activity''. In Dr
Wright's report's appendix of fracking operations, she lists
45 instances in Taranaki from 1989 to 2012, eight in the
Waikato since 2007 and two in Ohai, in Southland in 1995.
The Ohai drilling by Southgas Resources was two holes, once
of which was fracked three times at a depth of 480m and the
second four times at 350m.
Dr Murry Cave has supplied reports on the Ohai work, and when
contacted said while chemicals were used in 1995, the
additives were less than 0.05% of the entire mix, and a that
proportion would not be considered toxic.
It is the depth and proximity to groundwater aquifers which
are of concern to environmentalists. The industry counters by
saying fracking usually takes place hundreds of metres below
aquifers, which are relatively closer to ground level.
In dealing with wastewater from fracking injection, Dr Wright
said it could be sent to an industrial waste facility for
treatment, held in evaporation ponds or be discharged
directly. She noted that at Southgas Resources' holes in
Ohai, they reported ''wastewater was discharged into a
[unnamed] stream near two Southland coal seam wells'' after
''The Southland coal seam gas wells were unsuccessful, so
were abandoned,'' the report said.
Listed L&M Energy, while not using fracking, is exploring
for coal seam gas around Ohai and Kaitangata in Otago.
Fracking is only used to boost production flows, as opposed
to being an exploration method.
In a note of ''other uses'' for fracking, Dr Wright said that
some fracking did not use any proppants or chemicals.
Dr Wright said other uses for fracking included testing for
rock strength and in 1983 during the Clyde dam construction,
it was used to measure stress.
''Sections of a borehole were sealed off and pressurised
until the surrounding rock failed,'' she said.
While 21 field tests were completed at the Clyde dam, she
said ''few meaningful stress results were obtained''.
The ORC said in the Ida Valley groundwater report the
availability of the aerial geophysical survey data gave it
the opportunity to locate potential groundwater sources with
In 2007-08, the ORC paid about half of gold explorer Glass
Earth Gold's $4 million geophysical aerial survey costs,
covering large swathes of Otago.