National Food Plan – Submission
My main concern is the apparent belief that mining and coal seam gas (CSG) operations are
widely compatible with farming. This is often supported by examples, eg. from experience in
the Surat Basin, Queensland. I believe it is grossly premature to draw this conclusion. I would
make the following observations:
1.
In the Margaret River region of Western Australia an application for coal mining has
been rejected, as have applications for coal exploration leases. These rejections were
not simply based on the risks mining would present to both ground and surface water
(and thereby, of course to farmers), but equally because these risks could
demonstrated:
 It was known the coal measures were overlain by an aquifer, an aquifer that
supported groundwater dependent ecosystems..
 Cores and logs through the coal measures indicated high porosity and
permeability.
 Hydrographs within the coal measures unequivocally confirmed hydraulic
connectivity to the overlying aquifer.
 Water samples within the coal measures and aquifers were almost identical and of
the same very young age.
 Seismic evidence and cores showed a high degree of faulting and fracturing,
exacerbating hydraulic interconnectivity and risk of mine roof collapse.
 A number of other supporting aspects of evidence and analogues.
It can be readily appreciated that with such clear and overwhelming evidence why the
proposal to mine and exploration leases were rejected.
2.
Other regions cannot claim to have the benefit of such strong evidence of risk. But
because the risk cannot be assessed does not mean that the risk is less, let alone
acceptable. For example, I refer to the Surat Basin in Queensland, and for illustration
to the report “Draft Underground Water Report, Surat Cumulative Management
Area, prepared by Coal Seam Gas Water, Queensland Water Commission, May
2012”, and in doing so I refer only to selected qualifications within that report. The
CSG operations are within the Walloon Coal Measures, part of the Great Artesian
Basin, and the coal seams alternate with clastic sediments, including aquifers of high
economic and, as they feed springs, ecological importance.
 4.2.1 “The Springbok Sandstone (an aquifer) and the Walloon Coal Measures
show a very high degree of variability.”
 4.3.1 “.. although in reality the geology is complex, layers thicken and thin
and are not continuous.….the Walloon Coal Measures are considered to an
aquitard although in places it (sic) functions as an aquifer.”
 4.3.2 re the Bandanna Formation coals “…. The coal seams split and coalesce
… and cannot be correlated over any significant distance.”
 4.4.1 “Only a few bores that penetrate through the alluvium into the coal
measures have lithological logs that provide information about the thickness,
permeability and spatial distribution of this layer (ie between the coal
measures and the Condamine Alluvium, an important aquifer) ……… There is
little monitoring data to assist in understanding the interconnectivity between
the formations ………There is limited water level monitoring in the deeper
Walloon Coal Measures under the Condamine Alluvium ….. the way in which
the Condamine interacts in a regional setting is not well understood.”
 4.4.2 “The Springbok Sandstone is highly variable ….. There is very little data
on the vertical permeability which has a direct influence on connectivity with
overlying and underlying aquifers ….. There is little historical water level
monitoring.”
I could go on. The point is that, despite a wealth of qualifications about the knowledge
of the basins hydrogeology, CSG operations in the Surat Basin have been approved.
The fact that CSG operations and farming appear to co-exist at this point in time is
short term and dangerous thinking. Even ignoring the heavy qualifications referred to
above, the above report states (6.3.2) “Maximum impacts in any aquifer will occur at
different times at different locations. ….Maximum impacts in the coal formations, the
Springbok Sandstone and the Condamine Alluvium are expected to occur between
2060 and 2075.”
The critical question is not how well CSG operations and farming coexist at this time,
but how will they continue to do so?
I would also make the observations that through the process of
depressuring/dewatering a coal seam there is potential for contamination of ground
water through acidification and extraction of heavy metals from the coal, and this has
not been discussed in the report, nor has the aspect of hydraulic fracturing (which may
or may not be carried out) in coals of unpredictable horizontal extent and which have
a variable and at times unpredictable relationship to aquifers. Contamination of
groundwater can be catastrophic and irreversible.
3.
While the science presents difficulties and attempts have been made to address these,
little attention has been paid to operations, or what can be termed as “good oil field
practice.’ With at least 40,000 CSG wells to be drilled on Queensland there will be
mishaps (as already evidenced). It is predictable that there will be numerous gas leaks
through poor cement jobs (ie. casing to formation, isolating the productive zone from
other formations). These will come to light over the years, they will introduce gas into
aquifers and will be difficult and expensive to remedy.
In summary, I consider it misleading to cite apparent harmonious coexistence between
CSG operations and farmers as an argument for further approval of such operations.
Peter Lane