Attachment 7C - Flora and Fauna Survey Assessment_Noosa Landfill - Revision 3

                                                                                      Native Foresters




3.5      Surface water / Ground water Assessments

An assessment of the hydrogeology of the site by a qualified Hydrogeologist was not
provided to Native Foresters. The following assessment is based on field observations and
surface water monitoring at selected sites. To address impacts/potential impacts on
groundwater and groundwater-dependent flora and fauna, further detailed investigations
and ground-truthing assessments of the geology, lithology, groundwater resources and
hydraulic connectivity within the landfill and immediate surrounds should be conducted.

3.5.1 Hydraulic connectivity
Connectivity refers to the degree of hydraulic interaction between aquifers, between
different parts of the same aquifer, and between groundwater and surface water systems.
Connectivity is important in determining whether the excavation and construction of new
cells and the associated changes to landfill profile and drainage will affect groundwater-
dependent ecosystems to the near east of the proposed landfill expansion area.
Historical groundwater monitoring since 2011 shows the groundwater levels along the
eastern boundary of the landfill have been recorded as fluctuating between 0-5m below the
ground surface. The exception to this is in the vicinity of Borehole 15 where waters sit
between 2 and 10m below the ground surface.

There is insufficient data on the degree of hydraulic connectivity between the groundwater
resources on the eastern landfill boundary and the groundwater resources that underlie the
ecosystems further east. Information from historical landfill processes including lowering of
groundwater for cells 2.1 and 2.2 and exploratory bore holes to the east of the landfill may
be useful in this regard. However based on our current understanding, it is likely that the
lowering of groundwater to RL 13m under Cell 2.3 and RL 15m under Cell 2.4 will remove
the seasonal fluctuation of groundwater levels away from the surface in areas between the
landfill and the RL 13m and RL 15m contour to the north east of the site boundary
respectively.

3.5.2 Induration

Groundwater resources can be divided into shallow, perched unconfined groundwater
bodies and deep (basal) partially confined groundwater bodies. These bodies have differing
hydrological processes and chemical composition and may be separated by a more or less
impervious layer of indurated material (e.g. organic hard pan or coffee rock).

Observed ponding of tannin-stained acidic surface water (pH 4.5 – 5.6) in areas of Swamp
Crayfish and Wallum Froglet habitat 100 to 200 metres east of the landfill suggests the
presence of shallow groundwater perched above an organic hardpan or coffee rock (Ed
Meyer, pers.comm). Refer to Appendix H – Surface water and Ground water Monitoring
and Field Observations.




Noosa Landfill & Resource Recovery Centre – Fauna and Flora Assessment – Revision 3
                                                       47