Metropolitan Coal Project Independent ... - Peabody Energy

METROPOLITAN COAL PROJECT INDEPENDENT ENVIRONMENTAL AUDIT
4.9 Groundwater 3
[Project Approval Schedule 3 condition 2 (Catchment Management Plan), and conditions 6 and 7
(Second Workings); and Schedule 4 condition 15 Surface Facilities Water Management Plan)]
4.9.1 Groundwater Management and Monitoring
Groundwater management is addressed in the Water Management Plan section 6.3 for Long-walls
20-22, prepared to satisfy Project Approval Schedule 4 condition 15 and groundwater monitoring is
also addressed in the Catchment Monitoring Program section 3.5, prepared to satisfy Project
Approval Schedule 3 condition 2 Catchment Management Plan, dated 14 May 2010.
4.9.2 Performance of the Project
A review of the 2010 and 2011 Metropolitan Mine Annual Reports showed that none of the
performance measures or performances indicators relating to groundwater were exceeded for the
project.
There is no evidence to indicate a change in swamp groundwater and shallow groundwater levels or
water quality that is attributable to mining activities.
Deep groundwater piezometers close to the mined long-walls show substantial depressurisation, but
this is consistent with the predicted impacts outlined in the Water Management Plan and the
Environmental Assessment.
4.9.3 Director-Generals Assessment Report
The Director-Generals Assessment Report June 2009 section 5.6 recommended the following
improvements to the groundwater monitoring regime:
Shallow piezometer installations for the monitoring of groundwater levels/pressures within
significant upland swamps, drainages and any connected alluvium;
Groundwater quality classification through regular sampling and analyses at installed
piezometers;
Deep piezometer installations for the monitoring of pore pressures within the natural rock
strata with a high level of confidence;
Strata hydraulic property measurements to facilitate calculation of sub-surface flows.
Additional core sampling and testing is recommended to confirm the presence and continuity
of aquitards beneath the Woronora Reservoir;
Implementation of the recommendations in the Director-General’s Report is ongoing:
Four new shallow groundwater bores were installed between August and September 2010;
Four new groundwater quality sites were established for continued baseline monitoring at
existing sites.
One additional deep groundwater bore has been drilled with further bores proposed to be
drilled before commencement of future long-walls.
Performance of hydraulic property measurements for sub-surface flows and additional work to
assess the continuity of aquitards beneath the Woronora Reservoir, have yet to be
undertaken.
3 Australian Groundwater and Environmental Consultants
24 trevor brown & associates
applied environmental management consultants
aemc