Wambo Coal AEMR 2011-2012 - Peabody Energy

2011-2012 AEMR
3.4.2.4 Electrical Conductivity and Total
Dissolved Solids
Monitoring of EC and TDS during the reporting
period of the natural creek water systems varied
depending on the volumetric flows within these
creek systems. This relationship between EC
concentrations and flow can been seen from
monitoring data at both gauging stations within the
Wollombi Brook 8 (Appendix 2C).
The EC and TDS concentrations within the mine
water system typically depends on the quality of the
fresh water added to the system and the mine water
pumped around site. EC and TDS results recorded
during the 2011-2012 reporting period are
graphically presented and tabulated in Appendix
2C.
Wollombi Brook recorded average EC values of
408S/cm, 458S/cm, 425S/cm and 450S/cm at
surface water monitoring sites SW01, SW02, SW03
and SW40 respectively. The annual average EC
concentrations for Wollombi Brook during the 2011-
2012 AEMR reporting period were lower compared
to the average EC concentrations recorded in the
previous 2010-2011 AEMR. The relationship
between the lower EC concentrations and water
flows in Wollombi brook is displayed in Appendix
2C.
All monthly recorded EC values during 2011-2012
were within the SWMP surface water quality criteria,
in contrast with the results from SW03 during the
2009-2010 AEMR. During the 2009-2010 reporting
period there were five occasions at SW05 where the
EC criteria was not achieved due to low flows in the
brook. However, the Wollombi Brook sustained
good flows during this reporting period, resulting in
lower EC concentrations.
South Wambo Creek and Stony Creek recorded
average EC values of 439S/cm, 547S/cm and
346mg/L at surface water monitoring sites SW06,
SW07 and SW08 respectively. All annual average
EC concentrations for South Wambo Creek and
Stony Creek during the 2011-2012 AEMR reporting
period were comparable to the average EC
concentrations recorded in the previous 2010-2011
AEMR.
All monthly recorded EC values during 2011-2012
were within the SWMP surface water quality criteria
for SW06, SW07 and SW08. During the previous
2010-2011 reporting period the monthly EC criterion
was not achieved on several occasions at SW06
and SW07. Both SW06 and SW07 are upstream of
8 Data supplied by the NSW Office of Water
WCPL mining operation and therefore considered
outside the influence of mining.
North Wambo Creek average EC values of
430S/cm, 1627S/cm and 280mg/L at surface
water monitoring sites SW27, SW05 and SW04
respectively. Monthly EC concentrations for North
Wambo Creek at SW27, SW05 and SW04 during
the 2011-2012 AEMR reporting achieved the criteria
for EC. On comparisons to the previous reporting
period EC results at SW05 did not meet the EC
criteria of 2140S/cm for August 2010 and
September 2010.
EC concentrations at SW39 achieved the water
quality criteria of 492mg/L during the reporting
period. On comparisons to the previous reporting
period EC results at SW39 did not meet the EC
criteria on several occasions. SW39 is to the north
west of the operations where grazing activities occur
on WCPL land under a private lease arrangement
and therefore considered outside the influences
from mining.
Results from the WRD water monitoring program
show that EC in the Wollombi Brook achieved the
EC criteria.
As discussed above, surface water sites at Longford
Creek (SW43 and SW44) are adjacent to the
Golden Highway and considered outside the
influence of any WCPL activities. Additionally
surface water sites at Doctors Creek (SW46 and
SW45) are immediately downstream from non
WCPL agricultural and mining activities, including
cattle grazing and coal stockpiling.
Doctors Creek also provides for the passage of
mine water discharged from a neighbouring mine to
the Hunter River. During the reporting period there
were a number of visual confirmations that several
discharges to Doctors Creek were being
undertaken. The high EC periodically recorded at
Doctors Creek is consistent with these events.
3.4.2.5 Oil and Grease
Oil and grease results recorded during the reporting
period concluded that oil and grease concentrations
in the surrounding waters were generally in
compliance with the criteria set out in the WRD
SWMP. Oil and grease results recorded during the
2010-2011 reporting period are tabulated in
Appendix 2C.
3.4.2.6 Flow Monitoring
In consultation with NOW, WCPL completed a
program to re-install all nine surface water flow sites
destroyed during the June 2007 floods. The
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