HVO 2009 Annual Environmental Management Report - Final

Coal & Allied – Hunter Valley Operations
0
Carrington Groundwater SWL Trends
5
10
Standing Water Level (m)
15
20
25
30
Jan 09
Feb 09
Mar 09
Apr 09
May 09
Jun 09
Jul 09 Aug 09
Date
Sep 09
Oct 09
Nov 09
Dec 09
Jan 10
CGW39 CGW45 CGW46 CGW49 CGW51A CGW52 CGW52A CGW54A CGW6
Figure 47: Carrington Groundwater SWL Trends
Interpretation of Groundwater Monitoring Results for Carrington Piezometers
CGW6
CGW6 is located in alluvium near the Hunter River, just upstream of Carrington.
The mean pH at CGW6 was 7.5 in 2009. A spike in pH values was noted from CGW6 (pH 8.6) occurring in
September 2009, however this spike was consistent with bores in the vicinity and within historical ranges for
groundwater located in this alluvium area.
CGW6 EC levels averaged 2,050μS/cm for the 2009 reporting period. This value is closely aligned with
historical data. The average EC value is slightly increased on the 2008 reported average (1,700μS/cm) and
represents the return to normal conditions for the aquifer in the vicinity of this piezometer following the dilution
caused by the large flood of June 2007.
Water levels at CGW6 were recorded at an average depth of 9.45m (60.0m AHD) through 2009.
CGW39
Samples for pH and EC analysis from CGW39 were only available during the last quarter of 2008. CGW39
was reported as dry with depths of around 13m (65.04m AHD) over the past three years. However water
levels and samples were able to be collected following purging of the bore in September 2008. It is therefore
difficult to establish trends based on the data available.
The 2009 reporting period represents the first consistent year for data collection from this site.
The mean pH at CGW39 was 7.4 in 2009. A spike in pH values was noted from CGW39 (pH 8.0) in
September 2009, however this spike was consistent with bores in the vicinity and within historical ranges for
groundwater located in this alluvium area.
CGW39 EC levels averaged 7,897μS/cm for the 2009 reporting period. Consistent data and minimal
fluctuation around for EC and SWL support that the bore is functioning within normal limits.
Water levels at CGW39 where measured at an average depth of 11.08m (65.5m AHD) through 2009.
AEMR 2009 98