Page 83 - AGL Sustainability Report 2011

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Environment
Sustainability Performance Report 2011 81
Watermanagement
Consumed water
Water is an essential resource for AGL’s operations.
AGL operates in regions where water restrictions are
common, and seeks to minimise water consumption
where possible.
Approach
AGL consumes water for a variety of purposes. AGL’s largest
consumptive uses of water are outlined below:
>> AGL’s largest consumer of water is the Torrens Island Power
Station, where water is consumed in the production of steam.
Around 90% of the water used at this power station is sourced
from a deep aquifer located approximately 130 metres below the
site. This saline water is passed through a reverse osmosis unit
and a demineralisation process to remove salts prior to use in the
power generation process.
>> Cooling water is required at the Hydrocarbon Extractions Plant
to cool the process that takes Caltex Refnery waste fuel gas to
extract LPG and Naphtha.
>> At Somerton Power Station, water is injected into the combustion
chamber to reduce emissions of nitrogen oxides from the plant.
>> At Upstream Gas exploration and production projects, water
is used to lubricate and cool drill bits during drilling operations.
>> Water is essential at all of AGL’s offces for provision of
basic amenities.
Performance
In FY2011, approximately 64% of the water consumed at AGL’s sites
comprised groundwater drawn from beneath the Torrens Island
Power Station, while 35% comprised potable water purchased from
retail water suppliers. The remaining 1% consisted of a number of
other water sources such as recycled water purchased from other
organisations and harvested rainwater.
In addition, AGL makes important non-consumptive use of water
resources. This is discussed separately under ‘Managed Water’ on
page 84.
For power generation assets, the amount of water consumed is
proportional to the amount of power generated over a particular
time period. As Torrens Island Power Station consumes the largest
amount of water of all AGL’s operated assets, total water use
is strongly influenced by the power generated by this asset in a
given year.
Power output was up at Torrens Island Power Station in FY2011
compared to the two preceding years and this is reflected in water
consumption data. Power output at Somerton Power Station during
FY2011 was down compared to previous years and the water
consumption data reflects this decrease.
In recognition of the need to use water sustainably across coal
seam gas operations, AGL will prepare water management
strategies during FY2012 for drill water, and fracture stimulation/
flowback water. These strategies will sit alongside AGL’s Produced
Water Management Strategy and, together with a Brine Water
Management Strategy, form AGL’s overarching water management
framework for coal seam gas projects.
Water use
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
Major
AGL offices
3,4
Cooper Basin
Oil and Gas
Project
Silver Springs
Oil and
Gas Project
Galilee
Gas
Project
Hunter
Gas
Project
Gloucester
Basin Gas
Project
Camden
Gas Project
Hydrocarbon
Extractions
Somerton
Power Station
Torrens Island
Power
Station
kL
Notes
1 FY2010 was the frst full year that the Gloucester, Hunter and Galilee coal seam gas exploration projects have been owned and operated
by AGL and so there is no water consumption data available for preceding years.
2 AGL took ownership of Silver Springs and Cooper Basin assets in October 2010. Full FY2010 data for these assets is provided.
3 In FY2011, major AGL offces included North Sydney (NSW), Canberra (ACT), Brisbane (QLD), Spencer Street and Collins Street offces in Melbourne and East Burwood
(VIC) and Eastwood (SA)
4 Where offce buildings are occupied by multiple tenants, AGL’s water consumption has been estimated based on property management data for the building, pro-rated to
refect the amount of building foor space occupied by AGL.
Legend
FY08
FY09
FY10
1
FY11
2