How are we tracking?

Indicator: Ecological and carbon footprints of business activities

We calculate our environmental footprint using an internationally recognised methodology.1 We have calculated our footprint for 2010–11. Data for 2011–12 was not available in time for publication in this report.

Carbon footprint

Calculating our carbon footprint helps us estimate the impact of carbon and energy prices on our operations. It also helps us identify opportunities to reduce operational costs and environmental impacts.

In 2010–11, our full supply chain carbon footprint for operations and capital works was 0.9 million tonnes of carbon dioxide equivalent emissions (CO2-e), down from 1.1 million tonnes in the year before. We report our footprint as a gross number (ie before accounting for carbon offsets) because this reflects our carbon risk exposure. In 2010–11, we surrendered carbon credits to reduce our footprint by 25%. In 2009–10, we offset 16% of our carbon footprint in this way.

About five per cent of our carbon footprint came from direct emissions. These include methane and nitrous oxide emissions2 from wastewater treatment plants (WWTPs) and fuel used by our motor vehicles and plant and equipment.

Electricity use made up 35% of our carbon footprint. Although our electricity use has not increased significantly, it now makes up a higher proportion of the footprint due to reductions in other areas. Water and wastewater operations are energy intensive and we are among the top 200 largest users of energy in Australia.3 Of our total electricity use, we used almost 50% in WWTPs and 30% in water pumping stations.

About 60% of our carbon footprint came from indirect emissions produced through our supply chain. This includes energy to produce construction materials and treatment chemicals. It also includes energy used by the Sydney Catchment Authority to treat and supply bulk water to us. Our operations supply chain was 42% of our carbon footprint in 2010–11. Another 18% of our carbon footprint was due to carbon embedded in capital works projects. The Sydney Desalination Plant contributed only a small amount to our footprint as it offsets 100% of its electricity use with renewable energy.

Figure 15 – Our full supply chain carbon footprint 2010–11

Image of Figure 15 – Our full supply chain carbon footprint 2010–11

Note: Emissions are defined in the Greenhouse Gas Protocol, www.ghgprotocol.org

As part of our Energy Management Plan 2005–10, we implemented energy efficiency improvements and renewable energy projects to manage the cost of carbon and reduce our footprint. These projects have reduced our emissions by about 90,000 t CO2-e a year. This represents an avoided carbon cost of more than $2 million a year and much more in energy cost savings. We are now working to reduce emissions by a further 40,000 t CO2-e by 2020. In 2010–11, renewable energy projects supplied about 10% of our energy needs. Completing major capital works projects also helped reduce our footprint.

1Sydney Water uses the hybrid Environmentally Extended Input Output Analysis methodology developed by the Integrated Sustainability Analysis team at Sydney University. Our footprint total includes expenditure on capital projects during the year as well as all operational expenses.

2Sydney Water uses a different method for calculating its scope 1 nitrous oxide emissions from effluent disposal for the carbon footprint than that used for the 2010–11 National Greenhouse and Energy Report (NGER). The new Federal Department of Climate Change and Energy Efficiency guidelines use this methodology, which applies to the 2011–12 NGER.

3Department of Climate Change and Energy Efficiency, 2011, National Greenhouse and Energy Reporting – Greenhouse and Energy Information 2010–11, www.climatechange.gov.au