Under international Paris Agreement, Australia’s climate change target is to reduce our greenhouse gas emissions by 26-28% below 2005 levels by 2030.
To achieve this target, we need to know where our emissions are coming from and have effective policies to reduce the environmental impact of those emissions.
This article is focused on wastewater and although the percentage of emissions within the big picture may be small, for councils and council controlled organisations operating wastewater treatment plants, the GHG emissions associated with wastewater and sludge treatment can form a substantial portion of their specific carbon inventory.
Australian wastewater 2020-2030
According to Australia’s emissions projections report, 2020 waste accounts for 12 Mt CO2-e (2%) of Australia’s Greenhouse Gas (GHG) emissions.
These emissions are produced from waste decomposition, treatment and combustion. This includes solid waste in landfill (the major source in this category), waste in wastewater and compost.
This is reported to see a small decline of 1 Mt CO2-e from 2020 to 2030. This gradual decline is estimated to be the result of lower GHG emissions from landfills due to a reduction of waste deposited and an increase in methane capture.
However, the impact on the environment through domestic and commercial wastewater emissions are projected to increase slowly from 2024 as wastewater facilities support a growing population.
Greenhouse gas emissions from industrial food production are projected to remain relatively unchanged to 2030. Carbon dioxide emissions from the incineration of solvents and clinical waste are also projected to remain unchanged staying below 1 Mt CO2-e every year out to 2030.
The operation of wastewater treatment plants result in direct emissions of greenhouse gases (GHG) from the biological processes, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), emissions resulting from the generation of electrical energy also add to this load.
Municipal wastewater treatment plants in Australia treat a major portion of the domestic sewage and commercial wastewater. Some industrial wastewater is treated on-site and discharged either to an aquatic environment or to the domestic sewer system which then feeds into a municipal wastewater treatment plant.
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“Every State and Territory government in Australia now have a 2050 net zero emissions target,” explains Matt Lyon , WSP Senior Water Treatment Engineer. “While some State governments have invoked legislation, others have settled on aspirational targets and the impact of the differences of these policies on the water industry is significant.” https://www.wsp.com/en-AU/insights/net-zero-for-australian-water |
Wastewater Inventory
It is incumbent on both local and regional councils to maintain constant improvement with regard to wastewater treatment plants and emissions management in order to at least keep pace with the 2030 targeted projection.
The first step to enable organisations in both the public and private sector to report on, manage and (where possible) reduce their greenhouse gas (GHG) emissions, is to understand the amount, nature and source of the GHG emissions, as well as the energy usage within the boundaries of the WWTP.
Collection of data on the wastewater system and performing a detailed inventory of the data concerning materials used, energy and substances, and pollution emission into the environment at given life cycle stages, for each of the elements of the system enables an assessment of the greenhouse gas emissions and the potential environmental impact throughout the life cycle of a system of wastewater collection, transport and treatment, from construction, use and end-of-life stages.
Commissioning of an Inventory provides this relevant information, and this knowledge provides the baseline to all subsequent initiatives to minimise, reduce or neutralise direct or indirect emissions.
The conditions shaping wastewater management are complex and the long process of implementing wastewater management systems ought to be preceded by an in-depth analysis concerning the selection of the optimal solution.
When looking at undertaking carbon inventory of a WWTP there are a number of factors which are taken into consideration and can include the following:
- Treatment Process type
- Receiving environment
- Sludge treatment process
- Destination of sludge: e.g. to land or landfill
- Mass of sludge produced
- Biochemical oxygen demand (BOD)
- Nitrogen content
A WWTP inventory can be tracked over time and used to identify areas of improvement and can assist in making business and operational decisions around energy recovery, energy neutrality and your organisations carbon footprint.
One of the key indicators of an organisation’s efforts towards being a more environmentally sustainable organisation is your annual Greenhouse Gas (GHG) emissions report.
As a wider goal, undertaking a Carbon Inventory report is the first step in having transparency with a commitment to report and reduce carbon emissions.
Related Articles:
- The importance of carbon reduction
- Carbon Emissions Management - What it is and why you need it?
- Project Case Study - Greenhouse Gas Assessment
Contact us to enquire about how we can assist you in understanding of the nature and forecasted quantities of emissions on your projects.