Wastewater Treatment Plants and GHG Emissions
In New Zealand’s 2021 National Inventory Report, submitted to the United Nations Climate Change Commission, wastewater treatment and discharge were only estimated to contribute around 0.4% of New Zealand’s national emissions.
Though, 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.
With the inevitable population growth and increased economic activity, the volumes of solid waste and wastewater will undoubtably increase over the coming years, therefore 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.
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.
In the past wastewater treatment plant performance purely focused on obtaining a good quality effluent. However, in today’s emission sensitive environment, energy consumption and greenhouse gas (GHG) emissions have become key factors defining the performance of wastewater treatment plants.
On the 22nd April 2016, New Zealand ratified the Paris Agreement at a ceremony in New York.
This means New Zealand’s has legally committed to reduce greenhouse gas emissions through our Nationally Determined Contribution (NDC), which will apply from 2021.
In practical terms this means New Zealand’s NDC is to reduce greenhouse gas emissions by 30 per cent below 2005 levels by 2030. By ratifying the agreement New Zealand commits to having an emissions reduction target and regularly updating it. The ratification also commits New Zealand to regularly report on emissions and on the progress towards meeting predetermined targets.
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.
This is accomplished by commissioning a carbon inventory. An inventory will provide a baseline and guide for all subsequent initiatives to minimise, reduce or eliminate emissions.
There are approximately 317 municipal wastewater treatment plants in New Zealand and around 50 smaller government or privately owned treatment plants serving populations of more than 100 people. Most of these wastewater treatment processes are aerobic, shown in the diagram below, which require oxygen to break down organic contaminants and other pollutants.
Typical Aerobic Wastewater Treatment Plant (Referenced from Carbon and Energy Professionals New Zealand– “Preparing a Carbon Inventory”)
Admittingly these are early days in which New Zealand’s public and private sector are starting to better understand their obligations with regards to climate change and ascertaining what their Carbon footprint actually is.
Therefore, undertaking the development of a Carbon Inventory is the first step in a commitment to report and reduce carbon emissions.
Siecap is certified to provide, impartial inventory auditing services, in accordance with ISO14065 and the GHG Protocol, Corporate Accounting and Reporting Standard:
ISO14064-1, design, develop, manage and report on an organisations GHG inventory.
ISO14064-2, Quantify, monitor and report emission reduction and removal enhancement oGHG Protocol, Corporate Accounting and Reporting Standardn GHG projects or project based activities.
ISO14064-3, Specification with guidance for use for the verification and validation of GHG statements
Contact us to enquire about how we can assist you in getting your business ready for carbon emission reduction: