As far as safely and permanently isolating hazardous waste goes, nothing beats a geological repository such as Tellus’ Sandy Ridge—the sole operational facility of its kind in Australia.
Buried in kaolin clay under our air dome, with kilometres of impervious granite below, hazardous chemical and low-level radioactive waste won’t be bothering anyone, human or animal, for the fullness of geological time.
That’s pretty obvious. But did you know geological permanent isolation is also one of the most environmentally friendly forms of disposal, and that it could help Australia achieve its ambition to achieve net zero carbon emissions by the middle of the century?
Here’s how it works.
Many types of carbon-based wastes release carbon back into the atmosphere in the form of gases like carbon dioxide and methane when treated or incinerated, or when breaking down in landfill. The United Nations Economic Commission for Europe (UNECE) estimates that landfills and waste contribute up to 16 per cent of global methane emissions alone. These harmful gases are released by bacteria that eat the waste.
To survive, bacteria need food, water and oxygen. All these factors are abundant in landfills, allowing the bacteria that eat waste to thrive. Our geological repository – in contrast – is dry, with no liquid leachate running through the waste. Without moisture, bacteria that produce methane and carbon dioxide cannot survive. Where bacteria cannot thrive, there are no harmful gases like methane and carbon dioxide released into the atmosphere.
The Tellus geological repository at Sandy Ridge is dry. This is due to several factors, including:
- All waste that enters the cell is tested against Tellus’ strict standards in our onsite laboratories.
- Our waste cells do not contain any leachate or free liquid – no liquid waste is entombed in the cell.
- The highly adsorbent properties of kaolin clay, the material in which we have entombed more than 100,000 tonnes of hazardous waste.
- The complete absence of an interconnected groundwater system.
- Finally, the air dome itself covers the cell and protects against rain.
Take contaminated wood as an example. In a landfill or in the environment, it would be exposed to water, oxygen and bacteria. This is the ideal environment for bacteria to thrive and release methane and carbon dioxide into the atmosphere. Our geological repository is the perfect place to protect contaminated wood from the processes that generate these environmentally harmful gases.
So not all permanent isolation methods are created equal. Alongside its unique safety features, Sandy Ridge’s carbon-capturing properties are another way Tellus can realise its vision of supporting Australia’s sustainable future.