From the magazine, Oil, gas and energy

Climate change threatens soil contamination

This Summer, Australia faced devastation from harsh weather conditions after experiencing some of the worst bushfires on record, extreme dust storms across New South Wales, flash flooding in Queensland and long periods of drought. The Intergovernmental Panel on Climate Change (IPCC) reported temperatures could rise by 1.7°C by the end of the 2100 and sea levels could continue to rise globally – changes and impacts to the environment that must be seriously considered.

The climate is changing Australian soil

Contaminated soil is a key contributor to hazardous waste in Australia, yet the full extent of soil contamination is not yet fully known due to varying accounts between districts and a lack of historical reporting.

In 2014, the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC Care) reported there are approximately 160,000 contaminated sites in Australia where the soil has been contaminated with heavy metals, hydrocarbons, organic matter and manmade chemicals for decades, yet only a small percentage have been remediated.

Due to high temperatures and recent bushfires, the subsequent increase in soil temperatures has led to increased soil toxicity and greater bioavailability as well as having devastating effects on Australian soils.

These weather patterns will additionally unearth years of historical contamination, considering CRC Care research shows Australia’s average soil erosion has grown to an estimated 70–300 t per hectare compared to a previous 60–80 t per hectare.

With this increased level of soil erosion, dust storms will accelerate the spread of toxic pollutants in exposed soil. These contaminants – including lead, mercury and arsenic – can then enter the air and water before finally settling into the soil again.

Devastating health and environmental risks arise from this movement, including the contaminants entering the food chain and being ingested by humans or breathing in harmful toxins that are present in the air.

CDEnviro’s solution

Mr Wong says that CDEnviro’s bespoke soil washing solutions utilise a suite of mechanical, chemical and biological processes for recovering washed solids such as sand and aggregates. Contaminants are transferred into the water phase, which are effectively treated to produce recycled water for reuse within the process.

“Our bespoke solutions can be tailored based on tonnage and level of contaminants to ensure maximum efficiency within every project we deliver,” says Mr Wong.

“Our systems provide savings on landfill charges, prevent extra investment in waste storage equipment, and introduce new materials for reuse. We can no longer ignore soil contamination; we must utilise remediation technology to help us eliminate potential risk to human health and to protect the world around us.”

Mr Wong says that many industry professionals will argue that the contaminated soil sites urgently requiring remediation are those surrounding waterways and agriculture lands, with peers of CDEnviro in the waste industry and local government determined to clean up years of contamination – though more need to join on board to try and make Australian soil safe again.

For more information visit the CDEnviro website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

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