Impact of climate change on soil remediation: CDE

Following extreme weather conditions across Australia, Daniel Webber of CDE explains the reality of climate change and how it threatens to unearth the history of Australia’s soil contamination, highlighting remediation solutions that can remove toxins from the environment.

This summer, Australia faced devastation from harsh weather conditions, having experienced some of the worst bushfires on record, extreme dust storms across New South Wales, flash flooding in Queensland and long periods of drought.

Daniel Webber, CDE Business Development Manager, says without stark intervention, the consequences of global warming will be felt for decades to come.

Indeed, the Intergovernmental Panel on Climate Change reported temperatures could rise by 1.7°C by the end of 2100 and sea levels could continue to rise globally.

Daniel explains that there lies a delicate balance between climate and its impact on Australian soils, and the rate of change is having a negative impact on contamination levels.

Contaminated soils are a key contributor to hazardous waste in Australia, yet the full extent of soil contamination is not yet fully known,” he says. 

This is due to variants in reporting between districts, Daniel says, and a lack of historical reporting.

The Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE) reports over 160,000 contaminated sites nationally. Of these, it’s estimated less than 10 per cent have been remediated.

“Australian soil has been contaminated with conventional and emerging contaminants for decades, including heavy metals, hydrocarbons, organic matter and manmade chemicals,” Daniel says. 

He adds that increasing soil temperatures from climate change and recent bushfires has led to increased soil toxicity and greater bioavailability.

“These weather patterns are having devastating effects on our soils and will unearth years of historical contamination,” Daniel explains. 

“In fact, research has shown the long-term effects of climate change, with increasing floods and drought conditions facilitating the movement of soil-based contaminants and soil erosion.”

A study by CRC CARE found soil erosion at a rate of 70-300 tonnes per hectare (tph), compared to what were defined as typical losses in the region of 60-80 tph.

“Our changing weather is causing the level of soil erosion to increase and dust storms will accelerate the spread of toxic pollutants in exposed soil,” Daniel says.

The movement of contaminants in dust storms presents significant health and environmental risks, as pollutants enter the air and water before finally settling into the soil again.

“Exposure to toxic contaminants can have a devastating impact on our health so we must find ways to diminish the risk,” Daniel says.

Many argue contaminated soil sites surrounding our waterways and agriculture lands are those which urgently require remediation.

“Our peers in the waste industry and local government are determined to clean up years of contamination and have already successfully remediated inorganic and organic materials. Yet we cannot do this alone, we need more to join us as we try to make Australia’s soils safe again.”

Successes had been reported. In its 2016 paper, Soil: Formation and Erosion, Australia State of the Environment stated soil ‘erosion rates are equal to soil formation rates.’

However, it remains to be seen how recent and unprecedented bushfires will affect this ratio, or by how much it will set remediation efforts back,” Daniel says. 

Outlining how CDE’s bespoke soil washing solutions can support this effort, Daniel says the company’s technologies 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.”

According to Daniel, CDE’s bespoke solutions can be tailored based on tonnage and level of contaminants to ensure maximum efficiency within every project CDE delivers. 

“Our systems provide savings on landfill charges, prevent extra investment in waste storage equipment, and introduce new materials for reuse,” he says. 

“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.”

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Celebrating the recycling of organics during ICAW

From May 3 to 9, leading compost networks from around the world will unite during international compost awareness week (ICAW).

The organizations are pioneering awareness on the importance of organics recycling and the use of compost to help regenerate the health of soils and soften the impact of human activity on our planet.

ICAW is celebrating 25 years and is the largest and most comprehensive education initiative of the compost industry.

Centre for Organic Research & Education (CORE), a not-for-profit charity has been supporting the international campaign in Australia for the past 15 years.

CORE Chairman, Eric Love, said recent weather catastrophes have given us a wake-up call to be more proactive about building our resilience to changes in our climate conditions, irrespective of the differing views on the causes.

“Having personally experienced the impacts of drought, fires, dust storms, floods, ultra-high temperatures and severe winds, has strengthened my resolve to support the proliferation of climate responsive measures to improve livability in our communities,” said Mr. Love.

AORA is an Australian partner involved in the international initiative, and is encouraging Australians to add compost to soil to improve its organic matter content, of fundamental importance to soil health and productivity.

The use of landfill space and incineration can be reduced by at least one-third when organics are recycled.

“Focused attention on recycling organic residuals is key to achieving high waste diversion rates,” AORA said in a statement.

“Compost offers a significant answer to climate change mitigation.”

Soil health and productivity is dependent on organic matter in the form of compost or humus to provide the sustenance for the biological diversity in the soil.

“Plants depend on this to convert materials into plant-available nutrients and to keep the soil well-aerated. Additional benefits include the reduced need for pesticide usage to ward off soil-borne and other plant diseases,” AORA said in a statement.

To promote the benefits of compost and organics recycling, the 2020 campaign for international compost awareness week is “soil loves compost” and “for the love of the earth”.

Traditionally, throughout the week of ICAW, community and business events and programs are held to encourage and celebrate the recycling of organics.

This year, reflective of the need for social distancing, people will be promoting ICAW through social media, emails, online workshops, and alternative ways to reach out to the public.

Executive Officer of Grampians Central West Waste & Resources Recovery Group (GCWWRRG), La Vergne Lehmann said encouraging residents in Australian communities to compost more at home and use compost in their own gardens is the best outcome for dealing with organic waste.

“Our support for ICAW is all about engaging our communities to do just that,” Ms Lehmann said.

ICAW international partners include the European Compost Network, The Compost Council of Canada, Composting Council Research & Education Foundation, Italian Composting and Biogas Association, Garden Organic UK and Composting & Anaerobic Digestion Association of Ireland.

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International Compost Awareness Week kicks off in May

International Compost Awareness Week (ICAW) will see global organisations band together to build awareness of the benefits of compost.

Activities and celebrations will take place in Australia, the United States, Canada, Europe, Ireland and the Czech Republic in the first full week of May.

Starting in Canada in 1995, ICAW has grown into an annual international event as more people, businesses, municipalities, schools and organisations begin to recognise the importance of compost and the long-term benefits of organics recycling.

Australian Organics Recycling Association National Executive Officer Diana De Hulsters said the goal of the program is to raise public awareness of how the use of compost can improve and maintain high quality soil, grow healthy plants, reduce the use of fertiliser and pesticides, improve water quality and protect the environment.

“Globally we have seen that innovative programs and successful efforts have improved organics recycling and sustainability,” Ms Hulsters said.

“International partners are coming together to broaden the understanding of compost use and promote awareness of the recycling of organic residuals.”

Ms Hulsters said while details vary amongst countries, a number of the facts about organics recycling and compost use transcend political and cultural boundaries.

“Soil health and productivity are dependent on organic matter in the form of compost or humus to provide the sustenance for biological diversity in the soil,” Ms Hulsters said.

“Plants depend on this to convert materials into plant-available nutrients and to keep the soil well-aerated. Additional benefits include the reduced need for pesticide usage to ward off soil-borne and other plant diseases.”

Ms Hulsters also highlighted the climate change mitigation benefits of composting by explaining how compost soil returns serve as a carbon bank.

“Diverting food and yard waste from landfills reduces the emission of methane, a greenhouse gas twenty-five times more powerful than carbon dioxide,” Ms Hulsters said.

“The use of landfill space and incineration can be reduced by at least one-third when organics are recycled. Focused attention on recycling organic residuals is key to achieving high diversion rates.”

The ICAW program includes tours of compost facilities, school gardening programs, compost workshops, lectures by gardening experts and compost give-away days.

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