Soil contamination occurs when a pollutant is present at higher than background concentrations and is causing, or has the potential to cause, adverse effects on society or the environment (WA EPA 2007, ITPS 2015). These contaminants may adhere to soil particles, air, or water and their transport can lead to both on-site and off-site issues; the toxicity and persistence of soil contamination is a serious concern (WA EPA 2007). Contamination is a large and complex topic though, as the effects of soil contamination depend on soil properties as these control their mobility, bioavailability, and residence time (Eugenio et al. 2018). It is clear though that severe contamination degrades the ecosystem services provided by soil and reduces agricultural production capacity by limiting the end market opportunities of contaminated produce (Eugenio et al. 2018).
Contaminated sites are usually associated with past land uses of industry and agriculture where inadequate action was taken to prevent contamination (WA EPA 2007). The discovery of contaminated land in or near residential areas causes significant community concern and distress (WA EPA 2007); consider for example, the increasing attention that per-and poly-fluoroalkyl substances (PFAS) are receiving (VIC EPA 2018). Severe contamination can render land uninhabitable and significantly constrain land use options over the mid to long term (WA EPA 2007, ITPS 2015). As such, the economic costs of contaminated land generally outweigh the costs of remediation however rural sites can prove more difficult to remediate without external support due to their low land values (WA EPA 2007, NSW EPA 2015). Even though legacy sites continue to exist, soil contamination is improving in Australia due to improved regulation and remediation of contamination producing activities and contaminated sites (ITPS 2015).
Unfortunately, soil contamination continues to occur and actions that landholders take to improve one aspect of their business can have negative effects on other aspects. For example, pesticide and herbicide use is increasing in production systems, particularly in association with the adoption of no-till and minimum-till cropping (WA EPA 2007); these contaminants can raise significant public concerns (ITPS 2015). Agricultural contaminants usually involve build-up, leaching or transport of agricultural chemical and fertilisers (WA EPA 2007). Accidental release of contaminants also occurs, often due to inappropriate storage, transport, or handling; deliberate dumping of wastes due to economic pressures are also sources of environmental contamination (WA EPA 2007). Inappropriate mine management or closure is frequently associated with contaminated soil and water; these sites are likely to remain unsuitable for other uses without extensive rehabilitation (WA EPA 2007, ITPS 2015). Contamination of land and water resources, regardless of intent, often causes conflict between the landholders affected (Fergusson 2017, Metcalfe and Bui 2017).
Eugenio, N. R., M. McLaughlin, and D. Pennock. 2018. Soil pollution – a hidden reality. Food and Agriculture Organization of the United Nations, Rome.
Fergusson, L. 2017. Anthrosols and Technosols: the Anthropogenic Signature of Contaminated Soils and
Sediments in Australia. Water, Air, and Soil Pollution 228.
ITPS. 2015. Status of the world’s soil resources technical summary. FAO – Intergovernmental Technical Panel on Soils, Italy.
Metcalfe, D. J., and E. N. Bui. 2017. Australia state of the environment 2016: land. Australian Government Department of the Environment and Energy, Canberra.
NSW EPA. 2015. New South Wales State of the Environment 2015. New South Wales Environment Protection Authority, Sydney.
VIC EPA. 2018. Victorian State of the Environment 2018 scientific assessments. Authorised by the Commissioner for Environmental Sustainability, Melbourne.
WA EPA. 2007. State of the Environment Report: Western Australia 2007. Perth.
Soil Science Australia acknowledges the traditional owners of the land and pays its respects to their Elders, past, present and future.