Tag Archives: contaminated soil

How Soil Can Fight Pollution

Soil biodiversity is essential for most of the ecosystem services and functions that soils
provide and perform. Soil microbes (i.e., bacteria, fungi) and microfauna (i.e., protozoa
and nematodes) transform organic and inorganic compounds into available forms. These transformations are critical for nutrient cycling and availability, for plants, and other species growth, for cycling of soil organic matter and carbon sequestration, and for the filtration, degradation, and immobilization of contaminants in water and soil.

An important part of the food web is represented by mesofauna, such as springtails and mites, which accelerate litter decomposition and enhance nutrient cycling and availability (especially nitrogen), and predators of smaller soil organisms.

Soil macro, and megafauna such as earthworms, ants, termites, and some mammals act as ecosystem engineers that modify soil porosity, water and gas transport, and bind soil particles together into stable aggregates that hold the soil in place and thus reduce erosion.

Soil biodiversity can mitigate threats to ecosystem services, for instance by acting as a powerful tool in bioremediation of contaminated soils. Biostimulation and bioaugmentation are environmentally sound strategies that contribute to the filtration, degradation, and immobilization of target contaminants. Furthermore, the integral use of organisms such as microbes (bioaugmentation), plants (phytoremediation) and earthworms (vermiremediation) as a bioremediation strategy in hydrocarbon-contaminated soils has proven to be a viable alternative for increasing hydrocarbon removal. On the other hand, soil macrofauna, such as earthworms, termites, and ants, play an important role in improving soil structure and aggregation, which can improve resistance to soil erosion caused by wind and water.

Excerpt from FAO, State of Knowledge of Soil Biodiversity, Report 2020

Nuclear Waste in Australia: rusting and leaking

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) is the federal government agency for scientific research in Australia.
CSIRO faces a $30 million clean up bill after barrels of radioactive waste at a major facility were found to be “deteriorating rapidly” and possibly leaking.

An inspection found “significant rusting” on many of the 9,725 drums, which are understood to contain radioactive waste and other toxic chemicals.  Much of the radioactive waste was trucked to Woomera from Sydney in the mid 1990s.  CSIRO flagged a $29.7 million budget provision for “remediation works” at a remote location in its latest annual report.

Almost 10,000 drums of radioactive waste are stored at a CSIRO facility in Woomera, South Australia.  The Woomera facility is currently one of Australia’s largest storage sites for low and intermediate-level radioactive waste.   A damning report of the Woomera facility was issued by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) after an inspection in April 2016.   “Evidence was sighted that indicates the drums are now beginning to deteriorate rapidly,” read the report, seen by Fairfax Media.  “Significant rust on a number of the drums, deterioration of the plastic drum-liners and crushing of some stacked drums was observed.

Tests confirmed the presence of radioactive isotopes at one location and inspectors said there was a possibility the drums were leaking.”Although unlikely, there is the possibility that the presence of deceased animals such as rodents and birds may indicate that some of the drums, which contain industrial chemicals, may be leaking into the environment.”  The mixture of water and concentrated radioactive material inside some of the drums also had the potential to produce explosive hydrogen gas, inspectors found.

They also noted CSIRO had little knowledge of what was inside many of the barrels, some of which are believed to date back more than 50 years.  “Without full knowledge [of] the contents of the drums, risks cannot be fully identified and risk controls cannot be appropriately implements to protect people and the environment,” inspectors noted in the report.

Many of the drums are understood to contain contaminated soil generated by government research into radioactive ores at Melbourne’s Fishermans Bend throughout the 1940s and 1950s.  The toxic soil was discovered by the Department of Defence in 1989, who sent it to Sydney’s Lucas Heights facility before it was palmed off to Woomera in 1994.

The country’s other major radioactive waste storage facility at Lucas Heights, Sydney, is rapidly approaching full capacity. 

Coupled with issues at the CSIRO site, the revelations highlighted the urgent need for a national radioactive waste storage solution, experts said.

Excerpts from Rusted barrels of radioactive waste cost CSIRO $30 million, Sydney Morning Herald, Mar. 13, 2017