Remediation of Agricultural Areas

 

Types of Remediation

Decontamination methods for agricultural land include: the removal of vegetation either manually using a strimmer or mechanically using a grass-cutting machine; soil redistribution or inversion using a spade or mechanical rotavator, or by ploughing; or soil removal (sometimes preceded by soil solidification using a resin spray).

 

Soil redistribution operates by dispersing the strongly particle reactive caesium from a thin surface layer (typically less than 5 cm thick) into a deeper layer.  As the gamma rays emitted from radio-caesium are substantially attenuated by 10 cm of soil, this approach significantly reduces external dose rates, as well as reducing the concentration of radio-caesium in soil that is available for plant uptake.

 

In soil inversion, the upper 5 cm of topsoil is removed and set aside.  The remaining topsoil to a depth of about 50 cm is then removed.  The top 5 cm of topsoil is then replaced and covered with the 45 cm of underlying topsoil.  This procedure transfers the most contaminated soil to a depth of 45 to 50 cm.  Again, this reduces both the external dose rate and plant uptake.

 

 

Deep Ploughing

Manual Topsoil Stripping

Weeding using a Hammer Knife Mower

Topsoil Stripping using a Solidifying Agent