Contaminated soil doesn’t always need to be removed from the site, in fact sometimes it’s extremely difficult to do so, however there are a range of on-site treatments we can use, depending on the situation.
Bioremediation
This is an environmentally friendly, and cost effective approach to site remediation where we use a variety of microorganisms to degrade the contaminants in the soil. Depending on the nature of the contaminant, we can add additional culture to speed up the natural degradation process or we can add additional supplements to achieve the same goal.
Soil Vapor Extraction
This is physical treatment process where we would sink a series of screened wells into the contaminated soil, and pump air through them with a compressor. The air rise to the surface carrying contaminated vapours with it, and these ‘off-gases’ are separated, and removed.
Chemical Treatment
This is where we add chemicals that oxidise with the contaminant to produce less harmful substances, for example using lime treatment to help with acid rock drainage. The other alternative is where would add a reducing agent to convert the contaminant into a less harmful form, as with heavy metals for example..
Solidification and stabilisation
Often used together, these remediation techniques don’t actually remove the contaminant from the soil, however they do prevent it from spreading and causing harm. Solidification will transform the soil, and contaminant, into a solid block so it can’t move and is less permeable to water, while stabilisation makes the contaminant less able to leach into the groundwater, or surrounds.
Permeable Reactive Barriers
Often used for groundwater remediation, a permeable reactive barrier is literally a wall that’s placed underground, allowing the contaminated water to flow through and come into contact with a range of reactive materials that either trap, or neutralise the contaminant accordingly.