Phase 3 - Remediation

Based on the findings of a Detailed Quantitative Risk Assessment, the risks posed by a sources of contamination at a site in relation to human health or controlled waters will be quantified. As part of any development the risks identified within the DQRA will need to be mitigated.

The remediation or mitigation measures required will be dependent upon the nature and severity of the contamination identified and the medium within which the contamination is located. The aim of all remediation techniques is to break the pollution linkage between source and receptor, so the technique employed will not only be dependent upon the nature of the contamination, but also the source and the receptor scenario.

Physical remediation techniques include:-

  • Capping – Hard-standing or ‘Inert’ soil cover systems providing a barrier and/or reducing infiltration
  • Removal – Excavation and disposal of contaminated ‘Hotspots’ to a suitable landfill
  • Vertical Barriers – Subsurface barriers to minimize movement of contaminants and/or groundwater
  • Horizontal Barriers – Reduce downward movement of contaminants
  • Capillary Break – Prevents upward movement of contaminants by capillary action

Treatment technologies may also be employed to remediate contamination, which may include:-

  • Vapour Extraction – Vacuum pumps or fans are used to reduce vapour pressure in wells causing air and VOCs to flow out causing volatilization of contaminants
  • Bioremediation – Introduction or stimulation of micro-organisms to break down organic contaminants
  • Soil Washing – Water based technique for separation of contaminants from granular soils
  • Solvent Extraction – Use of solvents to selectively remove contaminants from soil
  • Pump and Treat – Water is pumped out of a contaminated zone, treated and recycled
  • Thermal Treatment – Ranges from incineration to thermal desorption of volatile and semi-volatile contaminants
  • Stabilization/Solidification – Fixing of contaminants in a resistant solid matrix i.e. Lime

At Terragen our consultants have experience of selecting, designing and implementing a wide range of remediation programmes. Through continued dialogue with our clients and the regulatory authorities we ensure that the most appropriate, efficient and practical remedial measures are implemented to achieve the remediation goals of the project.

If you would like further information on remediation techniques, or would like to discuss a particular project then please contact us as info@terragenenvironmental.co.uk