What we do Land remediation

Land remediation

Completion of an appropriate site investigation will enable the formulation of a robust Conceptual Site Model, which considers plausible pollutant linkages. Where plausible pathways between actual contaminant sources and potential receptors are identified, remediation will be required, either treatment/removal of the source, or “breakage” of the pathway.

  • Isolation beneath cover
  • Ex-situ bioremediation
  • Soil washing
  • Solidification or stabilisation
  • Recovery of coarse fraction
  • Soil vapour extraction
  • Excavation & disposal

In addition, Lithos also consider the need for ground improvement, and\or the earthworks necessary to create a platform on which development can commence. Choice of the most appropriate remediation option(s) is influenced by:

(a) The Conceptual Ground Model, including:

  • Geology, hydrogeology, proximity to watercourses etc
  • Volume and distribution of soil requiring remediation
  • Nature (eg gravely or clayey) of soil requiring remediation
  • Nature of the contaminants – the “mixture”, mobility, volatility, and resistance to degradation

(b) Classification of the soil for the purposes of disposal to landfill:

  • Site’s size – area available for remediation activities
  • Site’s location – consideration of odour, dust and noise associated with remediation activities
  • Redevelopment proposals
  • Estimated costs and timescale associated with the proposed remediation technique
  • Degree of confidence/certainty in proposed remediation technique
  • Views of the Local Authority

Remediation options for contaminated soils include:

  • Isolation beneath cover
  • Ex-situ bioremediation
  • Soil washing
  • Solidification or stabilisation
  • Recovery of coarse fraction
  • Soil vapour extraction
  • Excavation & disposal

And for contaminated groundwaters include:

  • Pump & treat
  • Chemical oxidation
  • Dual-Phase Vacuum Extraction (DVE)
  • Bioremediation
  • Attenuation monitoring

Once a specific development scheme has been decided, we can prepare a Remediation Strategy Report, for submission to the Local Planning Authority.

A Remediation Strategy outlines the remediation objectives necessary to protect environmental receptors, and render a site suitable for the proposed end use.

The Remediation Strategy will include site-specific clean-up criteria for contaminants of concern; the latter such criteria are usually derived by Quantitative Risk Assessment (QRA).

We produce MMPs to facilitate and record the sustainable reuse of soils in accordance with the Definition of Waste Code of Practice (DoWCoP).

The code sets out good practice for the development industry regarding the appropriate reuse of soils, and the Environment Agency (EA) have confirmed they will take account of the DoWCoP when deciding whether to regulate the materials as waste.

In advance of any works: a formal Materials Management Plan (MMP) must be prepared; reviewed by an independent Qualified Person (QP); and an online declaration submitted to CL:AIRE .  Each new source of material for import must be included in formal revisions to the MMP.

We can perform the role of QP, although it should be noted that Lithos cannot act as the QP for projects where we have undertaken the site investigation, and/or prepared the Remediation Strategy.

Anyone who is found to have knowingly caused or permitted the disposal of waste at an unauthorised site would then become liable to pay landfill tax at the standard rate (£102.10/tonne from 1st April 2023).  HMRC can also impose an additional penalty of up to 100% of the tax due.

Lithos can supervise remediation works, and on satisfactory completion will prepare a Verification Report to stand as certification that works have been carried out in accordance with the approved Strategy.  The Verification Report also provides recommendations with respect to:

  • Foundation solution(s)
  • Gas measures
  • Placement of soil cover
  • Handling and management of excavation arisings generated during construction