Phase 3 - REMEDIATION

If remediation is deemed necessary following the Phase 2 works, such as in the case of heavily contaminated sites e.g. former petrol stations, gas works or chemical plants, then a site specific remediation strategy can be produced. Design of a site specific remediation strategy, as with all stages of investigation, involves consultation with the regulatory authorities to ensure satisfactory design and implementation of the remediation programme. This can include removal of contamination hot spots, further soil sampling, chemical analysis and additional monitoring, if additional information is required to supplement the previous investigation(s).

A wide range of remediation techniques are available and the methods chosen are dependent upon a range of factors including contaminant type and distribution, environmental sensitivity of the site, intended end use, cost and timescale.

If the Site Investigation report identifies unacceptable geotechnical, environmental or contamination risks which would make the development unsuitable for the proposed end usage, then remedial actions or control will be necessary to meet legislative requirements and satisfy planning conditions. The Remediation Statement is a site-specific document and represents a formal agreement between the developer and the regulatory authorities through the remediation process.

Solmek have an experienced multi-discipline team who appraise the most suitable remedial options; in line with Environment Agency CLR11 guidance, these options may include:

  • Bioremediation
  • Capping and encapsulation of contamination
  • Contamination treatment (such as soil washing)
  • Excavation, segregation of materials and validation for potential reuse
  • Formation of earth mounds or bunds
  • Ground gas protection methods
  • Installation of underground barriers (such as geotextile membranes)
  • Removal, disposal and replacement of contaminated soils
  • Removal and treatment of contaminated water
  • Soil stabilisation

 

Solmek has proven experience working closely with developers in the recommendation of many varied remediation techniques. The primary consideration when selecting remedial techniques is given to the effective severance of all pollution linkages and the reduction of risks to acceptable levels. However, where practicable we employ a pragmatic and sustainable approach considering the time required, cost-effectiveness and wider environmental cost of each option.

After the selection of remediation techniques, detailed plans for the verification of the remedial works are produced. Remedial target criteria state the levels of contamination that can remain on-site without posing an unacceptable risk to any receptors. Depending on the project, contingency plans are produced if the remediation proves unsuccessful or if unexpected contamination is encountered.

It is beneficial to consult the regulatory authorities at the early design stages of the Remediation Statement, as their involvement can streamline the acceptance of proposals and the following validation process.