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The Site Investigation Procedure - Advice for Developers

The site investigation procedure needs to identify the potential for contamination and identify possible areas that may require remedial works in order to make a site suitable for use.

The site investigation should be done in phases in order that resources are appropriately targetted.

  • Phase 1 investigation should establish whether there have been any former contaminative uses on the site or adjacent properties which could impact upon the development. The Phase 1 should include a preliminary conceptual site model.
  • Phase 2 investigation should determine the nature, extent and severity of contamination using risk based criteria. It should provide details of remedial options, health and safety issues, potential impacts on the environment and a detailed work plan. It should assess the risks to human health, controlled waters and the wider environment.
  • Phase 3 Remediation Method Statement should provide details of proposed remedial options, health and safety issues and a detailed remediation strategy.
  • Post Remediation Validation Report should provide a summary of remedial works carried out together with relevant documentary evidence and post remediation test results.

Procedure

The site investigation procedure involves specialist technical knowledge and it is essential that all phases of the site investigation procedure are conducted by competent and experienced people (who should hold recognised and appropriate qualifications). Where a geotechnical study and a contamination study are combined within one report the consultant should be able to demonstrate competency and has expertise to provide advice on both.

Sampling Strategy

In the past we have received reports submitted on behalf of developers, which have not used a proper scientific or appropriate sampling strategy in order to assess risks from land contamination. It is essential that developers conduct their site investigations in accordance with current good practice.

Examples of current good practice can be found in the following documents:

Model Procedures for the Management of Land Contamination, Contaminated Land Report 11, Environment Agency 2004

BS 10175:2001 British Standard Institute (2001) Investigation of Potentially Contaminated Sites- Code of Practice, British Standard Institute. London.

Environment Agency (2001) Secondary Model Procedure for the Development of Appropriate Soil Sampling Strategies for Land Contamination. R&D Technical Report P5-066/TR. Water Research Centre, Swindon

Environment Agency (2000) Technical Aspects of Site Investigation (2 Vols.). Research and Development Technical Report P5-065/TR. Water Research Centre, Swindon

Environment Agency (2000) Guidance for the Safe Development of Housing on Land Affected by Contamination. The Stationary Office. London

Documents

The following documents detail local policies and guidance that should be followed in respect of:

  • Importation of topsoils and subsoils as a growing medium
  • Verification of clean capping systems
  • Validation of gas protection measures
  • Modified: Jan 9, 2012 4:28:32 PM