Article Contaminated Land Laboratories

BS 10175 Updated

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Tags: contamination Geoenvironmental Geotechnical risks

BS 10175:2011 (Investigation of Potentially Contaminated Sites – Code of Practice) was published in March 2011. It is much improved compared to the 2001 version both in content and the way that guidance and information is presented. It meets the initial brief for the revision and has also addressed a number of other issues (see Box). There have been many changes and those familiar with the old version should not assume that they know what the new version says. It must be read, pondered on, and digested.
Unfortunately, there is no reason to expect those who ignored the old version to pay any more attention to the new one unless induced to do so by regulators and informed potential clients. Contamination has been an issue for at least 35 years (the Greater London Council first published guidance in 1976) but we still see reports that would have been regarded as poor thirty years ago. The bottom end is as bad as it ever was. Some reports proudly announce that they have been done in accordance with BS 5930 with no mention of BS10175 thus revealing the writer’s ignorance of good practice.
There is a place for well crafted combined geotechnical and geoenvironmental investigations that properly address both aspects. However, there remain some geotechnical specialists who still think that a few samples taken from random depths from a few random locations and analysed for an unjustified suite of potential contaminants constitutes an adequate investigation for contamination. I should add here, that when I have checked, the culprits have not been AGS members – and that in itself says something about them.
PPS23 (Planning Policy Statement 23: Planning and Pollution Control – Annex 2: Development on Land Affected by Contamination) is about to be withdrawn. This currently indicates that site investigations for contamination should be in accordance with BS10175:2011. It seems likely to be replaced by a single phrase in the simplified planning guidance that the government is intending to introduce. This will make it all the more important for AGS to continue to try to educate both its members and clients about good practice.

 

BS10175:2011 What has changed?

BS10175  gives recommendations for, and guidance on the investigation of land potentially affected by contamination and land with naturally elevated concentrations of potentially harmful substances, to determine or manage any risks.

The brief for the revision was to:

  • align BS 10175 with International Standards (e.g. ISO 10381 series) especially those adopted as British Standards
  • update in relation to legislation and authoritative guidance
  • update technically
  • include additional guidance on sampling uncertainty
  • extend guidance on application of on-site analytical methods (align with draft BS ISO 12404)

All these issues have been properly addressed during the revision. In addition, a number of other significant “general” changes have been made:

  • clearer separation between “Normative text” (i.e. guidance) and informative text
  • clarification of some terminology, e.g. “contamination”
  • emphasise on the importance of early consultation with regulators and including provision of information on the role of local authority “contaminated land officers”
  • tightened reporting requirements
  • introduction of  a requirement concerning the qualification of drillers etc. (as in CP 5930 as amended 2010).

The importance of the conceptual model is emphasised and the process of investigation is characterised as one that seeks to reduce the uncertainty in the conceptual model.

The definition of “contamination” has been amended to:

  • Presence of a substance or agent, as a result of human activity, in, on, or under land, which has the potential to cause harm or cause pollution.

There is no assumption in this definition that harm results from the presence of contamination.
The change aligns BS10175 more closely with the definition in “BS ISO 11074 Soil quality – Vocabulary” and helps to make it clear that the definition in Part IIA of the Environmental Protection Act 1990 has only a narrow application. It should also help to discourage the use of the oxymoron “natural contamination”.

Requiring Planning Conditions or similar regulatory requirements to be noted in the introduction to reports will, hopefully, discipline consultants to get proper briefing from their clients and to consult regulators when they are required to do so (the potential benefits of consultation with regulators when there is no formal requirement is also emphasised). It will be clearer whether regulatory concerns have been addressed and proper consultations carried out.