SearchBS10175 provides key guidance for the investigation of potentially contaminated land and land with naturally elevated concentrations of potentially harmful substances.
It has been fully revised. However, it is inevitable when a document that has undergone several revisions since it first appeared in 2001 (it has deeper roots going back to guidance produced by the GLC Scientific Branch in 1976[1]) that the changes are incremental consisting mainly in changes of emphasis, technical clarifications, and regulatory alignment, rather than major technical innovations.
In summary, the changes are:
- Amendments 1 and 2 have been consolidated into the core text and external references updated to reflect the latest UK and international guidance.
- New technical content, including an informative annex on leaching tests and expanded sections on bioavailability, bio-accessibility and the use of on-site measurement methods.
- Attention to broader issues that have grown in relevance over the past decade, including climate change, sustainability of site investigation activities, and worker wellbeing.
BS 10175:2026 is intended for use by those with an understanding of the risk-based approach to the assessment of sites (as described in the Environment Agency’s guidance on land contamination risk management (LCRM) (available at https://www.gov.uk/government/ publications/land-contamination-risk-management. lcrm)).
Investigation and assessment of potentially contaminated sites will almost always require involvement of people with differing professional and technical backgrounds. The subject is so multi-faceted that an individual is unlikely to have all the skills and expertise required to deal with complex sites. However, each specialist involved in a project usually needs to have an awareness of knowledge outside of their own discipline, especially as they become more involved in the design of investigations and the assessment of the results. This creates the need for the extensive informative text and annexes to aid the understanding of technical aspects that might be outside of a user’s direct training and experience.
Given the diverse usage and application of the code of practice, it is essential that consistent terminology is used in BS 10175:2026 and, as far as practical, related standards, to avoid serious misunderstandings between those with differing backgrounds. This includes the meaning attached to “contamination” and exactly what do we mean by “soil” (see Box 1). Terms need to be defined in reports to avoid unwitting ambiguity.
BS 10175 is a Code of Practice. It provides recommendations and guidance. It is not to be quoted as if it were a specification. Users may substitute any of the recommendations with practices of equivalent or better outcome. However, any user claiming compliance with this British Standard is expected to be able to justify any course of action that deviates from its recommendations.
The requirement for users to apply judgement in this way is important because BS 10175 relies on many other standards (e.g. members of the BS ISO 18400 series) for additional guidance and information, which will often themselves need some updating. A case where this has been important in the revision is the guidance provided on purging of groundwater monitoring installations which is now “stand alone” in BS10175 rather than relying on other published standards and guidance documents.
The development of a Conceptual Site Model (CSM) at an early stage is vital step on the way to a successful investigation. BS 10175:2026 employs the definition in BS EN ISO 21365 Soil quality – Conceptual site models for potentially contaminated sites. BS EN ISO 21365 emphasises that CSMs are “of the mind”, their dynamic nature including the need to continuously revise them as new information becomes available, and the need to produce different CSMs for different purposes as projects progress. It also emphasises the need to have regard to models developed for other purposes including the geotechnical ground model and the ecological and archaeological aspects of the site.
Further discursive accounts of BS 10175:2026 can be found at:
https://bit.ly/4qWRQJ8 and BS 10175 – Executive Briefing
Finally, thanks to all those who contributed to the revision BS10175. It would not have come to fruition without the efforts of BSI staff, the members of the drafting panel, and all those who found the time to comment on the Draft for Public Comment (DPC). The public comment stage is vital for the technically sound development of all British, European and International Standards.
[1] Greater London Council (GLC) – Materials Information Group, Development and Materials Bulletin (2nd series) No. 98, Aug/Sept 1976 – “Some guidelines for the re‑use of industrially contaminated land.”
Or see:
Chapman W B, Baker P and Burns D, Some guidelines on the re-sue of industrially contaminated land, Journ. Assoc. Public Analysts, 1977, Vol 15, pp 1-25. [Paper to Symposium on Toxic Waste and Environmental Pollution, London, March1976].
| Box 1: A few key definitions in BS10175:2026 |
| Conceptual site modelB is defined as:
“synthesis of all information about a potentially contaminated site relevant to the task in hand with interpretation as necessary and recognition of uncertainties.” ContaminationA is defined as: “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 to cause pollution.” Note that no judgement is made as to whether the presence of the contamination matters. This will depend upon the context, including what is present, how much is present and what are the actual or potential receptors (e.g. humans, groundwater, etc.). SoilA is defined as: “topsoil and subsoils; deposits such as clays, silt, sand, gravel, cobbles, boulders and organic matter and deposits such as peat; material of human origin such as wastes; ground gas and moisture; and living organisms.” Sources: A – BS10175:2011, B – BS EN ISO 21365:2020 |
Article provided by Mike Smith, Chair Technical Committee EH/4 Soil quality