Article Contaminated Land Laboratories

BS 10175 Updated

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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Statement 23: Planning and Pollution Control – Annex 2: Development on Land Affected by Contamination) is about to be withdrawn.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.


Article Data Management

Diggs ploughs on in quest for improved data handling

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The DIGGS (Data Interchange for Geotechnical and Geoenvironmental Specialists) working group is continuing.  DIGGS is an international initiative to extend the data transfer format not only to other countries, but also to other parts of the geotechnical industry, such as piling and infrastructure management. It has been based on the AGS data format, which is the only truly international data transfer format in use. At the same time the opportunity has been taken to implement modern IT technology such as XML and GML.

DIGGS is promoted by:

  • The United States Federal Highways Administration
  • The United Kingdom Highways Agency
  • Twelve US Departments of Transport
  • The United States Geological Survey
  • The United States Army Corps of Engineers
  • The United States Environmental Protection Agency
  • CIRIA (the UK Construction Industry Research and Information Association)
  • AGS (the UK Association of Geotechnical and Geoenvironmental Specialists)
  • COSMOS (Consortium of Organizations for Strong-Motion Observation Systems)
  • The University of Florida

Further details of DIGGS can be found at  and

DIGGS will be implemented through a group of SIGs, (Special Interest Groups) who will look after the national and disciplines within the geotechnical industry.   In the UK this will be the AGS and the next version of the AGS data format, which has the development title of “AGS4”, will be DIGGS compliant.  Work is underway to ensure that this version is thoroughly integrated with the interests of the UK Ground Industry, including the provision of specifications and contract clauses for its use.     Documentation for the users, developers and managers of companies using the format is in preparation.

Before it can be adopted, it is essential that the relevant software is available to implement this new format.  Whilst specialist software will be required to obtain maximum advantage, the fact that the format is in the universal XML language will open up the possibilities of using many other software packages directly.  This will govern the release date of the format, and it is inevitable and intentional that AGS3 will continue for some time into the future. It is intended that software to convert AGS3 files to AGS4 will be made available.

DIGGS will build on the AGS data format and be an opportunity to promote the work carried out by the Ground Investigation industry, to raise the profile of work and provide the means to streamline the work process. It provides the next steps for improved handling of data at all stages of a project from investigation through to construction and completion.  It will include geotechnical, geo-environmental, construction and asset management information within one system.



A Workshop will take place on 18 June, 2008 at the National Motorcycle Museum in Birmingham, the spiritual home of the AGS Data Format group.  The Workshop is provisionally entitled “Site Investigation to Piling, and the availability of Electronic data”.

Papers are invited, in particular case histories are always welcome

Article Contaminated Land Laboratories

ISO/TC190 Meeting, Paris Note prepared by Peter Rodd

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For the fourth year running I attended the ISO/TC190 Soil Quality meeting, this year in Paris. The meeting comprises sessions of the various Sub Committees and their working groups plus plenary sessions for the Sub Committees, and the TC190 and CEN TC345 (both Soil Quality) meetings. I attended 7 sessions.

As previously, I was representing the BSI committee EH/4 (Soil Quality) on which I serve, in turn, representing the AGS.

As with last year’s meeting in Brno, the Czech Republic, much of the general discussion concerned the Horizontal Project originally instituted by CEN. The purpose of this project is to harmonize standards across matrices.. Once a Horizontal Standard has been created and endorsed by CEN it becomes a European Standard and supersedes equivalent National Standards and International Standards within the EC. If it is also accepted by ISO the new standard supersedes the equivalent ISO Standard in the rest of the world; if not accepted by ISO it runs side by side with the ISO as a European Standard. It is now ISO TC190’s first function to respond to CEN requests to develop new standards while continuing to develop standards that have international support. Everything clear so far?

Although the function of EH/4, ISO TC190 and CEN TC345 is Soil Quality from the soil science perspective, there are clearly overlaps with geotechnical and geoenvironmental engineering, particularly in light of the Horizontal Project, and this is the reason why the AGS agreed to have representation on the EH/4 committee. Topics of particular relevance are the chemical test methods being developed that will be used for compliance issues arising from the sludge directive.

The function of EH/4 is to assist in the development and review of International and European standards, and to put forward comments received initially from the EH/4 sub committees on early committee drafts (CD), and at a later stage comments from interested parties more generally on draft international standards (DIS). The latter stage is where AGS members get the chance to make comments (which can be funnelled through me) to EH/4 and thence to the ISO TC190 working groups. The annual meeting is the usual forum for discussion of such comments. Following DIS stage the document becomes a final draft (FDIS) at which stage comments are largely restricted to editorial issues. The member countries then vote to determine whether the document should become an International Standard. If BSi give a positive vote and the document is passed as an International Standard it automatically becomes a British Standard. If a member country votes ‘No’ then they do not adopt the ISO standard, even if passed, as their National standard.

The sessions I attended were: ” CEN 345 – Characterisation of soils; ” ISO/TC 190 Plenary – Soil Quality; ” SC7 WG4 – Human Exposure; ” SC7 WG6 – Leaching; ” SC7 WG7 – Background Levels; ” SC7 Plenary – Soil and Site Assessment; and ” SC3 Plenary – Chemical Methods.

The CEN meeting concentrated on various existing standards and whether they were suitable as Horizontal Standards. Previously questionnaires had been sent to member countries to get their views but only brief responses were forthcoming. One standard of particular relevance to the AGS is ISO 11277 ‘determination of particle size distribution in mineral soil material – method by sieving and sedimentation’. It was felt by the delegates that this test method is time consuming and is not generally used, therefore, it will not be recommended as a Horizontal standard but will remain as an ISO and should be used as a reference method. Other test methods discussed were: ISO 10381-3 on safety, ISO 10381-4 Guidance on the procedure for investigation of natural, near-natural and cultivated sites, ISO 10694 organic and total carbon after dry combustion (elementary analysis), ISO 11261 Total Nitrogen, ISO 11263 Phosphorus spectrometric soluble in sodium hydrogen carbonate, ISO 14255 Nitrate, ammonium and total soluble nitrogen using calcium chloride, and ISO FDIS 16772 mercury in aqua regia. It was felt that none of the standards could be recommended to Horizontal without review and that ISO 10381.4 was to general and would conflict with national standards, and ISO 11263 was not used and should also not be recommended.

Registration of new work items for CEN and their terms of reference will be controlled by BT TF151, a task force set up for that purpose and to receive the Horizontal draft CEN standards. They will also co-ordinate the CEN response to these standards.

One item of interest from the ISO TC190 plenary meeting was that methods for the analysis of asbestos were considered to be outside the scope of soil quality and that TC146 will develop methods although TC190 will be involved in the handling and sampling aspects.

The SC7/WG4 session considered to documents; ISO 15800 on the characterisation of soils with respect to human exposure that was reported as having been issued as a full standard, and CD 17924 on the bioavailability of metals in contaminated soils – physiological based extraction method which will be amended in light of the discussions and comments received and issued as a DIS in June 2005. The stated aim of this document is to establish a list of parameters and is aimed at risk assessors.

I attended the second session of SC7/WG6 and discussion focused on CD 19492 ‘Leaching procedures for subsequent chemical and ecotoxicological testing of soils and soil materials – influence of pH on leaching with initial acid/base addition’. The procedure is considered to be generic. An annex will be added to explain the use of the various pH levels and extraction solutes. Validation of the method is required but funding will be required and so the document, initially, will be a technical specification. The delegates did not agree with the UK’s definition of ‘leaching’ but in any case it is defined in the document. It was considered that the agitation levels given in the document are likely to break most glassware, guidance was requested from the delegate countries. A guidance document was also discussed but this was at a very early stage of development.

SC7/WG7 discussed DIS 19258 ‘Guidance on the establishment of background values’ which was issued late due to a problem with obtaining the French translation. The DIS was approved prior to the meeting with only the UK disapproving. Although such a guidance document would be useful the EH4 committee considered that there is too much confusion in the document particularly with the terms that are used. In particular the term ‘usual background’ was considered to be somewhat imprecise and the main definitions will be re-written. Another problem with the document is that if it becomes a standard and the UK approve it, there may well be a conflict with BS 10175 which would probably have to be withdrawn.

On that alarming note I shall end my report. The next meeting will be in Japan in October.

Article Contaminated Land Laboratories

ICRCL 59/83 – Beyond 20 December 2002

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R G Clark, CL Associates

Most AGS members are aware or should be aware that ICRCL Guidance Note 59/83, 2nd edition was withdrawn by DEFRA in a letter from Steven Griffiths of the Contaminated Land Branch on 20 December 2002. The letter referred to the fact that the CLEA package (published by DEFRA and the Environment Agency), consisting of Contaminated Land Reports (CLRs) 7 to 10, the CLEA 2002 software, certain toxicological reports (TOX) and certain Soil Guideline Values (SGVs) is considered by DEFRA to represent the key instrument for generic assessment of the human health risks from contaminated land.

The reasoning put forward for the withdrawal of ICRCL 59/83 was that the guideline values are out of date and that they are not in line with the current statutory regime (Part IIA of the Environmental Protection Act 1990) and associated policy.

Up until that time many practitioners had relied heavily on the use of the ICRCL 59/83 guideline values for assessing human health risks associated with contaminated land. Others had already started to use alternative risk based methodologies such as RBCA, R&D P20, SNIFFER and of course CLEA. In many instances ICRCL or Dutch guideline values were used as a first screening before progressing to a quantitative risk assessment (QRA) for those contaminants of particular concern that were above the guideline values for a particular site.

The letter dated 20 December 2002 was immediately followed by a Briefing Note, also dated December 2002, from the Contaminated Land Branch of DEFRA. This briefing note emphasised that ICRCL 59/83, and especially Tables 3 and 4, should no longer be used. It can be noted that other ICRCL guidance has not been withdrawn. The DEFRA Briefing Note recognises the continued use of these other ICRCL guidance documents provided that they are not used as the sole source of information on which decisions are based.

A number of Local Authorities have now adopted the position that for the assessment of contaminated land, only UK based guidance is applicable. They will, therefore, no longer accept both ICRCL 59/83 and the Dutch Guidelines. In effect this means that where no published SGV exists then it is necessary to carry out a site specific QRA for each contaminant even before an initial screening can be undertaken. This constitutes a potential problem where there is also no TOX Report available, in that each organisation that carries out such risk assessments has to source appropriate and verifiable toxicological data.

An update of the existing CLEA Model was published in March 2003. A new version of the CLEA Model (open architecture version) is anticipated which is a spreadsheet version that allows more user-functionality.

SGVs have been published for Arsenic, Cadmium, Chromium, Lead, Mercury, Nickel and Selenium. TOX Reports are available for Benzo (a) pyrene, Benzene, Inorganic Cyanide, Dioxins, Furans and Dioxin like PCBs but no SGVs. The Environment Agency have stated that they will be issuing additional SGVs in batches of 5 or 6 at quarterly intervals over the next 2 years.

But what is to happen in the interim ? – chaos according to some. At various conference and technical committee venues both consultants and Local Authorities have expressed their concerns over the rapid withdrawal of ICRCL 59/83 without a sufficiently comprehensive UK alternative being available.

In conclusion, AGS members should be aware of their responsibilities to their clients. If a geoenvironmental specialist were to continue to use ICRCL 59/83 in reports that they prepare for a client and those reports are subsequently submitted for approval to a regulator (such as part of a Planning Application) or to some other body such as a funding organisation and are rejected due to the use of ICRCL, it may very well be considered that the specialist has failed in its duties to the client because it has used reference material that has been officially withdrawn.

Equally there is a risk that the use of Dutch guidelines could be rejected. This will depend on the approach of the particular regulator. The alternative, apart from using the CLEA Model, is to use SNIFFER etc (see above). However, for all of these methods it is necessary to research toxicological data and to be able to verify these data within a UK context. Site specific criteria are therefore being based on a variety of sources of toxicological data of varying quality. How are those, such as regulators, who have the task of approving these derived values going to make judgements on the reliability and applicability of the toxicological data ?

There is no easy answer at present.