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.