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STANDARD PROCEDURE

GEOENVIRONMENTAL ENGINEERING

The Environment Agency's MCerts accreditation for contaminated land laboratories comes into force in September, with implications for all involved in environmental work. Hazel Davidson reports.

Acrucial stage in the land remediation process - the testing of soils to determine how contaminated they are, and with what - is about to undergo a dramatic change.

The industry has been in dialogue with the Environment Agency (EA) for several years, a process made much more efficient by the recent assistance of the Environmental Industries Commission (EIC).

These discussions will culminate in the requirement, effective from September 2004, that all contaminated land testing must be performed by MCerts accredited laboratories.

The EA's Monitoring Certification Scheme (MCerts) standards are intended to improve the quality of sampling and analysis, to regulate suppliers and to provide a better framework for consultants and clients to evaluate and compare data.

MCerts accreditation for air/ stack monitoring has been in place for almost two years. The EA published MCerts Version 2, for soil testing, in May 2003. The first laboratory received accreditation in April this year.

Contaminated soil testing became a growth market from the early 1980s, with many small laboratories (and water companies) jumping on to the bandwagon.

Unlike water analysis, there were few well documented methods for soil testing available.

Most laboratories used in-house modified versions of USEPA (United States Environmental Protection Agency) methods, developed new techniques, or adapted water methods.

This resulted in a plethora of methods, many of which were not particularly fit for purpose (for a range of soil types), and produced inconsistent data when samples were sent to different laboratories.

In 1993, the DTI, working with Valid Analytical Measurement and the Laboratory of the Government Chemist, set up a proficiency testing scheme called Contest, and most laboratories involved with testing contaminated soils subscribed to this. It became apparent that the spread of data was very wide.

In 1996, the DTI set up a series of focus groups to investigate the problems experienced in various analytical fields. The committee for soil testing was known as Eagle (Environmental Analysis Group for Laboratory Excellence).

Eagle decided to pool the Contest data, to compare methods and determine the most appropriate procedures. It rapidly became apparent that the major discrepancies in data were caused by different sample preparation and extraction techniques and that the end analytical methods were less prone to significant variation.

Over the next year or two, the Eagle laboratories harmonised on the critical points of the most commonly requested analyses, and these were issued to the EA in a document known as Sacs (Specification for the Analysis of Contaminated Soils). This document provided input to the MCerts programme for contaminated land laboratories, and a draft version of the standard was published in February 2002.

However, Eagle members were unhappy with many aspects of the draft standard, and found their concerns were not being listened to.

To gain access to professional lobbying capabilities and promotional expertise, Eagle merged into the EIC, becoming its Environmental Measurement and Monitoring Working Group in July 2003.

Quite quickly, the EIC implemented an EIC/EA/UKAS (UK Accreditation Service) MCerts steering group. This meets regularly and provides a channel for the industries that will work with and be affected by MCerts to raise their concerns and share their expertise with the EA.

EIC also prepared a leaflet explaining the implications of MCerts for consultants which the group members disseminated to their clients late last year, spelling out new responsibilities with regard to choosing laboratories and reporting data.

Compliance with MCerts involves rigorous performance testing of all accredited methods, involving three different matrices (clay, sand and topsoil), at low and high concentrations, over a minimum of 11 days in duplicate.

CRMs (Certified Reference Materials) must also be run to prove a method is fit for purpose, and the precision/bias data must meet the EA's performance targets, as defined in the MCerts document.

Reporting formats also needed several changes, as more information is required by the EA. For example: sample descriptions; temperature of drying; whether analysis is performed on wet or dry samples; and the status of the analysis with respect to both ISO 17025 as well as MCerts accreditation.

MCerts states that all tests must be accredited by September 2004, not just the laboratory, and this may prove problematic for the less common parameters. The EA is producing regular briefing notes, and is likely to produce a Version 3 this year. It has also recently published guidance notes for consultants and end users.

The group is now pushing to have the MCerts requirement extended to leachate testing and on-site sample collection techniques, as these are integral parts of the site analysis process.

Overall, the MCerts standard is beneficial to the construction industry as a whole and will improve the quality of data produced by the laboratories; this has been the most significant outcome of all the validation work so far.

In the short term, some smaller laboratories may decide not to attempt accreditation, and will therefore no longer be competitive in the market. MCerts will help consultants and end users to gain a better understanding of the uncertainties associated with the data, and thus improve the risk assessment process.

Consultants and others involved in the commissioning of analytical work, the collection of samples for such work or the interpretation of results, should familiarise themselves with MCerts.

Hazel Davidson is operations manager of ALcontrol Land, part of ALcontrol Laboratories, a member of EIC's Environmental measurement and monitoring working group.

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