Article Contaminated Land Laboratories

Weighing up the Risk

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Ecological Risk Assessment (ERA)

A new framework for assessing risks to ecological systems from contaminants in soils was published by the Environment Agency in October 2008, superseding the draft methodology from 2004. The new methodology is designed to establish whether pollutant linkages are likely to exist between soil contamination and designated ecological receptors, and to gather information for making decisions on whether harm to receptors is occurring or could occur in the future.

The ERA framework fits into the established structure of the Environmental Protection Act 1990 (Part 2A Contaminated Land Regulations) for assessing risks from contaminated soil and is now a standard part of contaminated land assessments where ecological receptors are identified.

As well as the contaminated land regime, the guidance is relevant to planning and pollution control, habitats and conservation regimes, and the Environmental Damage Regulations. ERA will be applicable either for assessing risks during a due diligence process or for under-writing environmental insurance. It is also appropriate for assessments relating to environmental permit applications or for justifying an appeal against an Environmental Damage Notice.

The framework follows a three-tiered process:

  1. Screening: compares chemical data to UK published soil screening values (SSVs) or with published data from other countries;
  2. Survey: the use of ecological surveys and bioassays to gather evidence of harm to receptors;
  3. Assessment: the establishment of a connection between the established harm to the species or habitat and the soil contamination.
Soil Screening Values (SSVs) have been published for twelve compounds. The assessor can use the published values or derive a “predicted environmental concentration” specific to the site, using a simple “decision tool” that is available on the website.

SSVs are based on a “predicted no effect concentration” to an ecological receptor and are, therefore, extremely conservative. Published values are lower than equivalent guideline values for human health. Exceeding SSV triggers further assessment and is not an automatic requirement for remediation.

 

At PBA, we have already updated our existing assessment procedures to take account of the new framework and will continue to provide a full range of contamination and ecological services to enable effective management of ecological risks from soil contamination.

Jenny Allen (Environment)
jallen@peterbrett.com

Catherine Copping (Geo)
ccopping@peterbrett.com

Article Contaminated Land Laboratories

Testing times for soils

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The Environment Agency has issued a revised version of its MCERTS policy for the chemical testing of soils. The Agency established its Monitoring Certification Scheme (MCERTS) to ensure high standards of environmental monitoring, and in 2003 it extended the scheme to include soils testing. The Agency’s policy is that the MCERTS standard should apply to all chemical testing of soil where the results are submitted to the Agency for regulatory purposes.

This latest version of the policy clarifies the Agency’s position on in situ testing. The Agency believes that in situ testing has a valuable complementary role to play in improving the quality of site investigation and remediation as well as reducing costs. Appropriate on site testing can be used for improved targeting of conventional sampling, better spatial delineation of contaminated areas, and the development of conceptual site models.

The document has been published on the Land Contamination section of the Agency’s web site at:

http://www.environment-agency.gov.uk/subjects/landquality/113813/590825/?version=1&lang=_e

Article Contaminated Land Laboratories

Reinforced soil design code to be revised

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When BS 8006, the code of practice for Strengthened / Reinforced soils and other fills, was first published in 1995, it was acclaimed as an international benchmark in the field. Nearly ten years on, the Standard remains the most comprehensive National Standard on reinforced soil, and is adopted as practice in many other countries. In keeping with BSI policy, the Standard BS8006 is presently undergoing its 10 year review and it is expected that new developments in the field and the development of new European standards, will be included in the revised Standard thus ensuring it remains at the forefront of good practice.

In December 2003, British Standards Institution gave the go ahead to revise the document and BSI Technical Committee B 526/4 met to start the process in April 2004. Representatives are drawn from industry, trade associations and learned bodies (Institution of Civil Engineers (ICE), International Geosynthetics Society, Association of Geotechnical and Geo-environmental Specialists (AGS), Institution of Highways and Transportation (IHT), Association for Consultancy & Engineering (ACE), Department for Transport, Highways Agency (DfT), British Apparel & Textile Confederation (BATC)) to provide a mix of experience from the original drafting committee combined with input from some new members, all chaired by Steve Corbett of Faber Maunsell.

Several task groups have now been formed to review all of the main sections of the documents including the design of reinforced slopes, walls, embankments and soil nailing. Comments, suggestions, and proposals for improvements are invited from users of the document and other interested parties, either via their trade association or directly to the BSI secretary Sina Talal. It is hoped to provide regular updates on progress within Ground Engineering, as work proceeds. In the meantime, BS8006 should continue to be used until the new revision of the document is available, anticipated for 2006.

Please forward any comments or suggestions to committee secretary Sina Talal at SINA.TALAL@BSI-GLOBAL.COM.

Article Contaminated Land Laboratories

MCERTS

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The Environment Agency have advised that a policy titled ‘Chemical Test Data on Contaminated Soils – Qualification Requirements (307_03)’ has recently been published. The purpose of the policy is to implement the ‘MCERTS Performance Standard for Laboratories Undertaking Chemical Testing of Soils’, which was published in March 2003.

Chemical test data on soils is used by the Agency to support its regulatory activities under a number of regimes, such as Part IIA of Environmental Protection Act 1990, Pollution, Prevention and Control (England and Wales Regulations) 2000 and Waste Management Licensing Regulations 1994. The Performance Standard will be applicable to all laboratories and procurers of analytical services where results generated from the chemical testing of soil are presented to the Agency for regulatory purposes. After September 2004, the Agency expects that all soil testing results submitted will be from methods which have been accredited to BS EN ISO/IEC 17025:2000 for the MCERTS performance standard.

In the interim period, it is encouraged that all data provided to the Agency should be from a testing method accredited to BS EN ISO/IEC 17025:2000 and be accompanied by a brief method description, together with bias and precision estimates.

In addition to the policy, the Agency are producing a document for those who procure soil testing, for example consultants or local authorities, titled ‘Brief guide for procurers of analytical services’ which outlines what is expected of them and why it is required. All the documents mentioned above will be available from the Agency’s MCERTS website at www.mcerts.net.

Any technical queries relating to MCERTS should be addressed to Mike Healy, Technical Advisor, by email (Mike.Healy@environment-agency.gov.uk) and queries relating to the policy itself should be directed to Nicky Skidmore, Land Contamination Policy Advisor (Nicky, Skidmore@environment-agency.gov.uk).