The Way Forward: why it is still unclear for many

Despite the Government publishing the outcomes of its Way Forward exercise on soil guideline values, much uncertainty still surrounds it, argues Paul Sheehan

In July of this year, Defra released the outcome of the Way Forward exercise on soil guideline values (SGVs). The document announced improvements to the technical guidance that helps assessors decide when land qualifies as contaminated land under Part 2A of the Environmental Protection Act 1990. It gave details of the package of improvements, and explained how it relates to Defra’s Way Forward exercise.

While this long-awaited document is to be welcomed, a degree of uncertainty remains. The paper suggests that the more radical ideas – ideas that would have set down in guidance numbers or pointers as to where legal trigger points for the significant possibility of significant harm (SPOSH) might lie – will not be implemented.

The document confirms that parts of the Way Forward will be implemented, including new versions of CLR 9, CLR10, CLEA software and handbook. These measures are included in a list of 14 actions which also comprise:

  • Withdrawal of all the previous CLR7-10 documents
  • A technical review of body weight and height data used within the contaminated land exposure assessment (CLEA) model
  • A technical review of physical-chemical properties for use within the CLEA model for deriving SGVs
  • Once toxicology and exposure methodologies are published, the Environment Agency (EA) will update existing SGVs and produce new guideline values

Updating much of the existing CLEA guidance and publication of new EA documentation, with support from other government bodies, is due shortly and is seen as a positive move forward. But it is unfortunate that Defra suggests the more radical Way Forward ideas will not proceed – these are issues that really need defining.

Just not challenging enough
The changes, which would have altered the nature of the non-statutory guidance to describe where the legal trigger point might lie, are the changes everyone in the industry had been waiting for. It appears Defra had intended to implement these aspects, but as the work was being finalised it became clear that scientific and legal difficulties were insuperable.

With respect to scientific issues, Defra notes that any technical guidance used to make contaminated land determinations must be based on good science. But the Government’s scientific advisors appeared to have real concerns with the science proposed.

This is particularly with the proposals for trigger points linked to estimates of excess lifetime cancer risks, because of the uncertainties involved. So, does this suggest that future health criteria values will be calculated using the margin of exposure or another approach?

On the legal side, it would seem that government lawyers advise against using non-statutory guidance to indicate where the Government considers the legal trigger point of SPOSH should lie, given that there are no such thresholds in the law. They also note that even if they had full scientific backing, it is ultimately for the courts to decide what SPOSH is. And they would be under no obligation to take heed of non-statutory guidance.

The lack of scientific backing would raise a high risk that if the matter were ever tested legally, a court would take a different view. Does this suggest, therefore, that such a decision could be made via a statutory route – for instance, change in the primary/secondary legislation? If so, this will require a regulatory risk assessment, which is unlikely to take less than 12 months at the very best. The question is, what now for those involved with clients under pressure to make decisions in this continuing hiatus?

To support decision making, Defra has also published a document, Guidance on the Legal Definition of Contaminated Land. This guidance aims to clarify the definition of contaminated land in part 2A, particularly what is meant by stating that land is contaminated if it poses a significant possibility of significant harm.

Limited value in the meantime
While, undoubtedly, it is a positive move that more robust technical guidance is being produced, until we get to see this guidance, the value of this publication is limited. Local authority officers, and their advisors, will still have to make decisions without the support of either statutory or non-statutory guidance describing where the legal trigger point for the determination of contamination lies. This will leave local authorities even more exposed to legal challenges. It will also detract from efforts to provide a consistent approach.

What will happen, for example, if one local authority decides that 6mg/kg of a PAH in a back garden was significant – using a margin of exposure approach for a one-to-two-year-old child – whereas another decided it was only significant above 12mg/kg? It may be that we see councils face legal challenges from developers if they take the conservative option, and from householders if they do not. If this lack of decision-making by Defra does encourage such legal challenges, we will certainly be in for an interesting time.

Paul Sheehan is regional manager for environmental engineering at Parsons Brinckerhoff. He is also a member of the EIC’s contaminated land working group

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