EHJ April 2003, pages 100-103 Roger Braithwaite says he is "exasperated" by the "intolerable" position the Government has placed local authorities in when it comes to enforcing the contaminated land regime. Here he says why

Having taken a wholly unnatural interest in contaminated land for the last 15 years, I am now embarrassed about the fact that, after all this time, I am still groping in the dark trying to answer the following simple question about land known to be contaminated: "so what if it is?"

Tomes of guidance exists on strategy formulation, data handling, industrial processes, priority contaminants, site investigation, site characterisation, model procedures, where to dig, how to dig, how to drill, how much to sample, where to sample and when to sample. We have UKAS accredited laboratories that use mind bogglingly expensive state of the art technology to extract milligrams from kilograms and micrograms from litres. Yet when we have completed this costly and time-consuming exercise, what do the pages of numbers we receive from the lab tell us? A little or a lotto?

A new beginning in contaminated land regulation was heralded in with 33 pages of primary legislation in the form of section 57 of the Environment Act 1995. This replaced (for all intents and purposes) a mere 17 words that had served us well since the beginning of time: "any land in such a state as to be injurious or likely to cause injury to health". Not only 33 pages, but also new contaminated land regulations and a lengthy circular with detailed guidance from the Secretary of State that we had to wait a further five years for. Some of the stated aims were for:

• a more tailored regulatory mechanism;
• improved focus and transparency of controls;
• increased consistency of approach by different authorities; and
• enabling of all problems resulting from contamination to be handled as part of a single process.

All in all, the new system seemed to promise the earth - ambiguity removed forever, robust and clear procedures to follow, and consistent and reliable outcomes. But has it worked?

As an independent environmental health practitioner specialising in contaminated land investigation, assessment, and training, I meet local authority officers the length and breadth of the UK every week who are struggling to come to terms with, what seems to many, an impossible regime. The complexity of the law is only exceeded by the nightmarish confusion and costs relating to the investigation and assessment of contaminated land.

The problems are far too many to consider in any detail here. But, let's briefly contemplate one: the assessment of contaminated land and how you answer the simple question above - so what if the land is contaminated, does it actually matter?

Environmental health staff have been given the task of implementing this challenging new regime. Not something to shirk from, after all they have been identifying hazards and assessing risks for over 150 years. How is this done? Invariably, by quantifying a problem and then enforcing against a known standard. A standard that has been objectively calculated by those in the best position to judge using all the known scientific and technical data at their disposal. This is without doubt a most complex task that requires great knowledge and skill. As well as an exhaustive technical exercise, it sometimes takes a difficult political judgement too, as desired outcomes in a perfect world are often unachievable in the real one.

As a result, we have standards for drinking water, rivers, air quality, emissions from chimneystacks and car exhausts, hundreds of chemicals, dust and fibres in the workplace, food and noise at work etc. Our library shelves are groaning with lists of standards dictated by environmental, safety and health law. But not for contaminated land.

Only last month, we were notified that our trusty old friend the ICRCL "trigger value" had been consigned to the contaminated land dustbin.1 Developed in the late 1970s and early 1980s by Mike Smith, the then Secretary of the Committee, these were a short list of contaminants (19) we were told to beware of when considering the redevelopment of contaminated sites. Not only this, we were also offered (for some) two "trigger" concentrations in soil: the first below which you could be sure all would be well for the proposed use; the second above which it would not. In between, you decided for yourself, depending on the risks presented by the development. These were known as the threshold trigger value, and action trigger value respectively. Reassuringly simple.

While never considered scientifically robust by the establishment, there was little else to use, so these standards have formed the backbone of contaminated land remediation for the last twenty years. Your house may well be built on land based on these now redundant standards, so if it is, are you safe?

Well, now we have CLEA 2 and the Government has said: "The ICRCL trigger values are not suitable for assessing 'significant possibility of significant harm to human health' in the context of the Part IIA regime..." While in contrast, CLEA's new soil guideline values (SGVs) are. Unfortunately for those of us whose houses are built on "ICRCL land", four out of the seven SGVs calculated to date are lower than the respective ICRCL threshold trigger values. Bear in mind also that CLEA SGVs are "intervention values", ie levels above which there is an unacceptable risk to human health (similar to the ICRCL action trigger value). They are not clean up or remediation standards, which we have to determine ourselves.

The CLEA SGVs are calculated to protect humans against chronic, lifetime risks from single contaminants at the ground surface. They do not consider pathways via drinking water pipes, well water, surface water, eggs, milk, meat or fruit. They do not consider human short-term acute risks or risks while at work. Neither do they consider the effect of combinations of chemicals, or radiological or biological risks.

Part IIA lists several other receptors (as well as humans) which we must also have regard to including: commercial or domestic crops such as fields of potatoes or cabbages on the allotment; cats, dogs, pigs, cattle and other livestock (classed as property); ancient monuments in the ground and most buildings, including relevant services to those buildings; ecosystems right down to your local nature reserve; and importantly, controlled waters, as defined, which includes virtually all water except self-contained garden ponds.

As if all this was not going to cause sufficient confusion for local authorities, the Government has identified approaching 50 elements or compounds that are classed as "having the potential to affect human health and the environment", 3 but only seven SGVs have been calculated to date. Where there is no SGV, do-it-yourself is advised using reliable toxicological data - but the Government has published toxicological reports for only one additional contaminant. 4 So if you want to do-it-yourself, a PhD in human toxicology and a few months on the internet are desirable. Even so, the chances of any two "experts" arriving at the same conclusion in any one instance must be pretty remote.

The fact is, to undertake this type of work you do not only have to be an all round genius and good egg, you also need decades of experience and endless spare time. I class myself as a reasonably well-informed contaminated land generalist, and I would not consider attempting to generate a soil guideline value under any circumstances. I would, however, be more than happy to cross examine in the witness box any well-intentioned contaminated land officer who feels that they know it all. It just is not possible.

Apologies if a little exasperation is showing through, but I genuinely believe that local authorities have been placed in an intolerable position by the Government. Every council in the country has been given the task of enforcing one of the most complex regimes on the statute book, but left high and dry without the tools to do the job. We could not be further from the stated aim of increased consistency. A clear lead must surely now be offered by the centre and sliding scales of soil guideline values and remediation targets produced for all priority contaminants linked to all statutory receptors. These must be established on current knowledge and experience and where they are not based on a full scientific understanding then this must be made clear in the same way the Dutch have done with "indicative levels for serious contamination".5 Is this too much to ask, or is it time to revolt?

References:

1. Interdepartmental Committee on the Redevelopment of Contaminated Land. Seven ICRCL guidance documents are still listed at DEFRA publications, tel: 08459 556000.
2. Contaminated land exposure assessment model (CLEA), Environment Agency R&D Publication CLR10, available free via: www.defra.gov.uk
3. Potential contaminants for the assessment of contaminated land, Environment Agency R&D Publication CLR8, available free via: www.defra.gov.uk
4. Collation of toxicological data and intake values for humans. Inorganic cyanide, Environment Agency R&D Publication Tox5, available free via: www.defra.gov.uk
5. Indicative levels for serious contamination, taken from Annex A of the Circular DBO/1999226863 on target values and intervention values from the Netherlands Ministry of Housing, Spatial Planning and Environment, February 2000. These values are established where there is inadequate ecotoxicological data to allow intervention values to be set.

Roger Braithwaite is an independent environmental health practitioner, Law Society approved expert witness and public sector training specialist. He is also director of Zero Environment Ltd. Tel: 01926 624966, fax: 01926 624926, e-mail: roger@zeroenvironment.co.uk or visit: www.zeroenvironment.co.uk