The new designations are based on the almagamation of the former NRA Groundwater Vulnerability maps and British Geological Survey mapping data.  Aquifers are split into two different classes; those within superficial (drift) deposits such as sands and gravels, and those within bedrock (solid permeable formations) such as sandstone, chalk and limestone.

The new aquifer designations are:

Principal Aquifers - a layer of rock or drift deposits that have high intergranular and/or fracture permeability – meaning they usually provide a high level of water storage.

Secondary Aquifers – a wide range of rock layers or drift deposits with an equally wide range of water permeability and storage.  Secondary aquifers are subdivided into two types:

Secondary A – permeable layers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of base flow to rivers. 

Secondary B – predominantly lower permeability layers which may store and yield limited amounts of groundwater due to localised features such as fissures, thin permeable horizons and weathering. These are generally the water-bearing parts of the former non-aquifers.

Secondary Undifferentiated – assigned in cases where it has not been possible to attribute either category A or B to a rock type.  In most cases, this means that the layer in question has previously been designated as both minor and non-aquifer in different locations due to the variable characteristics of the rock type.

Unproductive Strata – rock layers or drift deposits with low permeability that have negligible significance for water supply or river base flow.

Further information and guidance on the use of the new aquifer maps can be viewed on the Environment Agency website
http://www.environment-agency.gov.uk/homeandleisure/117020.aspx

BBC Radio 4’s Costing the Earth entitled ‘The Big Clean Up’ (follow link to listen) plays heavily on past mistakes by developers and regulators on contaminated land.  These mistakes (often catastrophic and occasionally subjective) result in human suffering and feed public fears and anxiety that regulations for the clean-up and development on brownfield land are inadequate.

Of foremost attention is the recent ruling against Corby Borough Council that it was negligent in its duty-of-care for the way it had dismantled a disused steelworks resulting in the release of ‘toxic’ dust deemed to have realistically caused local birth defects.  Despite clear breeches of reasonable duty-of-care the evidence of a direct causal link is uncertain.  Whatever the outcome of Corby’s application to the Court of Appeal, this ruling is being used by many as leverage to block brownfield redevelopment. 

The science behind the assessment and remediation of contaminated land in the UK is well established yet forever in constant debate.  In many respects this is a good as it prevents complacency and promotes development of a clearer understanding.  As consultants, it is an important lesson in how to handle public concern and communication at the earliest opportunity.  Whatever the scientific and regulatory opinion of contaminated land assessment and remediation works, it is very often as important to also convey this opinion at a public level.

It is stated that the decision “follows work over the last year to examine the implementation of the current regime, and input from a wide range of stakeholders.  It is now ten years since the Statutory Guidance was first introduced and we believe that there is a strong case for considering where it could be amended to reflect experience in delivering the regime and developments in our scientific understanding.”

“Defra will be meeting with key stakeholders in the contaminated land sector to discuss where improvements to the Guidance could be made with the aim of formally consulting on proposals to amend the Statutory Guidance later this year.  While this work proceeds, Local Authorities should continue to fulfil their legal duty to identify and deal with contaminated land. ”

Tom Coles from Defra’s Contaminated Land Policy informs that due to potential for changes to the Statutory Guidance, Defra will be postponing the publication of the proposed best practice guidance on contaminated land decision making until after any changes to the Statutory Guidance are made.

Dioxins are a family of compounds and are an unwanted byproduct of combustion.  They have been referred to as amongst the most poisonous compounds on Earth.  Natural sources include forest fires and volcanoes and are the most prominent environmental contributor.  On a local and regional level, man-made sources can prove to be highly significant; sources include power plants, waste incinerators and industrial processes (notably iron/steel and paper industries).

Humans derive most (estimated 90%) of their dioxin load from eating meat, dairy products and fish and from surface contamination of vegetables and fruits.  Dioxins (and pcbs and furans) are identified to have human developmental and reproductive impacts even at low (above natural background) levels.

The dioxin TCDD (2,3,7,8-tetrachlorodibenzodioxin) is a proven carcinogen and is recognised as being the most toxic. Trials of animals fed on elevated levels of TCDD for sustained periods developed kidney, skin and hair problems, miscarriages, birth defects and cancer. The toxicology in the case of human beings is not clearly known but there is consensus of opinion that for adults, a relative high dose of TCDD is required to cause acute disease and fatalities.  For children and foetal development, the impacts are significantly greater.

Ukraine President, Viktor Yushchenko, survived being poisoned by TCDD during the country’s 2004 election campaign.  Dioxin levels recorded in Yushchenko’s blood were reportedly 50,000-fold greater than normal.  Politics aside, and not condoning the use of such extreme measures, this incident did provide a rare opportunity to monitor human dioxin degradation and metabolism.

The British Medical Journal, The Lancet, published an article in October 2009 (Volume 374, Issue 9696) reporting on the subsequent studies of dioxins elimination in Viktor Yushchenko.  The half-life of TCDD in humans is around 5-10 years due to it high lipophilicity (fat binding property) and low metabolic breakdown.  The study on Yushchenko assessed his half live of TCDD to be around 15 months.

There is obviously some significant human variance in the rate of elimination and degradation of TCDD (and other dioxins).  Fat content is thought to be a major factor.  Yushchenko’s ‘rapid’ reduction in TCDD levels may account for a slender profile, however age and metabolic factors also play significant roles.  A one-fit-rule in deriving an acceptable daily intake value will not always be appropriate although it would be difficult to apply and regulate otherwise. 

Dioxins, derived from volcanoes and forest fires have contaminated Earth long before humans arrived, yet we seem to have evolved mechanisms which allow them to live with natural ambient levels.  Anthropogenic impact has resulted in elevated exposure of local populations, ie those living around industries, hazardous waste tips and incinerators.  A significant role of the risk assessor in such cases should be to determine the type and ratio of dioxin, as some, like TCDD, are far more toxic than others, and so even a slightly elevated (above background) presence of dioxins may be highly significant.

Least not forget the human impacts of dioxins on incidents such as Love Canal, widely recognised as one of the world’s greatest environmental disasters.  Lately, dioxins are also suspected for the significant increase in facial tumours and resulting deaths amongst Tasmanian Devils.

LINK: Contaminants in soil: updated collation of toxicological data and intake values for humans: Dioxins, furans and dioxin-like PCBs in soil

Public empathy for environmental regulation often takes a nose-dive during a recession despite the key service that local authority environmental departments undertake.  With respect to contaminated land, many authorities are vigorously reducing back this service to ‘core’ functions.  This may be good time to determine what the ‘core’ function is – a lot of people don’t know.

Part IIA of the Environmental Protection Act 1990 was imposed in by the Environment Act of 1995.  This is the key legislation that places obligation on the government to manage contaminated land.  It was not until April 2000 that the regulations and formal guidance was released placing this duty on local authorities.

Ultimately what constitutes a ‘core’ function will be a local decision, and contaminated land is a bigger issue and has a higher profile  in certain authorities than others.  In essence the legislation requires authorities to have produced an Inspection Strategy.  These were mostly written back in 2000 and very few have been significantly updated since.  It’s strange but there is very little in the legislation that suggests an authority has to actually implement its strategy. 

Regulatory ‘consideration’ of contaminated land issues is wider in scope.  Planning Control, Building Control and Policy departments all have duties in some form to consider contaminated land.  Planners (if they’re keen) will refer to Planning Policy Statement No.23 and Building Control officers will refer to Part C of the Building Regulations.  There is nothing however requiring local authorities to physically undertake this assessment work; just ensure that it is completed.

There is nothing stated that requires authorities to have a dedicated Contaminated Land officer.  Some authorities have teamed up and share officers thereby reducing staff costs.  Others place day-to-day contaminated land duties on to Environmental Health teams.  In most authorities there is a dedicated officer yet their duties will often be combined with others such as air quality management.

Contaminated Land officers are a funny breed.  There are many well qualified and pragmatic officers who will engage well with consultants, developers and land-owners.  There are some however that will endeavour to scrutinise and reassess consultants’ reports over and over.  There is nothing wrong in questioning and satisfying oneself with a clear understanding; it is something we encourage and consider it invaluable in making us better consultants, it does however draw criticism in that this is not the ‘duty’ of the authority’s.  The emphasis of the legislation places the duty with the developer.

It is our view that having a dedicated Contaminated Land officer is essential for all local authorities.  Having a knowledgeable regulator that knows their area and associated issues is vital.  In our work as consultants, we take seriously the advice of Contaminated Land officers.  In a time where the approach of contaminated land assessment is still greatly open to professional scrutiny, having a ‘helping’ hand to discuss, progress and share the burden of decision making is greatly welcome.  Duty or no duty, and even at the continuing expense of liaising with the occasional megalomaniac officer, it would be a sad state of affairs if many authorities did away with contaminated land posts and offloaded responsibility.  There must be better ways to make savings.

Warren Anderson was the CEO of Union Carbide at the time of the Bhopal disaster in 1984.  Widely recognised as the world’s worst industrial disaster in which thousands died and many hundreds of thousands suffered from health impacts.

It must rank as any CEO’s worst nightmare. 25 years on from the tragedy in Bhopal, an Indian court has re-issued an arrest warrant for the former CEO.

Union Carbide manufactured pesticide for the Indian market, using a chemical methyl isocyanate.  The introduction of water into a tank containing the chemical, led to a reaction that resulted in the toxic gas release. The dense gas affected thousands of nearby residents leading to massive loss of life and suffering.

Despite unproven claims that the cause was sabotage, there were clear failures on the part of management to contain such a problem. Safety equipment was inadequate resulting in the system that was vulnerable to cataclysmic failure.   Certainly for a company dealing with toxic chemicals, greater protection measures should have existed.

In addition, staff reductions and lower levels of training for those dealing with the most dangerous chemicals had been introduced. Standards had slipped overall, in comparison with the operation pre-1982 when health and safety factors had been held in high importance.

Other factors came to light after the event. For instance, all supervisors were taking a break at the same time, in contrary to company procedure. Once the scale of the disaster became known, operatives altered records to try to cover up any evidence that might be used to suggest they were to blame for the leak.

Union Carbide may been seen to be unfortunate in that up until the time of the disaster the company was accepted as not being particularly badly run.  Its systemic failings were no worse than other companies where fatal incidents had occurred, however the consequences of these didn’t achieve anywhere near the scale of those at Bhopal.

In essence, Union Carbide did not know enough about how its Indian subsidiary was managed. Its failure ultimately was to not take ownership in a real sense and grasp an understanding about its risk of operating in a different country. It’s one thing to oversee and manage day to day operations – what about when it all goes horribly wrong?

The legislation only relates to synthetic chemicals and not natural materials, many of which are poisonous:  modified natural chemicals are treated as synthetic.  Over 100,000 synthetic chemicals are used to manufacture products for the market place and since 1981 Europe and the USA have been safety-testing all novel compounds that have/are being produced but these represent only 3% of those in use – many of  the 97% of the  ‘older’ chemicals have received little or no attention. These are now to be addressed by the REACH legislation.

The Nature publication suggests that those who drew up the REACH proposals, “had underestimated the scale of the challenge”.  In the pre-registration of chemicals which ended in 2008, almost twice as many companies than expected had made submissions relating to more than 140,000 chemicals (almost five times as many as expected). The safety analysis of all of these materials was supposed to be completed by 2018 but in view of the complexity of the task, the completion date would now seem to be far beyond this date. In recent times Europe has only been testing 200-300 chemicals a year so to cope with the ‘REACH load’ there will need to be a large increase in investment and effort.

The problem with the synthetic, factory-produced derivative is that if there is the slightest hint, no matter how low the probability, that it could cause ill health then the media will invariably exaggerate this danger. The result will be large numbers of people who will demand caution and a ban on the use of the chemical no matter how important it may be for the economy.

The widespread application of REACH legislation in the UK is important to protect people from clearly identifiable chemical hazards particularly those who work in the chemical industry. However, if its application is over cautious or poorly implemented, it may not protect people from redundancy and the country from economic damage.

As a final thought, a recent Lancet publication predicted that children born now are likely to live for 100 years. This is without the future intervention of REACH and so the synthetic chemicals in the environment may not, so far, be a significant health problem in terms of longevity.

Following the ruling, Corby Borough Council said: “The judge concluded that this contamination affected pregnant women. A child, so affected, has 21 years from birth to make a claim and thus any work since the late 1980s which has not met the standard of care indicated in this judgment could be challenged in this way. For both local authorities and developers alike this is a significant concern because the standard of care has been drawn very highly, and could cause a rethink of the way that reclamation is carried out in the UK, even though the facts of the case are historic.”

Link to full judgement (external site)

They are not definitive studies but they introduce some of the technical considerations that need to be borne in mind at the start of an investigation for possible contamination.

The 47 original publications in the series have been scanned and created into PDF documents by Defra and are now available as free PDF downloads. As a result the quality of the documents are poorer than normally provided by both Defra and ourselves.

However their usefulness to the risk management process is such that the decision was made to provide access to them in this format.

Original printed versions of the documents are still available for purchase from the Defra website from their land quality pages.

Link to DoE Profiles (external site)