Article Contaminated Land

SoBRA – Accreditation Scheme Launched July 4th 2016

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The Society of Brownfield Risk Assessment (SoBRA) was established in 2009 to support the growing number of professionals working in land contamination risk assessment. It recently launched a new accreditation scheme to demonstrate competence as a land contamination risk assessor. This is a standalone scheme. However, the scheme presents an opportunity for its members to demonstrate to a Suitably Qualified Person (SQP), under the Land Forum’s upcoming National Quality Mark Scheme, that they are sufficiently competent to support the SQP in undertaking or reviewing the risk assessment element of their project. For the many members of the AGS interested in land contamination this a great opportunity to demonstrate competency recognition.

SoBRA is a learned society for individuals, with membership drawn from the private, public, voluntary and academic sectors.  Its goals are to improve technical knowledge in risk-based decision-making related to land contamination applications and to enhance the professional status and profile of practitioners.

Risk assessment is a critical element in the evaluation of land affected by contamination and provides the cornerstone for wider decision making in land management.  To date there has been no single industry-wide scheme to demonstrate competence as a risk assessor. The SoBRA Register of Risk Assessors has been developed to fill this gap, recognising and rewarding the technical skills associated with land contamination risk assessment.

Inclusion on the SoBRA Register of Risk Assessors will not demonstrate that an individual is an expert but will demonstrate that the individual possesses the technical, scientific and communications skills required to design, perform and critically evaluate land contamination risk assessments.  The scheme is focussed on the technical detail associated with risk assessments but also requires that applicants have a broader understanding of the context and impact of risk assessment on the management of land affected by contamination.

The SoBRA Register of Risk Assessors has two grades of membership to reflect an individual’s experience and skills.  The entry level is Registered Grade; individuals who are capable of undertaking and/or reviewing routine generic quantitative risk assessments without supervision but who are likely to need some assistance or guidance in conducting more complex risk assessments.  The advanced register entry will be the Fully Accredited Member Grade which would be someone with a thorough understanding of land contamination risk assessment, with experience of carrying out and/or reviewing more detailed and site specific risk assessments.  On admission to the register, individuals will be permitted to use the post-nominal signature designations of RSoBRA and ASoBRA respectively.

As many risk assessors have differing levels of experience in different practice areas such as human health risk assessment or assessing risks to water environment or ecological receptors, registration entries will be linked to their specific areas of competence.  In very broad terms the two grades have been designed to be consistent with the Level 3 and Level 4 of the SiLC Land Condition Skills Development Framework.

The application procedure will require the submission of written evidence to demonstrate competency, attested by referees and attendance at an interview.  There is also a strict requirement for all register entrants to maintain membership of a professional body and a requirement for those seeking the Fully Accredited Member Grade to be chartered.

The first tranche of applications are anticipated to be accepted from July to October 2016.  If you are interested in being included on the register, then please visit for full details on the application requirements and start gathering your evidence for your written submission!

Follow us also on LinkedIn, for the latest news on technical issues, workshops and updates. See also our summer workshop in Bristol upon Risk Assessment to support Historical Landfill Redevelopment or simply visit our Stand at Contamination EXPO 2016 to learn more!

For editorial comment and contact on this please contact the SoBRA executive committee at


News Contaminated Land

National Quality Mark Scheme for Land affected by Contamination open for consultation

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The proposed National Quality Mark Scheme for Land affected by Contamination (QMLC) is a scheme that has been developed by the Land Forum to provide visible identification of documents that have been checked for quality by a Suitably Qualified and experienced Person.  It is hoped that this will provide increased confidence and improved quality of submissions made under regulatory regimes, particularly planning applications, related to previously used land.


Through endorsement by the Land Forum and through joint ownership by Land Forum members the scheme can be considered to have support and acceptance across the community and to be nationally recognised.


The initiative is supported in principle by the Department for Communities and Local Government and the Department for Environment, Food and Rural Affairs. A positive response has also been received from individual devolved administrations. The scheme is intended to be launched in autumn 2015.


The consultation is being led by the Land Forum to gather stakeholders’ feedback on the proposed National Quality Mark Scheme for Land affected by Contamination (QMLC) ( will run to May 15th 2015To participate in the consultation please follow the link:

News Contaminated Land

Panel debate on Asbestos in soil

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Understanding the risks posed by Asbestos in soil will be explored  through a panel discussion that brings together Dr Richard Ogden (co-author of CIRIA’s C733 document) and members of the AGS Contaminated Land Working Group. The panel debate will take place during AGS Members’ Day, on 18 March and is scheduled for 3.30pm.

Dr Ogden will be giving a presentation to put the discussion in context and introduce the known issues and inferred risks surrounding the presence of asbestos in soils. These include topics such as the risks on construction sites during and post works, what laboratory tests are required and the international effort to understand the soil-air relationship.

Following this presentation AGS Chairman Seamus Lefroy-Brookes,  Chris Swainston, Steve Moreby, and Contaminated Land Working Group chairman Neil Parry will join Dr Ogden to discuss the issues.


Report Contaminated Land

Contaminated Land Working Group Report

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Neil Parry, Chairman, CLG writes:

Our last meeting was held on 10th January 2015, 17 members attended. Below is a summary of ongoing activities.

Environment Agency (EA)

Further to the meeting with Bob MacIntyre (EA Hazardous Waste) a further (or extended) Working Group meeting is proposed once the Waste classification and assessment Technical Guidance WM3 has been published. Agreement from the Main Committee was required (Ann-Marie to forward additional room costs).


A separate working group has been set up to look into sampling protocols for contaminated soil and waste. We have been in contact with Murray Lark from the BGS and he has agreed to contribute to the sub group.


Karen Thornton reported on the statistics for NHBC and research projects on low energy, SUDS, soil stabilisation. A new Basement Construction chapter 5.4. A full review of standards is due to take place up to April this year.

Land Forum

Chaired by Seamus Lefroy-Brooks. Work being carried out on QMLC Scheme for competence.


SAGTA held a meeting at the beginning of February. It was agreed that Karen Thornton would feed back information from the meeting to the CLWG.


A panel discussion on asbestos will be held on Members’ day.


Further to the AGS Position Statement on the UKWIR guidance (guidance for the selection of water pipes in contaminated land) further monitoring of the general water company requirements will be carried out.


Roger Clarke reported that there has been a drive for more assessors as the numbers in SiLC increase.


Code of practice for the characterization and remediation from ground gas in affected developments. Some progress on the new draft reported by CLWG members involved.

Article Contaminated Land Data Management Laboratories

Contaminated Land Analysis – Introducing Doubt Into An Uncertain World

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Let’s be honest, to most of us in the ground engineering community, chemistry is something of a black art. It’s a subject we never properly understood at school and certainly not one we intended to revisit in our professional capacities. We can muddle through the uncertainties of soil mechanics and a few of us claim a vague understanding of finite element analysis. Imagine our horror therefore when chemistry abruptly re-entered our world in the form of contaminated land. Our inattention and tomfoolery at the back of class has suddenly come back to bite us. Hazy schoolday recollections of sodium fizzing around in the sink or the exploding magic green fountain aren’t going to get us out of this one.

And it gets worse! Chemistry is no longer even just a disagreeable side issue for many of us and on many developments it sits, gloating, athwart our critical path, knowing full well that not only do we not know the answer, we are often unsure of the right questions to ask as well.

So where is our white knight, to whom can we turn for help and enlightenment? In the past we might have turned to our laboratory for help. However over the last 15 years or so, there has been a complete rationalisation of the chemical testing market. Laboratories have tended to become bigger and more automated, offering cost effective analysis but consequently less consultancy support. Intense competition amongst the key players means that margins are so tight there is little room in modern production line chemistry for added value services. Testing has become a numbers game.

There are now several degrees of separation between the engineer and the chemist. Yet we are in fact very similar in one key respect and it is here that we close the circle. They don’t understand what we do and we don’t understand what they do.

Laboratories must adopt operating practices which enable them to make a profit under conditions of intense price competition. Their choices fundamentally affect the quality and reliability of the data they produce. We don’t even know what questions to ask and many laboratories in turn are less than forthcoming in disclosing the limitations of their data. We work together in blissful ignorance even though our interaction (or lack of it) has a critical influence on the quality of the data they produce and we then use.

Accreditation schemes such as UKAS, compliance schemes (e.g. Contest, WASP) and the recently developed MCERTS scheme championed by the Environment Agency are all designed to address quality issues in laboratory testing. However all have significant limitations which are not readily apparent and are certainly not advertised to a largely ignorant consumer.

So what’s the problem. Well the example in box 1 below illustrates this nicely. In it we have simulated total soil cadmium data from two simulated laboratories. One of the simulated laboratories is a reputable, highly regarded outfit with excellent quality control and in the case of our simulated sample it has if fact got an answer which approximates to the true value. The only downside is that quality costs and it charges £1 to undertake the analysis. The other laboratory has a less robust quality system and the cost savings allow it to charge just 50p for a cadmium determination. However its reported total cadmium concentration is in fact in this case woefully inaccurate. See if you spot the wrong answer.




Total Cadmium

 617.2 mg/kg Cd

 617.2 mg/kg Cd

The problem is of course that you can’t tell by looking whether data is reliable or not. Because buyers of chemistry are largely ignorant of chemistry, and the product we buy does not readily reveal its quality, then the key differentiator becomes price. Whilst there is an industry bottom line which we might say is policed by accreditation schemes such as UKAS, we should not be naïve enough to believe that this is in anyway a guarantee of a right answer. Now the punch line, and you fanatically precise engineers are not going to like this. We should recognise that even good data is not ‘correct’ in the right and wrong sense and that some degree of uncertainty is inherent in every result. Sometimes this uncertainty is very large indeed, 617.2 mg/kg could actually mean anything from about 80-1000 mg/kg and that should give us all some food for thought.

So what are the questions we should ask. Well here are some important ones for starters.

Basis, basis, basis

The basis on which you send your sample to the laboratory could be as follows. It is a cold and wet day. The wind is making life difficult and you are worried about getting caught in the traffic if you don’t get off site soon. You shovel a couple of kilograms of rubble into the bag and leave the bag by the gate for the laboratory to pick it up sometime later in the week. In a couple of weeks the laboratory (UKAS accredited as the contract specified) reports back to you and you are relieved to see the thiocyanate content is 24.7 mg/kg, just below your limit of 25 mg/kg. You’re in the clear, you can sign the site off – or can you? Have you considered these questions?

How was the sample prepared, and by whom?
What is the precision and bias of the method used?
On what basis are method precision and bias measured?
On what basis is the data reported?
On what basis is your acceptance criterion calculated?

Sample Preparation

We can’t emphasise enough how important initial sample preparation is. If it is not right then everything that comes after is wrong. Unfortunately good sample preparation is expensive, labour intensive and very repetitive – it is simply not fashionable and therefore often neglected. You will almost always find the least qualified staff in a laboratory carrying out the most important function – sample preparation.

Accreditation schemes accredit results and sample preparation does not produce a result. It is debatable therefore whether sample preparation falls within the scope of accreditation. Imagine that – you use a UKAS accredited laboratory and their single most important operation is not actually capable of being accredited and is carried out by the least qualified personnel in the company.

The Quality Control Con

Laboratory quality control focuses on the instrumental side of the analysis. QC data is usually generated from a point after samples have been prepared for analysis. Prepared QC samples or certified reference materials are finely ground, dry, inherently homogenous materials. Real samples are sun drenched, windswept, dirty, heterogeneous lumps. Don’t believe, therefore, that quoted QC data will necessarily bear any resemblance to that achievable in your samples.

For example the QC data for samples which are normally analysed wet (like cyanide) may in fact be determined on dry, ground reference soils which are spiked immediately before analysis. Doing it this way ensures excellent QC data but doesn’t really relate all that well to the true bias and recovery one might get from a mixed, wet contaminated soil.

Precision, bias, repeatability & uncertainty

Each measurement a laboratory makes is subject to any number of errors. Good laboratories minimises the impact of such errors by sound methodology and quality control procedures. You cannot however eliminate uncertainty altogether and a knowledge of uncertainty could be critical to your remediation scheme.

For example if you have a clean up criteria of 2500 mg/kg of mineral oil on a scheme and your sample shows a concentration of 2000 mg/kg you might be forgiven for breathing a sigh of relief. If you knew that the true precision of the analytical method is more like +/- 100% you might have cause to re-appraise your hasty signing off of the site.

Bias, or recovery is, in simple terms a measure of the amount you get out knowing what you originally put in. For example a laboratory quotes a UKAS accredited method recovery for DRO as 95%. Fine you think a 95% recovery is very good, and the method is UKAS accredited. What you don’t appreciate is that the recovery is quoted on a reference sample that has been dried and finely ground. In other words the recovery quoted does not account for any volatiles lost during drying and grinding.

We can however welcome the (relatively) new MCERTS scheme championed by the Environment Agency in so far as precision and bias data should now accompany all results of analysis.

How is data actually reported

Understanding the basis for reporting is really, really critical. Some samples are analysed wet, some dry, some with stones removed, some without. Some data is reported dry and some wet, some whole and some just on the fines. Data on the same sample may be reported on a different basis. Do you know on what basis your samples are analysed and reported? Do you know on what basis the acceptance criteria you use (CLEA, Dutch) are generated?

The example below illustrates this point demonstrating the range of total mercury values you can get depending upon how you choose to express the data or how that laboratory chooses to prepare your sample.

A 100g sample of a contaminated clay is submitted for total mercury analysis. It contains 500ug of mercury, and is composed of the fractions set out below. For this example we assume (fairly reasonably) that all of the mercury is present in the fines. Our acceptance criteria are the CLEA Soil Guideline Values of 8 mg/kg Hg for residential uses with plants and 15 mg/kg Hg for residential uses without plants.

Soil fines (less than 2mm diameter)

30 grams

Stones (2-10mm diameter)

20 grams

Stones (greater than 10mm diameter)

25 grams


25 grams

Data reported on:-

Result (mg/kg Hg)



Whole sample




Fines, dry




Whole, dry




<10mm, dry




<10mm, wet




The example illustrates a huge variation in ‘right’ answers which completely span the selected acceptance criteria. It also reveals that the same (or very similar answers) can be obtained by using completely different assumptions – a whole dry basis being very similar to a <10mm wet basis in this example. What is more worrying is that the fines dry result (arguably the most common way of determining mercury in soil) is over three times higher than the result expressed on the whole sample (arguably the true result).

Sample Homogeneity

We all know that reliable data depends upon the sample from which it was extracted. We all also know how difficult it can be to take representative samples from very mixed fill and contaminated ground. The apparent precision of laboratory data can be very misleading. In reality a result of 645.37 mg/kg lead (as Pb) doesn’t actually mean that the horizon we sampled contains a concentration of 645.37 mg/kg lead. The problem is we don’t know what it means because we haven’t estimated the variability of the sampled horizon and we haven’t got a clue about the limitations of the techniques the lab uses to prepare, extract, analyse and then correct the raw data to produce the reported result. Engineers who are used to dealing with relative certainties would be horrified to learn that the true precision of chemical data is very, very poor. In many cases the best you could expect might be orders of magnitude.

Conclusions – The Key Questions

There is no doubt that the reliability of the analytical data our industry routinely uses is seriously limited. There is also no doubt that many (perhaps most) practitioners don’t realise this. This is not because the laboratories are producing poor quality work. Rather it is a combination of the uncertainty inherent in sampling and analysis coupled with the limitations a price driven market places upon laboratories. Factor in a lack of understanding on both sides of the effect (or even existence) of such limitations and it is easy to see that we can easily find ourselves skating on thin ice without even realising it.

What are the answers then? Well the answers are really a series of questions we should routinely ask ourselves when assessing our methods, our laboratories and their data.

1. Laboratories broadly use the same analytical equipment. What gives to allow some laboratories to be a lot cheaper than others? 2. What are the limitations of the selected analytical method? There are always limitations. Do they matter in this case?
3. Absolutely critical. What is the basis on which my data is reported? Does it match the basis on which my acceptance criteria are calculated?
4. Is the laboratory QC data realistic or has it been generated in ideal conditions using ideal samples which are unlikely to represent the conditions on my site.

If you can make a reasonable attempt at answering these questions you will be a long way to understanding the basis on which your data has been generated and in turn you will be reasonably confident when interpreting your data and able to take due account of the uncertainty that exists in your data.

If you can’t immediately answer these questions then you don’t know the basis on which you are interpreting your data/running your computer model/applying your acceptance criteria/remediating your site/providing your client with a collateral warranty. And it’s as fundamental as that.

Richard Puttock Partner
Michael Dinsdale Associate
Peter Brett Associates

Article Contaminated Land Laboratories

The Extension of MCERTS to Chemical Testing Of Soils – An Update

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In January 2003, issue number 45 of the AGS Newsletter contained an article by Bruno Guillaume, of Arup Geotechnics, who outlined the MCERTS performance standard for the chemical testing of soils. The following is an update, and a view from an analytical chemist`s perspective.

On the Environment Agency website reference has been made to the fact that the Agency is aware that it will take time for laboratories to gain approval through the appropriate accreditation process. An eighteen month period, starting from March 2003, has been given for laboratories to bring their soil testing methods up to the MCERTS standard.

During this period laboratories reporting data to the Agency have as a minimum to be accredited to the ISO 17025 standard for the soil test methods. It is also recommended that tests should have a brief method description together with estimates of bias and precision. From September 2004 only data from laboratories that have been accredited to ISO 17025 for MCERTS will be accepted.

Since the last article in the newsletter, Version 2 of the MCERTS standard has been published, and this was available from February 2003. The standard highlights particularly important areas, namely contract review, bias and precision targets, quality control( both internal and external), method validation, and uncertainty of measurement. Important differences from the first version are the exclusion of expected limits of detection for methods, and the inclusion of an improved protocol for validation.

The issues can be confusing but the standard simply aims to establish a level playing field in a competitive market, based on the Agency`s requirements, and to set a minimum acceptable performance. In short the data received by the laboratory`s customers must be accurate, reliable and comparable.

The analysis of soil is complex in terms of the chemistry involved. It aims to determine both macro and trace components in a matrix that is, quite often, dirty in both a physical and chemical context. There is a need to analyse for trace organic and metallic contaminants in soils that contain large quantities of other industrial materials, such as oil or tar, in a background that also contains high concentrations of naturally occurring, or artificially polluted, inorganic compounds.

We all use “parts per million” as routine terminology, but the significance is commonly ignored. 1 part per million is more easily visualised as 1 grain of salt in a swimming pool. When we talk of the concentrations of polynuclear aromatic hydrocarbons (PAH), an important environmental parameter, we often refer to micrograms per kilogram, which is three orders of magnitude lower.

The contaminated land testing industry has grown very quickly, and methodologies have been borrowed from other more well established areas of analytical chemistry, such as food or potable water. The only industry standard for analysis of soils in the UK are the robust and technically sound ” British Gas Methods “, but even these were not designed to tackle the lower end of detection, and do not take advantage of some of the more modern developments in analytical chemistry.

MCERTS effectively defines a standard for the performance of analytical methods, and includes the requirements of ISO 17025 in terms of certification of instrument performance, approved competency of personnel and the accreditation of laboratory procedures and organisation. It means that it is no longer sufficient that the laboratories follow a rigorous UKAS quality system in line with the international standard, but that the methodologies must also be demonstrated as fit for purpose.

The Environment Agency has not, in its standard, adopted the principle of prescriptive methods, as has been the example in the USA, through the so-called EPA procedures. This approach can commit the industry to inappropriate analytical techniques, a long time in their reform once committed to paper, and takes away the flexibility of developing new improvements for the industry as a whole.

It cannot be relied upon that environmental specialists, requiring the services of an analytical laboratory, will have the depth of technical to knowledge to understand the concepts of analytical bias or precision. MCERTS is designed to take away the need for such expertise.

Another variable that stops a customer from being able to compare “apples with apples” is the limit of detection (LOD) quoted. This can vary widely depending on how the laboratory defines it. A sound statistical principle is to use three times the standard deviation associated with a blank, or a sample with a very low concentration of the determinand of interest. This is all carried out interspersed with other standards and samples over eleven separate days. Other lesser definitions than this one seem to describe a “better” LOD, but mislead the customer into thinking they are getting an improved service, and can give false positive concentrations on soils where none of the contaminant actually exists.

All of these concerns are addressed by the MCERTS standard. Precision and bias must be of an acceptable standard, as must LOD. “Recoveries”, namely what happens when a soil is spiked with known amounts of the material of interest and is reanalysed, are examined in the standard to ensure acceptable performance. The validation must be carried out on three completely different soil types with two spiking levels, and include the use of certified reference materials wherever possible. Detailed methodologies, together with a prescribed uncertainty of measurement must also be given.

The Contract Review is the point at which the client`s needs must be understood, and the point at which the laboratory must document them. What does ” Total PAH” mean, or “Total TPH”, and what does the client consider to be the critical level of interest? This is an area quite often poorly addressed, and to which the standard lends some priority.

The laboratory`s quality control also comes under close scrutiny. At least 5% of the resources allocated to a test must be used to ensure validation. In addition the laboratory must participate in as many of the acknowledged external proficiency tests as is appropriate, such as Contest, Aquacheck, and the SPH test scheme. The results of these must be readily available for inspection by the client.

It is generally recognised amongst the community of analytical laboratories that there is a real challenge in order to be able to comply with the new version. The standards relating to bias and precision and, in particular, the guideline that “the limit of detection usually regarded as being fit for purpose is 10% of the concentration regarded as the critical level of interest” are extremely demanding. There are some method improvements required within the industry before these levels of performance can be achieved. Most laboratories, however, will feel a relief that any ambiguity is now removed, so that everyone can compete to provide a well defined product, and be able to market its expertise without confusion.

Whilst addressing the vagaries of analytical results the Environment Agency has also acknowledged the uncertainty associated with other areas, and is considering certification schemes to address field aspects, including sampling. Other subjects, for example the suitability of leachability tests, toxicity assessments and the bioavailability of metals need to be topics for guidance by the regulator.

Article Business Practice Contaminated Land Data Management Executive

AGS Response to Nigel Griffiths, MP

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On his appointment as Minister for Construction, Nigel Griffiths wrote to all trade associations and professional bodies and invited them to submit a concise briefing note on the issues which Members feel are vital to making Britain world leaders in construction. He indicated that he expected the note to raise our main concerns.

After discussion in the Working Group and the Executive Committee, the following response was sent on behalf of the AGS:

Making Britain World Leaders in Construction

The Association of Geotechnical and Geoenvironmental Specialists (AGS) is a trade association representing almost 100 companies who are specialists in ground engineering. Activities range from geotechnical engineering, ground investigation, and the design of foundations, to the geotechnical and chemical analysis of soil, rock and water and the identification, assessment and remediation of contaminated land.

In responding to the invitation from Nigel Griffiths MP for a concise briefing note, we have concentrated on issues on which our Members specialise and which are within the field of Government influence.

Additionally, the AGS as a Member of the Ground Forum, fully supports the comments made by Ground Forum, particularly in respect of, i) the need for greater funding of post graduate courses in geotechnical engineering and engineering geology; and ii) the need for clarity (possibly via a register) in defining areas of engineering expertise in order that clients can identify specialists with appropriate qualifications and experience for their projects.

1. Inadequate Ground Investigation 

The amount spent on investigation of the ground prior to construction is typically 1% to 5% of the whole project value (usually the lower end of this range). The cost of claims and additional expenses due to unexpected ground conditions (i.e. unexpected because the site investigation was not adequate) can be as high as 50% of the total cost overrun on the project. Furthermore, some (generally smaller) developments do not have any ground investigation at all. We believe very strongly, that an adequate ground investigation should be a requirement of the planning process. We understand that consideration is being given to harmonising building and planning regulations. This therefore presents an ideal opportunity to introduce such a requirement. We therefore propose that the Minister actively supports and promotes the introduction of such a requirement into the harmonised regime.

2. Insurance 

The current difficulties in the availability and cost of Employers Liability and Public Liability insurance have affected AGS Members, as other businesses. However, the major concern has been the soaring cost of Professional Indemnity insurance. This is compounded by the continuing trend for clients (including public sector clients) to require higher and higher levels of insurance cover with high/ unlimited limits of liability, often totally disproportionate to the value of the fees involved. This is particularly the case in regard to work involving contaminated land. It is a common misconception in many client organisations that a consultant’s Professional Indemnity policy is there to cover any loss incurred by the client, however such a loss occurs. This is of course, not the case. A consultant’s Professional Indemnity in there to protect the consultant in the event of a successful claim of negligence. All consultants in the AGS have signed up to our own Code of Conduct which is designed to ensure the potential for negligent act or omission is minimised. In addition, most companies have their own Quality Assurance system (many accredited through the British Standards Institute to relevant international standards, e.g. ISO14001). It is also a fact that to date the number of successful claims specific to our industry is very low.

It is therefore unfairly onerous on the industry for clients to require levels of Professional Indemnity cover and limitations of liability which are often out of all proportion to the fee charged for the services offered by our members (e.g. a liability level of £5m is commonly required for a project with a consultancy fee of less than £2,000). Such a requirement is particularly disadvantageous to small companies who are simply unable to obtain such cover, and are therefore excluded from contracts even when they have appropriate expertise and/ or relevant local knowledge.

Government and other public sector clients could helpfully demonstrate best practice in this respect by entering into such contracts with appropriate requirements for insurance (both level of cover and limit of liability) which reflect inter alia the fee for the project.

3. Onerous terms in Regional Development Agencies (RDAs) contracts

Members work for RDAs in connection with the assessment and remediation of contaminated land. The standard RDA contract terms require the consultant / contractor to provide a collateral warranty with unlimited liability for anyone using the site in the future, and to ensure that the site is ‘fit for purpose’ This is unreasonable on two counts:-

i) Neither unlimited indemnity nor ‘fitness for purpose’ can be covered by insurance . In the event of a successful claim therefore, the only recourse for the company will be to close down and surrender all their assets. This is a totally unacceptable way to enter into a contract.

ii) Contaminated land can be cleaned to a variety of standards, (e.g. the standard required for a factory car park is lower than that required for housing). It is not reasonable to expect the consultant /contractor, working to a specification (given by the RDA client) to warrant that the site will be suitable for all purposes and all users in the future – which is the legal implication of these terms. The normal standard is to warrant that the work has been carried out with due care and diligence.

RDAs (or their legal advisers) argue that their public duty requires these contract terms and that they will be held to account should a problem arise and the consultant/contractor is found to have limited liability. In reality, they are limiting their selection of consultants and contractors to the small number of concerns who are prepared, for what ever reason, to take the unreasonable risks that these contract terms represent. Furthermore, in pursuing this policy RDAs are endangering the Government’s targets for the redevelopment of brownfield land.

The Minister could usefully explore this matter with RDAs to ensure that an appropriate balance is obtained between the need to demonstrate appropriate accountability for public monies with the necessity of redeveloping brownfield land.

4. Environment Agency

Notwithstanding liaising with Environment Agency officials in our Committee and Working Group, in day to day, site specific activities, our members invariably find interaction with the Environment Agency extremely frustrating for a number of reasons:-

i) There is no consistency between local offices. Although the specialists in the EA issue guidance (generally after public consultation), there is no onus on local offices to follow the guidance. Consequently each office (and each officer within that office) follows their own understanding of how to implement the policy/guidance. Consequently a development which would be permitted in one area, in another faces undue, excessive costs, delays and may eventually be refused permission.

ii) There appears to be no way of appealing against a decision made by a local office even when higher officials acknowledge that the decision is wrong. The process of appeal is very unclear and local offices appear to have unchallengeable autonomy.

iii) Guidance essential to the development of brownfield land is delayed – often for years. For instance, only a very small number of soil guideline values (that specify the permissible amount of certain toxic chemicals in soil) have been issued. Chemicals not covered by SGV’s must be assessed in some other (unspecified) way. The EA has the right to reject the conclusion of the consultant if officials do not agree with the methodology. The local authority regulator is therefore in an impossible situation when trying to assess proposals for brownfield land redevelopment (particularly for housing schemes). The recent disbandment of the National Centre will exacerbate this problem.

iv) EA policy leads to uncertainty. Developers expect their consultants to be able to advise on the measures which must be taken in order to obtain planning permission. Because of the uncertainties (above), consultants cannot be confident in their advice. However, if the consultant’s advice turns out to be unacceptable to the EA (resulting in additional costs and delays) the client may try to recover costs from the consultant’s insurance – putting further pressure on insurance requirements and the viability of consultants businesses. (See Item 2).

Action, direction and resources to rectify these problems at the Environment Agency need to come from Government. The Environment Agency is not currently fulfilling its stated functions with an appropriate balance. Unless improved guidance, consistency and expertise is forthcoming from the Environment Agency, the Government targets for the remediation and redevelopment of brownfield sites will be seriously jeopardised.

5. Waste Management Licensing 

It is becoming increasingly clear that regeneration projects on brownfield sites are being frustrated by Waste Management Legislation and the Environment Agency’s approach to its implementation. The crux of the problem is the recent move by the Environment Agency to interpret the definition of waste more restrictively. The result is that a considerable number of practices on site that were not previously considered necessary to regulate now fall within waste management legislation. The consequence of this is as follows:

i) The requirement for / presence of a Waste Management License (WML) on a development site will severely inhibit redevelopment potential of many sites. This is particularly the case for re-development of large sites where phased development is the only way to make the redevelopment process financially viable. The presence of an active WML on a housing development would effectively prevent sale of homes during the development programme.

(ii) Property Blight: New houses built on ‘licensed’ land are often seen as being built on the equivalent of ‘Waste Tips’ resulting in loss of value. A recent RICS report suggests the negative effect on property prices can be as much as 40%

(iii) Loss of potential for re-use of site derived soils: The reluctance of construction companies to operate waste management licenses will result in materials defined as waste being removed to landfill rather than being re-used as secondary aggregates (and the consequent need to import virgin aggregates from quarries and pits, entailing haulage and other environmental impacts of quarrying).

DEFRA and ODPM are developing the option of a Single Regeneration Permit to overcome the problems highlighted above. In reality however, the government is progressing inappropriate and increasingly restrictive legislation in isolation of the legitimate needs of the construction industry. It is important to note that other European countries are not interpreting the legislation in the same way and are not imposing similar constraints on their construction industries. This restrictive approach will jeopardise the achievement of the Government’s target of 60% of new homes on brownfield sites. Government is therefore urged to address this matter will all interested parties and in particular the Environment Agency.

Article Contaminated Land Laboratories

ICRCL 59/83 – Beyond 20 December 2002

- by

R G Clark, CL Associates

Most AGS members are aware or should be aware that ICRCL Guidance Note 59/83, 2nd edition was withdrawn by DEFRA in a letter from Steven Griffiths of the Contaminated Land Branch on 20 December 2002. The letter referred to the fact that the CLEA package (published by DEFRA and the Environment Agency), consisting of Contaminated Land Reports (CLRs) 7 to 10, the CLEA 2002 software, certain toxicological reports (TOX) and certain Soil Guideline Values (SGVs) is considered by DEFRA to represent the key instrument for generic assessment of the human health risks from contaminated land.

The reasoning put forward for the withdrawal of ICRCL 59/83 was that the guideline values are out of date and that they are not in line with the current statutory regime (Part IIA of the Environmental Protection Act 1990) and associated policy.

Up until that time many practitioners had relied heavily on the use of the ICRCL 59/83 guideline values for assessing human health risks associated with contaminated land. Others had already started to use alternative risk based methodologies such as RBCA, R&D P20, SNIFFER and of course CLEA. In many instances ICRCL or Dutch guideline values were used as a first screening before progressing to a quantitative risk assessment (QRA) for those contaminants of particular concern that were above the guideline values for a particular site.

The letter dated 20 December 2002 was immediately followed by a Briefing Note, also dated December 2002, from the Contaminated Land Branch of DEFRA. This briefing note emphasised that ICRCL 59/83, and especially Tables 3 and 4, should no longer be used. It can be noted that other ICRCL guidance has not been withdrawn. The DEFRA Briefing Note recognises the continued use of these other ICRCL guidance documents provided that they are not used as the sole source of information on which decisions are based.

A number of Local Authorities have now adopted the position that for the assessment of contaminated land, only UK based guidance is applicable. They will, therefore, no longer accept both ICRCL 59/83 and the Dutch Guidelines. In effect this means that where no published SGV exists then it is necessary to carry out a site specific QRA for each contaminant even before an initial screening can be undertaken. This constitutes a potential problem where there is also no TOX Report available, in that each organisation that carries out such risk assessments has to source appropriate and verifiable toxicological data.

An update of the existing CLEA Model was published in March 2003. A new version of the CLEA Model (open architecture version) is anticipated which is a spreadsheet version that allows more user-functionality.

SGVs have been published for Arsenic, Cadmium, Chromium, Lead, Mercury, Nickel and Selenium. TOX Reports are available for Benzo (a) pyrene, Benzene, Inorganic Cyanide, Dioxins, Furans and Dioxin like PCBs but no SGVs. The Environment Agency have stated that they will be issuing additional SGVs in batches of 5 or 6 at quarterly intervals over the next 2 years.

But what is to happen in the interim ? – chaos according to some. At various conference and technical committee venues both consultants and Local Authorities have expressed their concerns over the rapid withdrawal of ICRCL 59/83 without a sufficiently comprehensive UK alternative being available.

In conclusion, AGS members should be aware of their responsibilities to their clients. If a geoenvironmental specialist were to continue to use ICRCL 59/83 in reports that they prepare for a client and those reports are subsequently submitted for approval to a regulator (such as part of a Planning Application) or to some other body such as a funding organisation and are rejected due to the use of ICRCL, it may very well be considered that the specialist has failed in its duties to the client because it has used reference material that has been officially withdrawn.

Equally there is a risk that the use of Dutch guidelines could be rejected. This will depend on the approach of the particular regulator. The alternative, apart from using the CLEA Model, is to use SNIFFER etc (see above). However, for all of these methods it is necessary to research toxicological data and to be able to verify these data within a UK context. Site specific criteria are therefore being based on a variety of sources of toxicological data of varying quality. How are those, such as regulators, who have the task of approving these derived values going to make judgements on the reliability and applicability of the toxicological data ?

There is no easy answer at present.

Article Contaminated Land Laboratories


- by

Bruno Guillaume, Arup Geotechnics

In October 2001, the Environment Agency launched proposals to extend its Monitoring Certification Scheme, MCERTS to the chemical testing of soils. The aim of the scheme is to deliver quality environmental measurements with product certification of instruments, the competency certification of personnel and the accreditation of laboratories based on an international standard. In its Land Quality Policy Statement (EAS/2703/1/6/Final 3, available on ), the Agency notes that it will only accept chemical testing data on contaminants in soils that has been produced by laboratories that have been accredited to the BS EN ISO/IEC 17025:2000 quality standard for the testing methods used.

The Agency has provided separate MCERTS performance standards in guidance available from To allow reasonable time for laboratories to complete validation of their testing methods to the Agency’s specification, the Agency will implement this policy over a period of twelve months from 1st April 2002. From the 31st March 2003*, the Agency will require that all chemical testing data on contaminants in soils, which is presented to it in support of regulatory compliance, must have an accompanying estimate of bias and precision and a description of the testing method used, with the laboratory being accredited to the BS EN ISO/IEC 17025:2000 standard for the test method.

The MCERTS proposals were discussed at the annual Contest meeting in June at which I was asked to speak on “the client’s view”. There is no doubt that the risk-based approach to contaminated sites and especially quantitative assessment requires greater confidence in data from site investigations. All laboratories should operate quality control and quality assurance schemes with calibrations, blanks, sensitivity checks and duplicate testing. UKAS accreditation is often quoted as evidence of quality assurance, but it gives no indication of the suitability of test for the intended purpose of the end user. Proficiency testing and participation in schemes such as Contest, Aquacheck or LEAP is a far better indication of a laboratory’s ability to undertake tests reliably. However, the results of proficiency testing are seldom available to third parties, such as those organisations commissioning tests from the laboratories. MCERTS has the potential to provide an indication of data reliability with performance standards set by an authoritative body.

Laboratories have expressed concerns over certain aspects of the MCERTS proposals as applied to the chemical testing of soils. Sampling is potentially a far greater source of data errors than is laboratory analysis, and there is as yet no comparable scheme addressing sampling, in-situ and field tests. The performance standards requested by the Environment Agency are too demanding and prescriptive for certain parameters (e.g. limit of detection of 20mg/kg for sulphates) and ill defined for certain parameters (e.g. are “polyaromatic hydrocarbons” represented by the sum of USEPA priority 16 or defined by other means?).

The Environment Agency is considering certification schemes to address field aspects including sampling. It is worth noting, at this point, that the Agency has produced guidance, (including Technical aspects of site investigation, P5-065/TR and Secondary model procedures for development of appropriate soil sampling strategies, P5-066/TR), though this has been poorly publicised.

Accreditation of laboratories to BS EN ISO/IEC 17025:2000 (General requirements for the competence of testing and calibration laboratories) is significant: clause 4.1.2 states that it is the responsibility of the laboratory to carry out its testing and calibration activities in such a way as to satisfy the needs of the client. The requirement for the laboratory to understand the client’s needs is explicit. Currently, too many clients will commission testing without discussing objectives with the laboratory. Unfortunately, the market is driven by price rather than quality and there are still laboratories that offer methods that are inappropriate. An uninformed client cannot distinguish between good and bad service providers. The introduction of MCERTS and accreditation to BS EN ISO/IEC 17025:2000 could act as a catalyst to encourage the engagement of laboratories earlier in the investigation process, thus ensuring that the laboratory methods are fit for purpose.

MCERTS does not specify the methods of analysis, and proficiency testing shows an astonishingly wide variation in results for certain parameters. This is due to the variety of methods in use and economic pressures in a market where there is over capacity, as well as poor parameter definition and lack of performance standards. Method specification through international standards is an extremely slow process and not favoured in the UK. Research has however been undertaken, funded by the Government and the Environment Agency, on appropriate methods of analysis, and the results of this research are still awaited.

Finally, the risk assessment approach to contaminated land requires further guidance which has yet to be provided by the regulators, including suitability of leaching tests, bio-availability and toxicity assessments. The process of investigation and assessment is complex and potential for errors considerable, but MCERTS should at least address one part of the process and raise the importance of appropriate data.

References: Environment Agency, Performance Standard for Laboratories Undertaking Chemical Testing of Soil, May 2002, Version 1 <> UKAP, Good Regulation and Competitiveness Network – Environment Sector Study, July 2001, <> Hazel Davidson, VAM Bulletin No. 21, 1999, 4 , <>

*Note: The intention to implement to this timetable has been withdrawn to allow a more realistic timescale for the accreditation of laboratories. A statement on the EA website reads:

‘Having recently met with UKAS and discussed the concerns of a number of laboratories with respect to the timescales for compliance, the Agency has decided to revise the phased approach to implementation of its requirements to allow a longer lead in time. In addition, the Agency has decided to take this opportunity to review the detail set out in the performance standard with a view to streamlining the additional requirements over EN ISO/IEC 17025:2000 which are already assessed. We will issue a revised implementation policy and performance standard shortly. In the interim, laboratories are urged to seek the accreditation to EN ISO/IEC 17025:2000 for the chemical testing of soils which is already available.