LQM is a specialist environmental consultancy based in Nottingham (UK) with an international reputation for assessing and managing the risks posed to human health and the environment by contaminants in soil. Increasingly this is being done within a context of sustainable development and specifically sustainable brownfield regeneration.
We provide consultancy, peer review and expert witness services, contract research and training courses on all aspects of the management of land contamination to problem holders, developers and local government.
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LQM are pleased to announce we will be hosting a summer series of Friday lunchtime (BST 1315-1430) Technical Briefing Webinars for Ground Gases to be delivered by Steve Wilson of EPG Ltd.
Steve Wilson is Technical Director of The Environmental Protection Group (EPG) Limited, who has authored numerous technical papers and publications and provided training relating to gassing issues over many years and is well known for his authoritative and sound practical advice.
Steve will be providing his insights into the ground gas queries that are regularly raised within contaminated land forums to clarify some of the major misconceptions, issues and ways to better inform your gas Conceptual Site Model (CSMgas).
Our ability to measure hazardous ground gases and vapours or detect low levels of dissolved phase contaminants in ground water rather than relying on conservative and poorly constrained modelling has improved in recent years.
New technologies are enabling real time data to be collected. New data analytical techniques are providing greater insights in the composition and potential origins of hazardous gas, vapour or dissolved phase contaminants.
For example so-called “emerging contaminants of concern” (around since the 1950s!) such as per- and polyfluoroalkyl substances (PFAS), and their brominated cousins, provide laboratories with exciting challenges to attain the detection levels required by regulators but also to help us understand the potential future risks they may pose. Conventional tests for PFAS measure a discrete list of up to about only 30 compounds and are not designed to quantify the suite of pre cursor compounds that may exist in soil and groundwater. Hence there are many additional PFAS compounds present at sites and within environmental samples that will not be determined during routine analysis. If you consider the environmental biotransformation processes that occur in biological waste water treatment plants, where significantly more PFOA and PFOS are measured at the outflow than the inflow, then you can begin to understand the importance of also identifying the important “precursors” to the perfluoroalkyl acids (PFAAs) to help us avoid underestimating the potential PFAS risk present in the environment. A new technique being offered by UK based labs is the Total Oxidizable Precursor (TOP) assay, which helps to quantify the concentration of non-discrete and difficult to measure PFAS compounds that are not determined by conventional analytical methods. Assessment of TOP assay data can help us to improve the potential risk from PFAS across a range of sites and situations.
Guidance has been available for many years on assessing the potential human health risks arising via vapour intrusion internationally (e.g. the US and Australia), although within the UK field sampling techniques and guidance is less well developed, early work was carried out by the late Colin ferguson and Victor Krylov. For example in a UK context when taking vapour samples, there is a lack of definitive UK guidance on what are the best tracer techniques to use with many relying on the use of a potentially significant cross-contaminant iso-propyl alcohol (IPA) which can compromise your vapour results, cost you time and money and can cause problems for the laboratory. Helium is a generally accepted, but costlier, preferred inert tracer of choice, and is becoming increasingly favoured where low limits of detection for your volatile organic compounds are required for sensitive land use risk assessments.
These are just some of the developments within the gas and groundwater sampling and analytical practices that contaminated land practitioners should be familiar with to help ensure they continue to provide sound advice to and defensible decisions for their clients and regulators.
As part of our continued commitment to raising standards among practitioners and regulators, LQM’s next Professional Practice Webinar, delivered by Paul Nathanail, will explore the role innovative sampling and analytical techniques have in better managing land contamination on post- industrial brownfield sites or, the rare, Part 2A sites.
Changing pattern of ground water levels and ground gas concentrations over 13 rounds of (spot) monitoring before, during and after leakage of discharge water from a Combined Heat and Power Plant (NOTE: hypothetical site & conditions). See QGIS2 course for full-screen hi-res video.
LQM have for many years had to make sense of myriad datasets, in multiple data formats and from varied site investigations … ranging from single house plots to large industrial sites or residential estates … previous investigations and risk assessments undertaken by small independents through to large multi-national companies.
One of the most consistently frustrating features of such work is a little more effort at combining the data collected with the right data analysis tools and data formats would have made the original decision-making more effective, cost efficient and ultimately sustainable. Robust data management, analysis and visualisation breeds the sound science and defensible decisions from site investigations regulators demand, stakeholders expect and clients deserve.
Roger Chandler of Keynetix in the Nov/Dec 2018 issue of the AGS Magazine clearly states the importance of using the AGS data format and you cannot argue against the logical efficiency of his two ‘Golden rules’ … only enter data once … and get someone else to do it!
Once you have all of this data in the right format you need a way to interrogate, visualise and evaluate it. For contamination investigations the LQM starting tool of choice is a Geographic Information System (GIS), as each sample you take or monitoring point has a location in space (Easting, Northing, Depth) and time. Your conceptual site model has the same dimensions and so there is a logical efficiency in using a GIS to store and present your data.
BS ISO 18400‑104:2018 ‘Sampling Strategies’ (and other members of the BS ISO 18400 series) is guidance intended to be used in conjunction with and take precedence over BS 10175:2011+A2:2017 ‘Investigation of potentially contaminated sites’. Part 104 provides guidance on the development of site investigation and sampling strategies taking into account the need to obtain representative samples and to have regard to relevant statistical principles. (We will leave the limitations of non-spatial statistics for another occasion – but Paul Nathanail did cover this in a webinar on geostatistics a year or so ago).
GIS helps us ensure we meet the current standards for data collection, visualisation, data analysis and dissemination of information.
The good news is that free and open source GIS tools such as QGIS are now widely available and have, for most contaminated land situations, comparable functionality to commercial software systems. Indeed QGIS can be integrated with data analytics (e.g. RQGIS). A host of user-friendly plugins also brings more conventional statistical and graphical spreadsheet analysis, such as summary statistics, X-Y scatter plots, histograms, box-plots and even ternary plots directly into the GIS environment (WARNING – non spatial statistics can give misleading results!). You can easily view site walkover photos using the GPS data in your digital photos or view borehole logs as images or tables. If you want to display your monitoring data as an animated video then QGIS can do that for you too. The major limitation of the QGIS for site investigations is knowing what it can do for you and how to do it.
If you would like to learn more; here’s some good news: LQM are running two one-day entirely hands-on courses to cater for both beginners (QGIS 1) and current users looking to more efficiently translate data into information (QGIS 2). These courses will help you to inform your conceptual site model, site investigation design, interrogate your SI data and produce informative spatial and temporal infographics and not just meaningless pages of data.
Given the requirements of the British Standards Institute and the important role that the AGS data format plays in achieving a more efficient approach towards site investigation and development, there is little excuse for not investing a little bit of effort to learn how to gain maximum value from some of the great free and open source GIS tools available to us.
Derelict, abandoned and underused buildings may be put to illegal uses, including the manufacture or processing of recreational drugs. The very nature of such activities poses challenges to those carrying out site walkovers and advising on the need for and scope of remediation if the sites are to be redeveloped, converted or sold.
The manufacture of synthetic chemicals or processing of for use as recreational drugs can result in contamination of soil and groundwater with chemicals that are not routinely considered in the investigation of potentially contaminated land.
The immediate responders – mainly the Fire and Rescue Service (FRS) in the UK – are most at risk. The risk posed by illicit drug laboratories, particularly ‘methamphetamine’, is increasing within the UK. There are many examples from Canada, the United States, Australia and New Zealand of emergency service first responders being killed by hazards associated with illicit drug laboratories.
Illicit laboratories may have engaged in extraction, conversion and/or synthesis processes. The materials involved as feedstock, products and associated wastes are hazardous. In some cases involving flammable solvents, accidental explosions and fires have resulted in fatalities as well as wider dispersion of contaminants.
Illicit drug laboratories may be identified or at least suspected from tell tale signs, odours and behaviour of occupants. Staff engaged in due diligence, pre -acquisition and phase 1 investigations may encounter such labs unexpectedly prior to entering a building. Inside the premises, drug production hardware, raw ingredient, final product and waste materials may be stored as liquids or solids or in the case of waste or accidental spills be strewn across the floor or find their way into drains.
Such accidental discovery should result in walkover personnel leaving the vicinity and informing the emergency services – both police and FRS. This not only ensures personal safety but also reduces the risk of compromising evidence at what may become a crime scene. Dealing successfully with such, very rare, discovery depends on the training and awareness of relevant staff.
As part of our continued commitment to raising standards among practitioners and regulators, LQM’s next Professional Practice Webinar, delivered by Paul Nathanail, will deal with the range of hazards involved in illicit drug laboratories, current, albeit limited, UK guidance and guidance from elsewhere where soil and groundwater contamination has received greater attention.
An introduction to five new British Standards in the ISO 18400 series (free webinar)
Wednesday 19 December at 1130 AM
The next in an occasional series of webinars from LQM to raise the sector’s technical awareness will summarise the content of five new British Standards in the ISO 18400 series.
The newly published standards are:
• BS ISO 18400-104:2018 Soil quality – Sampling – Strategies
• BS ISO 18400-202:2018 Soil quality – Sampling – Preliminary investigations
• BS ISO 18400-203: 2018 Soil quality – Sampling – Guidance on the investigation of potentially contaminated sites
• BS ISO 18400-205: 2018 Soil quality – Sampling – Guidance on the procedure for the investigation of natural, near-natural and cultivated sites
• BS ISO 18400-206:2018 Soil quality – Sampling – Guidance on the collection, handling and storage of soil for assessment of biological functional and structural endpoints in the laboratory
This free webinar will be delivered by Paul Nathanail and last for about 20 minutes. Places are limited to 99.
If you register for a place and are unable to attend the webinar, you will be sent a copy of the slides and access to the recording afterwards.
Delegates will gain an understanding of the scope and contents of each of these standards.
BSI have indicated that registrands will receive a code entitling them to a discount for the five new documents.
Get the chance to ask Paul questions!
Who should attend
This webinar is mainly relevant to regulators (including local authority staff) and consultants involved with sampling of potentially contaminated soil, of soil from natural, near-natural and cultivated sites and of soil for the assessment of biological functional and structural endpoints in the laboratory.
The Environment Agency has withdrawn the Soil Guideline Value (SGV) for mercury and the supporting reports following discussions with Public Health England (PHE) about a revised opinion from the European Food Safety Authority (EFSA). The SGV Report, the TOX Report, and the Supporting Information Document for Mercury will remain available for historical reference on the Government and Environment Agency archives and on the CL:AIRE Wall
The SGV for mercury was published in 2009. In 2012, EFSA published their scientific opinion on public health risk from inorganic mercury and methyl mercury in food. A summary and the full report are available here: https://www.efsa.europa.eu/en/efsajournal/pub/2985.
EFSA recommended oral TDI values for both inorganic mercury and methyl mercury that are lower than the oral HCV that was used in deriving the SGV. The EA are withdrawing their reports in light of this expert opinion. The Agency will not be updating these reports as it no longer undertakes work to derive new SGV or TOX reports, but it will continue to recommend that relevant public health bodies are consulted where industry has published or is developing alternative criteria for mercury which would also include elemental mercury.
A Note on the S4ULs for Mercury
In deriving the S4ULs for inorganic mercury and methylmercury LQM cited the EFSA (2012) opinion on the Provisional Tolerable Weekly Intakes (PTWIs) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) for methylmercury and inorganic mercury. LQM derived oral Tolerable Daily Intakes (TDIoral) based on TWIs established by EFSA (2012) that, as stated in Nathanail et al (2015), were lower than the oral TDIs used in deriving the SGVs by the Environment Agency (2009). LQM considered UK sources of information with respect to background intakes (food, water and air) as described by Nathanail et al (2015), including the 2006 UK Total Diet Study (FSA, 2009) that was used by EFSA in their dietary exposure estimates.
EFSA (2012) EFSA Panel on Contaminants in the Food Chain (CONTAM); Scientific Opinion on the risk for public health related to the presence of mercury and methylmercury in food. EFSA Journal 2012;10(12):2985. [241 pp.] doi:10.2903/j.efsa.2012.2985. Available online: https://www.efsa.europa.eu/en/efsajournal/pub/2985
Nathanail CP, McCaffrey C, Gillett AG, Ogden RC, & Nathanail JF. (2015). The LQM/CIEH S4ULs for Human Health Risk Assessment. Land Quality Press, a Division of Land Quality Management Ltd: Nottinghamshire, UK. Available online: https://www.lqm.co.uk/publications/s4ul/
According to the then Secretary of State, in November 2016 the Ministry of Defence estate covers almost 2% of the United Kingdom’s land mass—an area almost three times the size of Greater London. In March 2016 the Secretary of State for Defence announced “an ambitious programme of estate rationalisation” and identified 10 sites for release from the Defence Estate that would generate some £1billion and contribute up to 55,000 homes. These sites included barracks, training land, former RAF maintenance unit, fighter airfield and other former land uses. Other sites have been added to the list.
Under Part 2A of the Environmental Protection Act 1990, certain defence related activities would result in a determined contaminated land to be a special site.
Many defence activities, past and present, have or have had the potential to contaminate land. Such contamination could be of the sort encountered on non-military post-industrial brownfield sites – heavy metals, fuels, solvents, asbestos. However, there are also contaminants particularly associated with defence related former land uses: explosive ordnance from WWI and WWII aerial bombardment, munitions, pyrotechnics, firefighting agents, chemical weapon residues, propellants, radioactive luminescent paint.
For example, chemical weapons (CW) contamination is mainly associated with burial or burning pits, generally on current or former MoD (Ministry of Defence) and MoS (Ministry of Supply) land. CW agents were produced at only a small number of known sites in the UK. However, containerised or weaponised CW agents may be present on any MoD site since during WWII CW munitions were distributed widely rather than being concentrated at production and storage sites or the few Forward Filling Depots (FFD) as had been thought previously.
Explosives sites were built for both military and commercial use. Military explosives sites mainly manufactured explosives or involved ammunition filling with activity peaking during the two world wars and the Korean conflict. The period when a specific site was operating may indicate the types of explosives that could be present in the soil. Such sites are found across the entire UK but the largest sites had good access to the rail network.
Former military sites will contribute much of the new housing over the coming years. Ensuring future residents will be safe and demonstrating that the land is suitable for this sensitive land use requires a sound understanding of the nature and distribution of contamination across a site. Whether a naval dockyard, former air-force base or army barracks, understanding how a site has been used is an essential pre-requisite to developing an informed conceptual site model and designing an appropriate sampling and analytical strategy as well as eventually designing a successful remediation strategy.
Whether former aircraft hangars, vehicle maintenance, ordnance depots, weapons manufacture or fuel storage, military sites are an important part of securing safe and suitable for use land for new homes. Their rural or peri-urban location makes them very attractive to future residents – and therefore developers.
The topic of our next Professional Practice Webinar is Redeveloping Military Sites. The webinar will discuss the unique sources of contamination and unusual pathways that are present on military sites, review key sources of information, describe established and emerging methods of remediating military sites. LQM will be delivering this webinar at 1-3pm on 21 November 2018. You are most welcome to book a place via https://www.lqm.co.uk/webinars/rmsweb/
Paul Nathanail, Managing Director of Land Quality Management Ltd, will deliver this new series of lunchtime Webinars (1300-1500). Attendees at other Webinars Paul has delivered have enjoyed his authoritative, accessible and informal style of delivery.
In deriving generic or site-specific assessment criteria for soils, SR3 (Environment Agency, 2009) generally recommends using default inputs intended to be protective in all but the most extreme exposure scenarios. For example, with respect to the consumption of six groups of homegrown fruit and vegetables considered by the UK Contaminated Land Exposure Assessment (CLEA) model, it recommends that consumption rates that would be protective of 90% of the UK population (i.e. 90th percentile consumption rates) should be adopted.
In 2014, alternative guidance was published as part of the SP1010 research project (Defra, 2014), which also derived the initial six ‘Category 4 Screening Level’ (C4SLs). SP1010 generally recommends the use of “central tendency” inputs to avoid generating overly cautious assessment criteria. However, in order to ensure that assessment criteria are adequately protective, SP1010 recommends a “middle ground approach” with respect to consumption rates where by the 90th percentile is used “for the two homegrown produce groups expected to give the highest exposure” and mean consumption rates for the remaining four groups. This is known as the ‘Top Two’ approach.
CLEA V 1.071
There is functionality within the latest version of CLEA (Ver. 1.071) to implement the recommendations of SP1010, and so generate C4SL-like assessment criteria. However, in order to apply the ‘Top Two’ approach the user must first be able to identify and definethe ‘Top Two’ produce groups within the chemical-specific database. Therefore, in order to produce C4SLs (or any other SP1010-compliant assessment criteria) a risk assessor must first identify which are the ‘Top Two’ produce groups. This is not straightforward or readily decided and requires a series of calculations.
But how can the ‘Top Two’ be identified?
LQM have developed a ‘Top Two’ Calculator, which rapidly and easily identifies the Top Two, and we have been using internally for sometime. To find out more about the ‘Top Two’ approach, and how to use the Calcuator to identify the ‘Top Two’ produce groups please join us for a one-hour lunchtime webinar on the 5th of Sept 2018. To book your place please visit our website.
** Each delegate will also receive a free complimentary copy of the LQM ‘Top Two’ Calculator. **
Note: webinars can only be booked via online card payment but you will receive a 20% discount making the overall cost £50 excl. VAT.