Posts by Katie Kennedy

News

AGS Magazine: June / July 2021

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The Association of Geotechnical and Geoenvironmental Specialists are pleased to announce the June / July 2021 issue of their publication; AGS Magazine. To view the magazine click here.

This free, publication focuses on geotechnics, engineering geology and geoenvironmental engineering as well as the work and achievements of the AGS.

There are a number of excellent articles in this issue including;

New AGS guidance published on Assessment and Control of Asbestos Risk in Soil – Page 6
AGS Yellow Book Photography Competition – The Results – Page 8
UK Specification for Ground Investigation – revision update – Page 10
Digital transformation in ground engineering – hopes and fears? – Page 14
Incorporating Drone Technology into Ground Engineering Projects – Page 18
PFAS – the greatest challenge for the site investigation and laboratory industries? – Page 23

Plus much, much more!

Advertising opportunities are available within future issues of the publication. To view rates and opportunities please view our media pack by clicking HERE.

If you have a news story, article, case study or event which you’d like to tell our editorial team about please email ags@ags.org.uk. Articles should act as opinion pieces and not directly advertise a company. Please note that the publication of editorial and advertising content is subject to the discretion of the editorial board.

Article Geotechnical

Digital transformation in ground engineering – hopes and fears?

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Article provided by Neil Chadwick, Director, Digital Geotechnical and Stephen Lawrence West, Director, Ground Engineering, Ramboll

Digital transformation is a term that, within the ground engineering sector, can engender feelings of hope or fear or possibly both at the same time. The hope is for a future where we have tools that can help us all to do a better job for society’s benefit. The fear is of being left behind, individually or corporately, or concern about potential undesirable consequences if we allow the machines to take over. In this article we will explore some of these fears, a few of which are well founded, but our main goal is to accentuate the positives that digital transformation can bring and encourage creative thought and debate about this issue by the AGS members.

It starts with the data

The digital revolution is also a data revolution. The good news is that our industry is already pretty good at handling data. At the heart of this is our own AGS data transfer format for factual GI data. We take it for granted but it is probably the world’s most successful ground data transfer format. Other countries, and other parts of the construction industry, look at us with envy.

Despite this success we should not rest on our laurels – and we are not. The AGS format is adapting and expanding. We have introduced AGSi, for ground models and interpreted data, and a draft for AGS piling is now starting to gather some real interest. The AGS Instrumentation and Monitoring Working Group is also on the case, currently studying real world I&M data flows.

Few would doubt the value of digital tools for helping us to sort out the data, or the need for common standards for when we need share that data. The opportunity that digital transformation provides is a step change improvement on what we already have Our day to day experience of modern apps and websites has, quite rightly, increased expectations for the user experience of technical software. We want tools that are both smarter and easier to use. However, if we want our software vendors to provide these, then we need to be pro-active in telling them what we really need, and why.

Interpretation: humans vs machines?

Interpretation of data to inform design is perhaps the first flashpoint in the discussion about the nature and extent of machine input to our processes. We all know and accept that ground data is normally less than perfect, with outliers that are outliers for a good reason, albeit we don’t always know the reason at the time. In this country we have been reluctant to use even relatively straightforward statistical methods in our interpretation, so therefore it comes as no surprise to find that many get nervous when the digital evangelists start talking about data driven design and machine learning.

It is right that we should question these. Data driven design is just that. In many cases, a data driven design could give us the right answer, but data is subject to imperfections, bias and limitations. If we are not careful we may end up reinforcing the bias (as Amazon once found out, to their embarrassment), or we could get things completely wrong if we extrapolate outside the valid range of the data.  We also need to ask what is the ‘right answer’ when considering design solutions.  Can a purely data led design provide an answer that is right for the overall needs of a particular client and project that suitably weighs risk.  This is where the human element can provide insight to select the right answer having been guided by information provided from past data.

Machine learning goes further and can potentially unlock more value from our data, but the mantra here is ‘don’t forget the physics’. The realities of the ground are such that the machines will always need a human partner for their learning process, whose role will be to  define the geological and other rules that should be obeyed, and act as final arbiter to select the design ground model.

An example of the above is interpretation of geological horizons from borehole data. We already use computers to help us with this, but at present it typically needs need human intervention to account for features such as buried river channels that may be apparent from the desk study conceptual model, but may be have been missed by the existing boreholes.

Having said all that, the authors believe that we should be embracing these techniques, using them to help us make more informed and hopefully better decisions. The fact that 100 different engineers can come up with 100 different design lines from the same data is not something we should be proud of.

A good example of a positive experience from machine learning was given at the AGS Data Conference in 2017. One of the presentations looked at the machine learning applied to CPT interpretation for a large regional scale dataset. Human verification of selected interpretation was undertaken for control purposes. It was confirmed that some of the machine generated interpretations required correction after review, but these were outnumbered by the number of cases where, after review, the machine was considered to have got it right, not the original human!

Automation of the design process

This is where things start to get really interesting. There is plenty of scope for using automation to help with factual and interpretative reporting, but automation of analysis and design calculations is likely to be one of the main digital battlegrounds in the coming years.

As mentioned above, digital 3D ground models are already a reality on many projects. One area ripe for development is finding a better way to input these models directly into analysis/design software, replacing what is currently mainly a manual process. However, we need to think carefully about what model we use for input. We are most familiar with the ‘geological (observational) model’ which is our best guess of what we think might be going on based on the conceptual model and lessons learned from our education and experience. However, for analysis we should be using a ‘geotechnical design model’ which also takes account of uncertainties and code requirements.  These models can be compiled by an intelligent digital partner by prompting the geotechnical engineer to make key decisions relating to geological setting and how to account for ground related risks.

One of the main concerns expressed about automation of design is that we will forget how to do the design calculations, with the younger generation not learning at all. This is a legitimate concern, and it is by no means unique to ground engineering. If we automate (or perhaps when we automate is more correct) we will need redefine the role of the human in the design process. We will probably still be doing some sort of verification, which should allow us to practice our skills and judgement. We don’t have all the answers to this conundrum, but it would be wrong to allow this to be a barrier to much needed progress. We will have to work through it.

There are some who are ambivalent, or even hostile, to automation, fearing that many will lose their jobs. However, others see the opportunities that it can bring, such as allowing us to do more analysis, considering more scenarios, to create better designs for our clients. If we get this right, we should be able to spend more time on real design and less on manually transferring data from one bit of software to another. We need to make sure that, as an industry, we are all aligned in looking to deliver real change and real benefits. We must avoid being drawn into a race to the bottom (on time/cost). It is within our gift.

Automation in construction

Digital transformation is not confined to the design office. There are many opportunities for increased use of digital technologies on site.

Digital field capture of data for ground investigation and construction is now starting to become routine, although we still have some way to go on this.

Augmented reality, where models and the real world can be visualised together, is an under-used technology that certainly merits further attention.

Automation of construction processes is the next frontier. Will we see robots running around construction sites?  One day, perhaps, but the reality of construction automation may be slightly more down to earth. For example, it may include automated boring or piling rigs, or earthworks equipment, with humans still in attendance but with more of the work and decision making done by the machines.

Automation of earthworks operations is the one of the main subjects of research and development in the ground domain, and there are already many examples of digital technologies being used to good effect. Typical applications include tracking of compaction plant, to provide information on number of passes, to assess specification compliance. Another example, published recently in NCE, shows how a contractor is monitoring earthworks vehicle movements on a large linear infrastructure site, then using AI to optimise utilisation of the fleet.

This is not digitisation for the sake of digitisation as there are some important additional benefits that can be obtained by automating construction. Firstly, there is the obvious benefit to health and safety if we can keep as many humans as possible out of harm’s way. This is one of the main drivers for research in this domain.

The other benefits are perhaps not so obvious, but should be of interest to ground specialists. Digitisation and automation of construction will very likely lead to increased monitoring of the processes. This additional data could prove very useful, if we choose to leverage it. A further benefit should be improved consistency of processes which, when taken together with the extra monitoring, should leave us with better build quality, and better records.

We will still need humans to keep a close eye on things as the ground never ceases to conjure up surprises, but if we get this right we could end up in a much better and safer place.

Do we all need to be digital experts?

A good question, that has been answered many times by many people, with many different answers given. The reality is that we can only hold a limited amount of knowledge in our heads. It is unrealistic to ask all ground specialists to become digital specialists, and the authors believe that it would be wrong to significantly dilute or reduce most individual’s knowledge of ground engineering (whatever branch that happens to be) to make way for lots of digital skills.

However, getting digital specialists to do all of our digital legwork is not the right answer either. We should aim for a general increase in awareness and knowledge of digital issues and capabilities at all grades, including the oldies. Digital specialists may still be brought in for the heavy development work, but it would also be helpful to have some people with a foot in both camps.

Whatever the arrangement, we need ground and digital specialists to work together to identify the problems that need to be solved, and the improvements that can be made. If we leave it all to the digital people then we may get lots of shiny new toys, but not the ones we really wanted.

In conclusion

Much of this article has talked about some of the potential problems that digital transformation may bring. However, our mission has been to inform, challenge, and hopefully allay some fears. Digitisation is coming, and we should embrace it, as it will offer great opportunities for improvement within our industry and can be seen as an aid to help us communicate even more effectively with our colleagues, clients, and the public.

However, if we are going to get the most from it, we need ground specialists to work with the digital specialists. The digital specialists may know how to get there, but we need to tell them where to go.

Article

Incorporating Drone Technology into Ground Engineering Projects – Transforming the work of a remediation contractor

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Prepared by:

Blaise Hodges, Senior Land Surveyor, Cognition Land and Water, blaise.hodges@cognitionltd.com

Andy O’Dea, Technical Director, Cognition Land and Water, andy.odea@cognitionltd.com

Drones (Unmanned Aerial Vehicles – UAVs) are quickly becoming one of the most useful tools on a typical construction site, offering rapid data collection for topographical surveys or site 4D imagery.  Drone arial footage and 4D model mock-ups allow quick access to valuable site data and visual information.  Whether it’s for initial site pricing strategies, refining pre-design processes or recording work progress, our investment in drone technology is allowing our teams to work safer and more efficiently, whilst delivering tangible benefits for our clients.

As our drone uses GPS and obstacle avoidance systems, it can be programmed and manoeuvred accurately to precise locations on site and follow pre-determined flight paths.  This creates an extremely valuable and multi-faceted tool that can be used in a variety of situations. Such tools and facilities have had a big impact on our work, primarily in the management of earthworks projects.  Outlined below are a number of ways in which the application of drone technology and surveying techniques have delivered significant benefits, efficiencies and improvements in data capture and delivery on our projects.

Faster and more accurate site surveys

For most surveyors/engineers, there are two simple reasons for using drones for earthworks – speed and accuracy.  With conventional land-based surveying techniques, it can take many hours to walk the site and measure aggregates and stockpiles.  Subsequently, it often takes several days to process the data and deliver the required volumetric analysis or drawings.  Drone surveys allow all of this work to be done in a fraction of the time.

As an example, our Senior Land Surveyor recently carried out a drone survey of a large construction site in less than 20 minutes to collect data on earthworks stockpiles.  It was not possible to carry out the survey with traditional ground-based systems due to soft and overgrown ground conditions.  The post-survey processing took a matter of hours, despite handling thousands rather than scores of surveyed points across the site surfaces.  In addition to the very significant time saving, the far greater number of survey points provides scope for many more outputs such as an orthomosaic point cloud and a 4D digital terrain model (DTM) of the site.

Using proprietary Pix4D software, access to the survey model can be provided to the client and project team via a simple web link.  This then allows the whole project team to inspect, manipulate and interrogate the model as well as access to high resolution images, on screen visuals and tools to measure terrain dimensions, etc.  Stockpile volumes can be calculated, distances and areas measured, and OS co-ordinates given – all with a few mouse clicks.  It is a truly powerful data and imagery presentation system that is accessible to all.

Performing cut-and-fill volumetric analysis

We often utilise traditional GPS surveying in tandem with drone surveys to extract the best of both approaches.  Traditional ground-based surveying is used for key site features such as bottom of banks, edges showing changes of surfaces and heights. The drone data collection is then carried out on a grid throughout remaining areas, eliminating the risks associated with climbing stockpiles and providing truly accurate data.

Drones have dramatically reduced the manual work needed to perform a cut-and-fill volumetric analysis following the site survey.  Once the aerial data is collected, drone software platforms like Pix4D enables cloud processing and final export into Autodesk file formats like a DXF or a point cloud file that can be used in Civil 3D or LSS design software.

This has allowed us to streamline our cut-and-fill workflow, speeding up the process significantly.  We have estimated that we can now carry out volumetric analysis and cut and fill calculations in about one-third the time it took us previously.  This provides cost savings to our clients and greater time to interrogate the output of the analysis and formulate innovative and novel solutions to the ground engineering problems presented to us.

Verifying work and managing conflicts

During the course of an earthworks project, it is vital to regularly monitor progress, especially at key milestones, to ensure the works are progressing to programme.  Drone surveys have become an invaluable tool in this monitoring and verification process.

We fly our sites as often as is required by the project to satisfactorily record progress.  We then process the images into an orthomosaic, and hence into an elevation map that can be compared to the initial site plans as the project progresses.  This allows for clear and robust recording and monitoring at important phases of the project.  Importantly, this information enables more focused quality control as well as providing site managers with detailed information on progress to allow closer and more accurate management of resources and expenditure.  Such interim surveys also provide robust data for interim works measurement and payment applications.

Site inspections and tender support

We will often use drone surveys in support of our tender and estimating work.  A quick drone survey carried out at the tender stage can provide invaluable information to both the client and contractor on the site conditions, building (current and former) footprints, topography, site restrictions, earthworks volumes, building condition, etc.

Drones can capture images and videos, allowing for detailed mapping and easy access to inspect and prepare volumetric data for cut and fill calculations.  Gathering information through a single drone survey allows for a far better understanding of the key project risks, makes the costings on a project more accurate and saves significant time in the tender stage by avoiding multiple site visits.

The speed at which we can now perform quite complex and detailed imaging, topographic and volumetric surveys means that we will often provide our initial drone survey as a free service to our clients at the tender stage, giving us a clear advantage and differentiator against our competition.

Improved worker safety

In the field, surveyors and engineers spend hours on the ground collecting data or overseeing site-based work.  This is not only time-consuming but can be deemed as a risky activity.  Often, site rules or risk assessments will not allow personnel to access stockpiles or move freely around the site due to plant movement and other site risks.  Traversing steep slopes that are uneven and potentially unstable is an activity fraught with dangers.  This can all be avoided by the use of a drone survey.  Site engineers and personnel can inspect and quantify the site, earthworks, slopes and stockpiles from a safe distance avoiding all associated trip and fall hazards.

To assist with communicating key site risks to the workforce, a drone aerial photography survey will allow for a good overall representation of the site and help provide powerful visual information to site managers for use in site inductions or toolbox talks.  Drone surveys may even be used to conduct safety inspections or audits at large sites and this is something that we are looking to introduce shortly.

A powerful tool

We hope that the examples provided above give a flavour for the powerful benefits that drone surveys have made at our company and how investment in this technology has revolutionised the way in which we inspect, manage, record and report the work we do.  It is fair to say that it have been a game-changer for Cognition Land and Water and we would be happy to share our experiences with you further if that would be helpful.

Cognition Land and Water is a specialist ground engineering and contamination remediation contractor with the capability to deliver all ground-related aspects of construction projects from site investigations, remediation, earthworks and ground engineering, through to civil engineering and concrete-framed structures.

Article

Asbestos in soil and quantitative risk assessment – discussion on a way forward?

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Article contributed by:

Jo Wilding, Associate Technical Director, RSK (SoBRA Executive Committee)

Simon Cole,  Technical Practice Lead, AECOM (SoBRA Chair)

Feedback to info@sobra.org.uk

Laboratory reporting of asbestos in soil is a key data component of quantitative risk assessment for human health, and for the risk-based management of asbestos in soils. Asbestos in soil poses a hazard to human health when it becomes airborne, and the inhaled fibres can result in diseases including mesothelioma and lung cancer. Therefore the relationship between asbestos in soil and the resulting fibre concentration in air is a fundamental, but complex, element of human health risk assessment. In the UK, there is no current consensus on which air quality guidelines should be used to assess potential risks to human health from exposure to asbestos in soils once airborne. This in turn means that there is no UK regulatory or industry-agreed good practice for the assessment of risks from asbestos in soils, which are being – or could be – released to air and subsequently inhaled. Key elements to an asbestos risk assessment are (i) asbestos identification and characterisation, (ii) receptor exposure, (iii) an understanding of background exposure and (iv) assessment criteria at an appropriate risk level that distinguish between relative risks from different types and forms of asbestos.

The Society of Brownfield Risk Assessment (SoBRA) has recently published two discussion papers relating to asbestos in soil laboratory analysis and reporting. These were published alongside an update to the discussion paper on guidelines for airborne concentrations of asbestos fibres in ambient air: implications for risk assessment.  All three papers build on the series of SoBRA papers published by the asbestos sub-group in 2015 that looked at sampling protocols, activity-based sampling, conceptual models, and example decision making under Part 2A of the Environmental Protection Act 1990.

Data mining of laboratory data

SoBRA issued a request to major UK soil laboratories in 2016 to provide SoBRA with anonymised asbestos in soil laboratory data. The distribution of asbestos in soil discussion paper provides a factual presentation of the data shared by five UK laboratories (ALS, DETS, Envirolab, i2, and REC). The data presented in the paper is, naturally, a reflection of the soil samples sent to the testing laboratories rather than a reflection of background concentrations of asbestos in soils in the UK.  The datasets do not distinguish between sample origin – be that a greenfield site or a brownfield site nor do they distinguish between large datasets from one or a small number of sites and small datasets from a larger number of sites.

Typically laboratory testing follows a sequential three stage process akin to the one presented in the Standing Committee of Analysts ‘Blue Book’ method (withdrawn in October 2020; SCA, 2017). However, the data presented in the paper is a result of different laboratory methods or sub-sets of methods and will include analysis undertaken by different methods over time by the same laboratory.  The three stages are:

Stage 1: The determination and identification of presence or absence of asbestos using stereomicroscopy, plus higher magnification polarised light microscopy (PLM) analysis for fine fibres (see HSG 248, HSE, 2005).

Stage 2: The removal of asbestos containing material (ACM) and fibre bundles with identification and gravimetric analysis to determine percentage by weight.

Stage 3: The dispersion and collection of free fibres followed by fibre identification, counting and measurement of fibres to determine percentage by weight.

From a dataset of approximately 175,000 samples, during Stage 1, asbestos was not detected in the majority of samples submitted to the five laboratories. When positively identified the majority of asbestos detected was chrysotile. The majority of reported concentrations of free fibres detected in soils that have undergone Stage 3 analysis following a positive identification at Stage 1 were below the method reporting limit of 0.001% wt/wt. (Note that these samples are typically, but not always, those that have had a positive identification at Stage 1; it is rare for samples with a negative ID at Stage 1 to progress to Stages 2 or 3).

Variability in UK laboratory methods and reporting

There is, however, significant variability in UK laboratory methods for the identification and quantification of asbestos in soil. A SoBRA survey of 10 UK laboratories in 2018 raises questions about the data that is reported and its subsequent applicability for use in human health risk assessment.  The survey was designed to complement a similar survey of UK laboratories undertaken by the AGS and reported in February 2019 (Mitcheson, 2019).  The survey highlighted that laboratories do not follow the same sample preparation and analytical procedures, nor do they report in the same way.  Only 70% of laboratories follow the ‘Blue Book’ method; the method used by the remaining 30% of laboratories was not explored.  Even those who follow the ’Blue Book’ implement that method in different ways that could significantly influence the results reported.

When considering accreditation and proficiency, which is a key element for data quality, all laboratories surveyed participated in the HSL Proficiency Testing Scheme Asbestos in Soil Scheme (AISS) but only 70% of the laboratories responded that they held UKAS accreditation for Stage 1 identification of asbestos.

Total sample size (weight) requested, sample size (weight) used in Stage 1, and sample preparation for Stage 1 and Stage 3, varied considerably between laboratories. No laboratory routinely reported at what sub-stage within Stage 1 asbestos was detected (i.e. during visual inspection using stereomicroscopy or during higher magnification PLM microscopy) and therefore when the sample inspection stopped. All such variables could have implications for the determination and identification of presence / absence of asbestos in the soil samples, and the type of asbestos reported to be present in Stage 1.

With regards to the data needed to inform a human health risk assessment, only 20% of laboratory responses indicated that they would routinely provide comment on the condition of the asbestos identified in Stage 1 (i.e. weathered, degraded, non-degraded, disaggregated, not in original form) in addition to identifying the presence or absence of the three principal types of asbestos, and the form of that asbestos. A lines of evidence approach is often needed for asbestos risk assessment. For example, non-degraded asbestos material is that which despite being in or on the ground is in relatively good condition and capable of retaining most of the asbestos fibres. As such, non-degraded asbestos material may pose a lower risk to human health and should be considered within the risk assessment. Asbestos containing materials that have been significantly damaged or degraded will be more likely to release fibres and therefore pose a greater risk to human health.

A small number of laboratories did respond that they could provide asbestos type differentiation at quantification if required during Stage 2 and Stage 3, along with photographic evidence if requested, but this was not routine.

Reporting recommendations

The SoBRA paper on UK laboratory methods for the identification and quantification of asbestos in soil makes a series of recommendations for laboratory reporting of asbestos in soil results based on the requirement for human health risk assessment to be supported by clear, unambiguous laboratory data. One key element is the reporting of types and forms of asbestos, for all each type and form of asbestos identified. Within Stage 1 this should be for each of visual inspection, detailed inspection under x20-x40 stereomicroscope and pinch samples under x80-x500 magnification (PLM). Within Stage 2 individual masses for each type and form of asbestos identified should be reported, with mass reported in mg/kg not %wt/wt.

The SoBRA recommendations (the full detail of which is presented in the SoBRA paper) for laboratory reporting of asbestos in soil results would ensure that the data provided by the laboratory is clear and unambiguous. With the withdrawal of the of the SCA ‘Blue Book’ method for the determination of asbestos in soil, now is an opportune time for industry to adopt a new approach the analysis and reporting of asbestos in soil. Consistency is required in sample preparation, analytical procedures and reporting to ensure the resulting human health risk assessment can be undertaken with confidence.

When considering the data required within a human health risk assessment, there are other laboratory test methods that focus less on the reporting of the mass of asbestos present in the sample and focus more on the potential for airborne asbestos fibres arising from asbestos in soil. Two such methods that have been developed, or are in the process of being developed, by UK laboratories are:

  • Respirable fibre count per unit weight of sample (this can be used to estimate airborne fibre numbers in association with airborne soil particles), and
  • Dustiness tests (modified HSL drum tests designed to estimate the releasibility of asbestos fibres and provide normalised fibre to dust concentrations akin to those reported by Addison et al 1988).

Air quality guidelines for use in human health risk assessment

The SoBRA discussion paper on guidelines for airborne concentrations of asbestos fibres in ambient: implications for risk assessment was initially published in 2017. The paper has been prepared as an evidence base, with the aim of supporting the development of good practice for assessment of potential risks from asbestos at sites affected by land contamination.

The paper sets out a series of issues that need to be resolved before a UK air quality guideline value can be proposed for asbestos, but calls for the Asbestos in Soil Joint Industry Working Group to formulate a position regarding an air quality guideline for asbestos in the UK.

There are a range of existing air quality guidelines for asbestos fibres, provided both by international bodies (e.g. World Health Organisation) and national bodies (e.g. Health Council of the Netherlands). There are also different approaches in literature for calculating air quality guidelines for asbestos fibres, dependent on the exposure scenario under consideration. The SoBRA paper summarises a selection of internationally published air quality guidelines, together with the data upon which these are based, as well as calculating air quality guidelines using two different modelling approaches from literature. The existing air quality guidelines, and SoBRA calculated guidelines, are compared alongside published ambient background airborne concentrations to understand variability in thresholds for asbestos in air and the potential practicalities of those guidelines.

All models are having to extrapolate from relatively high occupational exposures that form the empirical evidence on which the models are based down to much lower environmental exposures.  The authors of these models differ in their interpretation of that empirical data and as a consequence there is variance in the model outputs for a given input exposure.  Risk estimates from these models can vary by an order of magnitude, and published air quality guidelines by more than two orders of magnitude due to differing assumptions on the relative potency of different asbestos types.

The updated paper includes risk estimates calculated using SoBRA’s workbook (beta version freely available at https://sobra.org.uk/resources/reports/) using the linear as well as the non-linear version of the Hodgson & Darnton model (Hodgson & Darnton, 2000) as well as updates on the age adjustment calculations. The paper recommends that the linear version of the Hodgson & Darnton model for pleural mesothelioma is used to estimate risk and calculate air guideline values in conjunction with the non-linear variants for peritoneal mesothelioma and lung cancer.

The tool allows users to select from the algorithm options presented in Hodgson & Darnton (2000), and enables users to perform model choice sensitivity analysis and evaluate the difference the use of alternative algorithms makes to estimated risk.  It is hoped that the tool will provide a consistent basis for the calculation and reporting of risk estimates and feedback on the tool is welcomed at info@sobra.org.uk.

References

Addition, J, Davies LST, Robertson, A, Wiley, RJ (1988). The release of dispersed asbestos fibres from soil. IOM Historical Research Report TM/88/14.

HSE (2005). Asbestos: The analysts’ guide for sampling, analysis and clearance procedures.

Mitcheson, B (2019). Variability in asbestos analysis in soil, AGS Magazine, February 2019 https://www.ags.org.uk/magazine/ags-magazine-january-february-2019/

SCA (2017). The quantification of asbestos in soil (2017), Methods for the examination of waters and associated materials, Standing Committee of Analysts, April 2017 [Withdrawn in October 2020].

Acknowledgements

The authors would like to acknowledge the work of the SoBRA asbestos subgroup, and in particular Barry Mitcheson for the development of the workbook tool, and both Barry and Simon Hay as primary authors of the risk calculations presented in the SoBRA air quality guidelines discussion paper.

Article Laboratories

PFAS – the greatest challenge for the site investigation and laboratory industries?

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Article provided by Geraint Williams, ALS Life Sciences, Member of the Contaminated Land and Laboratories Working Groups.

“Forever chemicals”.  This is the ominous title often given to PFAS (per- and polyfluoroalkyl substances) which hints at both the reason for their use and their potential impact to human health and the environment.  These substances are the latest entry into the list of contaminants that have resulted in long-term exposure over the last several decades. Their predecessors include lead, asbestos and hexavalent chromium, the focus of the 2000 Erin Brockovich film, plus many more.  But PFAS pose many difficulties their predecessors did not.  This article briefly reviews these challenges and provides an overview of emerging laboratory techniques for analysis of PFAS.

What are PFAS?

In 2015, the Swedish Chemicals Agency (KEMI) identified over 3,000 PFAS on the global market1. A more recent study identified approximately 4,700 Chemical Abstract Services (CAS) Registry Numbers associated with individual PFAS or PFAS mixtures2. In 2019, the US EPA assembled a master list of 6,330 PFAS that combines information from several existing lists into one3. The total number of PFAS may be even larger, given that some PFAS class members lack CAS numbers and many are not intentionally manufactured but are transformed in the environment.

PFAS can be broadly subdivided into four interrelated categories: perfluoroalkyl acids (PFAAs), PFAA precursors, perfluoropolyethers (PFPEs), and fluoropolymers4, 5. PFAAs are the most studied PFAS subgroup. They are recalcitrant and extremely persistent in the environment. Examples of PFAAs include perfluoroalkyl carboxylic acids (PFCAs) such as perfluorooctanoic acid (PFOA), perfluoroalkyl sulfonic acids (PFSAs) such as Perfluorooctane sulfonic acid (PFOS), perfluoroalkyl sulfinic acids (PFSiAs), perfluoroalkyl phosphonic acids (PFPAs), perfluoroalkyl phosphinic acids (PFPiAs), perfluoroether carboxylic acids (PFECAs) such as GenX, and perfluoroether sulfonic acids (PFESAs) such as 4,8-dioxa-3H-perfluorononanoate (ADONA). PFAAs and their precursors are further subdivided according to their chain length, which is viewed as indicative of their bioaccumulation potential.  By convention, the longer-chain PFSAs are those with six or more perfluorinated carbons; longer-chain PFCAs, PFPAs and PFPiAs are those with seven or more perfluorinated carbons5. The definition of longer vs. shorter-chain PFAS is less clear for perfluoroethers.

The focus of risk assessment has been on a very narrow sub-set of PFAAs which are all extremely persistent and are also known to be mobile and bioaccumulative.  This persistence, along with their high solubility, low to moderate sorption to soils, and lack of volatility can result in very extended groundwater plumes (potentially multiple miles).  PFAS have the potential to migrate over a much wider area than conventional contaminants6.

PFAS Regulation

PFOS and its salts, and perfluorooctane sulfonil fluoride (POSF) are listed as persistent organic pollutants (POPs) in Annex B of the Stockholm Convention, whereas perfluorooctanoic acid (PFOA), its salts, and related compounds are listed in Annex A7. Perfluorohexane sulfonic acid (PFHxS), its salts, and related compounds are currently under review for listing8. Several PFAS are included in the European Chemicals Agency’s (ECHA) Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Candidate List of Substances of Very High Concern (SVHC)9.

The EU annual average environmental quality standard (AA-EQS) for PFOS in surface freshwater is set at a very low criterion of 0.65 ng/l, based on the potential for secondary poisoning in humans due to fish consumption.

The US has set a lifetime health advisory level for PFOA and PFOS, individually or combined, of 70 ng/l in drinking water10.  Several US states have also set their own drinking water guideline levels for PFOA and PFOS.  Whilst in the UK, the Drinking Water Inspectorate (DWI) has recently revised our own standards11 which follow a 3-tier system where PFOS or PFOA requiring monitoring is set at 10 ng/l.  The concentration requiring treatment, as representing a potential danger to human health is set at 100 ng/l for PFOS and PFOA and the concentration at which exposure from drinking water should be reduced within 7 days is set at 1 µg/l.

Toxicology

The toxicology of PFAAs is evolving, but questions remain unanswered about the potential adverse health outcomes, though some are shown in the 2019 film Dark Waters12.  Potential adverse human health effects and risk factors from longer-chain PFAA exposure include increased serum cholesterol13, thyroid disease, immune dysregulation, pregnancy-induced hypertension, and kidney and testicular cancers.  Other studies have found positive correlations between long-chain PFAA exposure and low birth weight in humans, as well as suppressed immune system response, dyslipidemia and impaired kidney function.

The European Food Standards Agency (EFSA) set a new tolerable weekly intake (TWI) of 4.4 ng/kg/bw/pw.  Their opinion focused on the sum of four PFAS: PFOA, PFOS, pefluorononanoic acid (PFNA) and PFHxS14.

When some major manufacturers phased out the production of long-chain legacy PFAS, most industries turned to structurally similar replacements including homologues with fewer fluorinated carbons or other less well known PFAS e.g. per- and polyfluoroalkyl ether-based substances.  These replacement PFAS were marketed by producers as safer alternatives because of their presumed lower toxicity and lower level of bioaccumulation.  There are, however, several studies and growing evidence to suggest that certain replacement PFAS have become regrettable substitutes15.

Less is known about the thousands of polyfluorinated PFAAs precursors, which can transform in the environment through multiple intermediates to ultimately create PFAAs as end-products.  Intermediate transformation products include the 6:2 fluorotelomer sulphonate (6:2 FTS) and 5:3 fluorotelomer carboxylic acid (5:3 FTCA) which are described to bioaccumulate in marine invertebrates and rats respectively, and the final transformation products, the short chain PFAAs are shown concentrating in crops 16, 17.

Conceptual Site Models

A robust, site specific Conceptual Site Model (CSM) remains the basis for assessing potential risks.  It is necessary to have a detailed understanding of the topography, geology, hydrology and hydrogeology for all sites.  In addition, knowledge of the types, properties and fate and transport of PFAS along with biotransformation of precursors are all crucial aspects in conceptualising PFAS sources, pathways and receptors.

Because short-chain perfluoroalkyl substances have, to a large extent replaced the long-chain PFAS, the levels of short-chain PFAS such as perfluorobutanoic acid (PFBA), perfluorobutane sulfonic acid (PFBS) and perfluorohexanoic acid (PFHxA), have increased in environmental media.  Short-chain PFAAs are very soluble in water and therefore might represent even more of a risk to drinking water as a result of groundwater contamination.  The shorter chain PFAAs generally have lower organic carbon partitioning co-efficients than longer chain compounds.

The potential presence of PFAS should be taken into account during the preliminary investigation stage.  No direct reference is made to PFAS in the former Department of Environment Industry Profiles, which were written before there was increased awareness of these contaminants, however PFAS might be present at a range of sites including where they are primarily manufactured or have been used in the processing of related products.

The major industries and applications are summarised below:

  • Aviation and aerospace (military and civil airfields)
  • Carpet manufacturing
  • Chemical works (cosmetic/personal care products)
  • Chrome Plating sites
  • Electronics manufacturing
  • Firefighting – class B firefighting foams (fire training area/fire stations)
  • Landfills
  • Military bases
  • Paper and cardboard manufacturing
  • Petrochemical industry
  • PFAS production
  • Photolithography and semiconductor lithography
  • Textiles and leather manufacturing
  • Wastewater treatment works

This list is not intended to be exhaustive.

While PFAS sources are varied, the release of aqueous film forming foam (AFFF) is a common source of PFAS contamination at airports, military bases and major oil and gas facilities.  It is these types of sites that are subject to most investigation currently in the UK.  The combination of complex AFFF compositions and numerous types of foams used throughout decades of fire training, equipment testing and emergency response scenarios has resulted in highly diverse mixtures of PFAS being present in the subsurface.

Perfluoroalkyl sulphonates tend to sorb more strongly than perfluoroalkyl carboxylates of equivalent perfluoroalkyl chain length. Sorption of PFAS can also be influenced by the presence of co-contaminants such as nonaqueous phase liquids and nonfluorinated surfactants, which typically increase sorption potential to soils17.

PFAS can readily penetrate the concrete pad at fire training areas.  PFAS self-assemble on concrete surfaces which are relatively porous.  They then act as a long-term source of contamination in run-off and drainage.

The presence of cationic and zwitterionic precursors in many Class B firefighting foams could act as an on-going source of the more frequently regulated and measured PFAAs such as PFOS, PFHxS and PFOA.  These precursors are incompletely extracted from soils by current analytical techniques essentially developed for anionic PFAS (see below).  The cationic and zwitterionic classes can contribute up to 97% of the total PFAS mass especially in source zones soils18.

The analytical challenges and emerging techniques

PFAS are also challenging contaminants because most constituents cannot be detected by conventional analytical techniques.  Conventional methods used by UK laboratories allow for the analysis of around 20 different compounds.  There are, however, many more PFAS which will be left undetermined including a significant number of polyfluoroalkyl substances.

PFAS are primarily analysed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).  Water samples are extracted using solid phase extraction (SPE) and soils extracted with methanol.  As a “targeted” analytical technique, the results are limited to a fixed suite of components.  In other words, the results do not provide a comprehensive measure of the total extent of PFAS that may exist, nor does this approach measure the potential for targeted PFAS formation due to transformation of precursors over time.

In order to identify the presence of precursors, TOP assay (total oxidisable precursors) was developed.  Sample preparation follows the same procedures as are traditionally used for targeted LC-MS/MS analysis. TOP assay converts precursors in a sample which are detectable by routine analysis.  Results are provided both pre and post digest.  The assay includes steps to oxidise PFAAs precursors using heat and alkaline activated persulfate.  During the oxidation process, the assay generates an excess of hydroxyl radicals to convert these compounds.  TOP assay is widely available and has been used to estimate the concentration of PFAS which contain a detectable perfluoroalkyl group.  It is the most selective of PFAS surrogate analytical methods, in that it determines compounds that can be oxidised to form targeted PFAAs.

More recently, there has been increasing focus to develop and validate complementary screening tools that provide a comprehensive measure of total PFAS impact.  This has resulted in several methods for analysing Total Organic Fluorine (TOF) as a proxy for total PFAS contamination.  TOF is determined by Combustion Ion Chromatography (CIC) and measures extractable or adsorbable organofluorine in a range of matrices.

The concept of a “PFAS screening tool” approach is being evaluated by the US EPA, which is in the process of developing a new analytical method for measuring TOF in environmental samples. The USEPA TOF method is anticipated to be published later this year.  TOF analysis could be useful to use along side existing approaches although there is a trade-off between selectivity and inclusivity.

In addition, there have been recent advances in High Resolution Mass Spectrometry (HRMS) such as LC- Quadrupole time-of-flight mass spectrometry (LC-qTOF/MS) and Orbitrap techniques which can be used to determine both the chemical formula and structure of unknown PFAS.  These method have the potential to greatly increase the number of identified PFAS compounds and provide more accurate source identification.  HRMS is best suited for samples in which unknown PFAS are likely to be present in significant concentrations.  LC-qTOF/MS or other HRMS techniques give a more detailed understanding especially where chain-length specific concentrations are required.

Conclusions

As the transformation of precursors to PFAAs can have important implications for risk assessment, understanding their relative contribution to total PFAS concentrations is critical to determining the remediation options for impacted sites.  A robust and reliable CSM is required and techniques such as TOP assay have role to play.

Only a small fraction of known PFAS can been measured via targeted chemical analysis and many more PFAS are likely to occur in the environment than are routinely analysed.

PFAS are used in a wide range of applications and typically occur in complex mixtures which present a unique challenge to laboratories.  In contrast, there is a very limited number of laboratory standards available.

The more we learn about PFAS contamination, we realise that the problem is more widespread than previously thought.  The requirement to investigate much larger areas may become a necessity with better understanding of CSMs.  Non-targeted PFAS analysis could be used to screen extensive areas, identifying hot spots of contamination directing efforts for parts of the site that require further investigation and characterisation with targeted and traditional analytical methods.

Use of TOP assay in combination with other less selective methods like TOF may become a popular approach to gain additional information about the nature of the unidentified fluorine fraction and its relevance as a source of PFAAs.  The addition of HRMS for non-targeted and suspect screening analyses can offer valuable information about the unidentified fraction of organic fluorine.

References

  1. KEMI (Swedish Chemicals Agency). 2015. Occurrence and use of highly fluorinated substances and alternatives. Report from a government assignment. Swedish Chemicals Agency (KEMI) Stockholm, Sweden
  2.  OECD. 2018. Toward a New Comprehensive Global Database of Per- and Polyfluoroalkyl Substances (PFASs): Summary Report on Updating the OECD 2007 List of Per- and Polyfluoroalkyl Substances (PFASs). Series on Risk Management No. 39. ENV/JM/MONO(2018)7. Paris, France: OECD.
  3. U.S. EPA. 2020b. PFAS Master List of PFAS Substances (Version 2).
  4. Wang Z, DeWitt JC, Higgins CP, Cousins IT. 2017. A never-ending story of per- and polyfluoroalkyl substances (PFASs)? Environ Sci Technol 51(5):2508–2518.
  5. Buck RC, Franklin J, Berger U, Conder JM, Cousins IT, de Voogt P, et al. 2011. Perfluoroalkyl and polyfluoroalkyl substances in the environment: terminology, classification, and origins. Integr Environ Assess Manag 7(4):513–541.
  6. Ross I., Donough J., Mile J., Storch P., Kochunarayanan T., Kalve E., Hurst J., Dasgupta S., Burdick J. A review of emerging technologies for remediation of PFASs Remediation 2018: 28 101-126.
  7. UNEP (United Nations Environment Programme). 2020. All POPs listed in the Stockholm Convention.
  8. POPRC (Persistent Organic Pollutants Review Committee). 2020. POPRC recommendations for listing chemicals.
  9. ECHA (European Chemicals Agency). 2020. Candidate list of substances of very high concern for authorisation.
  10. U.S. EPA (U.S. Environmental Protection Agency). 2020a. Drinking water health advisories for PFOA and PFOS.
  11. Drinking Water Inspectorate (2021) Guidance on the Water Supply (Water Quality) Regulations 2016 (as amended) specific to PFOS (perfluorooctane sulphonate) and PFOA (perfluorooctanoic acid) concentrations in drinking water.
  12. C8 Science Panel. 2012b. Probable link evaluation of thyroid disease. 30 July 2012.
  13. Skuladottir M, Ramel A, Rytter D, Haug LS, Sabaredzovic A, Bech BH, et al. 2015. Examining confounding by diet in the association between perfluoroalkyl acids and serum cholesterol in pregnancy. Environ Res 143(pt A):33–38, PMID: 26432473, 10.1016/j.envres.2015.09.001.
  14. EFSA (2020) Risk to human health related to the presence of perfluoroalkyl substances in food
  15. Brendel S, Fetter É, Staude C, Vierke L, Biegel-Engler A. 2018. Short-chain perfluoroalkyl acids: environmental concerns and a regulatory strategy under REACH. Environ Sci Eur 30(1):9, PMID: 29527446, 10.1186/s12302-018-0134-4.
  16. Caverly Rae, J. M.; Craig, L.; Slone, T. W.; Frame, S. R.; Buxton, L. W.; Kennedy, G. L. Evaluation of chronic toxicity and carcinogenicity of ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)- propanoate in Sprague-Dawley rats. Toxicol Rep 2015, 2, 939− 949.
  17. Langburg, H. A., Breedveld G.D., Gronning H. M., Kvennas M., Jenssen B.M, Hale S. Bioaccumulation of Fluorotelomer Sulfonates and Perfluoroaklyl Acids in Marine Organisms Living in Aqueous Film-Forming Foam Impacted Waters
  18. Guelfo, J. L., & Higgins, C. P. (2013). Subsurface transport potential of perfluoroalkyl acids at aqueous film-forming foam (AFFF)-impacted sites. Environmental Science & Technology, 47(9)
  19. Nickerson A., Maizel A.C., Poonam R., Kulkarni R., Adamson D.T., Kornuc J.J., Higgins C.P. Enhanced Extraction of AFFF-Associated PFASs from Source Zone Soils. Environ Sci. Technol. 2020 54 4952-4962

 

 

Article

AGS Yellow Book Photography Competition – The Results

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In November 2020, the AGS launched their second photography competition, this time to source a suitable cover for the third edition of the UK Specification for Ground Investigation (Yellow Book) which is due to be published in early 2022.

A staggered 83 entries were submitted, each covering a range of topics across the geotechnical and geoenvironmental sector including site work, team work, landscape imagery and machinery shots.

AGS Chair, Sally Hudson, AGS Past-Chair, Julian Lovell and AGS Instrumentation and Monitoring Leader, Jonathan Gammon took on the challenging task to judge the images by scoring across four criteria;

  • Originality and Relevance
  • Composition
  • Colour, Lighting, Exposure and Focus
  • Overall Impression, Impact and Visual Appeal
  • Suitability for Yellow Book

Four images were shortlisted, and we’re pleased to announce that Mark Lindahl of Bridgeway Consulting was the overall winner of the competition and won a luxury Fortnum and Mason Hamper.

Our three runners up, who each won a bottle of Champagne are Bryan Laycock (Dunelm Geotechnical & Environmental Ltd), Jim Shields (BAM Ritchies) and Jon Ohashi (Soils Limited).

WINNING IMAGE 

Mark Lindahl, Bridgeway Consulting

Image description: Rotary percussive drilling to inform the design for new lift shafts under the access for all scheme on behalf of Network Rail Design Delivery Group. 20m borehole with SPT’s and Ut100 sampling

FIRST RUNNER UP

Bryan Laycock, Dunelm Geotechnical & Environmental Ltd

Image description: The photo was taken on a job in Co. Durham drilling a 150m deep borehole look at the feasibility for a mine water heat project. The borehole was sank using 4 strings of casing aiming for a roadway within a coal seam at approx. 158mbgl.

SECOND RUNNER UP

Jim Shields, BAM Ritchies

Image description: rotary coring setups for main ground investigation for Viking Wind Farm in Shetland Mainland.  Coring using T2-101 water flush.  Water being supplied to the drilling location by helicopter.

THIRD RUNNER UP

Jon Ohashi, Soils Limited

Image description: This was taken using a 360 camera. The image was taken in the following weeks after Rob Ainsworth sadly passed away, I was pretty close with that guy and was fortunate to be able to call him my friend, not just a brilliant boss! He always pushed for me to take photos not only for work but because he really liked them (I hope 😅) and he thought I had an eye for it.

The AGS would like to thank all those who took the time to enter the competition. The overall standard of entries was extremely high, and the judging panel found the task challenging in shortlisting the top four entries.

Article

Ground Risk: Landslide Risk Reduction Webinar Summary

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Tags: Featured

On 29th April, the AGS held their first webinar on the subject of ground risk, focusing on landslide risk reduction. The event was sponsored by RST Instruments, Geotechnical Engineering and Structural Soils.

This webinar saw Professor Mike Winter, (Director at Winter Associates Limited), Ian Nettleton, (Technical Director at Coffey Geotechnics Limited, A Tetra Tech Company) and Dr Andrew Ridley, (Managing Director at Geotechnical Observations Limited), discuss ground risks associated with slope instability. The event touched on risk assessment of landslide hazards, and the practical features to look for in the field. The speakers also provided insights into the instrumentation and monitoring of slope movements.

This paid for event was rated 4.5 stars out of 5, by our 125 registered delegates who attended from countries across the globe including Canada, Spain, Norway and Romania.

If you missed this webinar, the replay is now live and available for view on the AGS website. The webinar costs £25 for AGS Members and £30 for non-Members (prices exclude VAT). Click HERE to view the replay and download the speaker presentations and file handouts.

 

Report Safety

AGS Safety WG – Update

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Roseanna Bloxham, Leader of the AGS Safety Working Group, has provided an update on the top issues the Safety Working Group discussed at their last meeting which took place virtually in May 2021.

Client Guides

The Safety WG are in the process of developing a set of AGS Client Guides based on the documents which have been produced by the AECOM DOSIWG. The topics include Cable Percussion, Rotary Drilling, Dynamic Sampling and Trial Pitting.

Borehole Sites & Operating Regulations 1995

The Safety WG have been discussing the requirements of the ‘Borehole Sites & Operating Regulations 1995’ and will be producing guidance to advise AGS members of this requirement. The Safety WG will also be producing guidance on Coal Authority permits.

Upcoming articles / guidance

Articles and guidance on different topics are currently being prepared by members of the Safety WG. The topics include Health & Well-being, Vacuum Excavation and Decontamination Units.

Existing AGS Safety Guidance

There is number of AGS Safety Guidance documents which were published before 2014. It has been agreed by the group that these guidance documents need to be reviewed and amended or reviewed and withdrawn, as required.

If you would like to join the AGS Safety Working Group, please contact the AGS Secretariat at ags@ags.org.uk.

News

UK Specification for Ground Investigation – revision update

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The UK Specification for Ground Investigation, published by ICE Publishing, is currently undergoing a revision. The revised Third Edition has been produced by a working group led by the Association of Geotechnical and Geoenvironmental Specialists (AGS) with the support of major clients such as Highways England and Network Rail and other industry bodies such as the British Geotechnical Association (BGA), British Drilling Association (BDA) and Federation of Piling Specialists (FPS). The Third Edition will bring the document up to date, ensuring consistency with all current good practice, relevant standards and codes of practice. The new edition of the Specification has been expanded to include various new investigation techniques and practices that have been developed and entered routine use since the Second Edition was published in 2011.

A draft version for public comment has been released, with comments from industry to be returned by Friday 30th July 2021. All members of the industry are encouraged to review the draft and return any comments they have, and to help spread awareness of the draft amongst colleagues, to ensure this new edition will best serve the industry for years to come. The draft document and commenting template are available from the AGS website using the following link: https://www.ags.org.uk/2021/06/yellow-book-draft-for-public-comment

It is anticipated that the Third Edition UK Specification for Ground Investigation will be published in the first quarter of 2022.

 

Uncategorized

Yellow Book – Draft for Public Comment

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The draft version of UK Specification for Ground Investigation (Third Edition) has been released for public comment and can be viewed here.

All members of the industry are encouraged to review the draft and return any comments they have, and to help spread awareness of the draft amongst colleagues, to ensure this new edition will best serve the industry for years to come.

The commenting table can be accessed here. All comments have to be sent back using the commenting table to ags@ags.org.uk on or before 30th July 2021.

News

AGS Magazine: April / May 2021

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The Association of Geotechnical and Geoenvironmental Specialists are pleased to announce the April / May 2021 issue of their publication; AGS Magazine. To view the magazine click here.

This free, publication focuses on geotechnics, engineering geology and geoenvironmental engineering as well as the work and achievements of the AGS.

There are a number of excellent articles in this issue including;

AGS Annual Conference – Sponsorship Opportunities – Page 4

AGS Webinar Replays – Page 8

Ground movements on Underpinning – A problem with data? – Page 12

Why? Why? Why? Why? Why? Does Lean help with ground investigation? – Page 16

CPD and education for early careers geopractitioners – Page 20

Expectant and New Mothers in Construction – Page 29

Plus much, much more!

Advertising opportunities are available within future issues of the publication. To view rates and opportunities please view our media pack by clicking HERE.

If you have a news story, article, case study or event which you’d like to tell our editorial team about please email ags@ags.org.uk. Articles should act as opinion pieces and not directly advertise a company. Please note that the publication of editorial and advertising content is subject to the discretion of the editorial board.

Article Safety

Expectant and New Mothers in Construction

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Article contributed by Roseanna Bloxham, Senior Geo-Environmental Engineer, RSK and AGS Safety WG Leader.

Pregnancy is a part of life, its something us humans go through to keep our species alive. So why does it present such a stigma in the world of construction? Having done some research there is no official guidance to help employees and employers when pregnancy occurs for a woman working in the construction industry. This is, in part, due to its male dominated past.

We have taken the opportunity to talk to a number of women in the industry, to understand the challenges they faced and how we can help in the future.

Could you continue your role as normal when you were pregnant?

The experience for the woman during pregnancy is dependent on the physicality of their original role and the communication provided from their employer. The women interviewed that had a more office-based role found that during the pregnancy they were able to work as normal, however the women with a more site-based role had a very different experience.

It is obvious that a site role is going to cause challenges, especially when standard tasks include handling of heavy objects or working with contaminants. The majority of responses we received were positive, with women commenting that companies provided specific risk assessments and arranged for alternative staff to do manual tasks or cover the on-site portions of the project. However, in the absence of guidance, many contractors approached the issue differently. ‘It was interesting that each Framework Contractor approached my “condition” very differently with one Contractor actually not allowing pregnant women on to site at all.’

Did you feel supported by your company throughout the pregnancy?

The majority of women felt supported by their main employer including being offered flexible working hours to attend appointments. ‘I was able to take time for antenatal classes and go to various appointments.’

The support provided is somewhat dependent on the employer and line manager, some women felt isolated and ignored with little to no communication. ‘I was not consulted about my risk assessment, merely sent the assessment to sign, and the document implied that I had written it myself.’

Is there anything your company could have done differently to help you?

Aside from difficulties associated with maternity pay, which affects all industries. The main issue raised was the lack of generic risk assessment. All the women interviewed commented that risk assessments were developed by their company to assess their individual role and outline ways to adapt, however, this is not an instant process. ‘It would have been fantastic if a pre-existing, provisional risk assessment existed before I became pregnant, which could be used immediately and until a more specific one was in place.’

Upon returning to work did you feel supported to progress your career as you wanted?

‘Return to work was not well handled, I felt somewhat forgotten about. Keeping in touch and ensuring that staff are welcomed back is really important.’

The majority of women interviewed felt upon return to work they were treated differently with their role being ‘softened’ despite no longer having the risks associated with pregnancy. ‘Although I know this was coming from a good place, I felt his attitude to me returning to work, and my presumed ability to work, was antiquated.’

Most companies offered flexible working hours to new mothers, enabling them to adapt to the new work-life balance. However, most felt the push was on the mother to be the child carer with little discussion or foresight given to a father wanting the same role. ‘I’d really like to see a gender-neutral approach (post pregnancy of course!) with discussion around shared childcare and parental leave’. The UK government website states that up to 37 weeks of leave can be shared between the two parents, however within the construction industry there still appears to be a stigma over the split.

What was the one major challenge you faced during pregnancy at work?

The responses for this question were quite mixed dependent on the role of the individual.

‘At that time, lack of flexibility to work from home and adjust working hours.’

‘It’s a while ago now, but I can’t really think of one. I feel I have been really fortunate with the support I got during my pregnancies but, more importantly, not side-lined and given boring work when I returned part-time.’

‘Generally feeling unable to carry out, to the best of my ability, my site visits due to the “rules” of differing contractors.’

Coronavirus affecting pregnancy and young mothers

The current Coronavirus pandemic has meant that a larger number of people are working from home, and in some cases caused a disconnect in communication. During our interviews, we identified that some women who were pregnant when the pandemic started felt they were discriminated against because of their situation, with non-pregnant workers being given the majority of the work, causing the pregnant party to feel like that was the reasoning for being furloughed. Whilst this might not have been the companies intention, the lack of communication during the situation made the women feel forgotten.

On the other hand, some found that the pandemic has ‘levelled the playing field between working mothers and fathers’. The school and office closures have forced the main parent or bread winner to be at home at the same time as their children, they have therefore been ‘expected to contribute to the childcare situation more equally than they might have done in the past.’ One woman commented that they have ‘positive attitude shift from the male dominated senior management to leave work on time, keep meetings short etc.’

Whilst the lockdown has been difficult, it has opened up the conversation on not only new and expectant mothers but also childcare in general within the construction industry. This article is a small insight into a much larger conversation. We would like to hear your views on the topic. Do you feel a guidance document is needed? What has been your experience either being a pregnant woman or managing one?