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AGS Magazine: September 2026

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The Association of Geotechnical and Geoenvironmental Specialists is pleased to announce the September 2026 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;

  • The Changing Landscape of Land Contamination: All-day CPD Event – Page 4
  • AGS Annual Conference 2027: Save the Date – Page 10
  • Three Voices, One Industry: How Storytelling Can Help Secure the Future of Ground Engineering – Page 16
  • AGS Sustainability Charter Workshop: Webinar Details – Page 21
  • Overview of Pesticide Use on Agricultural Land, and Human Health Risk Assessment – Page 22
  • Horizontal Directional Drilling – Page 28
  • Guidance on SPTs Terminated Early, Extended Tests and Reporting of Seating Blows – Page 32
  • Collaboration for the Future: Practical Sustainability Guides for Our Sector – Page 36
  • AGS Guide to Good Gas Monitoring – Page 42

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 Sustainability

Collaboration for the future: practical sustainability guides for our sector

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Sustainability is a great catch-all term, covering everything from carbon reduction and water use through to wellbeing and inclusion. But this breadth also presents a challenge. How can an engineer, or a procurement lead, or a yard technician improve sustainability? What does sustainability even mean for our day-to-day work?

Recognising this challenge, the European Federation of Foundation Contractors (EFFC) and Deep Foundations Institute (DFI) have been collaborating to produce a series of free sustainability guides specifically for the geotechnical sector. The EFFC represents foundation and geotechnical contractors across Europe, while DFI represents geotechnical specialists mostly in North America, as well as Europe and India. The working group is co-chaired by Luke Deamer (Keller and EFFC) and Kimberly Martin (Keller and DFI).

Each free guide uses four questions to help geotechnical employees improve sustainability:

  1. What is the area of sustainability? What does it mean to geospecialists?
  2. Why does it matter? What drivers, or value, is behind these initiatives?
  3. How can geotechnical companies and individual employees improve that area of sustainability?
  4. Measure – What metrics can we use, at a company and project level, to measure their progress and set targets?

Importantly, the approach underpinning the guides aligns directly with the AGS Sustainability Charter. Both take an initiative-focused approach, using the United Nations Sustainable Development Goals (SDGs) as a common language to prioritise sustainability topics.

More generally, the EFFC/DFI guides are not written as standards or minimum requirements. Instead, they are practical support documents that share good practice and help organisations identify actions that are appropriate for their own circumstances.

What areas of sustainability are covered?

So far, the EFFC and DFI have published four sustainability guides, each focused on a specific sustainability topic that is material to geospecialists.

Carbon reduction

The first guide focuses on carbon reduction, addressing SDG 13 (Climate Action) and SDG 7 (Affordable and Clean Energy). Led by Luke Deamer, who is also an honorary member of the AGS sustainability working group, this guide focuses on carbon savings throughout site investigation, design, operations and office / maintenance yard work. Given the focus on carbon saving in our sector, this guide acts as a signpost to understand concepts, legal requirements, standards and of course practical carbon saving improvements. Later additions include case studies that bring these improvements to life.

Circular economy

The second guide focuses on the circular economy, supporting SDG 12 (Responsible Consumption and Production). The circular economy looks to encourage the use of secondary materials, extend product lifetimes and reduce waste at the end of life. Led by Alice Berry (formerly at Arup and EFFC), this looks to go beyond the typical focus on waste and recycling, instead broadening the approach to include improving resource efficiency and building for reuse. Much like the carbon reduction guide, case studies and a focus on facilitating foundation reuse reflect the research of EFFC and DFI members around the world.

In terms of geoenvironmental work, there is considerable crossover with remediation specialists as we look to minimise waste disposal, maximise material reuse and reduce environmental impacts associated with contaminated land management.

Climate adaptation and resilience

The third guide addresses climate adaptation and resilience, supporting SDGs 11 (Sustainable Cities and Communities) and 13 (Climate Action). Unlike carbon reduction, which focuses on mitigating climate change, adaptation focuses on preparing for the consequences of a changing climate. Led by Marla Gillow, originally a member of the AGS sustainability working group, this took two very different forms. The first of these focuses on how geotechnical designs and specifications should adapt as climate-related hazards change. The second focuses on how geospecialist contractors will be impacted by climate change directly and, therefore, how we need to adapt our operations.

Water use

The most recent guide focuses on water use, supporting SDG 6 (Clean Water and Sanitation). Water is a critical but often overlooked aspect of sustainability, with many of the initiatives taken from water-scarce regions. Construction activities can consume significant quantities of water while also affecting groundwater, surface water and wider catchment systems. Led by Alice Liddell (Sizewell C and EFFC), the water guide looks at minimising water use, groundwater interactions and avoiding water contamination throughout geotechnical projects. The guide explores practical opportunities to reduce water consumption, improve management practices and consider water risks during design and construction.

Looking Ahead

The sustainability journey does not stop here. Three more guides are currently in drafting stage. These upcoming EFFC/DFI guides are being developed to cover the following:

Nature

Led by Cerys Orriss (Aarsleff and EFFC), the nature guide focuses on how contractors and designers can influence nature and biodiversity on their projects. Currently nearing review stage, the guide focuses on core concepts and requirements around nature, supporting SDG 15 (Life on Land). Particularly given the biodiversity net gain requirements on UK projects, the guide has benefited from AGS input on minimising impacts on soil and groundwater ecosystem services.

Wellbeing

Led by Catherine Chauder (Keller and DFI), this guide focuses on wellbeing initiatives for site and office teams. Built from a collection of case studies from around the world, it covers the breadth of wellbeing, from mental and physical health through to financial and social wellbeing, supporting SDG 3 (Good Health and Well-Being). Given the challenges of site and field work, the guide has a particular focus on initiatives that reach field operators.

Gender equality and reduced inequalities

Led by Bradley Falcus (Central Alliance and AGS member), this guide will be the first to formally include AGS as a collaborator with the EFFC and DFI. This guide focuses on inclusion commitments for geospecialists, focusing on improving diversity and the benefits of an equitable approach for everyone in a company. Supporting SDGs 5 (Gender Equality) and 10 (Reduced Inequalities), this guide focuses broadly on gender equality, but also includes other protected characteristics such as disability, race and religion.

These upcoming guides reinforce themes already reflected within the AGS Sustainability Charter, promoting a broader understanding of sustainability that extends beyond environmental impacts to include people, communities and inclusion.

Why do these guides matter to AGS members?

Sustainability is increasingly becoming a business necessity, part of our licence to operate. The EFFC/DFI guides explain that there are multiple drivers for AGS members to improve sustainability.

Legislation

Across the UK, Europe and internationally, there are many legal requirements that impact geospecialists. This spans a broad range of standards, from corporate sustainability reporting, climate disclosures and carbon management, through to environmental performance requirements or engine air quality standards.

Even where legislation does not apply directly to smaller organisations, client requirements frequently pass expectations down through procurement processes and contractual obligations. The guides help make sense of these requirements, highlighting the key points for our sector.

Client demand

Client demand provides a financial incentive for geospecialists to improve sustainability. Whether it’s recognised directly as a weighted percentage of a tender or just a minimum standard to bid on a project / join a framework, public and private sector clients are pushing sustainability in tender documents.

Employee attraction and retention

Sustainability is also increasingly important to employees. As our sector struggles to attract the next generation of employees, sustainability is an increasingly important factor in attracting and retaining talent.

Beyond recruitment and retention benefits, there is a compelling ethical argument. Our sector helps shape the built environment for future generations. We are a carbon- and resource-intensive sector, putting a small, highly-skilled workforce in challenging physical and mental environments. This means we have a responsibility, and a real opportunity, to make a genuine difference for our own workforce, our local communities and the planet overall.

Efficiency

Anything that saves fuel, materials or time ultimately also saves cost. When we think of improvements, often we jump straight to the latest innovations in low carbon technologies, like electric equipment or ultra-low carbon cements. But there are many cheaper, often simpler, improvements we can make first. Many of the guides therefore provide hierarchies or improvement cycles to help prioritise these efficiency savings first, before adopting more innovative technologies.

Banks, investors and insurers

Financial institutions are increasingly assessing sustainability performance when making investment, lending and insurance decisions. Environmental, Social and Governance (ESG) performance is becoming an important indicator of long-term business resilience. Whether it is sourcing green funds for a project, minimising climate risk for insurers or preferential loans based on sustainability performance, these drivers translate sustainability performance into financial savings. For AGS members seeking investment, growth or major project opportunities, sustainability performance is therefore becoming an increasingly relevant commercial consideration.

How can we all make a difference?

One of the greatest strengths of the EFFC/DFI guides is their practical structure.

Rather than discussing sustainability at a purely strategic level, the guides break actions down by business function, helping individuals understand how sustainability relates directly to their role. These improvements are not just limited to engineers either, with advice from HR and procurement leads, through to health & safety and even IT teams. Everything is focused on making sustainability practical and actionable.

Every ‘how’ section begins with quick wins for companies looking to make a start on this area of sustainability. They also end with ‘future looking initiatives’ for those companies that are looking to innovate in these areas of sustainability.

The guides frequently demonstrate that improvements require collaboration across functions. For example, reducing carbon may require design optimisation, procurement engagement and operational changes simultaneously. Similarly, improving circularity can involve designers, remediation specialists, contractors and waste managers, all working together.

Measuring our progress

One of the key focus areas shared by both the AGS Sustainability Charter and the EFFC/DFI sustainability guides is that we need to be able to measure our progress on sustainability.

The guides therefore include metrics and indicators that can be used to monitor progress. Grounded in legislation requirements, standard specifications and geotechnical-specific datapoints, these provide a way to track progress against the initiatives in the guides. Given how we operate as a sector, these metrics are broken down into those for a project level, as well as those at a company level.

EFFC/DFI carbon calculator

Perhaps the most visible example of standardised measurement within the sector is the EFFC/DFI Carbon Calculator. Developed collaboratively by the EFFC and DFI over a decade ago, the calculator enables geotechnical companies to compare the footprint of geotechnical works to using a certified, consistent methodology. This consistency in calculation between geotechnical companies improves transparency and helps clients compare alternative solutions on a common basis. It also enables benchmarking activities, establishing estimated carbon footprints of different geotechnical solutions.

The calculator is currently being digitised in collaboration with Carbone 4. In the meantime though, it has been recognised by the EU as the only sector-specific carbon calculator in EFRAGs recommendations for small and medium enterprises. It has also therefore been written into specifications across Europe, from France to the Netherlands, as a standardised way to calculate and compare carbon emissions.

The EFFC/DFI Carbon Calculator has contributed to a number of calculation initiatives, including the AGS’s own efforts to promote simplified carbon calculations in the geo-environmental sector. Whilst foundation emissions are always an order of magnitude greater than those from ground investigations, both tools are useful for standardising and simplifying carbon calculations.

Conclusions

Ultimately, the EFFC/DFI guides aim to make sustainability practical, actionable and relevant to everyone working in our sector.

The EFFC/DFI sustainability guides provide AGS members with a practical, accessible and free resource to support that journey. Whether the goal is reducing carbon, improving resource efficiency, adapting to climate change or managing water responsibly, the guides help translate sustainability ambitions into tangible actions. By combining practical guidance and case studies with measurable outcomes, they offer a valuable framework for geospecialists, particularly if we’re looking to align with the AGS Sustainability Charter.

A big thank you goes to all the volunteers that have helped write these guides. Particularly, we must give a shout out to the AGS members that have contributed, including Alison Nicholson, Bradley Falcus, Marla Gillow and Chris Swainston. If you would like to be involved in the upcoming guides, particularly on wellbeing or gender equality and reduced inequalities, please contact Luke Deamer or Kimberly Martin.

You can download the guides for free from here: EFFC Sustainability Guidance Archives

There are plenty of webinars summarising the guides to date. You can view these for free on the EFFC or DFI’s website here: EFFC Webinars

Article by Luke Deamer, Group Sustainability Director, Keller

Article Geotechnical

Guidance on SPTs terminated early, extended tests and reporting of seating blows

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This guidance note on standard penetration test (SPT) procedure and reporting covers some issues that have recently arisen, specifically:

  • Procedure for tests terminated early, including a possible conflict between BS EN ISO 22476-3 and guidance from the British Drilling Association (BDA).
  • Reporting for tests terminated early, on logs and in AGS data.
  • Extending SPTs to 100 blows in soft rock and other materials.
  • Reporting of seating blows, on logs and in AGS data including discussion of BS EN ISO 22476-3 requirements.

Procedure for tests terminated early due to bouncing or similar

For the purposes of this guidance ‘terminated early’ refers to a test that has been stopped before any of the normal criteria for completion have been achieved, i.e. 300mm penetration or 50 blows for the main drive.

The BDA document Guidance For The Operation Of Cable Percussion Rigs And Equipment (Issue 2.7, 2024) includes the following:

“Where double hit or bouncing occurs or there is no penetration for 25 blows the test should be aborted and the total penetration reported, and test ‘refusal’ noted.”

This guidance can be perceived as being in conflict with the requirements of the test standard (BS EN ISO 22476-3 :2005+A1:2011 current at time of writing) which is silent on provision for early termination prior to 50 blows for the main test drive.

It is recommended that a common-sense approach is adopted when double hit or bouncing or similar occurs. If, based on understanding of the prevailing ground conditions and observations during the test, there is good reason to believe that continuing the test will not lead to further penetration and/or there is a risk of equipment damage, then it is considered reasonable and correct to terminate the test early. Reporting of this is covered in the next section.

The Investigation Supervisor should be informed at the earliest opportunity and the matter discussed, including agreement on action to be taken should the same situation arise again.

In making this recommendation it has been recognised that the most important information obtained in such cases is the observation of bouncing (or similar), i.e. something resistant to penetration has been encountered in the ground. This may be indicative of an obstruction that the design will need to consider, or that constructors need to be aware of.

In situations such as this, the SPT N value that may be interpreted based on actual penetration for a particular number of blows will rarely be useful for design. Such data points would normally be disregarded when interpreting a design line. Therefore, there is no merit in risking equipment damage merely to satisfy a very strict interpretation of the standard.

Requiring a contractor to redrill a borehole, despite that contractor following BDA guidance, would not be a common-sense approach.

Reporting for tests terminated early

Where a test has been terminated early in accordance with the above, this fact should be clearly indicated on borehole logs and/or test reports.

BS EN ISO 22476-3 reporting requirements include:

“all unusual events or observations during the operation (e.g. low blow count, penetration without blows, temporary obstructions, malfunction of the equipment);”

AGS does not offer any specific recommendation on the format or wording of such observations other than it should be clear and concise. This should be provided in addition to the usual reporting of blow count and penetration information.

For digital data supplied in the AGS data format*, it is recommended that the ISPT_REM field is used for reporting additional comments or observations.

However, data producers must ensure that this information is also shown on the logs produced from their data management software. If the log report forms do not show ISPT_REM data then there may be merit in duplicating this data in a field that will be seen on the logs, e.g. DREM_REM. Duplication is far from ideal but this is better than having this important information omitted from the logs.

Extending SPTs to 100 blows

BS EN ISO 22476-3 states:

“If a total of 50 blows for the test drive is reached, the test may be finished (N = 50); in soft rocks it can be increased to 100 blows (N = 100).”

Normal practice in the UK is to finish the test at 50 blows in all cases, unless extending to 100 blows has been specified, or there is a specific prior agreement to continue.

Specifiers should only consider extending to 100 blows when this will clearly and justifiably benefit the design. As suggested by the standard, one such case is weak rocks.

Another example, witnessed by the author on several projects, is extending to 100 blows in Thanet Sand, a very dense over-consolidated silty sand. Here the SPT results were used alongside other more precise (but expensive) tests to help identify design critical changes in clay/silt content with depth.

Blow counts > 50 may be encountered in very stiff clays. However, SPT are not normally extended in such conditions because extrapolation of the N value to account for early termination is usually found to be sufficient. Such extrapolation should only be undertaken by the designer, who will need to be mindful of its limitations.

Reporting of seating blows

BS EN ISO 22476-3 requires the incremental blow counts for the main drive to be individually reported. Either two or four increments may be used. Traditionally, in the UK we have reported four x 75mm increments, in accordance with the original BS 1377 Part 9.

For the seating blows BS EN ISO 22476-3 requires 150mm penetration or maximum of 25 blows. However, it also requires the seating blow count/penetration to be reported as one increment, not two as per past (and current) UK practice.

Therefore, a BS EN ISO 22476-3 compliant result reported on a log may look like this, using five increments:

“N=16  (9/4,3,4,5)”

whereas a traditional UK log may report the same in this format, using six increments:

“N=16  (4,5/4,3,4,5)” or “N=16  (4,5,4,3,4,5)”

Despite BS EN ISO 22476-3 having been published for many years now, it appears that the specific requirement for reporting seating blows has not been commonly adopted. However, it also appears that few have noticed. It is also fair to say that it is a relatively minor issue in the grand scheme of things.

It is considered that forcing a change in SPT reporting format across the industry is likely to lead to disruption and confusion, with no obvious benefit. Furthermore, it is possible that a future revision or clarification of the standard may permit reporting in six increments.

The recommendation is that both the five and six increment methods are acceptable, but one of these should always be applied consistently within a given report.

It is recommended that “/” is used as the separator between seating and main blows, with “,” separating the main blows, as shown above. This should provide a helpful visual cue for UK users used to interpreting the first increment(s) as seating.

In AGS format data, by rule the main blows/penetrations are reported in increments 3, 4, 5 and 6 as required, with increments 1 and 2 reserved for seating. If the BS EN ISO 22476-3 five increment system is used then seating should all be in increment 1 with increment 2 unused (blank/null entries preferred to make it clear), i.e. the total seating blows in ISPT_INC1 and the total seating penetration (normally 150mm) in ISPT_PEN1. Main blows then start at increment 3 as normal.

* In accordance with Association of Geotechnical & Geoenvironmental Specialists publication Electronic Transfer of Geotechnical and Geoenvironmental Data, AGS4, Edition 4.1.1 – March 2022 , or earlier editions thereof.

Article by Neil Chadwick, Director at Digital Geotechnical Ltd

Article Geotechnical

Horizontal Directional Drilling

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Horizontal directional drilling (HDD) is a form of trenchless crossing that is used to install utilities (e.g. power cable ducts and pipelines) beneath roads, railways, rivers and other sensitive land uses with minimal disruption compared with other forms of construction. It is an established technique with successful installations internationally as well as in the UK.

How does it work?

  1. Launching and receiving sites are established at the exit/connection points of the HDD installation.
  2. A pilot bore (typically 150mm dia) is drilled on a parabolic arc from one side to the other. The technique is fully steerable in the horizontal and vertical planes. For increased lengths, straight lengths can be incorporated within the overall drill profile. Depending on ground conditions, installation technique and site access, lengths of several km are possible.
  3. After the pilot drill has punched out at the exit pit, a back reamer is attached and pulled back through the drill shot to enlarge the bore. Various drilling fluids may be used including water, polymers and bentonite.
  4. Progressively larger reamers are utilised until the final bore size is achieved. Final bore diameters generally range from 6” (152mm) to 26” (660mm) but can be up to 48” (1219mm).
  5. Once the bore is at the required diameter the final duct(s) / pipe is pulled through the bore before being cleaned and temporarily capped at both ends. The duct(s) / pipe is then ready to be connected to the rest of the network, which is typically at a nominal depth (<1.2m).

Typical Parameters

The bend radius is a function of tooling used and pipe being installed. On small scale rigs in soft ground a radius as tight as 75m can be achieved whereas large diameter bores or rock tooling requires bend radii in excess of 400m. Plastic pipes require bend radii of 25 times outside diameter typically. In contrast thin walled steel pipes require a radius of 1000 times outside diameter.

The length of a drill shot can vary significantly but is typically 60 – 250m. Longer drills (several hundred metres) are possible and typically required for landfall projects where offshore cables join onshore networks. Drill lengths of 1 to 3 km are now becoming more commonplace.

The drill can bend in the vertical AND horizontal planes. If undertaking a compound bend (vertical and horizontal at the same time) then individual bend radii should be reduced so that the overall bend remains within tolerance.

Drilling fluid

Throughout the drilling process, drilling fluid or ‘mud’ is continuously pumped into the bore via the drill head / reamer primarily to stabilise the bore and transport cuttings back to the entry pit. The mud recipe and pump rate is critical to ensure a successful HDD:

  • Too viscous means higher pressure required to move the cuttings, thereby increasing the risk of heave
  • Too fluid and the bore may be unstable and subsequently manifest as excessive settlement.
  • A mud mixture is site specific and tailored to the ground and groundwater conditions anticipated.

Key advantages of HDD

It is trenchless! Closing a motorway or railway to install a utility is often not a feasible option. Traverses below canals, rivers and subsea installations are also possible with this technology.

HDDs create very little disturbance at the surface. The entry pit is typically of the order of a few metres in length and width and a nominal 1m depth. The exit pit is usually similar unless there are significant elevation differences. The limited excavations have a notably less environmental impact than an equivalent trenching option.

Trenching often creates a soft line in the ground due to inadequate compaction during the backfill process, akin to trial pitting during a GI. This leads to ongoing settlement and possibly abrupt changes in surface level that could pose risks to users (e.g. drivers). In contrast, the settlement profile that may develop post HDD construction is generally much more gradual, if any movement is experienced at all, due to the ground being much less disturbed. Settlement of <5mm is common.

All HDD works are undertaken by personnel at the surface. This has clear safety benefits by eliminating the need for deep shafts or excavations that would be required for other trenchless techniques such as microtunneling

Key constraints of HDD

HDDs should not be considered a silver bullet and have two principal limitations: coarse ground conditions and space to string out the pipe / ducts.

The drilling process is versatile and can successfully drill through a variety of ground conditions including soft ground and rock. However, coarse ground conditions (coarse gravel and cobbles) can be particularly challenging. Bores in such ground conditions can be unstable, which causes further overbreak and potentially manifesting as increased settlement at the surface. The usual method of mitigating this issue is to install a casing through such ground conditions, akin to cable percussion drilling.

Boulders can also be problematic by causing the drill to deflect from the intended trajectory. It can sometimes be feasible to partially withdraw and then steer around the boulder. However, usual practice is to try again nominally offset from the issue – similar to cable percussion drilling!

The second limitation is associated with site practicalities. Only small diameter ducts can be transported to site on a reel. All other ducts and pipes require welding on site to create the pipe string. The length of the pipe string is equal to the length of the drill and therefore can be hundreds of metres long. There needs to be space on site to laydown the completed pipe string prior to pull back. Due to the flexibility of the pipe it can snake past obstacles while strung out as illustrated in Figure 1.

Figure 1:  Example of pipe sting out prior to pullback

Steering – How accurate is it?

There are three ways of steering an HDD:

  • Walkover locating using a radio sonde
  • Magnetic wireline
  • Gyro

The walkover as the name suggests involves a person with a hand held device receiving a signal that is transmitted from the drill head. This locates the drill head and allows steering adjustments to be made. Due to the walkover nature of the technique it is limited to simple low risk crossings.

The wireline system involves laying a surface tracking grid that emits an artificial magnetic field that the drill head uses to provide a precise location. A grid is often required on both sides of the crossing with the middle part effectively being ‘blind’ as the drill passes from one grid to the other.

The best form of steering is the Gyro, which has an accuracy of 0.01°. From previous experience on long drills (>200m) this can be considered to be centimetre accurate at worst. However, the high accuracy attracts a similar price tag and is therefore reserved for the long or complex drills.

What can go wrong?

A principal risk on all HDD projects is the frac out of fluids during drilling, which is intrinsically linked to surface heave. Frac out is ultimately due to the downhole pressure exceeding the confining pressure which results in fluid travelling upwards and eventually out at the surface. In the event of a frac out it should be contained (example below) and then cleared away.

Figure 2:  Example of surface frac out and subsequent containment

Excess pressure can be caused by:

  1. Collapse of the bore behind the drill head stopping the drilling fluid flushing the bore
  2. Cuttings remain in the bore due to insufficient fluid rate
  3. Incorrect drilling fluid recipe
  4. Heavily fractured or fissured ground conditions providing preferential pathways

Calculations can be undertaken with commercially available software to assess the risk of frac out. The risk is highest during pilot drilling due to the smaller annulus between the bore and drill pipe. The results should be considered guidance only and just because it suggests frac out will occur it doesn’t mean it will, and vice versa. There is often a risk close to the exit pit where drill pressures remain relatively high and cover thickness is minimal.

HDDs also have the potential to cause ground movement, which may manifest as settlement at the road surface or beneath existing buried utilities. Relatively simplistic formulae are used to estimate the long term settlement trough.

The size of the trough is a function of ground conditions and depth of cover. Cohesive soils produce wider troughs but a smaller maximum settlement (smax) when compared to non-cohesive soils. Similarly, installing the drill at greater depth reduces smax but widens the trough.

Early Contractor Involvement

Engaging early with a specialist contractor is highly recommended. The contractor can advise on the suitability of an HDD versus other techniques. This will likely include conceptual design to estimate length and depth of any drill. Consequently, they should also provide input into any ground investigation scope.

Article provided by Angus Wilson, Geotechnical Manager, AMS No-Dig

Article

Three Voices, One Industry: How Storytelling Can Help Secure the Future of Ground Engineering

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Engineering has the power to shape lives, communities and futures. Every day, geotechnical and geoenvironmental professionals contribute to safer homes, resilient infrastructure, sustainable development and thriving communities.

Yet despite the critical role engineering plays in society, many young people still struggle to see themselves within the profession.

For those from underrepresented backgrounds, the challenge can be even greater.

If people cannot see themselves reflected in an industry, it can be difficult to imagine that they belong there.

At a time when the engineering and construction sectors continue to face skills shortages, an ageing workforce and increasing technical complexity, this is a challenge that affects all of us.

The future success of ground engineering depends not only on technical excellence, but on our ability to attract, retain and develop the widest possible talent pool.

Representation, visibility and belonging are therefore not simply Equality, Diversity and Inclusion issues.

They are industry issues.

Three voices. One shared purpose.

Chai & Chat Engineering was created from a shared belief that engineering should be visible, relatable and accessible to everyone.

The podcast is hosted by three engineers whose careers span geotechnical engineering, infrastructure delivery and major programme leadership. Although they work in different parts of the industry, they share a common experience: each has spent significant parts of their career as one of very few people who looked like them in the room.

Dipalee Jukes

Dipalee Jukes is a geologist, ground engineer and entrepreneur, and co-founder and CEO of Ground & Water, a geotechnical and geoenvironmental engineering consultancy established in 2009. With more than two decades of experience in the industry, she is a passionate advocate for inclusive leadership, developing people alongside projects and creating businesses that deliver both technical excellence and social impact. Alongside her work in ground engineering, she is involved in mentoring, school governance and wider industry initiatives focused on gender equality and representation.

Era Shah

Era Shah is a Chartered Civil Engineer and programme management professional working across the infrastructure and built environment sector. Her experience spans complex infrastructure delivery, transformation programmes and strategic programme management. Beyond her professional role, she actively supports future generations through mentoring, STEM outreach and trustee work, championing both technical excellence and social responsibility.

Malika Kapasi

Malika Kapasi brings over two decades of experience in major infrastructure and transport programmes. As a planning director and commission lead, she works at the intersection of project delivery, governance and strategic leadership. Through Chai & Chat Engineering, she is passionate about sharing the often unwritten lessons of leadership and demonstrating that diverse voices belong at the highest levels of engineering decision-making.

Together, the three co-hosts represent different technical disciplines, sectors and career paths. What unites them is a shared desire to help create an industry where future generations see engineering as a place where they belong.

From a chance meeting to a global platform

The origins of Chai & Chat Engineering can be traced back to London Build Expo in 2021.

The three co-hosts met for the first time at the event and quickly discovered common experiences despite working in different parts of the industry. Conversations about careers, visibility, leadership and identity revealed striking similarities in their personal and professional journeys. Each had experienced periods where they felt like outliers in engineering spaces. Each had questioned whether they truly belonged. And each recognised how powerful visible role models could have been earlier in their careers.

From that conversation emerged a simple idea.

What if there was a platform where honest discussions about engineering, leadership and lived experience could take place?

What if the stories often missing from industry narratives could be brought to the forefront?

That idea became Chai & Chat Engineering, which launched in October 2022.

Today, the podcast reaches listeners in more than 37 countries and has become a growing platform for conversations about engineering careers, leadership, resilience, inclusion and the future of the profession.

Why conversation matters

The podcast takes its inspiration from the cultural tradition of sharing stories over a cup of chai.

At its heart is a simple belief: conversation has power.

Engineering is often presented through a technical lens. We discuss specifications, standards, designs, risk assessments, site investigations and project delivery. These are fundamental aspects of our profession. Yet engineering is just as much about people as it is about projects – creativity, teamwork, communication and the ability to turn ideas into impact.

And, behind every project is a human story.

For many young people, engineering remains an unknown career. They may have heard the term “engineer”, but have little understanding of what engineers actually do, how they entered the profession or what opportunities exist within it.

This is particularly true for specialist disciplines such as engineering geology, geotechnical engineering and geoenvironmental consultancy.

Stories bridge that gap.

When people hear authentic accounts of career journeys, setbacks, successes and lessons learned, engineering becomes more human and more accessible.

It becomes easier to imagine a place for themselves within it.

The support of the Institution of Civil Engineers

In 2026, the Institution of Civil Engineers recognised the impact of Chai & Chat Engineering through an article titled Three Voices, One Industry, A Shared Goal: Help Others See Themselves in Engineering. The article explored the podcast’s mission to widen participation and help individuals from underrepresented backgrounds see engineering as a profession where they belong.

The ICE highlighted the podcast’s focus on open and honest dialogue, describing how the three hosts had created a platform that challenges perceptions of who belongs within engineering and the built environment. It recognised the importance of creating welcoming spaces where conversations about careers, leadership and lived experience can take place openly.

The support received from the ICE has been significant.

It demonstrates that attracting future engineering talent is not solely about promoting technical careers. It is also about building connections, raising visibility and showcasing a broad range of voices and experiences.

The role of representation in tackling skills shortages

Ground engineering faces many challenges.

Climate change adaptation, sustainable development, renewable energy infrastructure, brownfield regeneration and increasingly complex geotechnical risks all require highly skilled professionals.

At the same time, the wider engineering sector continues to experience challenges around recruitment and retention.

The profession therefore needs to appeal to a broader audience than ever before.

Research consistently demonstrates that diverse teams bring benefits including stronger decision making, increased innovation and improved organisational performance. Diverse teams also better reflect the communities that engineering ultimately serves.

The challenge is not simply encouraging more people to enter the profession.

It is ensuring that once they arrive, they feel they belong.

Many of the guests featured on Chai & Chat Engineering have spoken candidly about imposter syndrome, confidence, leadership and career progression. These conversations reinforce an important truth: creating inclusive cultures is not solely about policies and programmes.

It is about people.

People who feel valued are more likely to stay.

People who feel visible are more likely to progress.

People who feel they belong are more likely to thrive.

Changing perceptions of who belongs

The podcast has welcomed guests from across engineering, infrastructure and the built environment, including former ICE President Professor Anusha Shah. Guests have included engineers, academics, project leaders, entrepreneurs and changemakers, each bringing unique perspectives and experiences.

Many discussions focus on topics rarely addressed in traditional technical forums.

How does someone build confidence early in their career?

What does leadership really look like?

How do people navigate challenges, setbacks and self-doubt?

What support mechanisms make the most difference?

These discussions matter because they reveal the human side of engineering.

Conversations also often go beyond professional milestones to explore the personal influences that have shaped their journeys, from their upbringing to their cultural backgrounds.

All in all, this helps to challenge outdated assumptions about who an engineer, leader or technical expert should look like.

What can AGS members do?

The good news is that meaningful change does not always require large budgets or complex programmes.

Often, it starts with simple actions.

AGS members can:

  • Share their career journeys more openly.
  • Support mentoring and sponsorship opportunities.
  • Engage with schools, colleges and universities.
  • Increase the visibility of diverse role models within their organisations.
  • Encourage early career professionals to speak, publish and present.
  • Create environments where people feel comfortable bringing their authentic selves to work.
  • Listen to the experiences of others and seek to understand different perspectives.

Most importantly, everyone can play a role in helping people feel that they belong.

Looking to the future

The future of ground engineering will undoubtedly be shaped by emerging technologies, changing regulations, sustainability challenges and new technical solutions.

But it will also be shaped by people.

By the students who have yet to discover geology.

By the graduates who are just starting their careers.

By the future leaders who may currently be questioning whether they belong.

As an industry, geotechnical and geoenvironmental specialists spend much of their time thinking about foundations.

Perhaps one of the most important foundations we can build is a profession where every talented individual can see a place for themselves.

Because when more people can see themselves in engineering, the profession becomes stronger, more innovative and better equipped to tackle the challenges ahead.

And sometimes, that journey begins with something as simple as a conversation over a cup of chai.

How to get involved

The hosts welcome connections with geotechnical and geoenvironmental professionals who are passionate about inspiring future talent, sharing their stories and helping create a more representative profession for the next generation. For AGS members interested in listening, all episodes of Chai & Chat Engineering are available on Spotify and Amazon Music.

Listen to the podcast:

Contact us:

chaichatengineering@gmail.com

LinkedIn:

Dipalee Jukes | LinkedIn

Era Shah CEng MICE | LinkedIn

Malika Kapasi | LinkedIn

By Dipalee Jukes, Era Shah and Malika Kapasi, Co-hosts of the Chai & Chat Engineering Podcast

Article Contaminated Land

Overview of pesticide use on agricultural land, and human health risk assessment

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Tags: Featured

Pesticide is a generic term for a substance used for preventing and controlling insects or other organisms harmful to cultivated plants or animals1. Within agriculture they can be split into three broad categories: herbicides, fungicides and insecticides.

They can exist in many forms, such as solid granules, powders or liquids, and consist of one or more active substances co-formulated with other materials.

Today there are approximately 1,300 approved pesticides within the UK1.  The majority of pesticides used on arable farmland are fungicides (such as tebuconazole) and herbicides (such as glyphosate)2.

Regulatory Regime

Pesticides have been around for a long time, for instance during the mid-18th Century inorganic substances such as arsenic and copper sulphate were used to prevent fungal diseases in wheat.  However, traditional methods of pest control such as crop rotation and tillage were prevalent until the development and commercialisation of synthetic insecticides (organochlorines and organophosphates) from the 1930s to 1950s3.

The environmental impacts of these substances were not known by the general public, but a notable decline of wildlife during the 1960s, and the publication of the infamous book ‘Silent Springs’ by Rachel Carson4, brought the potential detrimental impact of pesticides (namely Dichlorodiphenyltrichloroethane, commonly known as DDT) into the public eye and instigated the establishment of the Countryside Act 1981.  This act was not specifically related to pesticides, but prohibited methods of killing wild animals e.g. poisoning.

As the human and environmental risks became more apparent, further legalisation was passed.  The ‘Control of Pesticides Regulations’ (1986)5 introduced a registration system for pesticides as well as requiring appropriate labelling and training on their application.  In the UK, pesticides such as DDT were withdrawn from registration in 1984 by the Health and Safety Executive, followed by the  ‘drins’ ( Dieldrin, Aldrin, and Endrin) during the 1990s and therefore were no longer authorised for use in the UK.

The Stockholm Convention was adopted by the UK in 20016 (enacted in 2004), which sought to protect human health and the environment from persistent organic pollutants (POPs), which are resistant to environmental degradation, by reducing or eliminating harmful use of POPs.  This included aldrin, chlordane, DDT, dieldrin, heptachlor, mirex, toxaphene and PFAS (per- and polyfluoroalkyl substances).

Further regulation was introduced in 20081 (Pesticide Maximum Residual Levels Regulations, England and Wales) which was enacted to ensure compliance with the European Union pesticide residual limits on food, animal feed and animal origin to protect human health and environment.

In 2025, the UK government introduced the Pesticide National Action Plan7, which aims to reduce pesticide use by at least 10% by 2030.  The action plan proposes to do this by encouraging uptake of integrated pest management, setting targets for the reduction of the use of pesticides, and strengthening compliance.

Human health risk assessment.

Greater awareness of the environmental and health risks and increased regulatory oversight have increasingly prevented or limited the use of pesticides that are known to pose an environmental risk, although there is still some way to go.  For instance, there are currently over 30 pesticide products in the UK that contain PFAS, which are known to be persistent in the environment, and increasingly are being recognised as a risk to health, land and aquatic ecology.

Pesticides that are spread over wide tracts of agricultural land represent a diffuse source of contamination, and following breakdown in the environment, or removal by surface run-off  / leaching, the risk to human health reduces.  Organic pesticides naturally break down in the environment through volatilisation, photodegradation, and microbial degradation, with the latter most prominent.  The break-down process depends on a variety of factors such as the chemical composition of the pesticide and soil type.  The longevity of pesticide in the environment is measured by its half-life (the time it takes to reduce by half) and may be taken into consideration as part of a risk assessment.  Examples of pesticide half-lives in agricultural soils are presented in Table 1, below. However, in oxygen-depleted or waterlogged environments, the half-life can be significantly extended.

Table 1 Pesticide half-lives

Pesticide Group Topsoil half life
(aerobic & photolysis)10
Organochlorines 2 to 15 years
Organophosphates 1 to 3 months
Carbamates 10 days to 2 months
Pyrethroids 1 to 4 months
Triazines & triazoles 2 months to 4 months
Neonicotinoids 2 months to 5 months (longer in dry conditions)
Glyphosate Up to 1 week

 

The Pesticides Properties Database (PPDB) is a useful source of information developed by the Agriculture & Environment Research Unit (AERU)9 at the University of Hertfordshire. The database contains information on pesticide approvals, physio-chemical properties, environmental fate, human health and ecotoxicological data.   However, the database does not contain any generic assessment criteria.

An increased risk and therefore focus of any human health risk assessment should be on pesticides which can remain in the environment, such as POPs  (including PFAS), and where their usage could have been concentrated through intensive use, cleaning of equipment, and disposal, or where they can be trapped in anaerobic conditions (e.g. sediments and burial of wastes). Examples include sheep dips, greenhouses, orchards, former slurry pits and vehicle wash down areas. These features can often be identified on historical maps, however without knowledge from the previous landowners it can be very difficult to determine exactly which pesticides have been used. It may therefore be prudent to screen against a range of POPs and other historical pesticides that could have been used within a particular agricultural setting. Table 2 below sets out a list of widely used pesticides in agriculture (not exhaustive) and their uses.

Table 2 Widely used pesticides and their uses

Type Use
Organochlorines such as DDT, the ‘drins’ heptachlor, chlordane, endosulfan, dicofol and lindane. Used as insecticides since the 1940s – banned/withdrawn from use in the UK. Classified as POPs under the Stockholm Convention
Organophosphates such as Chlorpyrifos, Malathion, Diazinon, Parathion

 

 Used as insecticides since the 1940s – banned/withdrawn from use, except for Malathion.
 

Pyrethroids

 Insecticides used since the 1950s – not banned, but used as a last resort.
 

2,4-Dichlorophenoxyacetic acid

 

 Herbicide – used since the 1940s, still approved for use within the UK.
Triazine pesticides such as atrazine, simazine, and propazine Herbicide used since the 1950s.  Atrazine was withdrawn from use in 2004.
Glyphosate Herbicide used since the 1970s – still commonly used today. Classified as a possible carcinogen with reproductive/developmental effects on human health.
Tebuconazole Fungicide used since the 1970s – still commonly used today.  Classified as moderately persistent with highly hazardous properties*
Note:  Pesticides highlighted in bold are classified as POPs by the Stokholm Convention.

* Agriculture & Environment Research Unit

 

To quantify risk where pesticides are encountered, generic human health assessment criteria (Suitable for Use Levels (S4ULs)), has been published in the UK by Land Quality Management and the Chartered Institute of Environmental Health for nine pesticides8.  These are, Aldrin, Dieldrin, Atrazine, α-Endosulfan, β-Endosulfan, α-Hexachlorocyclohexane, β-Hexachlorocyclohexane and Lindane (y-Hexachlorocyclohexane).   Assessment criteria for other pesticides can be found on the US Environmental Protection Agency website, but should be used with caution given the differences in the UK and US approaches to risk assessment.

Conclusions

There has been a long history of pesticide use within the UK, which really intensified from the 1940s onwards along with agricultural practices.  The risk to human health and the environment was overlooked or poorly understood until decades later when legislation and registration were enacted, and some of the harmful pesticides such as DDT were banned.  Legislation and research on toxicology and environmental fate still struggle to keep up with chemical use in agriculture, and there remain numerous pesticides in use that will potentially lead to an ongoing legacy of contamination, such as the continued use of PFAS.  However, awareness of these issues is increasing, and efforts are being made to limit pesticide use.

In relation to the risks to human health, the greatest risks are from the more persistent pesticides that can remain in the environment for long periods of time, and where their use was concentrated.  These should be the focus of any risk assessment.

Only a limited number of generic assessment criteria for human health risk assessment have been derived to date for pesticides. The UK contaminated land industry would certainly benefit from the publication of some additional criteria as well as specific guidance on the assessment of pesticides if someone would be prepared to take on the challenge.

References

1 Health and Safety Executive, 2026, ‘Pesticides’, (www.hse.gov.uk/pesticides/).

2 Fera, December 2024, Pesticide Usage Survey Report (https://pusstats.fera.co.uk/published-reports).

3 Pollenzie, May 2022, ‘The History of Pesticide Use in the UK: A Pollenize Perspective’, (https://www.pollenize.org.uk/the-buzz-blog/the-history-of-pesticide-use-in-the-uk-a-pollenize-perspective).

4 Carson, R, 2002, ‘Silent Spring, Penguin Classics.

5 Control of pesticide Regulations (1986), (https://www.legislation.gov.uk/uksi/1986/1510/made).

6 Secretariat of the Stockholm Convention, 2026, ‘Stockholm Convention on Persistent Organic Pollutants (POPs)’, (https://chm.pops.int/TheConvention/Overview/tabid/3351/Default.aspx)

7 Gov UK, 2025,’ UK Pesticides National Action Plan’ ( https://www.gov.uk/government/publications/uk-pesticides-national-action-plan-2025)

8 LQM/CIEH, 2015, ‘Suitable 4 Use Levels’.

9 University of Hertfordshire, 2026, ‘Pesticides Database’ ,https://sitem.herts.ac.uk/aeru/bpdb

10 Dhakal, G., Thapa Magar, S., & Fujino, T. (2025). Pesticide Degradation by Soil Bacteria: Mechanisms, Bioremediation Strategies, and Implications for Sustainable Agriculture. Environments, 12(12), 492. https://doi.org/10.3390/environments12120492

Article by Andrew Tranter, Senior Principal Geoenvironmental Consultant at Stantec UK

 

 

 

 

 

 

News

AGS Magazine: July 2026

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Tags: Featured

The Association of Geotechnical and Geoenvironmental Specialists is pleased to announce the July 2026 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;

  • The Changing Landscape of Land Contamination Conference – Page 4
  • AGS Annual Conference 2027: Save the Date – Page 10
  • Vivien Dent and Julian Lovell Elected as AGS Honorary Members – Page 12
  • AGS Webinar Replay: Individual Competence – Understanding How Government Reforms Will Affect You and Our Industry – Page 13
  • Q&A with Jonathan Gammon – Page 14
  • PFAS Analyses – The Numbers Alone Are Not Enough – Page 18
  • Updating the DoE Industry Profiles – Page 24
  • Hazard Observations: Strengthening Safety Through Awareness and Action – Page 30

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

Hazard Observations: Strengthening Safety Through Awareness and Action

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Tags: Featured

Introduction

Learning more about the situations which harm workers, through planned formal and informal hazard observation, can play a critical role in reducing and preventing workplace injuries and safeguarding lives.

Workplace incidents rarely occur without some kind of pre-warning, although these are often missed, misinterpreted or even just not considered as of importance or relevance. They are often the result of unsafe conditions, unsafe acts or omissions, hazardous and often changing environments, human behaviours and factors, or overlooked hazards. Effective hazard observation interrupts this progression and can enable timely intervention before harm occurs.

The Value of Hazard Observations at Every Level

All hazard observations are important, regardless of whether they are proactive, reactive, or related to a near miss and each observation contributes to a broader understanding of workplace risk.

Historical research has long shown that serious injuries and fatalities are often preceded by a much larger number of minor incidents and near misses. Tackling these early warning signs is one of the most effective ways to prevent more severe outcomes.

For this reason, reporting and acting on hazard observations should be strongly encouraged. A situation that resulted in a favourable outcome today may not do so next time, especially if the factors that prevented injury or loss are no longer present.

It is worth noting that some research suggests an over‑emphasis on minor observations can create a false sense of security, leading organisations to believe that low‑frequency, high‑severity incidents are less likely than they actually are. This makes it especially important to be organised and to ensure that hazard observations are of high quality and genuinely meaningful. (https://onepetro.org/SPEHSE/proceedings-abstract/10HSE/10HSE/SPE-126661-MS/106407)

Common Hazards and the Consequences of Unresolved Issues

The HSE has grouped together the most common causes of serious injury at work, such as slips and trips or working at height (see table below, taken from https://www.hse.gov.uk/simple-health-safety/risk/common-workplace-risks.htm#contentContainer), many of which are particularly relevant to the ground engineering industry (see bold text).  Note that the bold text are regularly the causes of the most frequent significant accidents in the UK workplace based on accident statistics previously issued:

Asbestos Confined spaces Display screen equipment Electrical safety Equipment and machinery Fire safety
Gas safety Harmful substances Manual handling Noise Personal protective equipment Pressure equipment
Radiation Slips and trips Vibration Working at height Workplace transport Work-related stress

 

H&S practitioners sometimes identify accidents/incidents arising from two sources (https://www.hse.gov.uk/humanfactors/assets/docs/core2.pdf):

  • Active failures: immediate actions or errors made by frontline staff, with consequences that appear straight away and can often be prevented through better design, training, or systems.
  • Latent conditions: “hidden” weaknesses within organisational culture and behaviours, management practices and arrangements, or system design. These may present themselves as:
o   Poorly designed plant or equipment o   Weak communication
o   Ineffective training o   Lack of necessary resources
o   Insufficient supervision o   Unclear roles or responsibilities

 

Underlying “latent” issues may go unnoticed until they combine in unexpected ways and contribute to human error or rule‑breaking. As everyone is capable of making mistakes, identifying and addressing both active and latent factors is essential for preventing incidents.

Immediate Causes and Contributing Factors

Below are common examples of immediate causes of accidents and their contributing factors:

Job‑related factors

  • Poorly designed equipment or instruments
  • Frequent interruptions or distractions
  • Missing, unclear, or confusing instructions
  • Equipment that is not properly maintained
  • Excessive workload
  • Noisy, uncomfortable, or unpleasant working conditions

Individual factors

  • Low skill levels or insufficient competence
  • Fatigue, boredom, or low morale
  • Complacency
  • Risk-taking behaviour or cutting corners
  • Personal or medical issues affecting performance

Organisational and management factors

  • Inadequate work planning that creates high pressure
  • Lack of effective safety systems or protective barriers
  • Poor follow‑up or weak responses to previous incidents
  • One‑way communication from management
  • Unclear responsibilities or poor coordination
  • Weak health and safety management
  • A poor overall safety culture

Understanding both the immediate and underlying causes of an accident or near miss is essential for preventing similar events and establishing effective controls. This is the core purpose of any incident investigation.

Equally important, however, is the practice of identifying and reporting hazards before they lead to an incident. Proactive hazard observation plays a critical role in stopping unsafe conditions from escalating into actual harm. Hazard observation is a skill that improves with deliberate practice, particularly through regular field-based observation where risks are most visible and best understood.

Hazard Observations in Practice

Observations or hazards in practice can be undertaken in several ways, including:

  • Planned and structured observations, such as routine inspections and formal safety checks, but also supplemented by informal (albeit structured) observations by staff.
  • Day-to-day observations, where individuals take a moment to assess what they are being asked to do and identify potential risks before commencing work.

However, hazard observations are far more effective when they involve direct discussion with workers or colleagues about the task at hand. This is distinct from a pre‑task briefing and can be especially powerful for several reasons:

  • Workers can explain the real‑world challenges they face while carrying out the task
  • They often offer practical, experience‑based suggestions for completing the work more safely or efficiently
  • These conversations support the legal duty to consult workers when developing safe systems of work
  • Informal, face‑to‑face engagement demonstrates genuine interest from supervisors, managers, and leaders in workers’ wellbeing and perspectives, reinforcing that their insights can help improve safety for everyone

Reporting Systems and Organisational Processes

When carried out with the aim of understanding real hazards and the effectiveness of existing controls, a hazard observation can be formally recorded in a management system or similar platform. This creates valuable evidence of worker engagement and compliance, and it contributes to broader organisational learning and improved safety practice.

Employers and organisations benefit greatly from maintaining an accessible and straightforward hazard observation reporting process, which can be further enhanced through tools such as smartphone applications. Keeping these records provides valuable insight into the real risks workers encounter in the field and enables the organisation to take meaningful action to address them.

Demonstrating consistent care for workers in this way, and being visibly committed to it as standard practice, creates a safer, more trusting environment for everyone.

However, it is essential that hazard observations are not perceived by workers as attempts to “check up on” or “catch out” individuals. Without clear and genuine intentions, and without workers believing those intentions, that is exactly how such activities can be interpreted. This can seriously undermine trust between workers and employers and, in turn, weaken the overall quality of health and safety on a project.

Observers must therefore recognise this risk and plan their approach carefully: how they conduct the observation, how they hold the discussion, and how they record the findings all matter. Many organisations choose not to formally report these interactions for this very reason, while others deliberately omit names or specific work locations.

The primary aim should always be organisational learning, not policing compliance.

A clear and well-communicated process can contribute to:

  • Workers having a voice in how the work is carried out
  • Observations being reviewed, investigated, and acted upon
  • Emerging trends and recurring issues being identified
  • Reduced risk while worker engagement and productivity can be enhanced

How to Observe during a Hazard Observation

Good hazard observation starts with planning, including:

  • Knowing what physical works and tasks are expected to be taking place
  • Understanding which equipment and personnel should be involved
  • Being aware of the controls that are expected to be in place to manage the pre‑identified hazards

Looking at the risk assessment and method statement beforehand is useful and important.

On approaching the site/workplace, observe from a safe place and at a distance so you can see the wider aspects of the work being carried out. This will help you to understand:

  • Whether there are others doing different tasks close by
  • Whether the work environment looks as it was envisaged in the RA/MS,
  • Whether there are different environmental conditions potentially affecting the way we are working (weather, groundwater, livestock etc.)

This will then allow you to:

  • Take time to observe the people, equipment, and work methods in use. Be methodical: work through each task, identify the associated hazards, and compare the controls in place with what you expected from your pre‑planning.
  • Consider whether the situation matches those expectations and whether the planned controls are genuinely effective in keeping workers safe. The aim is not to find non‑compliance, but to identify where controls may be insufficient.
  • Make notes for your own reference and for communicating findings later. Keep the details factual, specific to the task, and grounded in what you observed. This level of detail is far more valuable than broad or generic statements.

Ensure you speak with the worker at a time that is safe and convenient for them. During the conversation:

  • Explain who you are and the purpose of your visit or observation
  • Ask how the task is going, what has changed, what is proving difficult, and whether they have suggestions for making this task—or similar tasks—safer or more efficient
  • Ask what hazards they have encountered, including any that were unexpected
  • Check whether the controls in place are effective and practical, such as whether PPE is suitable and comfortable
  • Avoid arguing or justifying; focus on listening. Be human, show genuine care for them and for colleagues doing similar work
  • Invite them to share any additional information, concerns, or ideas they may have
  • Thank them for their time and for pausing their work to support yours. Encourage them to contact you if they have further ideas, and provide your contact details
  • If, and only if, the task being carried out is unsafe (for example, if there is serious and imminent danger to health and safety), stop the task, explain why, and involve the appropriate project personnel to make the situation safe

Do not use a hazard observation exercise as an opportunity to enforce minor safety infringements. This time should be focused on learning from the task, from the environment, and especially from the workers themselves.

How to Record and Report a Hazard Observation

If it is agreed with the Employer that hazard observations will be documented, recording and reporting should follow a straightforward, preferably structured and repeatable process that captures all useful details, preferably linking to the Employer’s/contractor’s H&S information system. It might just involve a digital form, a smartphone application, or filling out a paper record.

Each observation should:

  • Include the date, time and location and describe the task and your observations, along with relevant environmental conditions.
  • Include photographs or videos to help provide clarity. Ensure these are permitted and agreed with the worker.
  • Keep the information factual, specific, and focused on behaviours, equipment and environmental factors.
  • Consider what the impact or consequence might be if the potential hazard is left unaddressed, particularly where a different or new hazard has been observed (eg. a change in environmental conditions, weaker or uneven ground, a different piece of equipment being used which may have not been allowed for or are significantly different from the RA/MS).
  • Be based on discussions with the worker and your own considerations, and include a suggested practicable control method where possible, even if it is only a temporary measure.

Fig 1. Photo of Kevin Puckett, Health & Safety Manager. Taken by Rachael Parry.

It should be understood if escalation (including immediate) is necessary due to what you have observed or learned.

Hazard observation is not well suited in the event of an incident or near miss and certainly not immediately following one. In those cases, the incident must be reported and investigated in accordance with employer/site procedures, including immediately to the Site Manager or similar.

Recognising Positive Safety Behaviours

Hazard observation systems can also be an effective way to recognise and reinforce positive behaviours. Submitting positive observations allows organisations to acknowledge individuals who show outstanding commitment to health, safety, and wellbeing. In some workplaces, this recognition is further supported through formal health and safety awards or commendations and can help to strengthen overall culture and boost morale.

Creating a Culture of Accountability and Care

Documenting hazards is not about assigning blame or identifying fault. It is about protecting people, learning from experience, and reinforcing a shared commitment to safety. When individuals are encouraged and supported to raise concerns without fear, safety becomes proactive rather than reactive.

A strong safety culture is built on shared responsibility. When everyone takes ownership of safety, trust grows, engagement improves, and people naturally look out for one another. For this to happen, managers and leaders must consistently demonstrate their commitment to workers’ safety. Workers need to see and believe that their wellbeing genuinely matters.

When carried out with the intent to learn and improve, hazard observation can play a significant role in reinforcing this commitment and strengthening the overall safety culture.

Driving Continuous Improvement

Hazard observations can support the ongoing development and refinement of safe systems of work. They enable organisations to:

  • Recognise positive behaviours and good practices
  • Verify compliance with Health and Safety Procedures
  • Improve Risk Assessments and Method Statements (RAMS)
  • Strengthen Standard Operating Procedures (SOPs)

Safety is not simply a compliance exercise, it is a mindset. Each observation represents an opportunity to learn, adapt, and improve.

Article provided by Rachael Parry, Operations Support Manager at Geotechnical Engineering Limited

Article

Q&A with Jonathan Gammon

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Tags: Featured

This year, the AGS has presented two lifetime achievement awards. Here, we speak to the second recipient, Jonathan Gammon. Jonathan has been involved with the AGS for over 30 years, serving as Chair of the AGS from 2007-2009, and has taken part in multiple Working Groups over the years including the Senate, Business Practice and the Instrumentation and Monitoring Working Group.

What first inspired you to pursue a career in the geoscience industry?

When I was studying for my degree in Civil Engineering at the University of Surrey in the early 1970s, I fell under the spell of Noel Simons and Bruce Menzies who taught us Soil Mechanics.  I had intended to start a career in bridge engineering.  During my year in industry, I had worked for contractor Marti AG on the construction of the fantastic Felsenau Bridge in Bern, Switzerland.   However, I was easily persuaded to change career direction and had their support to gain a place on the MSc Course in Soil Mechanics at Imperial College and graduated there in 1975, now more than 50 years ago! With further academic study at Imperial under the spell of Professors and Lecturers including Skempton, Bishop, Vaughan (my Tutor/Supervisor), Hutchinson, Chandler, Skinner, Hoek, Knill, De Freitas, and Ambraseys,  I was more  than adequately inspired to pursue a career in the geoscience industry.

Looking back over your career, which achievement or moment are you most proud of?

If I had to chose just one event it would be receiving my AGS Lifetime Achievement Award at this year’s AGS Annual Conference.  That was a total and wonderful surprise.  If I was allowed to add others they would include being Chair of AGS, assisting with the establishment of AGS in Hong Kong when working there again from 1996 to 2002,  and the opportunities I was given at the University of Surrey and Imperial College, in 2018 and 2019 respectively, to give talks about my career.

Has there been a particular turning point that significantly shaped your professional journey?

Yes.  In broad terms it would be turning to live and work overseas after a fantastic foundation to my career as a Graduate and then Chartered Civil Engineer at WS Atkins and Partners, based in Ashtead, Surrey.  After working through the Middle East on projects in Algeria, Egypt, Saudi Arabia, and Iran with Atkins, it was time for a move to Hong Kong in 1980.  From there we moved to New Zealand in 1984 when, as another proud achievement, I was appointed to set up a Geotechnical Section in one of New Zealand’s largest consultancies, then Murray-North, now AECOM.  Being granted New Zealand citizenship was also a proud achievement.

How has the industry evolved since you first started, and what changes stand out most?

The Geotechnical Department at WS Atkins I joined in 1975 comprised of seven members of staff!  Now there are several hundred members of staff world-wide. That was a perfect time to join the industry.  Consulting Engineers were recognising the increasing need for demonstrable specialist skills as the geotechnical demands of projects increased enormously.  Think of offshore production platforms in the ferocious North Sea, for example.  Always having a keen interest in my projects, not just the geotechnical aspects, enabled me to support the work of the Civil, Structural, and Transportation Engineering Departments at Atkins as well as engage in exciting work with the Research & Development Team.  A step change in the industry occurred in the early 1990s because of the Environmental Protection Act.  At that time, the worst recession ever in the construction industry had started to hurt.  The need for, and ability to provide, geoenvironmental skills helped the ground engineering community maintain momentum during that tough time.  Indeed, the initial name of AGS as the Association of Geotechnical Specialists was expanded in name, but not abbreviation, to become the Association of Geotechnical and Geoenvironmental Specialists.  Another important development was the introduction of the Chartered Geologist qualification by the Geological Society of London. For too long, before that, Engineering Geologists had felt their career progress threatened by an inability to secure a professional qualification enjoyed by their colleagues with a Civil Engineering background.

How important have collaboration and professional bodies such as AGS been throughout your career?

Very important.  I was fortunate that becoming a Chartered Civil Engineer at the Institution of Civil Engineers at the earliest opportunity enabled me to secure Membership of the Hong Kong Institution of Engineers (HKIE) and what was then the Institution of Professional Engineers New Zealand (IPENZ), now Engineering NZ,  when arriving in those countries. Such professional qualifications were vital to securing project work.  Establishing AGS in Hong Kong brought me rapidly in contact with those working across the entire ground engineering sector: consultants, contractors, testing laboratories, suppliers, and the like; a situation that would not have been achieved by Membership of HKIE alone. I also enjoy my membership of the British Geotechnical Association, the British Tunnelling Society, and the Railway Civil Engineers Association.

What role has mentoring or supporting the development of others played in your professional life?

I have been fortunate to have worked for and with wonderful senior management and staff throughout my career.  There was a magical moment, in my experience, when it was possible to ease back – not entirely! – on personal ambition and to encourage the development of those working for me and to recognise fully their skills and ability, some of which I admit I had not possessed.  I am thrilled to find out how members of my teams have progressed in their careers.  Some formed their own highly successful consultancies; some now head up major companies. In my early career I received wonderful support from mentors and marvelled at how easy it was to engage in conversation with leading figures in our areas of work.  Much as I enjoy seeing the establishment of Early Careers Groups, and the like, I am concerned the these must not become a barrier to conversation across the entire range of ages from students and fresh graduates to those like me, in our seventies, and older.

What advice would you offer to early career professionals entering the industry today?

Fully appreciate the exceptional and unique opportunities that our industry provides to engage with the entire range of types of projects around the entire world.  Seize those opportunities when they arise.  Accept a job overseas if available.  My work in Switzerland provided me with the added benefit of fluency in the German language.

In your view, what skills or qualities are essential for long-term success in this field?

Now retired, I envy those still engaged in work as this is an amazing time to enjoy the benefits that the likes of Artificial Intelligence and ChatGPT bring to the workplace.  I am fortunate to have had the mind-set during my career that Computer Aided Draughting (CAD) and Building Information Management (BIM) would prove hugely beneficial to our areas of work, despite the upset and controversy surrounding their introduction to traditional working practice.  I admire the work of Bentley, for example, who persevered with CAD all that time ago and now provide us with an ability to gather, interrogate, and make sense of the huge amounts of data that the electronic and wireless world is capable of sourcing and generating, using software such as Leapfrog.  I am confident that the inherent skills and qualities that had led someone to start out in our industry will sustain them throughout their careers.  In my early years, being a specialist was viewed as career limiting.  Thankfully, that proved not to be the case for me and, not without its setbacks, I still reflect on my career with immense joy and a true sense of excitement for the future of our industry and those taking part.  Provided one grasps the opportunities to broaden knowledge and experience, to spend time on site, and to keep up with what technology can wonderfully provide, then long-term success should result and be enjoyed.

What does receiving the AGS Lifetime Achievement Award mean to you personally?

I have partly answered this at Question 2., above.  I was incredibly grateful to be made an Honorary Member of AGS several years ago.  That has enabled me, now fully retired and without a company affiliation, to remain engaged with AGS as a whole and with the Instrumentation and Monitoring Working Group (I&MWG) which I set up in 2019 with the enthusiastic support of then-Chair Julian Lovell. The I&MWG is now very ably led by Tim Clegg.  Unexpected as it was, receiving the Award means a huge amount to me personally.  It is a lifetime highlight.  Thank you to all those involved in providing me with such a special honour.

Article Contaminated Land

Updating the DoE Industry Profiles

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This article describes work that has been undertaken to begin updating the industry profiles that were created by the then Department of Environment (DoE) over thirty years ago. It covers the reasons for updating the profiles, the content of the new profiles, the review process used to ensure accuracy, and the next steps.

Background

The DoE published a series of 47 industry profiles in 1995. These profiles provide information on the processes, materials and wastes associated with individual industries with regards to land contamination. The profiles have not been updated since their original publication. Changes in legislation, industrial practices and the emergence of new contaminants mean they are now, to varying degrees, out of date; some significantly so. Although there are sections of the profiles that are out of date, they still contain a lot of very useful historical information when carrying out a Stage 1 risk assessment in line with Land Contamination Risk Management. They currently reside in The National Archives and are signposted on the CL: AIRE Water and Land Library (WALL).

In 2023/24, the Environment Agency provided funding to CL:AIRE to undertake a short project to investigate whether the DoE profiles could be better signposted and presented in a more accessible way (Phase 1). As part of Phase 1, an industry questionnaire and workshop were undertaken. A template for the profiles and a beta online portal was created with five draft profiles. The main conclusions of Phase 1 were:

  • The profiles are still well-used.
  • There is great interest and support in updating the profiles into a tool that is clear, succinct, accessible and searchable on all platforms.
  • There is interest in developing some new profiles covering industries that have had contaminative processes on site that are not covered by current profiles.
  • It is important to update the profiles to ensure that emerging and persistent contaminants are covered.

In 2025/26 Phase 2 of the project to update 15 of the 47 industry profiles was undertaken with funding from the Environment Agency, Association of Geotechnical & Geoenvironmental Specialists and Natural Resources Wales. Phase 2 involved the five profiles from Phase 1 plus 10 further profiles which were selected from the industry consultation, where feedback was gathered about which profiles were most used or in most need of an update. These are listed alphabetically below:

  1. Airports
  2. Chemical works – coatings (paints and printing inks) manufacturing works
  3. Chemical works – organic chemicals manufacturing works
  4. Dockyards and dockland
  5. Dry cleaners (miscellaneous)
  6. Engineering works – electrical and electronic equipment manufacturing works
  7. Engineering works – railway engineering works
  8. Gas works, coke works and other coal carbonisation plants
  9. Oil refineries and bulk storage of crude oil and petroleum products
  10. Printing and bookbinding works (miscellaneous)
  11. Railway land
  12. Road vehicle fuelling, service and repair – garages and filling stations
  13. Sewage treatment works
  14. Timber treatment works/timber products manufacturing works
  15. Waste recycling, treatment & disposal sites – landfills and other waste treatment or waste disposal sites

Note that (5) and (10) were part of the Profile of miscellaneous industries which actually contains six separate industries. Also the steering group decided to combine the two timber industry profiles hence the 16 profiles listed above.

Layout & Content

The industry profiles are presented at claire.co.uk/doe where there is an initial landing page that explains the project and gives a link to the overview table. Figure 1 provides a screenshot of part of this overview table. In the table, 15 industries have been listed alongside potential contaminants in generic groupings that may be associated with the different industries. As mentioned earlier, the aim was not to rewrite the original profiles, but to update them for contaminant groups such as per- and polyfluoroalkyl substances (PFAS) and persistent organic pollutants (POPs) and present the information in a more accessible way, via a simple interactive online matrix.

Figure 1: Screenshot of part of overview table.

Each industry profile is hyperlinked to a dedicated page giving a greater level of detail about the background of the profile and associated potential processes and operations relevant to that profile. In the updated profiles this text is kept succinct with the emphasis on the potential contaminants of concern, along with likely locations of contamination (as shown in Figure 2). Table 1 explains some of the rationale behind the contaminant groupings and likely locations.

 Figure 2: Screenshot of contaminant/location table for Airports profile.

Table 1: Important notes to bear in mind when reading the industry profiles:

Contaminant groupings

 

 The potential contaminants of concern table is divided into (i) organic and inorganic contaminant types and (ii) into contaminant groups taken from the Environment Agency remediation options applicability matrix. It is recognised that there is overlap between some groupings (e.g. VOCs and halogenated/non-halogenated hydrocarbons; PFAS and POPs, and others).

 

The contaminant groups are the same for all profiles and a black dot is shown for contaminants in that group that might typically be associated with a specific industry. Other contaminant groups (and hence other contaminants) may be present at a particular site. Where there is a blank row (i.e. no black dot), these contaminant groups are not typically found on these sites. To help the user with their understanding, three examples from each contaminant group are provided in a separate table called Example Contaminants. Of course it is essential to consider other contaminants within those groupings.

 

At the bottom of some of the contaminant tables there is a row for “Other potential contaminants of concern”. This is where examples of contaminants not covered by the generic groups are listed and where readers are directed to the original profiles for a more extensive listing of individual chemicals that may be present. Again this list is not exhaustive.

 
Locations

 

 Most profiles contain several site locations where contaminants are typically found, marked by black dots. Where there is a blank row (i.e. no black dot), these contaminant groups are not typically found at these locations.

 

Where locations are common to most industrial sites they have not been included in the contaminant tables unless they are considered to have a close association with that site. Common locations and their main contaminant group include: fuel storage areas (non-halogenated hydrocarbons), electrical transformer areas (PCBs) and buildings/building fabric (asbestos).

 

Some profiles have just a single “site-wide” location (e.g. Waste recycling, treatment & disposal sites) and this reflects the information provided in the original profile and the fact that contaminants are likely to be widespread across these sites rather than in a particular location.

 

 

Review Process

CL:AIRE reached out to industry via its eAlert, Jiscmail and LinkedIn to seek individual reviewers or relevant organisations that would volunteer to review the profiles. The response was fantastic such that each profile was reviewed by two or three volunteers and then also by the CL:AIRE Technology and Research Group.

The main task of the reviewers related to the assignment of dots to potential contaminants of concern and their likely locations and providing additional information sources.

The potential contaminants of concern were cross-checked with the contaminant tables in CLR8 – Potential Contaminants for the Assessment of Land (Environment Agency, 2002) but these do not assign likely locations. There were also instances where the industry profile and CLR8 did not align and the reviewers were asked to comment on this and provide evidence to support their decision. The steering group were able to weigh up the evidence and have the final say.

Additional sources of information on the potential contaminants associated with these industries were identified by the volunteers and have been listed with links provided where available. These include useful documents like the EC Best Available Techniques Reference Documents (BREFs) and new and forthcoming publications such as the PFAS site profiles. These resources were selected if they are freely accessible documents or webpages (i.e. not behind a paywall) or websites which have multiple free information sources. Links to related industry profiles are provided to either the web page if the profile is one of the 15 updated ones, or to a searchable PDF of the original industry profile. Figure 3 provides an example of the types of further information sources.

The industry review was a key part of the project. If the reviewer gave consent to be mentioned then they have been listed on the acknowledgements page.

 Figure 3: Screenshot of additional information sources for the Waste recycling, treatment and disposal sites: landfills and other waste treatment or waste disposal sites profile.

Feedback and Next Steps

The industry profile project is a live project. General feedback on the information provided is welcome and there is a feedback form to capture comments. This also applies to technical feedback/input. Suggested changes to the assignment of black dots to contaminant groups/locations must be supported by a reference with the recognition that these are “typical” contaminant groups/locations that may not be applicable to all sites. Of course, please also share documents, webpages or websites which are free to access and contain information about contaminant sources and they can be added to this resource.

The next steps are to seek further funding to update the remaining 32 profiles and also to consider developing new profiles covering industries that have had contaminative processes on site that are not covered by current profiles.

As a final note the industry profile pages can be accessed at claire.co.uk/doe

Article provided by Rob Sweeney, Technical Director, CL:AIRE

Article Contaminated Land Laboratories

PFAS Analyses – the numbers alone are not enough

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It has been said that a professional is someone who has specialist knowledge, skills and expertise that has been independently validated and who operates under a code of practice.  However, another take on this is a professional is someone wise – and brave – enough to say that something is outside their area of competence – and then works with someone who has that missing competence.

This article is written as a conversation between an analytical chemist with deep expertise in how accredited laboratories operate and a risk assessor who advises on the need for remediation under specific legal contexts.

Modern analytical chemists are operating at the critical interface between complex environmental matrices and the generation of legally and scientifically defensible data. Within laboratories accredited to standards such as BS EN ISO/IEC 17025:2017, their role extends beyond the execution of methods to the critical evaluation of method applicability to the substances and media of interest, measurement uncertainty, detection capability, and data fitness for purpose. This includes ensuring appropriate sub-sampling strategies, preservation techniques, extraction efficiencies, calibration models, and quality control systems are in place and functioning. For emerging contaminants such as PFAS, the analytical chemist must also recognise the limitations of current methodologies, including compound coverage, matrix effects, and potential artefacts, and communicate these transparently to data users – sadly this is not usually the case.

The GB-based risk assessor works usually under the context of the planning regime or Part 2A of the Environmental Protection Act 1990 (as amended). Both are chemical agnostic. In the context of protecting human health, remediation is needed to ensure land is safe and suitable for its intended use or to remove a significant possibility of significant harm.

Turning to that large and very diverse family of synthetic chemicals, PFAS pose a specific challenge to both risk assessor and analytical chemist. Never mind that they may be persistent and widespread, the real challenges arise from what Greenleaves III calls epistemic uncertainty – the lack of relevant knowledge about the behaviour of PFAS in soil, water and within our bodies.

Analytical chemistry’s epistemic uncertainty stems from the inherent limitations in our ability to comprehensively measure the large, structurally diverse of PFAS family using finite, targeted methods. Current PFAS analyses typically quantify a relatively small subset of known substances, while thousands of other PFAS, particularly precursors and transformation products, remain undetected or only partially characterised. This gives rise to uncertainty associated with:

  • Scope of analysis: Targeted methods exclude unknown, novel, or poorly characterised PFAS, leading to systematic underestimation of total burden.
  • Transformation and precursors: Many PFAS exist as precursors that can degrade into terminal compounds over time; standard analyses may not capture this latent mass without specialised approaches (e.g. oxidative conversion techniques).
  • Matrix effects and recovery: Complex environmental media (soil, sediments, biota) can influence extraction efficiency, affecting quantification accuracy and comparability.
  • Analytical variability and uncertainty: Measurement uncertainty, particularly at low concentrations near reporting limits, can be significant and is often underappreciated in downstream decision-making.
  • Standard availability and calibration: Quantification relies on the availability of authentic standards, which do not exist for many PFAS, constraining both identification and accuracy.
  • Cross-laboratory comparability (PT Scheme): Differences in methods, reporting limits, and compound lists can lead to variability between laboratories, complicating the interpretation of datasets.

Taken together, these factors mean that PFAS analytical data are not absolute representations of environmental concentration, but conditional estimates bounded by method capability. The “numbers alone” therefore risk misinterpretation unless accompanied by a clear understanding of what has, and has not, been measured, and with what degree of confidence.

The risk assessor has to inform decisions on the need for remediation that accounts for epistemic uncertainty in, for example, the dose-response relationship, effects of mixtures, rate of transformation of precursor to terminal substances in the environment, behaviour of different species (neutral or ionised).

A better understanding of these two sources of epistemic uncertainty will help refine the decisions on whether or not to remediate even as science develops a better understanding to reduce those uncertainties.

On analytical uncertainty

What does the method detection limit (MDL) mean?
The MDL represents the lowest concentration of a substance that can be distinguished from analytical noise with a defined level of statistical confidence, rather than a threshold of quantification or risk relevance. It is method, matrix, and laboratory-specific, and is influenced by sample preparation, instrument sensitivity, and background contamination. For PFAS, MDL can vary significantly across compounds and matrices and may fall above or below levels of toxicological concern. Consequently, a “non-detect” does not equate to absence, but rather indicates that any presence lies below the method’s capability to reliably quantify it.

How does inter-laboratory comparability help?
Inter-laboratory comparability, typically assessed through proficiency testing (PT) schemes and inter-laboratory studies, provides an external benchmark of analytical performance. It allows laboratories to evaluate their bias, precision, and consistency relative to peers using similar or different methodologies. For PFAS, where method variability and compound coverage differ from laboratory to laboratory, such comparisons help identify systematic discrepancies. However, comparability does not guarantee accuracy; it demonstrates consistency within the bounds of current methodological limitations.

Are Harmonised analytical protocols possible?
Harmonised protocols are both desirable and partially achievable, particularly for well-characterised PFAS in relatively simple matrices such as drinking water. Standardised methods (e.g. based on LC-MS/MS) can improve comparability and regulatory confidence. However, full harmonisation remains constrained by the diversity of PFAS chemistries, the absence of standards for many PFAS, and the variability of environmental matrices. As such, harmonisation is likely to remain partial and evolving, with a combination of standard methods and fit-for-purpose adaptations required.

Are quality assurance/quality control (QA/QC) procedures at the same level of stringency in different laboratories?
While accredited laboratories operate under common frameworks (e.g. BS EN ISO/IEC 17025:2017), the implementation and rigor of QA/QC procedures can vary in practice. Differences may arise in areas such as blank control, use of isotopically labelled standards, calibration strategies, acceptance criteria, and treatment of data near detection limits. For PFAS, where ultra-trace analysis and contamination control are critical, even small differences in QA/QC practice can materially affect results. Accreditation provides a baseline of competence, but not complete uniformity.

In this context, the United Kingdom Accreditation Service (UKAS) is actively working towards greater standardisation of PFAS methodologies. However, the process of extending a laboratory’s accredited scope to include PFAS analysis requires a high level of technical rigor, including extensive method validation, demonstration of measurement uncertainty, contamination control, and ongoing performance verification. This reflects both the analytical complexity of PFAS and the need to ensure that reported data are robust, reproducible, and fit for regulatory purposes.

How do the above influence whether nor not reported concentrations are a reliable and fit basis for regulatory decision-making?
These factors collectively determine the confidence that can be placed in reported concentrations. Data reliability is not solely a function of the numerical concentration reported on the certificate of analysis,  but of the supporting analytical context. Laboratories should therefore be prepared to report, on request, key quality indicators alongside results, including measurement uncertainty, recovery of surrogate standards, system suitability performance, blank contamination status, and other relevant QA/QC criteria.

For regulatory decision-making, particularly where threshold values are comparable to the MDL and consequences significant, transparency in these parameters is essential. Reported concentrations should be interpreted in light of method scope, detection capability, and demonstrated analytical performance. Decisions should therefore be based on a weight of evidence, incorporating these quality metrics and, where appropriate, complementary analytical lines of evidence, rather than relying uncritically on single numerical values.

On risk assessment

Should risk assessors consider the presence and potential transformation of precursor substances?
Yes, risk assessors should explicitly consider the presence and potential transformation of precursor substances when evaluating PFAS contamination, because failure to do so can lead to a systematic underestimation of both current and future risk. Many PFAS precursors are not captured by standard targeted analytical methods, yet they can undergo abiotic and biotic transformation in soils, groundwater, and biota to form persistent terminal compounds such as perfluoroalkyl acids, which are often subject to regulatory criteria. This means that a site with relatively low concentrations of measured PFAS may still represent a significant long-term source of contamination as precursors tranform over time. Incorporating this dynamic requires moving beyond static concentration data toward a more process-informed conceptual site model that accounts for transformation pathways, rates, and environmental conditions. In practice, this may involve the use of complementary analytical techniques such as the TOP assay to estimate precursor potential, alongside cautious interpretation of targeted data, and the application of total organic fluorine (TOF) measurements to provide an estimate of the overall fluorinated organic burden, including unidentified or unquantified PFAS. Where TOF significantly exceeds the sum of organic fluorine in targeted analytes, it provides a clear indication of unaccounted for missing mass and highlights the potential for both unknown compounds and precursor-derived contributions to risk. However, both the TOP assay and TOF approaches are subject to important limitations: the TOP assay may not fully oxidise all precursors, while TOF lacks compound specificity and may include non-PFAS organofluorine contributions, with results also influenced by extraction efficiency. TOP Assay is also affected by the intensity of the oxidation step.  Recognising precursor presence and the broader organic fluorine mass balance, while understanding the constraints of these techniques, aligns with a weight-of-evidence approach and is essential for ensuring that risk characterisation remains protective under conditions of analytical uncertainty.

What role do complementary analytical approaches (e.g. TOP assay, total organic fluorine)?
Analytical approaches such as the Total Oxidisable Precursor (TOP) assay and total organic fluorine (e.g. EOF/AOF) could help contextualise concentrations of targeted PFAS by addressing key sources of epistemic uncertainty inherent in targeted analyses. While targeted LC-MS/MS analysis provides robust, compound-specific quantification for a limited suite of well-characterised PFAS, it systematically underrepresents the total burden due to the exclusion of precursors and other unknown compounds. The TOP assay partially resolves this by forcibly converting oxidisable precursors into terminal perfluoroalkyl acids that can be measured, thereby revealing the latent PFAS mass that may tranform to terminal PFAS over time in environmental systems. In parallel, total organic fluorine approaches quantify the aggregate fluorinated organic content irrespective of molecular identity, enabling a mass balance

How could mass balance evaluations improve understanding of the total PFAS burden and long-term leaching risks?
Atoms can neither be created nor destroyed in a chemical reaction – the total number of fluorine atoms remains the same. Mass balance involves counting the number of F atoms in a sample, discerning which ones are bonded to carbon – organic fluorine – and accounting for those that are part of targeted analysis. The remainder are part of molecular structures that are not able to be analysed using targeted methods.  An understanding of how much of the organic fluorine load is present in identified molecular structures can be an important line of evidence in risk assessment and even more so in risk management.

Conclusions
Regulatory decisions about the significance of PFAS in water, soil and other media should be based on a broader appreciation of analytical results than simply the concentrations reported on Certificates of Analysis.

The need to consider PFAS beyond those that can be subject to targeted analysis requires methods such as TOP assay and organic fluorine analysis to establish the potential for precursor transformation into terminal PFAS.

Increasingly, high resolution mass spectrometry could bring more PFAS into the analytical spotlight and reduce the need for untargeted TOP assay and organic fluorine analyses – but that is a subject for a future article.

References
BS EN ISO/IEC 17025:2017 General requirements for the competence of testing and calibration laboratories (Currently Under Review)

NATHANAIL, C P, WILLIAMS, G and NATHANAIL, J F (2024) Good practice guidance: some per- and polyfluoroalkyl substances (PFAS) in soil and the water environment, C819, CIRIA, London, UK (ISBN: 978-0-86017-965-8)

Article by Ken Scally (Normec and Calibre Scientific) and Paul Nathanail (LQM)

 

 

 

 

 

 

Event Sustainability

AGS Sustainability Charter Workshop for Smaller Organisations: Turning Commitments into Action

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AGS Sustainability Charter Workshop for Smaller Organisations: Turning Commitments into Action
2026-09-2323rd Sep 2026
Microsoft Teams
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Join the AGS for a 90-minute online workshop exploring the AGS Sustainability Charter and how smaller organisations within the AGS membership can embed sustainable practices within their operations. The workshop will provide guidance specifically focused on developing relevant sustainability targets for smaller organisations, concluding with the company signing up to the AGS Sustainability Charter.

Taking place on Microsoft Teams on Wednesday 23rd September 2026 at 11am, the session will be led by Sustainability Working Group Chair, Alison Nicholson (Geoenvironmental Team Lead, Associate Director at Buro Happold), Natalie Cropp (Director (Sustainability) at Tony Gee) and Sam Setchell (Principal Engineering Geologist at Jackson Geo Services) and will consider the crucial role that the geotechnical and geoenvironmental industries play in shaping a sustainable future, and how members can put sustainability principles into practice.

Recognising the diverse nature of AGS membership, this workshop will highlight the importance of setting sustainability targets that are ambitious, practical and tailored to the unique capabilities and challenges faced by different organisations. It will also explore how the Charter supports existing sustainability commitments and legal obligations, while encouraging members to take actionable steps towards advancing the UN Sustainable Development Goals across environmental, social and economic dimensions. This session will be specifically focused on smaller companies and sign-up as an organisation rather than a geotechnical/geoenvironmental team within a larger company.

Attendees are encouraged to bring any relevant information available to support the workshop activities, such as carbon-related metrics, team or company goals, and sustainability case studies. The session will include an introductory presentation, after which participants will move into one of three tailored breakout groups of similar organisations based on attendees (e.g. contractors, designers/consultants, and laboratories). Each group will discuss appropriate sustainability targets for their organisation and will be provided support to complete the AGS Sustainability Charter sign up form.  After the workshop, attendees will then have a two-week period to review and refine their targets before confirming their commitment. After signing up as an organisation, you will receive a badge, ‘AGS Sustainability Charter Signatory’ to display on your website and social media.

This workshop is free of charge. Places are limited and will be offered on a first come, first served basis. Registration will close on 16th September 2026.

If you are from a smaller organisation (up to 50 specialists) and would like to register for the workshop, please email ags@ags.org.uk with your name and the breakout group you consider most relevant to your organisation e.g. contractor, designer/consultant, or laboratory.