Sustainability has become one of the most important factors to consider in any construction project, both within and outside of the ground engineering sector. The past few years have seen environmental and sustainability issues thrust into the spotlight on a global scale, including a more widespread understanding of governing bodies such as the Conference of the Parties to the United Nations Framework Convention on Climate Change (the UNFCCC COP), and large-scale adoption of initiatives such as the science based targets initiative (SBTi) and the Sustainable Development Goals (SDGs).

However, focus on improving sustainability in construction is largely focussed on the introduction of practices that include ‘easy wins’ such as electric or alternatively fuelled equipment and fleet vehicles, the use of lower-impact materials, and an increased focus on renewable energy procurement. But what about everything else? While these aspects are undoubtedly hugely important in achieving sustainability goals, there are so many other ways in which sustainability can be achieved across the entire lifecycle of a project.

At Fugro, we continuously rethink what we do and how we do it to ensure we are key contributors to the development of a safe and liveable world. We conduct our operations in many different sectors and such a broad scope of works has leant itself to the development of a number of innovative ways to increase sustainability in these areas.

Targeting problematic plastic use

Post-Covid, Fugro decided to analyse how we could be more sustainable in lesser considered areas, and we began this process by analysing consumption across the business. We soon realised that we consume a large amount of single use plastic, and it was here that we decided to introduce our Zero Plastic Initiative, aiming to completely eliminate Fugro-deployed single use plastics and to reduce supply chain plastics by 50%.The single use plastic dilemma has become one of the most prominent environmental crises in recent times and the impact of single use plastics on our planet is devastating. Microplastics from waste that has been carelessly disposed of are everywhere, having been found in human blood, in clouds, and even at the bottom of the Mariana Trench, one of the deepest oceanic trenches on earth that stretches further below the surface of the sea than Everest does above land. Chemicals from plastics pollute soils and waterways. The production of virgin plastics includes the use of fossil fuels such as oil and natural gas and is incredibly energy intensive, with a white paper by The Association of Plastic Recyclers[i] estimating that virgin plastic production can consume an estimated 70.4 MJ per kg of energy.

Whilst Fugro endeavour to encompass all 17 sustainable development goals wherever possible, we most closely align ourselves with:

• 7 – affordable and clean energy
• 9 – industry, innovation and infrastructure
• 11 – sustainable cities and communities
• 14 – life below water
• 15 – life on land

The manner in which Fugro was consuming plastics did not correspond with the objectives we believed we could best contribute to, nor did it resonate with the operational standards to which we aspire. With a strong determination to make the most substantial impact from the very beginning, we made the decision to tackle the most significant source of single-use plastic within our business operations first – the core liners.

Use of PVC core liners in our operations

The proper handling of waste stands as one of our most significant environmental responsibilities. PVC core liners are the most appropriate type of liner for carrying out our specific sample collection activities. Many of the projects in which we are involved present constraints related to space or weight. This is true whether we are drilling for core samples from a vessel situated in the middle of the North Sea or operating halfway up a mountain in the Scottish Highlands, as we did in 2023 as part of the SSE Renewables Coire Glas hydro pumped storage project.

There are numerous benefits to using PVC core liners, which play a crucial role in our geotechnical investigation works. Although they may seem like just simple plastic tubes, they offer significant cost savings and reduced weight compared to other options, they are durable, and because they are made from PVC rather than uPVC, they have the added advantage of flexibility. Their use helps reduce the risk of contamination, their transparency allows for easy observation, and they facilitate successful sample retrieval.

Whilst alternatives such as steel Shelby liners exist, they are significantly heavier and more expensive, and pose additional extraction risks when the sample is analysed in the laboratory. It is important to note that plastic itself is not inherently a bad choice – when used appropriately and handled correctly, plastic-based tools and parts can be invaluable in any geotechnical project. Therefore, completely phasing out the use of PVC core liners in favour of non-plastic alternatives was deemed unfeasible.

However, there is a notable downside to employing plastic core liners. Reuse, the subsequent tier in the waste management hierarchy, is unfeasible in this scenario. Upon arrival at our laboratories, the sample retrieval process necessitates the splitting of the liner, either partially or entirely, to extract the sample intact. Consequently, the liner cannot be reused and must be discarded. Our analysis of single-use plastic usage revealed that we were not handling this waste in the most environmentally responsible manner. Instead of implementing the recycle tier of the waste management hierarchy, we were resorting to the final tier, disposal/recovery.

Searching for a solution to recycle responsibly

We realised that it was imperative to instigate positive change, aligning with our commitment to support the SDGs and our sustainability objectives. However, we soon realised that finding a solution for PVC core liner disposal would prove to be a challenge.

The plastic recycling market predominantly favours easier to recycle plastics with higher rebate potential. uPVC (unplasticised polyvinyl chloride), commonly used in windows and doors, exemplifies this trend. In contrast, PVC (polyvinyl chloride) contains plasticising additives, rendering it somewhat malleable and structurally flexible, which is advantageous in certain applications but also presents challenges. These additives, such as phthalates, pose health hazards and contamination risks during recycling processes. Moreover, the high heat treatment typically involved in plastic recycling can release hydrochloric acid, posing corrosion risks to both equipment and workers. Many recycling companies are reluctant to bear the safety burden and associated costs relating to this.

In 2023, Simplas PVC Recycling embraced collaboration with us to realise our objectives. Aligned with Fugro’s values and vision, Simplas is committed to fostering more sustainable practices and reducing reliance on single-use plastics. Their dedication led to the attainment of Recovinyl® certification,  European certification scheme which verifies the process, quantity and quality of recycling PVC waste.

A secondary challenge lay in the requirement for cleaning prior to recycling, presenting another substantial obstacle due to the various mud and silt residues often stuck to the liners, as well as tapes and labels. Despite recognising the impracticality of cleaning them solely through manual labour, we remained determined to succeed. Through collaborative efforts among our internal departments, we pinpointed ultrasonic cleaning as the solution to achieve the cleanliness necessary to meet our objectives. Subsequently, we invested in two ultrasonic baths and crafted a tailored operating procedure, seamlessly integrating routine core liner cleaning into our daily operations.

PVC undergoes recycling via a mechanical process involving rigid plastic granulation. Initially, the core liners are shredded into pieces roughly a few inches in size. Subsequently, these pieces undergo a secondary processing phase, granulating them into even smaller fragments, typically just a few millimetres in size. Known as plastic pellets or ‘regrinds’ within the plastic recycling sector, these granules are ideally sized for sale to manufacturers of plastic goods. Manufacturers go on to melt the regrind to create new plastic items, avoiding the use of virgin PVC in manufacturing processes. While regrinds are often utilised in producing similar items, lower quality regrinds may also find applications in alternative products such as mats and traffic cones.

What’s the result?

All this effort brings considerable positive environmental benefit. Recycling PVC reduces primary energy demand by between 45% and 90% compared to virgin PVC production, resulting in approximately 2 kg of CO₂ saved per kg of recycled material[ii]. Further carbon savings can be achieved by diverting this waste from incineration – the combustion of PVC in energy from waste facilities emits around 21.28 kg CO₂ per tonne[iii].

To put this into perspective, Fugro disposes of around 4 tonnes of spent core liners annually, meaning that by simply working to ensure we recycle this waste stream we can save an additional 8.09 tonnes of CO₂ from being emitted each year – it would take approximately 400 trees a year’s worth of growth to sequester the same amount of carbon dioxide from the atmosphereⁱⁱⁱ. There are other notable benefits in addition to the obvious carbon savings. Recycling core liners diminishes the demand for natural resources, with the makeup of PVC comprising of 57% chlorine extracted from common salt and 43% ethylene sourced from fossil fuels or byproducts from sugar crops[iv].

Although various factors can make systemic sustainability challenging, Fugro’s core liner recycling project serves as compelling evidence that with steadfast willpower and determination, these challenges can be realistically and effectively addressed.

Plans for the future

We are committed to going beyond the initial success of our core sample recycling initiative – our next objective is to initiate the recycling of the poly bags and tubs used to store samples in our laboratories, of which we go through approximately 20,000 of these items annually. Our efforts will continue to extend further down the single-use plastic chain, encompassing every item, right down to the very last sample tag and zip tie.

Finally, we must ensure that we share best practice and lessons learned with those around us. Fugro operate in 57 countries across the world and our international colleagues often encounter similar issues around plastic recycling. By delivering tangible benefits and laying the foundation for enduring change, we can amplify and maximise the environmental benefits of such approaches across our global portfolio.

But why stop there? Engagement with clients, geotechnical specialists, and other stakeholders around the single use plastic crisis is critical to ensuring the ground engineering sector can fully realise the benefits of adopting a circular economy approach. The industry as a whole need to make sure that we continue on a path of true sustainability, using open communication and knowledge sharing to ensure that a combination of effective techniques are used. This allows the industry to achieve the best environmental outcomes operationally, benefitting not only ourselves but the planet too, and most importantly, ensuring a safe and sustainable environment for future generations.

[i] Source: https://plasticsrecycling.org/images/library/APR-Recycled-vs-Virgin-May2020.pdf

[ii] Source: https://www.vinylplus.eu/news/moving-the-pvc-industry-to-a-low-carbon-circular-economy/#:~:text=It%20has%20been%20calculated%20that,PVC%20and%20the%20recycling%20process

[iii] Source: https://www.gov.uk/government/collections/government-conversion-factors-for-company-reporting

[iv] Source: https://www.bpf.co.uk/plastipedia/polymers/PVC.aspx#Raw%20Materials

Article provided by Rachael Findlay, Environmental Adviser at Fugro

Information correct at date of writing, some operational elements of this scheme may be subject to change.

Image credit: Fugro