The Mineral Products Association (MPA) has published a report, From Waste to Resource, highlighting the high levels of recycling being achieved by the UK construction industry, and is calling for more robust waste data for the sector.
Defra statistics from 2014, which were referenced in the construction sector deal and resources and waste strategy, both published last year, show that around 120 million tonnes of construction, demolition and excavation (CDE) waste are generated by construction activity each year – around 60% of the entire amount of waste produced by the UK each year.
The MPA report acknowledges that CDE waste is the largest waste stream in the UK but says that, once hazardous waste and navigational dredging spoil is excluded, 76% of CDE waste is currently being recovered and recycled for alternative uses. This means the amount of waste requiring disposal to landfill is 26 million tonnes.
It says: “This level of reuse is significantly higher than other waste streams such as that from households, commercial & industrial activities and packaging.”
In addition, it calculates that 90% of ‘hard’ construction and demolition (C&D) waste is recycled or recovered in the aggregates market – this is typically material such as concrete, bricks, tiles and ceramics, wood, glass, plastic and metal. Meanwhile 57% of ‘soft’ excavation waste (EW) is used mainly in backfilling operations to recycle land – this material typically includes soils, stones and dredging spoil.
According to the MPA report: “General statements of the scale of CDE waste mask weaknesses in understanding the composition of the total waste stream. Overall, these perceptions are simplifying what is ultimately a complex situation. The assumption that vast quantities of waste are not used beneficially is misleading and underestimates the high degree of resource recovery taking place in the UK.”
From the MPA report: Four issues that are holding back recycling
On-site classification: waste or non-waste?
At the site of origin some material, such as soils, may be diverted away from the waste stream under schemes such as the CL:AIRE Definition of Waste: Code of Practice. This may influence the year-on-year metrics used to define ‘waste’ totals because different schemes will divert material away from the recorded waste stream. This may result in inconsistent data from year to year.
Changes in definitions of contaminated soils
Some EW will exhibit hazardous properties, so must be classified and disposed of appropriately rather than being available for reuse. For example, recent changes to the Environment Agency’s Technical Guidance WM3: Classification and assessment of waste may affect the amount of EW that is ultimately available for recovery as opposed to requiring disposal.
Regulation and permitting
Changes to permitting regulations will be influenced by case law interpretation. This will mean that the precise nature and quantities of waste recorded, along with their destination, are likely to vary year-on-year. As an example of this, a case won by appeal in 2015 has fundamentally changed the way in which deposit for recovery permits are determined.
Revisions resulting from case law can therefore influence the wider waste stream that is reported each year, whether in terms of the total tonnages that are generated or their final end-use.
There are a number of direct barriers that can constrain recovery and recycling. By understanding and addressing these, recycling and recovery could be further improved.
An example of this is the permitting and classification of soil products that are generated by screening CDE waste. The permitting requirements for such activities can be complex, and the time, effort and costs involved may prove a barrier and prevent some EW recycling operations realising their potential. It can be more straightforward to simply dispose of EW materials to landfill.
This can be compounded by the variability of the incoming waste because a high percentage of silt will make it uneconomic to recycle. Costs are also an issue because the complexity of EW recycling requires more substantial capital investment compared with the cost of processing plants for hard C&D waste.
Nigel Jackson, MPA chief executive, said: “The mineral products sector plays an important role in contributing towards the circular economy – whether recycling concrete and brick to be reused in construction or using soft excavation waste to restore old mineral sites and in turn recycle land.
“However, the absence of robust data relating to the generation of waste products and their subsequent use back into the ‘chain of utility’ must not be used to overshadow the performance of UK industry in recycling and recovery of waste resources. We need to understand what additional actions are needed to further reduce the 26 million tonnes of CDE waste produced by the construction industry that are actually being disposed of.”
The MPA is calling for more consistent and comprehensive data collection and monitoring of CDE waste arisings and resource use. It says this would allow limitations to recovery to be better identified and resolved, which would in turn help to improve recycling and recovery rates.
It says better data and understanding is particularly required around excavation waste: “EW plays an important role in the delivery of quarry restoration. However, the absence of transparent, quantifiable data to evidence this role has led to a general misunderstanding that EW is often disposed of, rather than being recycled or recovered.”
Julia Barrett, director of construction firm Willmott Dixon, concedes that the sector has “a massive part to play in the management of waste across the UK”, and that it is important to “recognise that CDE waste [comprises] three very different streams that our sector has to deal with”.
View from Willmott Dixon: Julia Barrett, Director
Future measures that might be taken and their challenges
The construction sector supply chain represents such a wide variety of businesses – from £1bn+ turnover companies to one-man bands – that a differentiated risk-based approach must be taken for it to work.
There are many material takeback schemes in operation; we have more than 65 such agreements with our supply chain partners to maximise the reuse of surplus materials, as well as agreements with community schemes such as the National Community Wood Recycling Programme, donating excess materials to avoid waste to landfill and provide local community benefits.
But these need to be expanded to cover more materials. Given the dispersed and temporary nature of building sites, coupled with the challenges of vehicle movements in our cities, there is a massive opportunity for greater collaboration for the collection and bulking-up of waste materials for recovery and recycling, learning the lessons from municipal waste collection systems.
In the short- to medium-term, an increase in off-site manufacturing and modular construction will enable a reduction in construction waste arisings on our sites, and indeed overall, as assembly happens in more repeatable and productised ways in controlled factory environments. However, the real game-changer will be embracing digital technology and ‘printing on demand’ on our sites which should, in theory, mean no wastage at all.
Extended producer responsibility (EPR)
Invoking the ‘polluter pays’ principle and EPR should help to ensure that producers pay the full costs of disposing of the packaging they place on the market. Furthermore, the introduction of a tax on plastic packaging with less than 30% recycled content should stimulate the demand for recycled plastic.
Our data shows that 25-30% of construction waste produced on Willmott Dixon sites is plastics and packaging. There is a real opportunity to work with our goods and material suppliers, and to collaborate across our supply chain partners, to show real innovation in how resources are used.
Resources and waste strategy
This provides a short- to medium-term opportunity to move on from Defra’s historic preoccupation with municipal waste to target all waste streams prioritised on economic and environmental benefit. Business ‘resource efficiency clusters’ could be the mechanism which transforms the efficiency and adoption of takeback as well as material exchange schemes.
Regulatory reform will provide a fantastic opportunity to improve the transparency of the management of excavation waste in particular, underpinned by stronger penalties for those who breach the rules, to ensure the right environmental outcomes are achieved without any unintended consequences for those seeking to do the right thing.
Construction sector deal
This addresses waste minimisation by seeking to develop a sector that is increasingly based on digital manufacturing technologies to improve the efficiency of construction techniques through building information modelling and smart systems technologies.
As these technologies are adopted, there will be a reduction in construction waste and, as we move to deconstruct these buildings at the end of their lives, on demolition waste arisings too. But in a sector with low margins, that invests very little in R&D, and has evolved little during the past century, we are at risk of simply digitising analogue processes.
Perhaps there needs to be more focus on new business models and enabling behaviour change, alongside leadership from the Government with innovation embedded as standard in its property procurement processes, to ensure that we achieve real change in the medium term.
She explains that after the success of the ‘Halving Waste to Landfill’ initiative for the construction sector, which was set up by WRAP and came to an end in 2012, Willmott Dixon turned its focus to reducing construction waste. It is on track to achieving its target of 60% reduction by the end of 2020.
Barrett says: “We have taken many innovative steps to minimise our waste arisings, such as redesigning our projects to eliminate waste, increasing the use of off-site manufacturing, using material storage areas and segregating waste on-site.
“We have also developed much closer relationships with our supply chain partners: reducing the number of products and methods of construction we use on our projects means that our people and our partners’ people do not have to re-learn how to deliver a quality product each time, which reduces errors and wastage.”
Barrett explains that, for the waste it has not been able to eliminate, “our waste supply chain partners, an increasing number of which comply with the independently verified PAS 402 [construction recovery standard], have been key to maximising recycling and minimising waste to landfill, resulting in a diversion rate of more than 97%”.
View from Mace: Isabel McAllister, director of responsible business
Reducing waste in construction is a complex challenge that requires a sector-wide response. It is not something that any one contractor can do on its own. On all our projects we work with clients and suppliers to explore where we can reduce waste and repurpose material where possible.
There are a number of innovations in the pipeline that will make waste minimisation more practical. For example, around 40% of materials now arrive prefabricated to our sites, significantly reducing site waste generated by individual trades.
We have set ourselves a 2022 corporate target that 85% of our materials will be prefabricated, which again will help to improve our waste position.
We are also seeing great energy and innovation among our suppliers with regards to single-use plastic. A number of them have focused their efforts during the past year to either completely remove single-use plastic from their activities or to create closed loop systems that reuse the waste.
In order to drive realchange we need everyone to work together. Government initiatives have made an impact, but the stronger driver for behaviour change is client expectations. When they demand action, the sector generates positive results much more quickly.
She adds that many in the construction sector also supported the ‘Right Waste Right Place’ campaign intended to educate SMEs on their duty of care responsibilities. “There are now more than 70 partners supporting the Supply Chain Sustainability School, which we helped to found back in 2012, to increase the skills and knowledge across our supply chain.
“Demolition waste is quite different,” she adds, “because we simply inherit a building from the past. Working with high-quality demolition contractors who share our values and approach each job as resource recovery rather than waste disposal ensures that we achieve a waste diversion rate of more than 85%.
“The mineral products sector plays an important role in contributing towards the circular economy – whether recycling concrete and brick to be reused in construction or using soft excavation waste to restore old mineral sites.”
“Finally, EW can often be the ‘forgotten man’ of waste in our sector. We work with our experienced groundwork supply chain partners and our customers to try to maximise the use of excavated materials on-site. Anything that cannot be used is taken by subcontract hauliers to approved sites.
“What has proved challenging for everyone in our sector is that, following a change in the regulations more than 12 months ago, excavation waste that was previously deemed as being of beneficial use is now classed as being landfilled although, in reality we are doing nothing differently.
“The regulations were amended for exactly the right reasons, but the changing classification has reflected badly on the sector’s performance statistics. Willmott Dixon currently achieves around a 70% diversion from landfill for excavation waste.”
View from Scotland: Focus on waste reduction
view from scotland
Construction Scotland Innovation Centre (CSIC) and Zero Waste Scotland (ZWS) announced in February that they were joining forces to encourage the construction industry to find innovative ways to reduce construction waste.
The partnership will deliver a supporting programme of activities, including a series of joint events to promote innovative ‘reuse, recycling and circular thinking’ initiatives within construction; issuing ‘innovation calls’ to generate projects around waste reduction and reuse themes; and collaborating on further sector-wide strategic projects.
Stephen Good, chief executive at CSIC, says: “Reducing construction waste and encouraging circular economy approaches should be a priority for everyone in the sector, and there is no doubt that it is increasingly becoming a driver for businesses.
“CSIC has already funded numerous projects in these areas, including reusing waste tyres in acoustic barriers and producing bricks made from construction waste. By working in partnership with ZWS, we hope we can support even more construction businesses to innovate and grow while helping to reduce the construction sector’s significant contribution to the country’s landfill.”
Iain Gulland, chief executive of ZWS, adds: “The construction sector faces major challenges in reducing its waste, but there are equally big opportunities for businesses to reduce costs and create new revenue streams in Scotland’s emerging circular economy. Achieving that will require new ways of thinking and working together to maximise our impact.”
The construction sector is the largest consumer of natural resources and the largest contributor to waste to landfill in Scotland, accounting for one-third of its overall waste to landfill.