With strict regulations on waste products that can be sent to landfill, there is a pressing need to turn gully waste and road sweeping waste into an opportunity.
Under European landfill regulations, liquid waste consisting of road sweepings with a water or liquid content of 10% or more can no longer be sent to landfill. In turn, this presents a challenge for disposing of this waste.
But for PMG Services (PMG), this challenge became an opportunity. Over ten years ago, the Bristol, southwest England-based firm purchased a waste recycling plant from wet processing experts CDE, which processed waste at a rate of 10 tonnes per hour (tph).
As their operation grew, so did the industry’s need for more recycled sand and aggregate products.
According to the Mineral Products Association (MPA), the UK’s market share of recycled aggregates is three times higher than the European average, highlighting the increased importance of repurposing waste.
With this in mind, PMG has invested in a new CDE waste recycling facility, which is more than double the capacity of the first plant.
The 25tph solution at Severn Beach is part of PMG’s ‘zero-to-landfill‘ movement and is setting the firm up for future growth goals, says Clare McGuinness, PMG Managing Director.
“We’re on a journey to process even more waste across the southwest of England. Our vision is to keep growing the waste processing capability at PMG and be able to divert more valuable material from landfill.
“We’re a family-run business with over 35 years of experience, and in that time, there has been a lot of change and investment, including moving to a new bespoke facility this year outside Bristol. This has given us the opportunity to design a site that works specifically for our unique operation.”
Continuing, Clare explains that having already worked together with CDE on the previous installation at PMG’s former base in Albert Road, behind Bristol Temple Meads train station, this facilitated a better understanding of the technology.
“During the early stages of this investment, we were able to ensure the design and layout were suited specifically to our operation. As we were doubling the size of the operation, we wanted to consider wider yard operations and traffic flow around the site, so we visited a few reference sites across the UK to get a better understanding.
“Due to the nature of the materials, it can be difficult to process the types of waste we’re working with, so with the new design, we were able to prioritise access for maintenance to ensure that the operation of the plant is easier, and so that we can continue to optimise the solution going forward.“
The solution, designed and engineered by CDE, comprises a R1500, one of CDE’s R-Series primary scalping screens, an AggMax scrubbing and classification system, an EvoWash sand washing system and an AquaCycle high-rate thickener and static screen.
When the tanker or road sweeper arrives on-site, it allows the water to drain out of the body into the pit, with any solids or lightweight organics removed. The remaining liquid contents are then pumped into the AggMax.
Once the truck has released the liquid, it will then discharge all the solid waste, such as road sweepings. This waste is then loaded into the R1500, where oversized material will begin to be processed. Anything under 80 millimetres will continue to the AggMax, which is eventually passed to the EvoWash.
All material that remains in the liquid and can’t be removed through solid removal is sent to water treatment. Any sludge is then sent to a centrifuge, where the silt is removed to ensure process efficiency.
The water gets returned to the system for further processing through the AquaCycle, which recycles up to 90% of the process water for immediate re-use in the system.
The solution enables PMG to produce two products: a 5-25mm aggregate and a 0-5 mm sand product for use in Bristol’s construction market.
The recycled aggregates are mainly used in earthworks, but also meet the specifications for highway works, pipe bedding, and cable laying. The sand is used for paving stones.
Clare notes that PMG’s operation not only supports sustainability objectives but also generates new revenue streams to benefit the local economy.
“This was an investment that we had been thinking of for several years, and we are delighted to see the plant in action. We’re proud to be recovering this material to transform it into high-value materials for the local industry.”
Fergal Campbell, UK Key Accounts Manager for CDE, says: “PMG’s commitment to recovering and repurposing material is second to none. Over the years, we’ve seen the ambition in the team grow and how sustainability really is at the heart of every decision they make.
“This type of material is challenging and costly to dispose of, but PMG identified the opportunity in this space over a decade ago, and since then, they’ve continued to push boundaries and invest in the right technology to divert even more material from landfill.
“With the depletion of virgin materials across the world, there’s a greater need now more than ever to turn today’s waste into tomorrow’s resource, and we will continue to champion the vital service that PMG is providing for the local industry.”
