Working in Tandem

13 October, 2025

Overview of Martell’s Quarry in Essex

First published in the October 2025 issue of Quarry Management

SRC Group continue to invest in CDE processing and waste-washing solutions, with the opening of a 135 tonne/h waste-recycling plant at Martell’s Quarry, near Colchester

Headquartered in Essex, SRC Group have grown over the past decade to become one of the UK’s leading independent aggregate producers, providing a diverse range of materials for key construction and large-scale civil engineering projects throughout the UK.

With demand for SRC’s high-quality aggregate products rising rapidly – emphasized by a commitment to strengthen the circular economy – the family-owned business opened a state-of-the-art CDE construction and demolition (C&D) recycling plant at Martell’s Quarry, near Colchester. The 135 tonnes/h wet-processing solution is one of more than 10 projects CDE have delivered for the building materials firm to date.

Importantly, it will allow SRC to process incoming inert and non-hazardous materials from their various business operations and maximize the recovery of high-quality recycled sand and aggregates, which can be returned to the local construction market as a cost-effective and sustainable alternative to virgin quarried materials.

Today, SRC operate from seven different sites, including four quarries and three waste-recycling depots. Powering the company’s rapid commercial growth in recent years is it’s trusted partnership with CDE, one of the industry’s leading suppliers of wet-processing solutions for the natural minerals processing and waste-recycling sectors, whose engineered solutions have helped SRC to increase their profitability by producing higher-quality washed/graded sand and aggregate products whilst maximizing throughput and yield.

According to Oliver Rees, SRC’s managing director, recycling is a crucial part of the business’s ethos and drive to achieve a more profitable and sustainable future. ‘In the past 10 years, SRC Group have grown from five employees and one quarry to operating four quarries, three recycling sites, and employing more than 250 people,’ said Mr Rees. ‘We’re on a high and fast growth trajectory and still see an opportunity for future growth. We see recycling having a vital role to play in the future of our business.’

As demand for SRC’s construction product range continues to increase, sustainable alternative aggregates that meet the specific needs of their customers in the local construction industry are required.

Mr Rees added: ‘Every six months, we’re recording significant increases in the volumes of material we’re moving. We anticipate that the upward trend will continue. As we grow, it is not sustainable – both for us as a business and for the environment – to maintain the same levels of quarried sand and aggregate products.’

Among the contracting services offered by SRC are demolition, earthworks, and site clearance for many large-scale civil projects, all of which provide a steady flow of incoming inert waste for the business.

‘A lot of our material is coming in from Greater London and throughout East Anglia, where void and landfill space is limited, so a restorative and circular approach is essential to fulfil the demand of the local construction industry,’ said Mr Rees. ‘There is a need for locally sourced, quality sand and aggregate products, and there is also a significant waste stream that can be better utilized to respond to that need.

‘We needed a solution that would recover materials from the waste coming in from our other business activities to the highest possible quality standards, so that they could be returned to the market for use in new construction and infrastructure.’

The heavy-duty AggMax modular scrubbing and classification system offers maximum performance and minimum wear with the most challenging feed materials

Continued loyalty

Recycling and wash plant specialists CDE and aggregate suppliers SRC have maintained a partnership for over 10 years. In 2010, SRC acquired their first CDE solution, which included an AggMax log-washer, an EvoWash hydrocyclone wash plant, and an AquaCycle thickener system installed at Elmstead Quarry, Colchester. Since then, the two companies have collaborated closely on no fewer than 12 key projects across SRC’s operational sites.

David Kinloch, strategic development director at SRC Group, highlighted that collaboration is the foundation of the longstanding, successful relationship between CDE and SRC. ‘We’ve been working together for many years, and during that time, both businesses have grown and evolved. It is CDE’s approach to co-creation with their customers that underpins the successful partnership with SRC.’

‘By working in partnership, they can understand a customer’s requirements from the outset and co-create a tailored solution that directly responds to their commercial and environmental aims and objectives. Once a project has been delivered and commissioned on site, we then continue that relationship through CDE’s unrivalled aftercare support.’

At SRC’s Martell Quarry, CDE proposed a customized wet-processing solution that included a R4500 primary scalping screen, AggMax modular log-washer, EvoWash fine classification system, AquaCycle thickener, and filter press. CDE’s R-Series primary scalping units are designed to optimize product yield from feed material by removing oversized material at the start of the process, ensuring the efficient delivery of difficult material to the wet-processing plant and maintaining optimal utilization of the processing equipment.

This material is transferred to the AggMax modular scrubbing and classification system, which has been specially engineered to operate in the harshest conditions, maximizing product yield from the most abrasive feedstocks. Its versatile design incorporates five processes on a single and compact portable chassis, including pre-screening, scrubbing/attrition, sizing, contaminants removal and stockpiling.

The heavy-duty AggMax log-washer can process challenging C&D waste materials containing large quantities of organic and other inert physical contaminants into high-value materials suitable for a variety of applications in the construction industry.

Fine material is processed by CDE’s pioneering EvoWash sand washing system, which screens and separates the smaller sand and gravel fractions through an integrated high-frequency dewatering screen, sump, and hydrocyclones. The compact, modular sand washing plant is said to provide unrivalled control of silt cut points, while eliminating the loss of quality fines with significant commercial value.

Using CDE’s patented dewatering screen technology, the EvoWash system offers optimal dewatering results that allow aggregate producers such as SRC to produce a range of high-quality sands that are market-ready straight from the belt.

As well as supporting SRC to extend the life of their quarry reserves through the recovery of high-value recycled sand and aggregates derived from inert waste, the CDE solution commissioned at Martell’s Quarry also incorporates market-leading water management to minimize SRC’s environmental footprint.

CDE’s AquaCycle thickener is a compact, highly efficient water-management alternative to water extraction and the costly process of pumping water to the waste-recycling plant by ensuring up to 90% of the process water is recycled for immediate recirculation. The water-management system uses a flocculant to separate clean water from solid particles, which form a sludge and are dried further in the filter press, recovering more water for recirculation and creating a dry filter cake that can be used for pipe bedding and landfill capping.

Mr Rees said that the consistency of material is one of the biggest challenges in the recycling sector. ‘The construction, demolition, and excavator waste coming in is never the same, so it’s about identifying the material and understanding how it’s going to behave as it goes through the process. Our CDE wet-processing plant at Martell’s Quarry is aware of these challenges and provides us with the flexibility to adjust the plant’s specifications to suit our incoming feed material.’

With the support of CDE’s wet-processing technology, SRC are extracting valuable sand and aggregate resources with substantial commercial value from incoming inert waste streams, generating additional revenue for the business and diverting significant tonnage from landfill. More than 80% of CDE’s incoming waste can now be processed, recovered, and returned to market as recycled sand and aggregate products.

SRC are diverting up to 800,000 tonnes of waste from landfill every year

Thanks to CDE technology, SRC are diverting up to 800,000 tonnes of waste per year from landfill. The engineered-to-order waste-washing plant is supporting the business to transform 135 tonnes/h of raw feed into six recycled construction products.

As well as supplying high-quality sand and aggregates directly to the local construction market, SRC are also utilizing recovered materials in the production of prefabricated concrete blocks for retaining structures and compacted concrete for paving.

With CDE’s wet-processing solutions, SRC can process incoming inert and non-hazardous materials whilst maximizing the recovery of high-quality recycled sand and aggregates

Commenting on the close working relationship between the two companies, Mr Rees said investment in CDE technology is an investment for life. ‘It’s not like purchasing a crusher or acquiring a new screen. To get the best from your plant it needs to be running efficiently and continuously with minimal downtime. The project doesn’t just end once the plant is operational. It requires maintenance, parts etc.

‘That’s why we’ve stuck with CDE for so many years. We have a great rapport with the parts department and CustomCare team and are reassured by their consistent and proactive support, which keeps us operational across all our sites.’

Indeed, every CDE project benefits from their ‘customer for life’ model, which ensures transparent and effective communication from the beginning of the project until commissioning, as well as superior after-sales support.

Mr Rees concluded: ‘SRC have invested in CDE and likewise CDE have invested in us. When we began to formalize plans for the future of Martell’s Quarry there was no question that we wanted CDE to be part of that journey. The CDE recycling plant has been an essential component in our success to date and will continue to play an important role in our future.’