By Kevin Vallelly, Chief Engineer, CDE
As Chief Engineer at CDE, I’m often asked the same question - sometimes in boardrooms, sometimes on site:
“Why does CDE believe washing is the only way?”
It’s a fair question, especially in a world where water availability is under scrutiny, and sustainability is rightly at the top of the agenda.
But here’s the truth: Washing isn’t a luxury. It’s a necessity. Not just for quality, but for performance, recovery, and the future of our industry. And when done right - with advanced recycling and intelligent water management - washing becomes the most responsible, efficient, and forward-thinking approach available. Let's discuss!

The Case for Clean
Whether we’re talking about virgin aggregates, recycled construction and demolition (C&D) waste, or industrial by-products, washed materials are better materials. They’re cleaner, more consistent, and compliant with higher-spec applications. They command stronger market value and reduce the long-term environmental footprint of construction.
Just look at the moves from major PLCs across our industry. Firms like Granite, Holcim, and CRH are aligning with ESG roadmaps that emphasise not just emissions but water stewardship as a core sustainability metric. From reducing freshwater withdrawal to closing the loop on process water, these organisations are signalling a shift: water is a resource to be managed, not feared.
Washing with Purpose, Not Waste
We don’t ignore the challenges. The Environment Agency has warned that water availability could soon threaten our way of life. But the answer is not to turn our back on water - it’s to use it smarter.
That's exactly what we're doing!

Proven Solutions
In our recent project with Granite near Salt Lake City (one of the most arid states in the USA), we delivered a high-spec washing solution that allows them to recover up to 97% of their process water, dramatically reducing reliance on mains supply. Similarly, with Scott Bros. in the UK, they upgraded their system to operate entirely on 100% recycled water. It’s the first of its kind globally. They installed ultra-fine 10-micron filters that enables every drop of water used in processing aggregates from construction waste to be recycled.
These aren’t exceptions - they’re examples of how modern washing systems, when engineered properly, make water circularity a reality.
Let’s Not Pretend Dry Processing is the Answer
Some argue that dry processing is the more sustainable route. But here’s the rub: it leaves value on the table. It limits what can be recovered. It struggles to meet the quality demands of modern infrastructure projects. And it often leads to more waste, not less.
It’s like trying to bake with dirty flour. You might get something in the oven, but you wouldn’t want to serve it.

Learning from Other Water-Dependent Industries
Across sectors, companies are investing in closed-loop water solutions. In tech, semiconductor plants recycle ultra-pure water dozens of times before discharge. In food production, breweries are reusing process water to clean equipment. These industries understand that water, managed properly, can be a strategic asset - not a liability.
Our industry needs to adopt the same mindset. At CDE, we’re not just selling equipment - we’re engineering resilience. We help customers assess local hydrology, model flow rates, and integrate high-efficiency recovery to make sure water is reused again and again.
Washing Isn’t the Problem - It’s the Path Forward
So when people ask me why we believe in washing, my answer is simple:
- Because it works.
- Because it adds value.
- Because it enables sustainability, not at the expense of water, but through better use of it.
As the industry continues to decarbonise and decouple from finite resources, we’ll need more than just good intentions - we’ll need engineered solutions.
At CDE, we’re proud to be building them.