News Dec 18, 2020

Grit and Determination: Tackling a Circular Economy with Scottish Water and Zero Waste Scotland

Jacobs is working with Scottish Water and Zero Waste Scotland to implement a full-scale trial to reuse recovered grit as recycled aggregate – with the potential to make significant cost and carbon savings.

Sunset through a clear globe

With ambitious circular economy and net zero carbon objectives, Scotland plans to lead the way internationally by implementing the principles of circular economy and building a circular society - where products, services and systems are designed to maximize use, minimize waste and regenerate natural systems.

Scottish Water supplies and manages Scotland’s water, and has recognized that a circular economy approach for the water sector is also fundamental to meeting the country’s legally binding target of net zero greenhouse gas emissions by 2045. Taking decisive action, Scottish Water has made the first step to implementing a full-scale circular solution by reusing and upcycling grit collected at wastewater treatment works.

Grit enters sewers from surface water runoff and has to be removed at wastewater treatment works to avoid costly downstream impacts to plant and equipment. Currently the grit removed from the system is sent to landfill – at considerable cost and carbon impact due to landfill emissions. Recognizing the need for greater ambition to meet the challenges faced by society and our planet, we are working with Scottish Water to develop a more circular, sustainable solution: Upcycling grit in recycled sand and construction products.

Jacobs delivered the first two phases of the project on behalf of Zero Waste Scotland, identifying and working with Small- to Medium-sized Enterprises within the recycled aggregate industry in Scotland and developing a high-level business case for grit recovery. We also showed the substantial carbon benefits to Scottish Water by avoiding landfilling the material. The next step is to develop a pilot trial for implementation with Scottish Water and aggregate recyclers; this will provide the regulatory, environmental and material quality information required to show grit can be recovered and reused to the benefit of the recycled aggregates industry and without having a negative impact on the environment.

“The need for all sectors to adapt to tackle climate change is evident – and we can see the appetite and momentum to do so building around the globe. This project is a great example of key organizations within a sector innovating and collaborating to take action,” shares Jacobs People & Places Solutions Senior Vice President, Donald Morrison. “There is substantial untapped value in the urban water cycle that can be recovered to help address the climate crisis and deliver the best solutions for people and our planet.”

“Grit from wastewater treatment is a great example of something we routinely remove during our treatment processes that can have a valuable second life,” explains  Scottish Water’s Environment Program Manager in Research and Innovation, Tamsyn Kennedy. “Re-purposing the grit will save waste from landfill and contribute to meeting our net zero emissions target – and we are pleased that the first skip of grit has been delivered for stockpiling ahead of the trial in early 2021.”

Read more about the project and its importance for Scotland’s circular economy here.