CIRQLR's People

David is a veteran of the UK and European waste and recycling sector having spent more than 35 years working in the sector.

Before starting and developing CIRQLR in 2023 in partnership with iCON Infrastructure LLP David was a Group Senior Vice President of SUEZ sitting on the Group’s Management Board overseeing Northern Europe. Before his Group role David spent 11 years as the UK CEO for SUEZ and a further 10 years in Scandinavia where he transformed the success and culture of both companies.

David was awarded an OBE by King Charles in 2023 for services to the sector both in the UK and Europe being recognised for his contribution through his roles as ESA Chair, the President of FEAD, a Board member of WRAP and Chair of the Swedish Waste Association.

David is a passionate believer in the development of a more Circular Economy and has spoken and written extensively on the subject.

Contact via: info@cirqlr.co.uk

Gareth joined CIRQLR as COO in 2025, bringing over 15 years of recycling and waste management experience. He has driven sustainable growth through the transformation of critical service delivery, supporting customers on their journeys toward greater circularity.

Gareth brings a proven operational track record in managing clients’ waste streams, built through over a decade of board-level leadership, including as Managing Director at Enva’s recycling, segregation, and collections business in Nottingham, Group Sales & Marketing Director at Orbis, and Executive Board Member at Safetykleen. 

Gareth’s fast-track career in operational and financial management was forged over six years at Regus/IWG, where he delivered exceptional service and projects across the UK.

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Nick brings over three decades of success at the highest executive and board level at companies across the UK and international utilities, energy, logistics and business service sectors.

Nick has spent the past decade as Chair at a variety of fast-growth energy infrastructure and support services companies. Nick spent his first two decades in the energy sector across several senior operational and executive leadership positions. He had an 11 year career at E.ON UK, the national power supply and infrastructure group, where from 2001 to 2007 he served as Managing Director of the Retail arm, where he set up their successful trading business. Nick then led Scottish Power as CEO during their critical growth years of 2008 to 2010.

Nick has since 2025 been part-time Chair of Aureos, the multi-disciplinary energy and transport networks specialist engineering services provider. Prior to Aureos, Nick served for five years as Chair of Smart Meter Assets while continuing as Chair of Horizon Energy Infrastructure, a role he first assumed in 2017. He was Chair of ESP Utilities from 2011 to 2019, while also at the time serving as Chair of Aldernay Renewable Energy from 2016 to 2018 and Chair of UK Power Reserve from 2014 to 2018.

Nick has served as a non-executive board director from 2010 to 2017 of Royal Mail Group and from 2011 to 2017 at Go-Ahead Group. He also served three years until 2014 as Chair of the Advisory Board for KPMG’s Energy & Natural Resources practice.

Nick provides the strategic oversight to help inspire people to be their very best in all the companies they work and deliver strong, sustainable returns for customers and investors.

Contact via: info@cirqlr.co.uk

Tristan was appointed as Group IT Director in 2025, bringing 20 years of leadership in transformative technology and data driven change to help a range of complex businesses integrate and improve their commercial operations. 

Tristain joins CIRQLR after over five years at Jersey Post, where he was Global Head of IT Service Delivery, developing internal technology infrastructure to deliver real-time data tracking and analysis of customers’ trading patterns. 

Prior to this, Tristan spent more than 12 years at technology distributor Exertis UK as an IT Systems and Business Analyst, partnering with companies across UK industry sectors nationwide to drive growth through the better use of integrated technology packages. 

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Katie brings over two decades of hands-on customer-focused organisational, can-do experience managing multi-site operations, bringing the best of people and operations, garnered across a career in the recycling, critical infrastructure and manufacturing sectors. Katie has successfully implemented a commitment to “on-time, in full” (OTIF) approach to recycling and waste services, collection and delivery.

Katie joined CIRQLR from Biffa, the UK waste and recycling company, where for three years until 2026, she had been their South-East Regional General manager, with strategic oversight and delivery responsibility for both collections and transfer stations, leading around 300 employees.

Prior to Biffa, Katie Treacy was for five years until 2023 Commercial Operations Manager at North Air (Aviation Into-Plane Fuel Services), leading operations at Gatwick and Heathrow airports and driving the transformation of operational agreements to deliver a more customer-centric approach while supporting sustainable profitability.

Katie spent the first 12 years in warehouse logistics and national distribution of goods for wholesale and major branded retailers, initially in the ceramics division of Saint Gobain (2005-14) then fulfilment e commerce for International Logistics Group (2014-17). Prior to her time with Biffa (2023-26), and before North Air (2018-2023), Katie was general manager at TR Fastenings, the UK steel bolts-to-couplings manufacturer which supplied both large infrastructure projects and national retailers.

Contact via: info@cirqlr.co.uk

Catherine brings 20 years of financial and operational management leadership with a particular expertise in vehicle fleet management and service provision in relation to critical infrastructure. Catherine has proven experience delivering services with a commitment to “on-time, in full” (OTIF) approach to customer fulfilment.

Catherine joined CIRQLR following a decade at North Air (Aviation Into-Plane Fuel Services) from 2016 to 2026, where she progressed to the role of Finance Director (Head of Finance). She held full responsibility for all financial matters, ensuring alignment between financial strategy and broader business objectives. She led the evaluation and coordination of major capital investments, including the procurement and management of a fleet of over 100 vehicles, and maintained full financial oversight of critical fuel supply operations serving commercial aircraft across up to 20 UK airports. During her time at North Air, Catherine also developed innovative financing solutions in partnership with Airport customers, enabling the timely delivery of key infrastructure upgrades while supporting operational efficiency and long-term profitability.

A qualified ACCA accountant, Catherine’s initial career was in financial services, chiefly with Equinti (2011-16) where, as finance business partner, she was tasked with improving operational efficiency, compliance and customer-focused communication for its range of complex pensions and retirement management platforms and providers.

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Dave is the Chief Executive of Castle Environmental. He joined Castle in 2004 and has held a number of roles within the business including Technical and Operations Director. 

With a background in chemistry and a broad base of experience in the management of hazardous waste, Dave leads a team of experienced and passionate waste professionals who are able to deliver customer focussed innovative solutions for challenging waste streams.

Holding a seat on the board of the Environmental Services Association, Dave is passionate about continuous improvement in the performance of the Castle Group and the wider waste management sector to deliver safe and secure management of hazardous wastes in line with the ESG goals.

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Started KP Waste in 1997 having worked for Cleanaway for 10 years

Built a small waste company from scratch specialising in providing services across London and the Home Counties .

Contact via: info@cirqlr.co.uk

Elliot has been with KP Waste for 15 years rising through the business to become Operations Director .

He has carried out all roles within the Company 

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Contact via: info@cirqlr.co.uk

Mark is the Founder and Managing Director of Sommers Waste Solutions, bringing over 35 years of experience in the waste management sector, including senior roles with national brokers as well as national and regional waste management businesses.

Since founding SWS in 2009, Mark has been instrumental in driving growth and profitability, building it into a highly respected, award-winning business known for exceptional customer service. He continues to lead the development of new initiatives, partnerships, and collaborations that expand SWS’s portfolio of services.

Contact via: info@cirqlr.co.uk