Building public trust,
one catchment at a time

Revolutionising water management with transparency and innovation

About Additive Catchments

Welcome to Additive Catchments, where our commitment to environmental stewardship and community trust guides everything we do.

Our pioneering Catchment Management as a Service (CMaaS) is at the forefront of ensuring water quality and compliance through continuous monitoring and actionable insights.

Leveraging advanced IoT-enabled sensors and AI applications, we empower water companies with the confidence to meet regulatory demands, specifically Section 82, while offering communities unparalleled transparency into the environmental impact of water management operations.

Our mission

At Additive Catchments, we are committed to revolutionising how informed decisions are made that impact our environment — from government agencies to utilities, communities, and businesses. Understanding the effects of these decisions on river health, public health, carbon footprint, and pollution levels is crucial. Our innovative Catchment Monitoring as a Service (CMaaS™) addresses this systemic need by providing better, real-time, and contextualised information. CMaaS empowers stakeholders to make well-informed choices that are crucial for sustainable environmental stewardship.


Our impact-driven, non-profit consortium is dedicated to delivering:

Regulatory compliance
Transparency & accountability
Actionable insights
Innovation & accessibility
Scalability & future-proofing

Impact-Focused Approach

As a majority-owned subsidiary of the non-profit organisation, Additive Catchments is deeply committed to pioneering beyond traditional environmental compliance standards. Our operational ethos is to build public trust and propel sustainability agendas forward through innovative practices. We focus on developing robust, scalable solutions that tackle the pressing ecological challenges of today while anticipating the needs of tomorrow.

This approach ensures that each project we undertake is not only a step towards compliance but a stride towards meaningful environmental regeneration. By integrating cutting-edge technology with systemic solutions, we equip stakeholders—from local communities to global enterprises—with the tools necessary to make substantial, informed impacts on environmental health.

Our team

At Additive Catchments, our team structure reflects a groundbreaking collaborative approach, blurring the lines between organisations within the CMaaS Consortium. 

Led by a group of passionate environmentalists, engineers, and data scientists from Additive Catchments and key representatives from our partners including Siemens, AtkinsRealis, Galliford Try, the University of Plymouth, and Isle Utilities, our team is united by a shared vision to enhance water management practices. This interdisciplinary group is not only composed of specialists in their respective fields but also strong advocates for sustainable water use and protection, dedicated to crafting impactful, innovative solutions.

Senior Leadership

Rob Passmore

Rob Passmore

CEO & Co-founder @ Additive Catchments
Rob leads on strategy, engagement and partnership.

Quinton Davies

CTO & Co-Founder @ Additive Catchments
Quin leads our technology function working closely with partners at Siemens

Dale Van Demark

Director @ Additive Catchments
Dale leads our corporate strategy and legal activity

Brett Grosvenor

Head of Delivery @ Additive Catchments
With 23 years at the Environment Agency, Brett leads programme delivery

CMaaS® Consortium Leadership

Adam Cartwright

Water Sector Strategic Director @ Siemens Global
Adam represents Siemens in the CMaaS® Consortium with his team of data scientists and sector experts

Dr Brian Cox

Practise Director – Water @ AtkinsRéalis
Brian leads AtkinsRéalis water consulting practise

Dr Christopher Yates

Principal Water Quality Scientist @ AtkinsRéalis

David Owens

MD Water Technologies @ Galliford Try PLC
David represents GT in the CMaaS® Consortium

Stuart Barefield

Head of Technical Development @ Galliford Try PLC
David represents GT in the CMaaS® Consortium

Oliver Raud

Principal Consultant @ Isle Utilities
Oliver supports service development and value optimisation

Join Us on Our Journey

We invite you to learn more about our work, explore our solutions, and join us in making a positive impact on our planet’s future. At Additive Catchments, we’re not just monitoring the environment — we’re actively improving it, one catchment at a time.

Short waterfall in the river

Talk to the team

Whether you’re in pursuit of new solutions, expert guidance or simply exploring how our technology can support your environmental goals, we’re here for you.

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