As implementation of the Industrial Emissions Directive (IED) continues across the UK water sector, companies must deliver compliance amid ongoing regulatory uncertainty. This presentation shares Southern Water's learning journey in managing regulator expectations within affordability constraints, internal delivery capabilities, and the pressures of a complex capital programme.

This presentation will explore how Southern Water progressed environmental compliance efforts despite shifting strategic and regulatory contexts. We will describe how we developed an IED investment plan without a fully defined compliance scope - navigating an evolving interpretation of Best Available Techniques (BAT) while balancing deliverability, affordability, and wider environmental outcomes. Using project examples, we will highlight the challenges of this approach and the importance of site-specific assessments, demonstrating how BAT requirements vary significantly across a diverse asset base and how this has shaped both our investment planning and delivery under live permit conditions. Ultimately, we will show how close collaboration with the Environment Agency and industry partners supported the development of a robust, adaptable plan that progressed through PR24 and is now being delivered alongside the CMA process.

Looking ahead, we will reflect on how uncertainty continues to influence decision-making. How should the PCD framework respond as permit conditions evolve? How should investment be categorised when BAT overlaps with asset condition? We will conclude by exploring how the sector can build more resilient, adaptive delivery frameworks for AMP8 and beyond.