In ‘Delivering for the Environment’ (Environment Agency, 2005), we made a clear commitment to adopt a risk-based, outcome-focused approach to modern regulation. Compliance assessment is central to this approach and provides the means to ensure operators comply with permits for regulated processes and activities. Our objective in this pilot study was to provide evidence that our approach to compliance assessment supports the principles of modern regulation. We also aimed to identify any need for further work to ensure our approach is supported by sound science. It is important that we have objective evidence to support our regulatory approach in the face of increased scrutiny by Government and other external stakeholders.