The current study analyses lead data collected over the 12 years following delivery of the optimised treatment solution that was implemented to meet compliance with the 10 µg/L standard in the northwest of England. Within it, a more in-depth analysis is carried out for a 5-year period with the purpose of seeing what information can be extracted about the disposition of lead risk and how this information could be used to re-optimise treatment and the strategic planning of lead pipe replacement.