Preliminary analysis identified six outliers (lead "hot-spots") zones with higher than expected levels of non-compliance. However, further analysis accounted for four of these by variation in the zonal proportion of properties of lead services (LPD). A fifth outlier zone was correctly identified as anomalous because a full treatment solution for that treatment zone was not delivered until after the period 2006-2010. Only one zone was found to be truly anomalous "hot-spot". To deal with this risk a costly full lead pipe replacement programme was undertaken in this zone. The analysis highlights the importance in including zone by zone the proportion of properties with lead service pipes in the analysis and for making comparative risk assessments.