As a result of the continuing improvement there is pressure to reduce the phosphate dose for and efficiency and environmental reasons ). However, before making changes in treatment water utilities must carry out a process of due diligence to avoid customers being exposed to unnecessary risk. Some have attributed the lack of due diligence as the root cause of the Flint debacle in the USA when supply water was switched to a new source. Previously a large increase in lead risk in Washington DC was observed as a result of a change in the disinfection regime . This emphasises the need in areas of identified lead risk for continual monitoring of lead in drinking water pre and post changes in treatment.