Water quality and treatment

The evolution of a risk-based approach to UK drinking water resources is described with a recognition that upgraded treatment must be accompanied by water demand control measures and improved catchment management with closer coordination between land use and water resource planning. It is difficult to see how prevention and reversal of upward trends in nitrate and chloride as required under the EU Water Framework Directive can be realistically achieved for much of the chalk aquifer of S E England. Delayed releases are still passing through the unsaturated zone in the Thames Basin which may take another 50 – 60 years to reach the underlying water table. A national strategic overview of the quality and capacity of water infrastructure is necessary to ensure a sustainable and affordable future service delivery.