Pumped storage reservoirs receiving river water from lowland catchments, such as those operated by Anglian Water in Eastern England, tend to have large inputs of nutrients and consequently suffer from large populations of algae. The current paper describes some measures taken at Grafham Water, one of the largest reservoirs in the U.K., to control algae and remove algal cells and algal products during the water treatment process. Marked changes in the algal community were observed following the installation of a destratification system with a decline in cyanobacteria in particular. Improvements have been made to the water treatment process including the installation of triple layer filters, ozonation and GAC absorbers. The penetration of algal cells through treatment is described before and after these modifications showing substantial improvements. Reductions were also achieved in THM and T.O.C. concentrations in the treated water.

You do not currently have access to this content.