The population of west Cardiff, Dinas Powys, Sully, Penarth and Barry are served by another new sewage treatment works. Cog Moors opened in 1990, from which treated effluent is discharged by a long sea outfall at Lavernock Point. In 2020 it was undergoing a £50 million upgrade to create an advanced anaerobic digestion plant, which will generate over 2MWh of electricity per year, using two engines powered by the biogas produced as the sewage sludge is digested.
