Barker, R., Vale, P., Wickens, D., Luck, R. and Richards, A., Severn Trent Water, UK(free)
In AMP2 Severn Trent (ST) built its first full scale Enhanced Biological Phosphorus Removal (EBPR) plant at Milcote Sewage Treatment Works (STWs) utilising the sidestream Phosstrip® process. The first mainstream EBPR at Derby STW was built in a University of Capetown (UCT) configuration.
ST have since built or converted numerous sites in a variety of EBPR configurations, including its 3 biggest: Minworth STW, Wanlip STW and Stoke Bardolph STW. Numerous smaller sites have also been built in different configurations including Alternating Double Ditches (ADD), pocket Activated Sludge modified Johannesburg conversions, and new build pocket ASPs. There are also some novel configurations, including a RAS fermenter at Loughborough STW. Some sites have been found to be doing EBPR without being designed to do so. Many of the sites chemical top up dosing, but some do not need to use it at all, or only rarely. A few sites no longer operate in EBPR or could not be made to achieve it, but the majority have been running reliably and with minimum intervention for a number of years. By the end of AMP6 ST will have over 30 sites (including 3 Nereda® plants) operating EBPR.
In AMP7, the increasing costs of chemical and issues with supply, combined with 156 new Total P permits, means ST is again focusing on EBPR to help meet the continuing Phosphorus challenge.