A range of water quality/sanitary indicators (WQIs: BOD, COD, Suspended solids, Chloride, Ortophos, T Phosphorous, suspended organic carbon, Ammonia as N, metals: Al, Fe, Mn) were analysed at Wessex Water at certain sampling points over the studied period in both Bath and Keynsham. Full experimental details may be found in the supplementary. Influent wastewater flows and rainfall over the studied period in both catchment areas were also reported (figure ).