A Treatment Reliability-Based Method for Supporting Infrastructure Asset Management of Wastewater Treatment Plants

A simple and consolidated reliability-based method widely used to unveil the real reliability stability of wastewater treatment plants (WWTPs) is herein proposed trigger decision making on operational improvements asset management for maintaining or improving effectiveness, reliability, efficiency. Five-year data (2015–2019) from 16 Portuguese activated sludge WWTPs were used. For 73% yearly which fitted a lognormal distribution, Niku’s coefficient was computed assess plant annual biological oxygen demand (BOD5), chemical (COD), total suspended solids (TSS). The standard deviation concentrations characterize stability, maximum deviations allowed comply with European discharge requirements urban derived. results demonstrate extended aeration more reliable stable than conventional (0.98 vs. 0.82 BOD5, 0.97 0.91 COD, 0.94 0.89 TSS). Furthermore, lower reliabilities stabilities found smaller WWTPs. These are important strategic designing rehabilitation system. At tactical levels, resources’ allocation operating conditions set up, WWTP’s variation allows establishing mean effluent required compliance given different scenarios requirements.