Increasing rainfall and ageing sewer systems are intensifying combined sewer overflow (CSO) events, creating urgent demand for high‑performance, rapid‑response treatment solutions. To address this challenge, Severn Trent developed the Storm Generator – an advanced test platform capable of replicating realistic CSO hydrographs under fully controlled, repeatable conditions. Two emerging technologies were evaluated: the Enpure’s StormBLOX silicon carbide (SiC) ceramic membrane system and Eliquo Hydrok’s Mecana pile cloth media filtration. Both technologies were tested using engineered storm profiles, with screened raw sewage (to simulate CSO spills first flush) and diluted sewage (to simulate other pollutant loads). Trials assessed performance with and without flow‑proportional ferric dosing, supplemented where applicable by a natural coagulant. StormBLOX removed >90% suspended solids, >96% phosphorus, and significant BOD and pathogen log‑reductions when chemical was dosed, maintaining stable performance during short, high‑load events. Mecana provided >84% TSS removal without chemicals, with improvements under coagulant dosing, and delivered substantial reductions in COD, BOD, phosphorus, and pathogens. Mecana and StormBLOX also showed potential for PFAS removal. Overall, the Storm Generator trials demonstrate that both StormBLOX and Mecana offer robust, adaptable treatment options capable of mitigating the environmental impacts of unavoidable CSO discharges and supporting compliance during extreme wet‑weather events.