Increasingly reduced discharge limits and growing urban population necessitate biological process intensification at existing municipal wastewater treatment plants, often constrained by limited footprint and time for expansion. This study presents a combined membrane aerated biofilm reactor (MABR) and densified activated sludge (DAS) system at the Bolton municipal WWTW (average daily flow: 151,000 m3/d) to achieve enhanced nitrification. The MABR technology relies on counter-diffusional oxygen delivery to a nitrifying biofilm; this enables ammonia oxidation in anoxic tanks and allows to add extra nitrification in existing volume (approx. 800 kgN-NH4/d at Bolton). Sludge densification improves sludge settleability, further expanding both biological and hydraulic capacity. Comprehensive operational data collected over one year of full-scale operation are presented and analysed, including modular increase of nitrification capacity over the installation phase, ammonia removal rates, oxygen transfer performance and SSVI. Results demonstrate the effectiveness of the MABR-DAS configuration in achieving consistent ammonia removal while improving resilience compared to conventional activated sludge systems. The findings also provide valuable insights into the practical implementation, operational optimization, and long-term performance of this innovative process intensification strategy for municipal wastewater treatment facilities facing similar regulatory and spatial constraints.