An Irish Water priority project entailing the replacement of pumps and switchgear in a critical element of Dublin's wastewater infrastructure, where a system failure could result in almost immediate city flooding. The works included installing six new foul pumps, at five floors below ground level, with each pump handling three tonnes of wastewater per second. The work had to take account of very high inflows, confined spaces and a high risk of flooding whilst minimising operational disruption. Energy efficiency was an important consideration with the upgrade saving energy, reducing CO2 emissions and providing a more reliable plant.