Abstract: A water injection system reduces nitrous oxide emissions in turbocharged internal combustion engines driving electrical power generators. A current-activated relay located in switchgear associated with the generator becomes energized asserted when the current output of the generator exceeds a value that corresponds to predetermined NOx permissible emissions level. The output of the relay activates a motor starter which controls a rotary vane pump. The pump draws distilled water from a water tank, forcing the water through a particle strainer, an adjustable flow regulator, a solenoid, a flow meter, and backflow check valves, to water injection nozzles located in the combustion airstream immediately after a turbocharger compressor. The nozzles provided include fine-mesh strainers and atomize the water to 100 micron particle sizes, and distribute the water particles in an 85-degree spray cone pattern.