The patented Floor Washer System is similar to Vaughan’s Foambuster nozzle/deflector, but with the deflector moved from below the nozzle to above it. The inverted splashplate spreads nozzle flow out across a floor in a fairly wide path to wash settled grit, sand or debris into a sump where a dewatering chopper pump can pump it out. The system is useful for attacking deposition problems in CSO tanks, storm collection tanks, equalization tanks, lift stations and influent channels.