Not sure where in the world you hail from, however down here our friendly health inspector will also ping you for not having a separate, dedicated hand washing station. No, you can't wash your hands in the same basin as you washed the celery.Yea olde health inspector will want to see hot and cold running water, a basin, and waste water properly disposed of, as well as soap and paper towels.
While it may cost a bit more, it is worthwhile to rent a handwash station from a rental co. This is a self contained unit made by Cambro, and it gets the nod from virtually every health jnspector.
Just a suggestion from someone who's been there.......