When I got back to the lab, there was enough water that it was seeping under the wall, and visible outside. Physical plant says it will take an hour before they can come, so I'm getting dinner, then will let them in.
The guy from physical plant came, and turned off the water to the kitchen sink. He is putting in a work order to have the plumbers come look at it on Monday morning. It looks like something is wrong with the water heater, and we're getting water out of the safety overpressure valve / pipe.
The wet things from under the sink are stacked (a little haphazardly) next to the cupboards.