A plumber replaced my sink/faucets in my bathroom yesterday and I’m having problems with the cold water. When I turn it on, it runs clear for a second and then becomes black and sooty and then runs clear again. If I wait two minutes and turn the water on again, the same thing happens. It is an old house … could it be a corroded reservoir? What else could it be? Did the plumber just disturb an older pipe that just needs to be “cleaned out” and the problem will correct itself fairly quickly? Any advice would be greatly appreciated. Thank you!