The tenant had a clogged kitchen sink drain. The water backed up into the sink very fast. This indicated either a major blockage of a clog very close to the sink. I checked the drain stack and it was empty. I pulled the trap to check and found a popsicle stick, hair, and some food clogging the trap. I emptied the trap and cleared the blockage. I ran the water in both basins to test. The water is draining free and clear with no leaks.