With cabinets due to be installed the next week, it was time to demo the island. First step was to address all the plumbing for the prep sink. I'd never really looked closely under here, but this is what I saw when I got to work. No, that's not an optical illusion. The black horizontal run goes 'uphill'. Almost an inch in a tick over 9 inches of horizontal travel. No wonder this sink drained so slow. It would have been SO easy to just cut the white PVC section down and had proper fall...