You vanished inside a toilet and were never heard from again. "The Tale of the Flushed Plumber" has become part of oral tradition. Or you just hurt your back and can't work.
You are self-employed but don't have the gumption to successfully market yourself. You get odd jobs here and there but not enough to pay for that 65" plasma you preemptively purchased.
You are a union plumber dealing mainly with water reservoir pipe systems. You earn enough to put food on the table, although you are still drinking tap water.
You are a non-union, self-employed, and well-established plumber who has trouble keeping pace with the work orders. The money floods in like the dirty water across the Johnsons' bathroom floor.
You started at a plumbing company when you were younger but have worked your way up to run the place. You make great money and get to send your 652 underlings out to do all the dirty work.