I was washing dirt off potatoes in the kitchen sink and wishing at the time I had a system where the water went to the garden rather than the treatment plant. I like your system. I wonder, do you ever get a foul smell from stagnant water? Do you send big chunks down the "drain" and do you do anything to winterize your system?

@Kathleen: Why not use a bucket of water to rinse the potatoes in? The contents of said bucket can then go back into the garden. Much easier than changing your plumbing.

Sometimes it is the simplistic of solutions that we can not see.