John Savage wrote:
. Second option: instead of the $16k you could twice annually
employ a plumber to drop his electric eel into the pipe and grind out
the roots.

You can do this yourself (BTDT). Just visit the local hire places. All
you need to find is where the inspection access is (usually near house),
but after $900(?) you should know this. You did watch him didn't you?

P.S. refill with sand after you dig it out the first time. Makes it so
much easier.