Posted 4/14/2009 18:00 (#680324 - in reply to #680318) Subject: copper sulfate
Central IL
I was going to post that, I use it at home to keep tree roots out of the sewer line, but not sure it would be a solution in this situation. It needs to just sit in the line in contact with the roots for 8-12 hours according to the label on the stuff I use. Treat mine once every 6 months or so to keep the snake put away. Kinda spendy at $10-$12 for a pound or 2 bottle.
Field tiles plugged with roots
