Chris from Welland, Ontario has problems with his leaching field plugging up. He has cleaned out the roots, but how can he keep them from growing back.
The problem is that anything that would kill the roots will at the same time kill the bacteria that is necessary for the septic tank to work. There are some home made remedies and rumors about chemicals that will do the job, but most of them are considered environmental hazards to the water table. The official ecological answer to this problem is to either move the leaching field, or move the trees. That is what Chris finally did.