F.Y.I

Problem...
The intrusion of roots into sewers is probably the most destructive single element that faces those maintaining a waste water collection system. (EPA 600/2-77-017d)

Roots grow toward moisture by a continuous process occuring at the very end of the root. One cell at a time is added at the end of the root enabling it to penetrate extremely small openings in pursuit of moisture...After a root enters a sewer pipe, it may divide hundreds times to form an enormous mass of tender root ends. The root mass usually collects a thick coating of grease, becomes heavy and hangs into the water causing grit settlement and shoaling. Debris and sewage solids continue to pile up on the root mass until a blockage occurs. (EPA 600/2-77-017d)

Solutions?
A typical emergency response to a sewer line blockage is to rod the line using an auger tool. The blockage will be revealed and a clump of roots is likely to be pulled out of the line. Unfortunately, much of the root mass will probably remain. The remaining roots respond to their injuries by producing traumatic acid in order to hasten and thicken their regrowth. (EPA 600/2-77-017d)

Use of copper sulphate inhibits root growth in sanitary sewers if the solution can be brought into contact with the roots for a sufficient length of time. Copper sulphate should be used sparingly because it is a toxic material and can cause interference with the treatment process. Generally, this is an inefficient and obsolete method of root control. (Manual of Practice #7-Water Pollution Control Federation)

A Better Way!
Chemical control with Vaporooter is not 100 percent effective, but repeated applications over several years approaches this limit. No other method of control approaches the effectiveness found...using Vaporooter. (EPA 600/2-77-017d)

Where root intrusion has occurred, chemical treatment can be successful in destroying root masses...It is best to use only chemicals proven effective and for which explicit instructions are available...With proper application of an effective herbicide, the roots in the sewer die, become brittle, and slough off into the flow. With proper treatment, regrowth may be inhibited for two to seven years. (Manual of Practice #7 <1980>-Water Pollution Control Federation)