Abstract: This invention relates to the application of herbicides in sewer lines to kill tree roots inside the lines and preventing re-growth into the lines for years after application. It relates to the discovery that latex polymers, organosilicone surfactants, deposition agents and other surfactants can be used to “glue” the herbicides to pipe surfaces. This discovery allows the use of plant killing herbicides to treat roots in sewer lines—killing them—which results in their subsequent removal by decay and erosion processes. It also allows for the use of the herbicides to prevent re-growth back into the sewer lines by applying the herbicides in a compound which adheres to the sewer line surfaces and forms a long term coating on the pipe and joint surfaces where the roots might attempt to grow back in. The compound resists erosion and washing away preventing long term root re-infestations in the sewer lines.