Huntsville Undertakes Nation’s Largest Root Control Project

By Jeff Griffin, Senior Editor | January 2009 Vol. 64 No. 1

Foam with a shaving cream consistency is pumped through a discharge hose filling the pipe and compressing against all pipe surfaces, into cracks and joints, into connecting pipes and into laterals. Roots die on contact, but trees are not harmed. "Dead roots," says Tillery, "decay and slough off. The time it takes for roots to slough off varies with the type of tree, septic conditions and flow rates in the pipe. The process usually is complete within two to four months after treatment. In most cases, it is not necessary to mechanically cut roots either before or after treatment."

The primary chemical used by Duke's has liquid diquat dibromide as its active ingredient. Tillery says the product has excellent root control efficacy, is environmentally friendly, non carcinogenic, nonvolatile and is approved by the EPA for aquatic uses.

The Duke's crew proceeded methodically with one to three two man crews on the job. Crews worked 10 days on, four days off and averaged 33,000 feet per week over the course of the project. Lines treated did not have to be taken out of service during application.

Expected benefits of the program included elimination of overflows in the areas treated, a reduction in homeowner’s calls about roots in laterals and that after treatment, pipes would be much easier to inspect and maintain without the presence of roots. In addition, by reducing the number of times crews had to perform redundant root control work, field crews would have time to focus on other priority needs.