How to Kill Tree Roots in a Septic Tank

Tree root infestation in septic systems can be a big problem. Any crack in a septic line can allow tree roots to enter. Tendrils, resembling spider webs, creep down into the cracks and send out roots, which have the potential to grow as large as the septic line itself. While a professional can best diagnose and remedy any issues, it’s helpful to know several approaches professionals use to kill tree roots in a septic tank.

One of the most common techniques is to use a mechanical auger. This method involves sending a powered sewer auger down a septic line. The rotating head is covered in teeth like a reciprocating saw blade. The rotating action cuts the roots, clearing them, but they'll start growing back almost immediately.

There are special chemicals designed to kill tree roots in a septic tank system so they don’t grow back. Copper sulfate septic treatments are the most common. This method is especially effective as it creates a poison barrier within the soil that kills the tree roots before they can grow into the pipe. Treatments that include foaming agents have the added advantage of coating the entire pipe, saturating the roots that grow from the top as well as the bottom.

An effective but potentially expensive way of clearing septic lines is with a hydro jetter. This machine uses a pump and pressurized water. After the hydro jetter does its job, the septic line can be flushed with a chemical to kill any roots still present.

Sometimes a septic line can't be cleaned or cleared with chemicals, a hydro jetter or an auger if it’s been damaged too badly. To assess the extent of the damage, a pro may insert a camera into the septic line that'll provide better diagnostics so they can determine the best course of action, which may include accessing the septic tank to remove the tree roots manually and repair any damage.