How to Use Copper Sulfate to Treat Sewer Lines

Sewer line issues can cause massive headaches and an unpleasant cleanup job. While a full-out stoppage requires a call to the plumber, a sluggish sewer line can be caused by tree root infiltration, especially during dry or drought conditions. Tree roots look for the easiest source of water, and sewer lines provide a ready source of water and organic material. Small cracks in the pipe are all it takes for roots to penetrate. The sooner you deal with the infiltration the better, since repairing and replacing sewer lines can be expensive and highly disruptive. Copper sulfate kills tree roots without killing the tree or other plants.

Tree root infiltration of a sewer line can result in costly problems.

Step 1

Pour two pounds of copper sulfate into the toilet, a half-cup at a time, flushing between additions. Do not pour it into sink or tub drains—it will cause damage to the thin metal pipes that connect to the drain.

Step 2

Allow the last half to sit in the toilet overnight before flushing in the morning.

Step 3

Repeat this once per season to keep the lines clear and to prevent issues.

Step 4

Place cooper sulfate around the root infiltration point to discourage future root growth to the area.

Step 5

Determine the location and depth of your sewer lines. Go to the municipal health department or public water and sewer department and get a copy of the map that locates the sewer line on your property. You can also hire a sewer company to use an endoscope to locate and map the line and locate where the roots have infiltrated.

Step 6

Drill a 2 1/2-inch hole in the ground above the infiltration spot with an earth auger, stopping about two feet above the pipe. Place a piece of 1 1/2-inch diameter PVC pipe with a cap on one end down the hole and cut it flush to the ground below the grass line.

Step 7

Remove the cap and pour copper sulfate down the pipe until it is half-filled, and then pour hot water to the top of the pipe. The mixture will slowly seep into the ground.

Step 8

Repeat this every six feet or so along the tree root, for extensive root problems. Make sure to map where these pipes are located for future reference. Insert copper sulfate and hot water in the pipes seasonally.