I have a huge weeping willow in my front yard. My next door neighbor swears the root system has invaded her septic line. She had a globe will previously taken out that was about 10 feet from her main water line while my weeper is about 30. My own line is about 15 feet from the weeper. Is there any validation to her statement?



Trees are often blamed for invading water lines and septic systems.  Tree root systems are quite extensive and their distance from the trunk underground can reach well beyond the drip line or canopy of the tree.  Tree roots and septic lines inhabiting the same area can be problematic in that the tree roots are seeking moisture and nutrients for tree growth.  The root system can get into septic lines, but only if there are already cracks and failures in the septic lines.  Tree roots opportunistically grow near these "leaks" and failures in the line, and if the cracks are large enough roots will start growing into the lines.  The only way to determine if there are roots in the septic system is to have a plumber who has a setup and video capabilities to go into the septic line investigate the drains and lines to see if roots are present. 

The integrity and age of the septic lines will be more of an indicator of problems than distance from the tree.

Posted on 14 May 2008

Maggie Shao
Horticulture Agent, Salt Lake County

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