Trees and Sewer Conflicts
The Indianapolis Urban Forestry Section often receives calls from distressed property owners who are experiencing sewer backups. Following a backup, property owners will discover roots in their sewers and place blame on street trees for their sewer problems. However, tree roots only invade sewer lines that have already broken due to earth settlement, dried joints or age. Broken sewer lines or joints leak sewage into the ground. Adjacent roots from trees or shrubbery, which need moisture and nutrients, soon invade the surrounding area. Roots enter the defective pipe and eventually block the flow.
Why do tree roots seldom invade water lines? Water lines are commonly made of cast iron that is screwed together and designed not to break or leak. Sewer lines, on the other hand, are usually model clay tiles glued together. Clay is fragile and eventually will crack due to soil settlement, past construction activities, or earth tremors. When this happens, tree roots may enter the line. A simple solution can fix this problem.
If you suspect that tree or shrubbery roots are invading your broken sewer line, treat the line with copper sulfate. Copper sulfate only kills the roots it contacts, not trees or shrubbery and it will not harm the bacteria in septic systems. In fact, the Indianapolis Water Company often uses it to remove algae from our drinking water. Most plumbers and garden centers stock small cans of copper sulfate. Larger bags are available and are often cheaper.
Applying copper sulfate once in the spring and once in the fall should prevent your sewer from clogging again, and it's easy to use:
· Pour two pounds of medium-sized copper sulfate into the toilet bowl one half-cup at a time.
· Flush the toilet after each addition.
· Allow one half cup of copper sulfate to stand in the toilet bowl overnight before flushing again.
· Most importantly, always administer copper sulfate through the toilet bowl; the chemical can eat through metal drains and plumbing fixtures.
Using copper sulfate to open clogged sewers is much better than removing a tree that contributes shade and beauty to your property and your entire neighborhood. And please remember, property owners are responsible for the costs associated with any damage made to the lateral line from their home to the city's sewer system, including damage caused by trees.
Problems can be prevented by:
· Proper construction of new sewer lines, including tight joints and a firm soil base that won't settle unevenly.
· Repair or replacement of defective sewers. Repeated root blockage may indicate a collapsed or badly damaged pipe.
· Finding ways to improve sewer design and construction. Cities that annually spend millions on sewer clearance would do better to invest in long-term solutions to the problem.