Do you have a MONSTER in your backyard?
Trees and Shrubs play an important role in our daily life - they enhance the environment whilst providing shade, windbreaks and aesthetic value to any home. However, many species are unsuitable for planting near your home's sewer pipes or Council's sewer mains.
How tree roots damage pipes
Roots anchor and support trees, but they also seek and supply moisture and nutrients for continued growth. Roots normally extend around 1.5 times the length of an adult plant's branches. During dry periods in particular, tree roots will search for any trace of moisture and nutrients, both of which can be found in sewer pipes. Tree roots are very persistent and surprisingly strong. They will take advantage of any and every opportunity to get inside sewer pipes. Often this is achieved through a small crack or fracture, or through ill-fitted pipe joints.
Few people realise how aggressive the roots of certain trees and shrubs can be in their search for moisture. Tree roots start as fine fibrous feeding masses, with their "tails" spreading long distances through the pipe, resulting in reduced flow rates and eventually complete blockage.
Types of pipes
The degree of risk and damage caused by tree roots depends on the tree species concerned, its proximity to sewer pipes, and the composition of the sewer pipes (terracotta, cast iron, concrete PVC, UPVC.
Council strongly recommends unplasticised poly-vinyl chloride pipes when laying new sewer pipes or replacing old sewer pipes in areas at risk of tree root intrusion. Roots find it virtually impossible to infiltrate well-constructed UPVC pipes, while the older style vitreous clay pipes are known to be prone to root infiltration.
What can I plant near sewer pipes?
Some sewer lines have easements and you cannot plant trees within the easement. If there is no easement, Council recommends that you leave at least 1.5 metres either side of the sewer. This will allow easy access should there be a problem. When planting near sewer pipes to minimise the risk of root intrusion you should select species that have a small root ball when fully grown. Planting distances can vary depending on the type and conditions of both the pipes and the soil on your property. But remember that too far from a pipe is much better than too close.
When selecting trees for your garden, remember to think "sewer friendly". By discussing a plant's root structure and growth with your nursery, you can avoid planting pipe loving trees and shrubs.
are my sewer pipes located?
The location of Council's mains and your pipes can be hard to identify without plans, although you should know where the boundary shaft cover is in your yard.
Council can provide you with a plan of your property showing where Council's sewer mains are located, while a qualified plumber can provide you with basic plan of where your sewer pipes are located.
What about trees causing problems
Planting the right tree at the correct distance will ensure that you don't experience damage to your sewer pipes. But what do you do about trees that may have begun to cause damage? Repair and reinforcement of the affected sewer pipes is the most practical option. As a short-term solution you can get a plumber to use special foam to inhibit root growth or use an electric eel. However, in severe cases you may need to consider moving the offending tree. If this is the case it is vital that you correctly identify which tree is causing the damage.
Note that you will need Council's approval to remove the offending tree/s.
You should seek the services of a tree removal contractor for advice and to undertake the removal of the tree.
For a plan of your property showing Council's sewer main or further information please contact Lismore Water at Council's Administration Building or phone 6625 0500.