Septic Tanks and Trees

How Does a Septic Tank Work?

The Allstate Blog has an excellent article at:

Money Down the Drain?

Many of our homes in HVR1 are nearing 15-20 or more years of age, which means our septic systems need more care.  The septic system may work less effectively over time, and tree roots can contribute to a problem.  Solution?

Recently a Happy Valley Ranch neighbor discovered their septic tank had been invaded by tree roots.  The solutions vary from the nuclear option – cutting the tree down – to asking the experts what they would do to preserve the tree and to find the best solution considering cost, esthetics, City of Scottsdale Environmentally Sensitive Lands Ordinance and the HVR1 Building Guidelines.

After removing the roots from the tank, a competent septic service company will advise that the homeowner use Root-X, a product that prevents re-growth of tree roots in the tank without damaging the tree, plumbing or septic tank (  The cost per annual treatment is also significantly less than removing a large tree ($400-500).  Root-X  is not a “do-it-yourself” product and should be used by a professional.

Large Palo Verde, ironwood, and mesquite trees are cherished aspects of our environment.  They add to the value of our homes and the neighborhood, provide homes and food for wildlife, shade and privacy to the areas surrounding our homes.  Removing a tree should be the last resort.

If you do have a diseased, wind damaged or other tree problem that requires attention by a tree professional, please contact the HVR1 Architectural Committee for advice.  We’re happy to help.  We can put you in touch with master gardeners and arborists/tree care companies that understand our native trees.


There are also cases where limited pruning is required around driveways, walkways, and street edges for access or safety.  Where needed, some trimming may be desired to follow Fire Department guidelines.  The key words here are “limited” or “minimal”.  The recommended guideline to maintain the tree’s health is never to take off more than 15% of the tree growth in any one pruning, and not more than 25% in one year.

A word of caution regarding most landscaping companies:  Most do not know how to trim our trees to keep them healthy.  Look at any shopping center parking lot and you will see over-pruned and damaged trees.  Unfortunately this has also happened in our neighborhood.  If your landscapers say your trees need to be pruned, ask them why.  Then ask how they will make the pruning cuts and ask them to show you the “collar” where cuts should be made.  If they cannot answer these questions, then do not let them work on your trees.

–Your HVR1 Architectural Committee